,transcriber's ,notes ,phrases printed in bold face1 italics or small capitals in the source document have been transcribed between equal signs or underscores1 or as ,,all ,,capitals for this e-text4 ,more ,transcriber's ,notes may be found at the end of this e-text4 ,,first ,,course ,,in ,,biology ,illustration ,,the ,,macmillan ,,company ,,new ,,york ,,boston ,,chicago ,,atlanta ,,san ,,francisco ,,macmillan ,,co41 ,,limited ,,london ,,bombay ,,calcutta ,,melbourne ,,the ,,macmillan ,,co4 ,,of ,,canada1 ,,ltd4 ,,toronto ,illustration3 ,,kentish ,,plover ,,with ,,eggs ,,and ,,young 7,,protective ,,resemblance7 ,from the ,exhibit in the ,british ,natural ,history ,museum4 7,morgan47 ,,first ,,course ,,in ,,biology ,,by ,l4 ,h4 ,,bailey ,,part ,i4 ,,plant ,,biology ,,and ,,walter ,m4 ,,coleman ,,part ,,ii4 ,,animal ,,biology ,,part ,,iii4 ,,human ,,biology ,new ,york ,,the ,,macmillan ,,company #aiji ,all rights reserved ,,copyright1 #aijh1 ,,by ,,the ,,macmillan ,,company4 ,set up and electrotyped4 ,published ,july1 #aijh4 ,reprinted ,october1 #aijh2 ,february1 ,september1 #aiji4 ,norwood ,press ,j4 ,s4 ,cushing ,co4--,berwick ,smith ,co4 ,norwood1 ,mass41 ,u4,s4,a4 ,,preface ,the present tendency in secondary education is away from the formal technical completion of separate subjects and toward the developing of a workable training in the activities that relate the pupil to his own life4 ,in the natural science field1 the tendency is to attach less importance to botany and zoology and physiology as such1 and to lay greater stress on the processes and adaptations of life as expressed in plants and animals and men4 ,this tendency is a revolt against the laboratory method and research method of the college as it has been impressed into the common schools1 for it is not uncommon for the pupil to study botany without really knowing plants1 or physiology without knowing himself4 ,education that is not applicable1 that does not put the pupil into touch with the living knowledge and the affairs of his time1 may be of less educative value than the learning of a trade in a shop4 ,we are coming to learn that the ideals and the abilities should be developed out of the common surroundings and affairs of life rather than imposed on the pupil as a matter of abstract1 unrelated theory4 ,one of the marks of this new tendency in education is the introduction of unit courses in biology in the secondary schools1 in the place of the formal and often dry and nearly meaningless isolated courses in botany1 zoology1 and physiology4 ,this result is one of the outcomes of the recent nature-study discussions4 ,the present volume is an effort to meet the need for a simple and untechnical text to cover this secondary biology in its elementary phases4 ,the book stands between the unorganized nature-study of the intermediate grades and the formal science of the more advanced courses4 ,it is a difficult space to bridge1 partly because the subjects are so diverse1 and partly because some teachers do not yet understand the importance of imparting to beginners a general rather than a special view point4 ,still another difficulty is the lack of uniformity in the practice of different schools4 ,it is not urged that it is desirable to have uniformity in all respects1 but the lack of it makes it difficult to prepare a book that shall equally meet all needs4 ,it is hoped1 however1 that the present book is fairly adaptable to a variety of conditions1 and with this thought in mind the following suggestions are made as to its use3 ,being in three separate parts1 the teacher may begin with plants1 or with animals1 or with human physiology4 ,if a one-year course is desired1 the topics that are printed in large type in ,parts ,,ii and ,,iii may be used1 and a choice from the chapters in ,part ,i4 ,for three half-year courses1 all the parts may be covered in full4 ,if the course in biology begins in the fall 7with the school year71 it may be well to study plant biology two days in the week and animal biology three days until midwinter2 when outdoor material becomes scarce1 human biology may be followed five days in the week2 in spring1 plants may be studied three days and animals two days4 ,if the use of the book is begun at midyear1 it will probably be better to follow the order in the book consecutively4 ,if it is desired to take only a part of the plant biology1 ,chapters ,,vi1 ,,xiv1 ,,xx1 ,,xxiii1 ,,xxiv may be omitted1 and also perhaps parts of other chapters 7as of ,x1 ,,xii1 ,,xiii7 if the time is very short4 ,the important point is to give the pupil a rational conception of what plants are and of their main activities2 therefore1 the parts that deal with the underlying life processes and the relation of the plant to its surroundings should not be omitted4 ,if more work is wanted it is best to provide the extra work by means of the study of a greater abundance of specimens rather than by the addition of more texts2 but the teacher must be careful not to introduce too much detail until the general subject has first been covered4 ,the value of biology study lies in the work with the actual things themselves4 ,it is not possible to provide specimens for every point in the work1 nor is it always desirable to do so2 for the beginning pupil may not be able to interest himself in the objects1 and he may become immersed in details before he has arrived at any general view or reason of the subject4 ,great care must be exercised that the pupil is not swamped4 ,mere book work or memory stuffing is useless1 and it may dwarf or divert the sympathies of active young minds4 ,every effort should be made to apply the lessons to daily life4 ,the very reason for knowing plants and animals is that one may live with them1 and the reason for knowing oneself is that he may live his daily life with some degree of intelligence4 ,the teacher should not be afraid to make all teaching useful and practical4 ,in many cases a state syllabus designates just what subjects shall be covered2 the topics may be chosen easily from the text1 and the order of them is usually left largely to the discretion of the teacher4 ,finally1 let it be repeated that it is much better for the beginning pupil to acquire a real conception of a few central principles and points of view respecting common forms that will enable him to tie his knowledge together and organize it and apply it1 than to familiarize himself with any number of mere facts about the lower forms of life which1 at the best1 he can know only indirectly and remotely4 ,if the pupil wishes to go farther in later years1 he may then take up special groups and phases4 ,,contents ,,page ,,general ,,introduction ,i xi ,,part ,i4 ,,plant ,,biology ,,chapter ,i4 ,,no ,,two ,,plants ,,or ,,parts ,,are ,,alike ,p #a ,,ii4 ,,the ,,struggle ,,to ,,live ,p #d ,,iii4 ,,survival ,,of ,,the ,,fit ,p #g ,,iv4 ,,plant ,,societies ,p #i ,v4 ,,the ,,plant ,,body ,p #ae ,,vi4 ,,seeds ,,and ,,germination ,p #bj ,,vii4 ,,the ,,root--,,the ,,forms ,,of ,,roots ,p #cb ,,viii4 ,,the ,,root--,,function ,,and ,,structure ,p #ch ,,ix4 ,,the ,,stem--,,kinds ,,and ,,forms--,,pruning ,p #di ,x4 ,,the ,,stem--,,its ,,general ,,structure ,p #ei ,,xi4 ,,leaves--,,form ,,and ,,position ,p #gc ,,xii4 ,,leaves--,,structure ,,and ,,anatomy ,p #hf ,,xiii4 ,,leaves--,,function ,,or ,,work ,p #ib ,,xiv4 ,,dependent ,,plants ,p #ajf ,,xv4 ,,winter ,,and ,,dormant ,,buds ,p #aaa ,,xvi4 ,,bud ,,propagation ,p #aba ,,xvii4 ,,how ,,plants ,,climb ,p #abi ,,xviii4 ,,the ,,flower--,,its ,,parts ,,and ,,forms ,p #acc ,,xix4 ,,the ,,flower--,,fertilization ,,and ,,pollination ,p #add ,,xx4 ,,flower-,,clusters ,p #aee ,,xxi4 ,,fruits ,p #afc ,,xxii4 ,,dispersal ,,of ,,seeds ,p #agb ,,xiii4 ,,phenogams ,,and ,,cryptogams ,p #agf ,,xxiv4 ,,studies ,,in ,,cryptogams ,p #ahb ,,part ,,ii4 ,,animal ,,biology ,i4 ,,introduction ,a #a ,,ii4 ,,protozoans ,a #aj ,,iii4 ,,sponges ,a #ag ,,iv4 ,,polyps ,a #bb ,v4 ,,echinoderms ,a #cd ,,vi4 ,,worms ,a #db ,,vii4 ,,crustaceans ,a #ea ,,viii4 ,,insects ,a #fc ,,ix4 ,,mollusks ,a #ig ,x4 ,,fishes ,a #aji ,,xi4 ,,batrachians ,a #abf ,,xii4 ,,reptiles ,a #aci ,,xiii4 ,,birds ,a #aej ,,xiv4 ,,mammals ,a #ahd ,,part ,,iii4 ,,human ,,biology ,i4 ,,introduction ,h #a ,,ii4 ,,the ,,skin ,,and ,,kidneys ,h #af ,,iii4 ,,the ,,skeleton ,h #bh ,,iv4 ,,the ,,muscles ,h #ci ,v4 ,,the ,,circulation ,h #ea ,,vi4 ,,the ,,respiration ,h #gj ,,vii4 ,,food ,,and ,,digestion ,h #hi ,,viii4 ,,the ,,nervous ,,system ,h #aag ,,ix4 ,,the ,,senses ,h #adb ,x4 ,,bacteria ,,and ,,sanitation ,h #aeh ,,general ,,index i ,,general ,,introduction ,,preliminary ,,experiments ,these experiments are inserted for those pupils who have not had instruction in chemistry and physics1 to give them a point of view on the subjects that follow4 ,at least a general understanding of some of these subjects is necessary to a satisfactory elementary study of biology4 ,elements and ,compounds4--,the material world is made up of elements and compounds4 ,an element is a substance that cannot be separated into two or more substances4 ,a compound is formed by the union of two or more elements4 ,all the material or substance of which the earth and its inhabitants is composed is formed of the chemical elements2 this substance taken all together is known as matter4 ,carbon and iron are examples of elements4 ,compare a bit of charcoal1 which is one form of carbon1 with a new iron nail4 ,which is brighter8 ,heavier for its size8 ,tougher8 ,more brittle8 ,harder8 ,more readily combustible8 ,resistant to change when left exposed to air and dampness8 ,there are two other forms of carbon3 graphite or black lead 7used in pencils and stove polish72 and diamond1 which occurs in crystals and is the hardest known substance4 ,iron does not have varied forms like carbon4 ,sulfur is another element4 ,what is its color8 ,has it odor8 ,taste8 ,will it dissolve in water8 ,is it heavy or light8 ,will it burn8 ,what is the color of the flame8 ,of the fumes8 ,phosphorus1 another element1 burns so readily that it ignites by friction and is used in matches4 ,rub the tip of a match with the finger4 ,what is the odor of phosphorus8 ,phosphorus exists in nature only in combination with other elements4 ,lead1 tin1 silver1 gold1 copper1 zinc1 nickel1 platinum1 are elements4 ,there are less than eighty known elements2 but the compounds formed of them are innumerable4 ,carbon is found in all substances formed by the growth of living things4 ,that there is carbon in sugar1 for example1 can easily be shown by charring it on a hot shovel or a stove until its water is driven off and only charcoal is left4 ,part of the starch in a biscuit remains as charcoal when it has been half burned4 ,oxygen and the ,air4--,the great activity of pure oxygen in attacking other substances can be shown by passing into a fruit-jar a lighted splinter1 a piece of lighted magnesium ribbon1 an old watch spring 7or a bit of picture wire71 the end of which has been dipped in sulfur and lighted4 ,about one fifth of the air is oxygen and about four fifths is nitrogen and other inactive gases4 ,pure nitrogen will quickly extinguish a lighted splinter thrust into it4 ,it is the oxygen in the air that supports all forms of burning4 ,less than one half of one per cent of the air is an inactive gas called carbon dioxid1 a compound of carbon and oxygen4 ,it is formed not only when wood or coal is burned1 but also by the life processes of animals and plants4 ,favorable and ,unfavorable ,conditions for ,evaporation4--,pour the same quantity of water 7half a glassful7 into three saucers and two bottles4 ,place one saucer near a hot stove2 place the other two in a cool place1 having first covered one of them with a dish4 ,place one of the bottles by the stove and the other by the remaining saucers4 ,after some hours1 examine the saucers and bottles and compare and record the results4 ,explain4 ,state three conditions that are favorable to evaporation4 ,state three ways in which evaporation may be prevented or decreased4 ,tests for ,acid1 ,alkaline1 and ,neutral ,substances4--,for acid tests1 use sour buttermilk 7which contains lactic acid71 or hydrochloric acid diluted in ten parts water1 or strong vinegar 7which contains acetic acid74 ,has the acid a characteristic 78sour07 odor and taste 7test it only when very dilute78 ,rub dilute acid between the fingers2 how does it feel8 ,is there any effect on the fingers8 ,obtain litmus paper at a druggist's4 ,dip a strip of red litmus and of blue litmus paper into the acid4 ,what result8 ,for alkaline tests1 dissolve in a glass of water a spoonful of baking soda or some laundry soap2 or dissolve an inch stick of caustic soda in a glass of water4 ,test odor and 8feel0 of last solution as with the acid2 likewise test effect of alkaline solution on red and blue litmus paper4 ,record results4 ,alkalies are strong examples of a more general class of substances called bases1 which have the opposite effect from acids4 ,test pure water4 ,has it odor8 ,a taste8 ,test it with red and blue litmus paper4 ,water is a neutral substance3 that is1 it is neither an acid nor an alkali 7or base74 ,after making appropriate tests1 write ac1 al1 or neu after each name in the following list 7or write in three columns73 vinegar1 soda1 saliva1 sugar1 juice of apple1 lemon1 and other fruits1 milk1 baking powder1 buttermilk1 ammonia1 salt water4 ,pour some of the alkaline solution into a dish1 gradually add dilute acid 7or sour buttermilk71 stirring with glass rod and testing with litmus until the mixture does not turn red litmus blue nor blue litmus red4 ,the acid and alkali are then said to have neutralized each other1 and the resulting substance is called a salt4 ,the salt may be obtained by evaporating the water of the solution4 ,most common minerals are salts4 ,if the last experiment is tried with soda and sour buttermilk1 the demonstration will show some of the facts involved in bread making with the use of these substances4 ,test for ,starch4--,starch turns blue with iodine4 ,the color may be driven away by heat1 but will return again as the temperature lowers4 ,procure a few cents' worth of tincture of iodine and dilute it4 ,get a half dozen pieces of paper and cardboard1 all different1 and test each for starch by placing it over mouth of bottle and tipping the bottle up4 ,if much starch is present the spot will be blue-black or dark blue2 if little starch1 pale blue2 if no starch1 brown or yellowish4 ,make pastes with wheat flour1 potato starch1 and corn starch4 ,treat a little of each with a solution of rather dilute tincture of iodine4 ,try grains from crushed rice with the same solution4 ,are they the same color8 ,cut a thin section from a potato1 treat with iodine and examine under the microscope4 ,to study ,starch ,grains4--,mount in cold water a few grains of starch from each of the following3 potato1 wheat1 arrowroot 7buy at drug store71 rice1 oats1 corn4 ,study under microscope the sizes1 forms1 layers1 fissures1 and location of nuclei1 and make a drawing of a few grains of each4 ,test for ,grape ,sugar4--,make a thick section of a bit of the edible part of a pear and place it in a bath of ,fehling's solution4 ,after a few moments boil the liquid containing the section for one or two minutes4 ,it will turn to an orange color1 showing a deposit of an oxid of copper and perhaps a little copper in the metallic form4 ,a thin section treated in like manner may be examined under the microscope1 and the fine particles1 precipitated from the sugar of the pear1 may be clearly seen4 7,fehling's solution is made by taking one part each of these three solutions and two parts of water3 7#a7 ,copper sulfate1 #i grams in #bej cubic centimeters of water2 7#b7 sodium hydroxid1 #cj grams in #bej c4c4 water2 7#c7 ,rochelle salts1 #dc grams in #bej c4c4 water47 ,test for ,nitrogenous ,substances1 or ,proteids4--,put a little white of egg into a test tube and heat slowly4 ,what change takes place in the egg8 ,put another part of the white of egg into a test tube and add dilute nitric acid4 ,compare the results of the two experiments4 ,white of egg is an example of a proteid2 that is1 it is the form of nitrogen most commonly found in plant and animal tissue1 and it can be formed only by life processes4 ,do acid and heat harden or soften most substances8 ,either of the above tests reveal proteid1 if present4 ,does cooking tend to soften or toughen lean meat8 ,another test for proteid is nitric acid1 which turns proteid 7and hardly anything else7 yellow4 ,proteid when burned has a characteristic odor2 this will be noticed if lean meat or cheese is charred in a spoon4 ,the offensive odor from decomposing proteid is also characteristic1 whether it comes from stale beans1 meat1 mushrooms1 or other things containing proteid4 ,test for ,fats and ,oils4--,place a little tallow from a candle on unglazed paper and warm4 ,hold the paper up to the light and examine it4 ,what effect has the fat had on the paper8 ,place a little starch1 sugar1 powdered chalk1 or white of egg on paper and repeat the experiment2 is the effect the same8 ,place some of the tallow in a spoon1 and heat4 ,compare the effect of heat on fat and proteid4 ,water also makes paper semi-transparent1 but it soon evaporates3 fat does not evaporate4 ,another test for fats is to mount a thin section of the endosperm of castor-oil seed in water and examine with high power4 ,small drops of oil will be quite abundant4 ,treat the mount with alcanin 7henna root in alcohol74 ,the drops of oil will stain red4 ,this is a standard test for fats and oils4 ,to make or liberate ,oxygen4--,if there is a chemistry class in school1 one of its members will doubtless be glad to prepare some of the gas called oxygen1 and furnish several glass jars filled with it to the biology class4 ,if it is desired to make oxygen1 the following method may be employed3 ,provide a dry glass flask of three to four ounces capacity4 ,it should have a glass delivery tube1 inserted through a one-holed rubber stopper1 and so bent as to pass under the surface of water contained in a deep dish4 ,fill several pint fruit-jars with water1 cover with pieces of stiff pasteboard1 and turn mouth downwards in the dish of water4 ,from one half to two thirds ounces of an equal mixture of potassium chlorate and manganese dioxid 7procured at drug store7 is put in the flask and heated by means of a gas or alcohol lamp4 ,when the oxygen begins to form1 collect some in jars by inserting the end of delivery tube under the jars as they stand in water4 ,caution3 ,remove delivery tube from water before cooling the flask1 to prevent any water being drawn back4 ,oxidation4--,that something besides wood or coal is necessary to a fire can be shown by shutting off entirely the draught of a stove4 ,fire and other forms of combustion depend on a process called oxidation4 ,this consists in the uniting of oxygen with other substances4 ,when wood decays1 the carbon in it oxidizes 7unites with oxygen7 and carbon dioxid gas is formed4 ,when wood burns1 the oxidation is more rapid4 ,when iron oxidizes1 iron rust is formed4 ,when hydrogen is oxidized1 water is formed4 ,kerosene oil contains hydrogen1 and water is formed when it is burned4 ,almost every one has noticed the cloud of moisture which collects on the chimney when the lamp is first lighted4 ,by using a chimney which has been kept in a cold place1 the moisture becomes apparent2 soon the chimney becomes hot and the water no longer collects1 but it continues to pass into the room as long as the lamp burns4 ,fats also contain hydrogen4 ,hold a piece of cold glass or an inverted tumbler above the flame of a tallow candle4 ,does water collect on it8 ,oxidation may be said to be the basis of all life processes for this reason3 oxidation gives rise to heat and sets free energy1 and all living things need heat and energy in order to grow and live4 ,the heat of animals is very noticeable4 ,the oxidation in plants also forms a slight amount of heat4 ,in both animals and plants oxidation is much slower than in ordinary fires4 ,that heat is formed even in slow oxidation is shown by fires which arise spontaneously in masses of decaying material4 ,the rotting of wood is not only accompanied by heat but sometimes by light1 as when 8fox fire0 is emitted4 ,rub the end of a match on your finger in the dark4 ,explain the result4 ,strike a match and notice the white fumes which rise for an instant4 ,these fumes are not ordinary smoke 7particles of carbon71 but they are oxid of phosphorus4 ,why will water 7oxid of hydrogen7 not burn8 ,sand is oxid of silicon4 ,explain how throwing sand on a fire puts it out4 ,see also experiments with candle and breath1 in ,the ,principles of ,biology4 ,inorganic and ,organic ,matter4--,test for ,minerals4--,the earth was once in a molten condition1 which would have destroyed any combustible material if any had then existed4 ,before plants and animals existed1 the earth consisted mostly of incombustible minerals1 known as inorganic matter4 ,substances formed by animals and plants are organic matter1 so called because built up by organized or organ-bearing or living things2 starch is an example1 being formed in plants4 ,organic substances are composed chiefly of carbon1 oxygen1 hydrogen1 and nitrogen4 7,see page #a of 8,animal ,biology407 ,coal-oil1 and all combustible materials have their origin in life4 ,hence1 burning to find whether there is an incombustible residue is also a test for minerals4 ,meat1 bread1 oatmeal1 bone1 wood1 may be tested for mineral matter by burning in a spoon held over a hot fire1 or flame of gas or lamp4 ,the substance being tested should be burned until all black material 7which is organic carbon and not a mineral7 has disappeared4 ,any residue will be mineral matter4 ,protoplasm4--,inside the cells of plants and animals is the living substance1 known as protoplasm4 ,it is a structureless1 nearly or quite colorless1 transparent jelly-like substance of very complex and unstable composition4 ,eighty per cent or more is water2 the remainder is proteid1 fats1 oils1 sugars1 and salts4 ,protoplasm has the power of growth and reproduction2 it can make living substance from dead or lifeless substances4 ,it has the power of movement within the cell1 and it is influenced 7or is irritable7 by heat1 light1 touch1 and other stimuli4 ,when protoplasm dies the organism dies4 ,physics is the science that treats of the properties and phenomena 7or behavior7 of matter or of objects2 as of such properties or phenomena or agencies as heat1 light1 force1 electricity1 sound1 friction1 density1 weight1 and the like4 ,chemistry is the science that treats of the composition of matter4 ,all matter is made up1 as we have seen1 of elements4 ,very few elements exist in nature in a free or uncombined form4 ,the nitrogen and oxygen of the air are the leading uncombined elements4 ,in order to express the chemical combinations clearly1 symbols are used to represent each element1 and these symbols are then combined to represent the proportions of each in the compound4 ,if ,c stands for carbon and ,o for oxygen1 the carbon dioxid might be represented by the formula ,,coo4 ,in order to avoid the repetition of any letter1 however1 a number is used to denote how many times the element is taken3 thus the formula always used for carbon dioxid is ,,co4 ,the formula for hydrogen oxid1 or water1 is ,h,o2 that for starch is ,c,h,o4 ,n stands for nitrogen2 ,p1 for phosphorus2 ,k1 potassium2 ,fe1 iron2 ,s1 sulfur4 ,biology is the science that treats of life2 that is1 of all knowledge of plants and animals of all kinds4 7,see page #a1 8,animal ,biology407 ,,how ,a ,,candle ,,burns ,some of the foregoing suggestions may be readily explained and illustrated by simple experiments with a burning candle4 ,the following directions for such experiments are by ,g4 ,w4 ,cavanaugh4 ,the materials needed for this exercise are3 a piece of candle about two inches long1 a lamp chimney 7one with a plain top is best71 a piece of white crockery or window glass1 a piece of fine wire about six inches long1 a bit of quicklime about half the size of an egg1 and some matches4 ,all of these1 with the possible exception of the quicklime1 can be obtained in any household4 ,if you perform the experiment requiring the lime1 be sure that you start with a fresh piece of quick or stone lime1 which can be had of any lime or cement dealer4 ,during the performance of the following simple experiments1 the pupil should describe what he sees at each step4 ,the questions inserted in the text are offered merely as suggestions in the development of the desired ideas4 ,the answers are those which it is desired the pupils shall reach or confirm by their own observation4 ,i4 ,oxygen ,light the candle and place it on a piece of blotting paper 7,a74 ,what do you see burning8 ,is anything burning besides the candle8 ,the answer will probably be 8no40 ,let us see4 ,place the lamp chimney over the lighted candle1 and partly cover the top by a piece of stiff paper1 as in ,fig4 ,a4 ,ask the pupils to observe and describe how the flame goes out2 i4e4 that it is gradually extinguished and does not go out instantly4 ,why did the flame go out8 ,the probable thought will be1 8,because there was no air40 7,if there was no air within the chimney1 some could have entered at the top47 ,illustration3 ,a4--,,the ,,beginning ,,of ,,the ,,candle ,,experiment4 ,illustration3 ,b4--,,supplying ,,air ,,underneath ,,the ,,chimney4 ,place two pencils beside the relighted candle and on them the chimney 7,b74 ,what is the difference between the way in which the candle burns now and before the chimney was placed over it8 ,it flickers1 or dances about more4 ,what makes boys and girls feel like dancing about when they go out from a warm schoolroom8 ,what makes the flame dance or flicker when the chimney is raised by the pencils8 ,because it gets fresh air under the chimney4 ,repeat the first experiment1 in which the flame grows gradually smaller till it is extinguished4 ,why does the flame die out now8 ,is it really necessary to have fresh air in order to keep a flame burning8 ,to prove this further1 let the candle be relighted4 ,place the chimney over it1 now having the top completely closed by a piece of paper4 ,have ready a lighted splinter or match1 and just as soon as the candle is extinguished remove the paper from the chimney top and thrust in the lighted splinter4 ,why does the light on the splinter go out8 ,what became of the freshness that was in the air8 ,it was destroyed by the burning candle4 ,evidently there is some decided difference between unburned air and burned air1 since a flame can continue to burn only in air that has the quality known as freshness4 ,this quality of fresh air is due to oxygen1 represented by ,o4 ,why was the splinter put out instantly1 while the candle flame died out gradually8 ,when the splinter was thrust in1 the air had no freshness or oxygen at all1 while when the candle was placed under the chimney1 it had whatever oxygen was originally in the air within the chimney4 ,endeavor to have this point clearly understood3 that the candle did not go out as long as the air had any oxygen and that the splinter was extinguished immediately because there was no oxygen left4 ,relight the candle4 ,a former question may now be repeated3 ,is anything else burning besides the candle8 ,when the subject of the necessity of fresh air and consequently of oxygen for the burning of the candle seems to be understood1 the following questions1 together with any others which suggest themselves1 may be asked3 ,what is the reason that draughts are opened in stoves8 ,why is the bottom of a 8burner0 on a lamp always full of holes8 ,,ii4 ,carbon ,let us now observe the blackened end of a burned match or splinter4 ,this black substance is usually known by the name of charcoal4 ,if handled1 it will blacken the fingers4 ,try this4 ,the same substance is found on the bottoms of kettles which have been used over a wood fire1 but it is there a fine powder4 ,let us see what was burning when the candle was lighted1 besides the oxygen in the air4 ,relight the candle and hold the porcelain or glass about an inch above the bright part of the flame4 ,what happens to it there8 ,next1 lower it directly into the flame 7,c74 ,what is the black stuff that gets on the glass8 ,look closely and see whether it is not deposited here also as a fine powder4 ,will this deposit from the candle blacken the fingers8 ,illustration3 ,c4--,,the ,,carbon 7,,or ,,soot7 ,,is ,,deposited ,,on ,,the ,,glass4 ,instead of using the name charcoal for this black substance1 let us call it carbon1 the better name1 because there are several kinds of carbon1 and charcoal is only that kind which is rather light and easily blackens the hands4 ,the carbon from the candle flame came mostly from the wax or tallow2 only a very small part came from the wick4 ,it cannot be seen in the tallow1 neither can it be seen in unburned wood1 and yet it can be found when the wood is partly burned4 ,why1 now1 is the glass blackened when held in the flame and not when held directly above it8 ,it is because the carbon from the candle has not been completely burned at the middle of the flame2 but it is burned beyond the bright part of the flame4 ,when the glass is held in the flame1 the carbon that is not yet completely burned is deposited on it1 because it is cooler than that in the surrounding flame4 ,a fine deposit of carbon can be had from any of the luminous parts of the flame2 and it is these thousands of little particles of carbon1 getting white hot1 which glow like coals in the stove and make the light4 ,just as soon as they are completely burned1 there is no more light1 as coals cease to glow when burned to ashes4 ,,iii4 ,carbon dioxid ,illustration3 ,d4--,,the ,,test ,,with ,,the ,,suspended ,,film ,,of ,,limewater4 ,let us now inquire what becomes of the carbon that we find in the bright part of the flame and of the oxygen that was in the air in the lamp chimney4 ,when the candle was extinguished within the chimney1 there was no oxygen left1 as shown by the lighted splinter1 which was put out immediately4 ,neither could any of the particles of carbon be found except on the wick4 ,yet they both still exist within the chimney1 but in an entirely different condition4 ,while the candle was burning1 the little particles of carbon that we find ascending in the flame are joining with the oxygen of the air and making an entirely new substance4 ,this new substance is a gas and cannot be seen in the air4 ,of what two substances is this new substance made8 ,it is ,,co4 ,place a bit of quicklime in about half a glass of water on the day previous to the experiment4 ,when ready for use there will be a white sediment at the bottom and a thin white scum on the top of the clear limewater4 ,the pupils should see this white scum1 as a question about it will follow4 ,make a loop in the end of the piece of wire by turning it around the point of a lead pencil4 ,remove the scum from the limewater with a piece of paper and insert the loop into the clear water4 ,when withdrawn1 the loop ought to hold a film of clear water4 ,pass the wire through a piece of cardboard or stiff paper1 and arrange as shown in ,d4 ,place the chimney over the lighted candle4 ,lower the loop into the chimney and cover the top of the chimney with the paper4 ,withdraw the wire two minutes after the candle goes out4 ,note the cloudy appearance of the film of water on the wire4 ,the cloudiness was caused by the carbon dioxid formed while the candle was burning4 ,omitting the candle1 hang the freshly wetted wire in the empty chimney4 ,let the film of limewater remain within the chimney for the same length of time as when the candle was used4 ,it does not become cloudy now4 ,the cloudiness in clear limewater is a test or indication that carbon dioxid is present4 ,what caused the white scum on the limewater which stood overnight8 ,how does the ,,co get into the air8 ,it is formed whenever wood1 coal1 oil1 or gas is burned4 ,the amount of ,,co in ordinary air is very small1 being only three parts in ten thousand4 ,if the limewater in the loop be left long enough in the air1 it will become cloudy4 ,the reason it clouds so quickly when the candle is being burned is that a large amount of ,,co is formed4 ,besides being made by real flames1 ,,co is formed every time we breathe out air4 ,renew the film of water in the loop and breathe against it gently for two or three minutes4 ,the presence of ,,co in the breath may be shown better by pouring off some of the clear limewater into a clean glass and blowing into it through a straw4 ,why does water put out a fire8 ,the answer is1 not alone because it wets and shuts off the supply of free oxygen1 but because it cools the carbon1 which must be hot in order to unite with the oxygen1 and prevents the oxygen of the air from getting as near the carbon as before4 ,,plant ,,biology ,,chapter ,i ,,no ,,two ,,plants ,,or ,,parts ,,are ,,alike ,illustration3 ,,fig4 #a4--,,no ,,two ,,branches ,,are ,,alike4 7,hemlock47 ,if one compares any two plants of the same kind ever so closely1 it will be found that they differ from each other4 ,the difference is apparent in size1 form1 color1 mode of branching1 number of leaves1 number of flowers1 vigor1 season of maturity1 and the like2 or1 in other words1 all plants and animals vary from an assumed or standard type4 ,if one compares any two branches or twigs on a tree1 it will be found that they differ in size1 age1 form1 vigor1 and in other ways 7,fig4 #a74 ,if one compares any two leaves1 it will be found that they are unlike in size1 shape1 color1 veining1 hairiness1 markings1 cut of the margins1 or other small features4 ,in some cases 7as in ,fig4 #b7 the differences are so great as to be readily seen in a small black-and-white drawing4 ,illustration3 ,,fig4 #b4--,,no ,,two ,,leaves ,,are ,,alike4 ,if the pupil extends his observation to animals1 he will still find the same truth2 for probably no two living objects are exact duplicates4 ,if any person finds two objects that he thinks to be exactly alike1 let him set to work to discover the differences1 remembering that nothing in nature is so small or apparently trivial as to be overlooked4 ,variation1 or differences between organs and also between organisms1 is one of the most significant facts in nature4 ,,suggestions4--,the first fact that the pupil should acquire about plants is that no two are alike4 ,the way to apprehend this great fact is to see a plant accurately and then to compare it with another plant of the same species or kind4 ,in order to direct and concentrate the observation1 it is well to set a certain number of attributes or marks or qualities to be looked for4 #a4 ,suppose any two or more plants of corn are compared in the following points1 the pupil endeavoring to determine whether the parts exactly agree4 ,see that the observation is close and accurate4 ,allow no guesswork4 ,instruct the pupil to measure the parts when size is involved3 7#a7 ,height of the plant4 7#b7 ,does it branch8 ,how many secondary stems or 8suckers0 from one root8 7#c7 ,shade or color4 7#d7 ,how many leaves8 7#e7 ,arrangement of leaves on stem4 7#f7 ,measure length and breadth of six main leaves4 7#g7 ,number and position of ears2 color of silks4 7#h7 ,size of tassel1 and number and size of its branches4 7#i7 ,stage of maturity or ripeness of plant4 7#aj7 ,has the plant grown symmetrically1 or has it been crowded by other plants or been obliged to struggle for light or room8 7#aa7 ,note all unusual or interesting marks or features4 7#ab7 ,always make note of comparative vigor of the plants4 ,,note ,,to ,,teacher4--,the teacher should always insist on personal work by the pupil4 ,every pupil should handle and study the object by himself4 ,books and pictures are merely guides and helps4 ,so far as possible1 study the plant or animal just where it grows naturally4 ,notebooks4--,insist that the pupils make full notes and preserve these notes in suitable books4 ,note-taking is a powerful aid in organizing the mental processes1 and in insuring accuracy of observation and record4 ,the pupil should draw what he sees1 even though he is not expert with the pencil4 ,the drawing should not be made for looks1 but to aid the pupil in his orderly study of the object2 it should be a means of self-expression4 ,laboratory4--,every school1 however small1 should have a laboratory or work-room4 ,this work-room may be nothing more than a table at one side of the room where the light is good4 ,here the specimens may be ranged and studied4 ,often an aquarium and terrarium may be added4 ,a cabinet or set of shelves should be provided for a museum and collection4 ,the laboratory may be in part out of doors1 as a school garden2 or the garden may be at the pupil's home1 and yet be under the general direction of the teacher4 ,,chapter ,,ii ,,the ,,struggle ,,to ,,live ,every plant and animal is exposed to unfavorable conditions4 ,it is obliged to contend with these conditions in order to live4 ,illustration3 ,,fig4 #c4--;,a ,,battle ,,for ,,life4 ,no two plants or parts of plants are identically exposed to the conditions in which they live4 ,the large branches in ,fig4 #a probably had more room and a better exposure to light than the smaller ones4 ,probably no two of the leaves in ,fig4 #b are equally exposed to light1 or enjoy identical advantages in relation to the food that they receive from the tree4 ,examine any tree to determine under what advantages or disadvantages any of the limbs may live4 ,examine similarly the different plants in a garden row 7,fig4 #c72 or the different bushes in a thicket2 or the different trees in a wood4 ,the plant meets its conditions by succumbing to them 7that is1 by dying71 or by adapting itself to them4 ,the tree meets the cold by ceasing its active growth1 hardening its tissues1 dropping its leaves4 ,many herbaceous or soft-stemmed plants meet the cold by dying to the ground and withdrawing all life into the root parts4 ,some plants meet the cold by dying outright and providing abundance of seeds to perpetuate the kind next season4 ,illustration3 ,,fig4 #d4--,,the ,,reach ,,for ,,light ,,of ,a ,,tree ,,on ,,the ,,edge ,,of ,a ,,wood4 ,plants adapt themselves to light by growing toward it 7,fig4 #d72 or by hanging their leaves in such position that they catch the light2 or1 in less sunny places1 by expanding their leaf surface1 or by greatly lengthening their stems so as to overtop their fellows1 as do trees and vines4 ,the adaptations of plants will afford a fertile field of study as we proceed4 ,struggle for existence and adaptation to conditions are among the most significant facts in nature4 ,the sum of all the conditions in which a plant or an animal is placed is called its environment1 that is1 its surroundings4 ,the environment comprises the conditions of climate1 soil1 moisture1 exposure to light1 relation to food supply1 contention with other plants or animals4 ,the organism adapts itself to its environment1 or else it weakens or dies4 ,every weak branch or plant has undergone some hardship that it was not wholly able to withstand4 ,,suggestions4--,the pupil should study any plant1 or branch of a plant1 with reference to the position or condition under which it grows1 and compare one plant or branch with another4 ,with animals1 it is common knowledge that every animal is alert to avoid or to escape danger1 or to protect itself4 #b4 ,it is well to begin with a branch of a tree1 as in ,fig4 #a4 ,note that no two parts are alike 7,chap4 ,i74 ,note that some are large and strong and that these stand farthest towards light and room4 ,some are very small and weak1 barely able to live under the competition4 ,some have died4 ,the pupil can easily determine which ones of the dead branches perished first4 ,he should take note of the position or place of the branch on the tree1 and determine whether the greater part of the dead twigs are toward the center of the tree top or toward the outside of it4 ,determine whether accident has overtaken any of the parts4 #c4 ,let the pupil examine the top of any thick old apple tree1 to see whether there is any struggle for existence and whether any limbs have perished4 #d4 ,if the pupil has access to a forest1 let him determine why there are no branches on the trunks of the old trees4 ,examine a tree of the same kind growing in an open field4 #e4 ,a row of lettuce or other plants sown thick will soon show the competition between plants4 ,any fence row or weedy place will also show it4 ,why does the farmer destroy the weeds among the corn or potatoes8 ,how does the florist reduce competition to its lowest terms8 what is the result8 ,,chapter ,,iii ,,the ,,survival ,,of ,,the ,,fit ,the plants that most perfectly meet their conditions are able to persist4 ,they perpetuate themselves4 ,their offspring are likely to inherit some of the attributes that enabled them successfully to meet the battle of life4 ,the fit 7those best adapted to their conditions7 tend to survive4 ,adaptation to conditions depends on the fact of variation2 that is1 if plants were perfectly rigid or invariable 7all exactly alike7 they could not meet new conditions4 ,conditions are necessarily new for every organism4 ,it is impossible to picture a perfectly inflexible and stable succession of plants or animals4 ,breeding4--,man is able to modify plants and animals4 ,all our common domestic animals are very unlike their original ancestors4 ,so all our common and long-cultivated plants have varied from their ancestors4 ,even in some plants that have been in cultivation less than a century the change is marked3 compare the common black-cap raspberry with its common wild ancestor1 or the cultivated blackberry with the wild form4 ,illustration3 ,,fig4 #e4--;,,desirable ,,and ,,undesirable ,,types ,,of ,,cotton ,,plants4 ,why8 ,by choosing seeds from a plant that pleases him1 the breeder may be able1 under given conditions1 to produce numbers of plants with more or less of the desired qualities2 from the best of these1 he may again choose2 and so on until the race becomes greatly improved 7,figs4 #e1 #f1 #g74 ,this process of continuously choosing the most suitable plants is known as selection4 ,a somewhat similar process proceeds in wild nature1 and it is then known as natural selection4 ,illustration3 ,,fig4 #f4--;,,flax ,,breeding4 ,a is a plant grown for seed production2 ,b1 for fiber production4 ,why8 ,illustration3 ,,fig4 #g4--;,,breeding4 ,a1 effect from breeding from smallest grains 7after four years71 average head2 ,b1 result from breeding from the plumpest and heaviest grains 7after four years71 average head4 ,,suggestions4--#f4 ,every pupil should undertake at least one simple experiment in selection of seed4 ,he may select kernels from the best plant of corn in the field1 and also from the poorest plant1--having reference not so much to mere incidental size and vigor of the plants that may be due to accidental conditions in the field1 as to the apparently constitutional strength and size1 number of ears1 size of ears1 perfectness of ears and kernels1 habit of the plant as to suckering1 and the like4 ,the seeds may be saved and sown the next year4 ,every crop can no doubt be very greatly improved by a careful process of selection extending over a series of years4 ,crops are increased in yield or efficiency in three ways3 better general care2 enriching the land in which they grow2 attention to breeding4 ,,chapter ,,iv ,,plant ,,societies ,in the long course of time in which plants have been accommodating themselves to the varying conditions in which they are obliged to grow1 they have become adapted to every different environment4 ,certain plants1 therefore1 may live together or near each other1 all enjoying the same general conditions and surroundings4 ,these aggregations of plants that are adapted to similar general conditions are known as plant societies4 ,moisture and temperature are the leading factors in determining plant societies4 ,the great geographical societies or aggregations of the plant world may conveniently be associated chiefly with the moisture supply1 as3 wet-region societies1 comprising aquatic and bog vegetation 7,fig4 #h72 arid-region societies1 comprising desert and most sand-region vegetation2 mid-region societies1 comprising the mixed vegetation in intermediate regions 7,fig4 #i71 this being the commonest type4 ,much of the characteristic scenery of any place is due to its plant societies4 ,arid-region plants usually have small and hard leaves1 apparently preventing too rapid loss of water4 ,usually1 also1 they are characterized by stiff growth1 hairy covering1 spines1 or a much-contracted plant-body1 and often by large underground parts for the storage of water4 ,plant societies may also be distinguished with reference to latitude and temperature4 ,there are tropical societies1 temperate-region societies1 boreal or cold-region societies4 ,with reference to altitude1 societies might be classified as lowland 7which are chiefly wet-region71 intermediate 7chiefly mid-region71 subalpine or mid-mountain 7which are chiefly boreal71 alpine or high-mountain4 ,the above classifications have reference chiefly to great geographical floras or societies4 ,but there are societies within societies4 ,there are small societies coming within the experience of every person who has ever seen plants growing in natural conditions4 ,there are roadside1 fence-row1 lawn1 thicket1 pasture1 dune1 woods1 cliff1 barn-yard societies4 ,every different place has its characteristic vegetation4 ,note the smaller societies in ,figs4 #h and #i4 ,in the former is a water-lily society and a cat-tail society4 ,in the latter there are grass and bush and woods societies4 ,illustration3 ,,fig4 #h4--;,a ,,wet-,,region ,,society4 ,some ,details of ,plant ,societies4--,societies may be composed of scattered and intermingled plants1 or of dense clumps or groups of plants4 ,dense clumps or groups are usually made up of one kind of plant1 and they are then called colonies4 ,colonies of most plants are transient3 after a short time other plants gain a foothold amongst them1 and an intermingled society is the outcome4 ,marked exceptions to this are grass colonies and forest colonies1 in which one kind of plant may hold its own for years and centuries4 ,in a large newly cleared area1 plants usually first establish themselves in dense colonies4 ,note the great patches of nettles1 jewel-weeds1 smart-weeds1 clot-burs1 fire-weeds in recently cleared but neglected swales1 also the fire-weeds in recently burned areas1 the rank weeds in the neglected garden1 and the ragweeds and ,may-weeds along the recently worked highway4 ,the competition amongst themselves and with their neighbors finally breaks up the colonies1 and a mixed and intermingled flora is generally the result4 ,illustration3 ,,fig4 #i4--;,a ,,mid-,,region ,,society4 ,in many parts of the world the general tendency of neglected areas is to run into forest4 ,all plants rush for the cleared area4 ,here and there bushes gain a foothold4 ,young trees come up2 in time these shade the bushes and gain the mastery4 ,sometimes the area grows to poplars or birches1 and people wonder why the original forest trees do not return2 but these forest trees may be growing unobserved here and there in the tangle1 and in the slow processes of time the poplars perish--for they are short-lived--and the original forest may be replaced4 ,whether one kind of forest or another returns will depend partly on the kinds that are most seedful in that vicinity and which1 therefore1 have sown themselves most profusely4 ,much depends1 also1 on the kind of undergrowth that first springs up1 for some young trees can endure more or less shade than others4 ,illustration3 ,,fig4 #aj4--,,overgrowth ,,and ,,undergrowth ,,in ,,three ,,series1--trees1 bushes1 grass4 ,some plants associate4 ,they grow together4 ,this is possible largely because they diverge or differ in character4 ,plants associate in two ways3 by growing side by side2 by growing above or beneath4 ,in sparsely populated societies1 plants may grow alongside each other4 ,in most cases1 however1 there is overgrowth and undergrowth3 one kind grows beneath another4 ,plants that have become adapted to shade are usually undergrowths4 ,in a cat-tail swamp1 grasses and other narrow-leaved plants grow in the bottom1 but they are usually unseen by the casual observer4 ,note the undergrowth in woods or under trees 7,fig4 #aj74 ,observe that in pine and spruce forests there is almost no undergrowth1 partly because there is very little light4 ,on the same area the societies may differ at different times of the year4 ,there are spring1 summer1 and fall societies4 ,the knoll which is cool with grass and strawberries in ,june may be aglow with goldenrod in ,september4 ,if the bank is examined in ,may1 look for the young plants that are to cover it in ,july and ,october2 if in ,september1 find the dead stalks of the flora of ,may4 ,what succeeds the skunk cabbage1 hepaticas1 trilliums1 phlox1 violets1 buttercups of spring8 ,what precedes the wild sunflowers1 ragweed1 asters1 and goldenrod of fall8 ,the ,landscape4--,to a large extent the color of the landscape is determined by the character of the plant societies4 ,evergreen societies remain green1 but the shade of green varies from season to season2 it is bright and soft in spring1 becomes dull in midsummer and fall1 and assumes a dull yellow-green or a black-green in winter4 ,deciduous societies vary remarkably in color--from the dull browns and grays of winter to the brown greens and olive-greens of spring1 the staid greens of summer1 and the brilliant colors of autumn4 ,the autumn colors are due to intermingled shades of green1 yellow1 and red4 ,the coloration varies with the kind of plant1 the special location1 and the season4 ,even in the same species or kind1 individual plants differ in color2 and this individuality usually distinguishes the plant year by year4 ,that is1 an oak which is maroon red this autumn is likely to exhibit that range of color every year4 ,the autumn color is associated with the natural maturity and death of the leaf1 but it is most brilliant in long and open falls--largely because the foliage ripens more gradually and persists longer in such seasons4 ,it is probable that the autumn tints are of no utility to the plant4 ,autumn colors are not caused by frost4 ,because of the long1 dry falls and the great variety of plants1 the autumnal color of the ,american landscape is phenomenal4 ,ecology4--,the study of the relationships of plants and animals to each other and to seasons and environments is known as ecology 7still written cology in the dictionaries74 ,it considers the habits1 habitats1 and modes of life of living things--the places in which they grow1 how they migrate or are disseminated1 means of collecting food1 their times and seasons of flowering1 producing young1 and the like4 ,,suggestions4--,one of the best of all subjects for school instruction in botany is the study of plant societies4 ,it adds definiteness and zest to excursions4 #g4 ,let each excursion be confined to one or two societies4 ,visit one day a swamp1 another day a forest1 another a pasture or meadow1 another a roadside1 another a weedy field1 another a cliff or ravine4 ,visit shores whenever possible4 ,each pupil should be assigned a bit of ground--say #aj or #bj ft4 square--for special study4 ,he should make a list showing 7#a7 how many kinds of plants it contains1 7#b7 the relative abundance of each4 ,the lists secured in different regions should be compared4 ,it does not matter greatly if the pupil does not know all the plants4 ,he may count the kinds without knowing the names4 ,it is a good plan for the pupil to make a dried specimen of each kind for reference4 ,the pupil should endeavor to discover why the plants grow as they do4 ,note what kinds of plants grow next each other2 and which are undergrowth and which overgrowth2 and which are erect and which wide-spreading4 ,challenge every plant society4 ,,chapter ,v ,,the ,,plant ,,body ,the ,parts of a ,plant4--,our familiar plants are made up of several distinct parts4 ,the most prominent of these parts are root1 stem1 leaf1 flower1 fruit1 and seed4 ,familiar plants differ wonderfully in size and shape1--from fragile mushrooms1 delicate waterweeds and pond-scums1 to floating leaves1 soft grasses1 coarse weeds1 tall bushes1 slender climbers1 gigantic trees1 and hanging moss4 ,the ,stem ,part4--,in most plants there is a main central part or shaft on which the other or secondary parts are borne4 ,this main part is the plant axis4 ,above ground1 in most plants1 the main plant axis bears the branches1 leaves1 and flowers2 below ground1 it bears the roots4 ,the rigid part of the plant1 which persists over winter and which is left after leaves and flowers are fallen1 is the framework of the plant4 ,the framework is composed of both root and stem4 ,when the plant is dead1 the framework remains for a time1 but it slowly decays4 ,the dry winter stems of weeds are the framework1 or skeleton of the plant 7,figs4 #aa and #ab74 ,the framework of trees is the most conspicuous part of the plant4 ,the ,root ,part4--,the root bears the stem at its apex1 but otherwise it normally bears only root-branches4 ,the stem1 however1 bears leaves1 flowers1 and fruits4 ,those living surfaces of the plant which are most exposed to light are green or highly colored4 ,the root tends to grow downward1 but the stem tends to grow upward toward light and air4 ,the plant is anchored or fixed in the soil by the roots4 ,plants have been called 8earth parasites40 ,the ,foliage ,part4--,the leaves precede the flowers in point of time or life of the plant4 ,the flowers always precede the fruits and seeds4 ,many plants die when the seeds have matured4 ,the whole mass of leaves of any plant or any branch is known as its foliage4 ,in some cases1 as in crocuses1 the flowers seem to precede the leaves2 but the leaves that made the food for these flowers grew the preceding year4 ,illustration3 ,,fig4 #aa4--,,plant ,,of ,a ,,wild ,,sunflower4 ,illustration3 ,,fig4 #ab4--;,,framework ,,of ,,fig4 #aa4 ,the ,plant ,generation4--,the course of a plant's life1 with all the events through which the plant naturally passes1 is known as the plant's life-history4 ,the life-history embraces various stages1 or epochs1 as dormant seed1 germination1 growth1 flowering1 fruiting4 ,some plants run their course in a few weeks or months1 and some live for centuries4 ,the entire life-period of a plant is called a generation4 ,it is the whole period from birth to normal death1 without reference to the various stages or events through which it passes4 ,a generation begins with the young seed1 not with germination4 ,it ends with death--that is1 when no life is left in any part of the plant1 and only the seed or spore remains to perpetuate the kind4 ,in a bulbous plant1 as a lily or an onion1 the generation does not end until the bulb dies1 even though the top is dead4 ,when the generation is of only one season's duration1 the plant is said to be annual4 ,when it is of two seasons1 it is biennial4 ,biennials usually bloom the second year4 ,when of three or more seasons1 the plant is perennial4 ,examples of annuals are pigweed1 bean1 pea1 garden sunflower2 of biennials1 evening primrose1 mullein1 teasel2 of perennials1 dock1 most meadow grasses1 cat-tail1 and all shrubs and trees4 ,duration of the ,plant ,body4--,plant structures which are more or less soft and which die at the close of the season are said to be herbaceous1 in contradistinction to being ligneous or woody4 ,a plant which is herbaceous to the ground is called an herb2 but an herb may have a woody or perennial root1 in which case it is called an herbaceous perennial4 ,annual plants are classed as herbs4 ,examples of herbaceous perennials are buttercups1 bleeding heart1 violet1 water lily1 ,bermuda grass1 horse-radish1 dock1 dandelion1 golden rod1 asparagus1 rhubarb1 many wild sunflowers 7,figs4 #aa1 #ab74 ,many herbaceous perennials have short generations4 ,they become weak with one or two seasons of flowering and gradually die out4 ,thus1 red clover usually begins to fail after the second year4 ,gardeners know that the best bloom of hollyhock1 larkspur1 pink1 and many other plants1 is secured when the plants are only two or three years old4 ,herbaceous perennials which die away each season to bulbs or tubers1 are sometimes called pseud-annuals 7that is1 false annuals74 ,of such are lily1 crocus1 onion1 potato1 bull nettle1 and false indigo of the ,southern states4 ,true annuals reach old age the first year4 ,plants which are normally perennial may become annual in a shorter-season climate by being killed by frost1 rather than by dying naturally at the end of a season of growth4 ,they are climatic annuals4 ,such plants are called plur-annuals in the short-season region4 ,many tropical perennials are plur-annuals when grown in the north1 but they are treated as true annuals because they ripen sufficient of their crop the same season in which the seeds are sown to make them worth cultivating1 as tomato1 red pepper1 castor bean1 cotton4 ,name several vegetables that are planted in gardens with the expectation that they will bear till frost comes4 ,illustration3 ,,fig4 #ac4--;,a ,,shrub ,,or ,,bush4 ,dogwood osier4 ,woody or ligneous plants are usually longer lived than herbs4 ,those that remain low and produce several or many similar shoots from the base are called shrubs1 as lilac1 rose1 elder1 osier 7,fig4 #ac74 ,low and thick shrubs are bushes4 ,plants that produce one main trunk and a more or less elevated head are trees 7,fig4 #ad74 ,all shrubs and trees are perennial4 ,illustration3 ,,fig4 #ad4--;,a ,,tree4 ,the weeping birch4 ,every plant makes an effort to propagate1 or to perpetuate its kind2 and1 as far as we can see1 this is the end for which the plant itself lives4 ,the seed or spore is the final product of the plant4 ,,suggestions4--#h4 ,the teacher may assign each pupil to one plant in the school yard1 or field1 or in a pot1 and ask him to bring out the points in the lesson4 #i4 ,the teacher may put on the board the names of many common plants and ask the pupils to classify into annuals1 pseud-annuals1 plur-annuals 7or climatic annuals71 biennials1 perennials1 herbaceous perennials1 ligneous perennials1 herbs1 bushes1 trees4 ,every plant grown on the farm should be so classified3 wheat1 oats1 corn1 buckwheat1 timothy1 strawberry1 raspberry1 currant1 tobacco1 alfalfa1 flax1 crimson clover1 hops1 cowpea1 field bean1 sweet potato1 peanut1 radish1 sugar-cane1 barley1 cabbage1 and others4 ,name all the kinds of trees you know4 ,,chapter ,,vi ,,seeds ,,and ,,germination ,illustration3 ,,fig4 #ae4--,,parts ,,of ,,the ,,bean4 ,r1 cotyledon2 ,o1 caulicle2 ,a1 plumule2 ,f1 first node4 ,the seed contains a miniature plant1 or embryo4 ,the embryo usually has three parts that have received names3 the stemlet1 or caulicle2 the seed-leaf1 or cotyledon 7usually #a or #b72 the bud1 or plumule1 lying between or above the cotyledons4 ,these parts are well seen in the common bean 7,fig4 #ae71 particularly when the seed has been soaked for a few hours4 ,one of the large cotyledons--comprising half of the bean--is shown at ,r4 ,the caulicle is at ,o4 ,the plumule is shown at ,a4 ,the cotyledons are attached to the caulicle at ,f3 this point may be taken as the first node or joint4 ,the ,number of ,seed-leaves4--,all plants having two seed-leaves belong to the group called dicotyledons4 ,such seeds in many cases split readily in halves1 e4g4 a bean4 ,some plants have only one seed-leaf in a seed4 ,they form a group of plants called monocotyledons4 ,indian corn is an example of a plant with only one seed-leaf3 a grain of corn does not split into halves as a bean does4 ,seeds of the pine family contain more than two cotyledons1 but for our purposes they may be associated with the dicotyledons1 although really forming a different group4 ,these two groups--the dicotyledons and the monocotyledons--represent two great natural divisions of the vegetable kingdom4 ,the dicotyledons contain the woody bark-bearing trees and bushes 7except conifers71 and most of the herbs of temperate climates except the grasses1 sedges1 rushes1 lily tribes1 and orchids4 ,the flower-parts are usually in fives or multiples of five1 the leaves mostly netted-veined1 the bark or rind distinct1 and the stem often bearing a pith at the center4 ,the monocotyledons usually have the flower-parts in threes or multiples of three1 the leaves long and parallel-veined1 the bark not separable1 and the stem without a central pith4 ,every seed is provided with food to support the germinating plant4 ,commonly this food is starch4 ,the food may be stored in the cotyledons1 as in bean1 pea1 squash2 or outside the cotyledons1 as in castor bean1 pine1 ,indian corn4 ,when the food is outside or around the embryo1 it is usually called endosperm4 ,illustration3 ,,fig4 #af4--;,,external ,,parts ,,of ,,bean4 ,seed-coats2 ,markings on ,seed4--,the embryo and endosperm are inclosed within a covering made of two or more layers and known as the seed-coats4 ,over the point of the caulicle is a minute hole or a thin place in the coats known as the micropyle4 ,this is the point at which the pollen-tube entered the forming ovule and through which the caulicle breaks in germination4 ,the micropyle is shown at ,m in ,fig4 #af4 ,the scar where the seed broke from its funiculus 7or stalk that attached it to its pod7 is named the hilum4 ,it occupies a third of the length of the bean in ,fig4 #af4 ,the hilum and micropyle are always present in seeds1 but they are not always close together4 ,in many cases it is difficult to identify the micropyle in the dormant seed1 but its location is at once shown by the protruding caulicle as germination begins4 ,opposite the micropyle in the bean 7at the other end of the hilum7 is an elevation known as the raphe4 ,this is formed by a union of the funiculus1 or seed-stalk1 with the seed-coats1 and through it food was transferred for the development of the seed1 but it is now functionless4 ,seeds differ wonderfully in size1 shape1 color1 and other characteristics4 ,they also vary in longevity4 ,these characteristics are peculiar to the species or kind4 ,some seeds maintain life only a few weeks or even days1 whereas others will 8keep0 for ten or twenty years4 ,in special cases1 seeds have retained vitality longer than this limit1 but the stories that live seeds1 several thousand years old1 have been taken from the wrappings of mummies are unfounded4 ,germination4--,the embryo is not dead2 it is only dormant4 ,when supplied with moisture1 warmth1 and oxygen 7air71 it awakes and grows3 this growth is germination4 ,the embryo lives for a time on the stored food1 but gradually the plantlet secures a foothold in the soil and gathers food for itself4 ,when the plantlet is finally able to shift for itself1 germination is complete4 ,early ,stages of ,seedling4--,the germinating seed first absorbs water1 and swells4 ,the starchy matters gradually become soluble4 ,the seed-coats are ruptured1 the caulicle and plumule emerge4 ,during this process the seed respires freely1 throwing off carbon dioxid 7,,co74 ,the caulicle usually elongates1 and from its lower end roots are emitted4 ,the elongating caulicle is known as the hypocotyl 78below the cotyledons074 ,that is1 the hypocotyl is that part of the stem of the plantlet lying between the roots and the cotyledon4 ,the general direction of the young hypocotyl1 or emerging caulicle1 is downwards4 ,as soon as roots form1 it becomes fixed and its subsequent growth tends to raise the cotyledons above the ground1 as in the bean4 ,when cotyledons rise into the air1 germination is said to be epigeal 78above the earth074 ,bean and pumpkin are examples4 ,when the hypocotyl does not elongate greatly and the cotyledons remain under ground1 the germination is hypogeal 78beneath the earth074 ,pea and scarlet runner bean are examples 7,fig4 #dh74 ,when the germinating seed lies on a hard surface1 as on closely compacted soil1 the hypocotyl and rootlets may not be able to secure a foothold and they assume grotesque forms4 7,fig4 #ag47 ,try this with peas and beans4 ,illustration3 ,,fig4 #ag4--,,pea4 ,grotesque forms assumed when the roots cannot gain entrance to the soil4 ,the first internode 78between nodes07 above the cotyledons is the epicotyl4 ,it elevates the plumule into the air1 and the plumule-leaves expand into the first true leaves of the plant4 ,these first true leaves1 however1 may be very unlike the later leaves in shape4 ,illustration3 ,,fig4 #ah4--;,,cotyledons ,,of ,,germinating ,,bean ,,spread ,,apart ,,to ,,show ,,elongating ,,caulicle ,,and ,,plumule4 ,germination of ,bean4--,the common bean1 as we have seen 7,fig4 #ae71 has cotyledons that occupy all the space inside the seed-coats4 ,when the hypocotyl1 or elongated caulicle1 emerges1 the plumule-leaves have begun to enlarge1 and to unfold 7,fig4 #ah74 ,the hypocotyl elongates rapidly4 ,one end of it is held by the roots4 ,the other is held by the seed-coats in the soil4 ,it therefore takes the form of a loop1 and the central part of the loop 8comes up0 first 7a1 ,fig4 #ai74 ,presently the cotyledons come out of the seed-coats1 and the plant straightens and the cotyledons expand4 ,these cotyledons1 or 8halves of the bean10 persist for some time 7b1 ,fig4 #ai74 ,they often become green and probably perform some function of foliage4 ,because of its large size1 the ,lima bean shows all these parts well4 ,illustration3 ,,fig4 #ai4--;,,germination ,,of ,,bean4 ,illustration3 ,,fig4 #bj4--,,sprouting ,,of ,,castor ,,bean4 ,illustration3 ,,fig4 #ba4--;,,germination ,,of ,,castor ,,bean4 ,endosperm at a4 ,illustration3 ,,fig4 #bb4--;,,castor ,,bean4 ,endosperm at a1 a2 cotyledons at b4 ,illustration3 ,,fig4 #bc4--;,,germination ,,complete ,,in ,,castor ,,bean4 ,germination of ,castor ,bean4--,in the castor bean the hilum and micropyle are at the smaller end 7,fig4 #bj74 ,the bean 8comes up0 with a loop1 which indicates that the hypocotyl greatly elongates4 ,on examining germinating seed1 however1 it will be found that the cotyledons are contained inside a fleshy body1 or sac 7a1 ,fig4 #ba74 ,this sac is the endosperm4 ,against its inner surface the thin1 veiny cotyledons are very closely pressed1 absorbing its substance 7,fig4 #bb74 ,the cotyledons increase in size as they reach the air 7,fig4 #bc71 and become functional leaves4 ,illustration3 ,,fig4 #bd4--,,sprouting ,,indian ,,corn4 ,hilum at h2 micropyle at d4 ,illustration3 ,,fig4 #be4--,,kernel ,,of ,,indian ,,corn4 ,caulicle at b2 cotyledon at a2 plumule at p4 ,illustration3 ,,fig4 #bf4--;,,indian ,,corn4 ,caulicle at c2 roots emerging at m2 plumule at p4 ,illustration3 ,,fig4 #bg4--;,,indian ,,corn4 o1 plumule3 n to p1 epicotyl4 ,germination of ,monocotyledons4--,thus far we have studied dicotyledonous seeds2 we may now consider the monocotyledonous group4 ,soak kernels of corn4 ,note that the micropyle and hilum are at the smaller end 7,fig4 #bd74 ,make a longitudinal section through the narrow diameter2 ,fig4 #be shows it4 ,the single cotyledon is at a1 the caulicle at b1 the plumule at p4 ,the cotyledon remains in the seed4 ,the food is stored both in the cotyledon and as endosperm1 chiefly the latter4 ,the emerging shoot is the plumule1 with a sheathing leaf 7p1 ,fig4 #bf74 ,the root is emitted from the tip of the caulicle1 c4 ,the caulicle is held in a sheath 7formed mostly from the seed-coats71 and some of the roots escape through the upper end of this sheath 7m1 ,fig4 #bf74 ,the epicotyl elongates1 particularly if the seed is planted deep or if it is kept for a time confined4 ,in ,fig4 #bg the epicotyl has elongated from n to p4 ,the true plumule-leaf is at o1 but other leaves grow from its sheath4 ,in ,fig4 #bh the roots are seen emerging from the two ends of the caulicle sheath1 c1 m2 the epicotyl has grown to p2 the first plumule-leaf is at o4 ,illustration3 ,,fig4 #bh4--;,,germination ,,is ,,complete4 p1 top of epicotyl2 o1 plumule-leaf2 m1 roots2 c1 lower roots4 ,in studying corn or other fruits or seeds1 the pupil should note how the seeds are arranged1 as on the cob4 ,count the rows on a corn cob4 ,odd or even in number8 ,always the same number8 ,the silk is the style3 find where it was attached to the kernel4 ,did the ear have any coverings8 ,explain4 ,describe colors and markings of kernels of corn2 and of peas1 beans1 castor bean4 ,gymnosperms4--,the seeds in the pine cone1 not being inclosed in a seed-vessel1 readily fall out when the cone dries and the scales separate4 ,hence it is difficult to find cones with seeds in them after autumn has passed 7,fig4 #bi74 ,the cedar is also a gymnosperm4 ,illustration3 ,,fig4 #bi4--;,,cones ,,of ,,hemlock 7,,above71 ,,white ,,pine1 ,,pitch ,,pine4 ,remove a scale from a pine cone and draw it and the seeds as they lie in place on the upper side of the scale4 ,examine the seed1 preferably with a magnifying glass4 ,is there a hilum8 ,the micropyle is at the bottom or little end of the seed4 ,toss a seed upward into the air4 ,why does it fall so slowly8 ,can you explain the peculiar whirling motion by the shape of the wing8 ,repeat the experiment in the wind4 ,remove the wing from a seed and toss it and an uninjured seed into the air together4 ,what do you infer from these experiments8 ,illustration3 ,,fig4 #cj4--,,muskmelon ,,seedlings1 with the unlike seed-leaves and true leaves4 ,,suggestions4--,few subjects connected with the study of plant-life are so useful in schoolroom demonstrations as germination4 ,the pupil should prepare the soil1 plant the seeds1 water them1 and care for the plants4 #aj4 ,plant seeds in pots or shallow boxes4 ,the box should not be very wide or long1 and not over four inches deep4 ,holes may be bored in the bottom so it will not hold water4 ,plant a number of squash1 bean1 corn1 pine1 or other seeds about an inch deep in damp sand or pine sawdust in this box4 ,the depth of planting should be two to four times the diameter of the seeds4 ,keep the sand or sawdust moist but not wet4 ,if the class is large1 use several boxes1 that the supply of specimens may be ample4 ,cigar boxes and chalk boxes are excellent for individual pupils4 ,it is well to begin the planting of seeds at least ten days in advance of the lesson1 and to make four or five different plantings at intervals4 ,a day or two before the study is taken up1 put seeds to soak in moss or cloth4 ,the pupil then has a series from swollen seeds to complete germination1 and all the steps can be made out4 ,dry seeds should be had for comparison4 ,if there is no special room for laboratory1 nor duplicate apparatus for every pupil1 each experiment may be assigned to a committee of two pupils to watch in the schoolroom4 #aa4 ,good seeds for study are those detailed in the lesson1 and buckwheat1 pumpkin1 cotton1 morning glory1 radish1 four o'clock1 oats1 wheat4 ,it is best to use familiar seeds of farm and garden4 ,make drawings and notes of all the events in the germination4 ,note the effects of unusual conditions1 as planting too deep and too shallow and different sides up4 ,for hypogeal germination1 use the garden pea1 scarlet runner or ,dutch case-knife bean1 acorn1 horse-chestnut4 ,squash seeds are excellent for germination studies1 because the cotyledons become green and leafy and germination is rapid4 ,its germination1 as also that of the scarlet runner bean1 is explained in 8,lessons with ,plants40 ,onion is excellent1 except that it germinates too slowly4 ,in order to study the root development of germinating plantlets1 it is well to provide a deeper box with a glass side against which the seeds are planted4 #ab4 ,observe the germination of any common seed about the house premises4 ,when elms1 oaks1 pines1 or maples are abundant1 the germination of their seeds may be studied in lawns and along fences4 #ac4 ,when studying germination1 the pupil should note the differences in shape and size between cotyledons and plumule-leaves1 and between plumule-leaves and the normal leaves 7,fig4 #cj74 ,make drawings4 #ad4 ,make the tests described in the introductory experiments with bean1 corn1 the castor bean1 and other seed for starch and proteids4 ,test flour1 oatmeal1 rice1 sunflower1 four o'clock1 various nuts1 and any other seeds obtainable4 ,record your results by arranging the seeds in three classes1 #a4 ,much starch 7color blackish or purple71 #b4 ,little starch 7pale blue or greenish71 #c4 ,no starch 7brown or yellow74 #ae4 ,rate of growth of seedlings as affected by differences in temperature4 ,pack soft wet paper to the depth of an inch in the bottom of four glass bottles or tumblers4 ,put ten soaked peas or beans into each4 ,cover each securely and set them in places having different temperatures that vary little4 7,a furnace room1 a room with a stove1 a room without stove but reached by sunshine1 an unheated room not reached by the sun47 ,take the temperatures occasionally with a thermometer to find difference in temperature4 ,the tumblers in warm places should be covered very tightly to prevent the germination from being retarded by drying out4 ,record the number of seeds which sprout in each tumbler within #a day2 #b days2 #c days2 #d days1 etc4 #af4 ,is air necessary for the germination and growth of seedlings8 ,place damp blotting paper in the bottom of a bottle and fill it three fourths full of soaked seeds1 and close it tightly with a rubber stopper or oiled cork4 ,prepare a 8check experiment0 by having another bottle with all conditions the same except that it is covered loosely that air may have access to it1 and set the bottles side by side 7why keep the bottles together874 ,record results as in the preceding experiment4 #ag4 ,what is the nature of the gas given off by germinating seeds8 ,fill a tin box or large-necked bottle with dry beans or peas1 then add water2 note how much they swell4 ,secure two fruit-jars4 ,fill one of them a third full of beans and keep them moist4 ,allow the other to remain empty4 ,in a day or two insert a lighted splinter or taper into each4 ,in the empty jar the taper burns3 it contains oxygen4 ,in the seed jar the taper goes out3 the air has been replaced by carbon dioxid4 ,the air in the bottle may be tested for carbon dioxid by removing some of it with a rubber bulb attached to a glass tube 7or a fountain-pen filler7 and bubbling it through lime water4 #ah4 ,temperature4 ,usually there is a perceptible rise in temperature in a mass of germinating seeds4 ,this rise may be tested with a thermometer4 #ai4 ,interior of seeds4 ,soak seeds for twenty-four hours and remove the coat4 ,distinguish the embryo from the endosperm4 ,test with iodine4 #bj4 ,of what utility is the food in seeds8 ,soak some grains of corn overnight and remove the endosperm1 being careful not to injure the fleshy cotyledon4 ,plant the incomplete and also some complete grains in moist sawdust and measure their growth at intervals4 7,boiling the sawdust will destroy molds and bacteria which might interfere with experiment47 ,peas or beans may be sprouted on damp blotting paper2 the cotyledons of one may be removed1 and this with a normal seed equally advanced in germination may be placed on a perforated cork floating in water in a jar so that the roots extend into the water4 ,their growth may be observed for several weeks4 #ba4 ,effect of darkness on seeds and seedlings4 ,a box may be placed mouth downward over a smaller box in which seedlings are growing4 ,the empty box should rest on half-inch blocks to allow air to reach the seedlings4 ,note any effects on the seedlings of this cutting off of the light4 ,another box of seedlings not so covered may be used for a check4 ,lay a plank on green grass and after a week note the change that takes place beneath it4 #bb4 ,seedling of pine4 ,plant pine seeds4 ,notice how they emerge4 ,do the cotyledons stay in the ground8 ,how many cotyledons have they8 ,when do the cotyledons get free from the seed-coat8 ,what is the last part of the cotyledon to become free8 ,where is the growing point or plumule8 ,how many leaves appear at once8 ,does the new pine cone grow on old wood or on wood formed the same spring with the cone8 ,can you always find partly grown cones on pine trees in winter8 ,are pine cones when mature on two-year-old wood8 ,how long do cones stay on a tree after the seeds have fallen out8 ,what is the advantage of the seeds falling before the cones8 #bc4 ,home experiments4 ,if desired1 nearly all of the foregoing experiments may be tried at home4 ,the pupil can thus make the drawings for the notebook at home4 ,a daily record of measurements of the change in size of the various parts of the seedling should also be made4 #bd4 ,seed-testing4--,it is important that one know before planting whether seeds are good1 or able to grow4 ,a simple seed-tester may be made of two plates1 one inverted over the other 7,fig4 #ca74 ,the lower plate is nearly filled with clean sand1 which is covered with cheese cloth or blotting paper on which the seeds are placed4 ,canton flannel is sometimes used in place of sand and blotting paper4 ,the seeds are then covered with another blotter or piece of cloth1 and water is applied until the sand and papers are saturated4 ,cover with the second plate4 ,set the plates where they will have about the temperature that the given seeds would require out of doors1 or perhaps a slightly higher temperature4 ,place #ajj or more grains of clover1 corn1 wheat1 oats1 rye1 rice1 buckwheat1 or other seeds in the tester1 and keep record of the number that sprout4 ,the result will give a percentage measure of the ability of the seeds to grow4 ,note whether all the seeds sprout with equal vigor and rapidity4 ,most seeds will sprout in a week or less4 ,usually such a tester must have fresh sand and paper after every test1 for mold fungi are likely to breed in it4 ,if canton flannel is used1 it may be boiled4 ,if possible1 the seeds should not touch each other4 ,illustration3 ,,fig4 #ca4--;,a ,,home-,,made ,,seed-,,tester4 ,,note ,,to ,,teacher4--,with the study of germination1 the pupil will need to begin dissecting4 ,for dissecting1 one needs a lens for the examination of the smaller parts of plants and animals4 ,it is best to have the lens mounted on a frame1 so that the pupil has both hands free for pulling the part in pieces4 ,an ordinary pocket lens may be mounted on a wire in a block1 as in ,fig4 ,a4 ,a cork is slipped on the top of the wire to avoid injury to the face4 ,the pupil should be provided with two dissecting needles 7,fig4 ,b71 made by securing an ordinary needle in a pencil-like stick4 ,another convenient arrangement is shown in ,fig4 ,c4 ,a small tin dish is used for the base4 ,into this a stiff wire standard is soldered4 ,the dish is filled with solder1 to make it heavy and firm4 ,into a cork slipped on the standard1 a cross wire is inserted1 holding on the end a jeweler's glass4 ,the lens can be moved up and down and sidewise4 ,this outfit can be made for about seventy-five cents4 ,fig4 ,d shows a convenient hand-rest or dissecting-stand to be used under this lens4 ,it may be #af in4 long1 #d in4 high1 and #d or #e in4 broad4 ,various kinds of dissecting microscopes are on the market1 and these are to be recommended when they can be afforded4 ,illustration3 ,a4--,,improvised ,,stand ,,for ,,lens4 ,illustration3 ,b4--,,dissecting ,,needle natural size4 ,illustration3 ,c4--,,dissecting ,,glass4 ,illustration3 ,d4--,,dissecting ,,stand4 ,instructions for the use of the compound microscope1 with which some schools may be equipped1 cannot be given in a brief space2 the technique requires careful training4 ,such microscopes are not needed unless the pupil studies cells and tissues4 ,,chapter ,,vii ,,the ,,root--,,the ,,forms ,,of ,,roots ,the ,root ,system4--,the offices of the root are to hold the plant in place1 and to gather food4 ,not all the food materials1 however1 are gathered by the roots4 ,illustration3 ,,fig4 #cb4--,,tap-,,root ,,system ,,of ,,alfalfa4 ,illustration3 ,,fig4 #cc4--,,tap-,,root ,,of ,,the ,,dandelion4 ,the entire mass of roots of any plant is called its root system4 ,the root system may be annual1 biennial or perennial1 herbaceous or woody1 deep or shallow1 large or small4 ,kinds of ,roots4--,a strong leading central root1 which runs directly downwards1 is a tap-root4 ,the tap-root forms an axis from which the side roots may branch4 ,the side or spreading roots are usually smaller4 ,plants that have such a root system are said to be tap-rooted4 ,examples are red clover1 alfalfa1 beet1 turnip1 radish1 burdock1 dandelion1 hickory 7,figs4 #cb1 #cc74 ,a fibrous root system is one that is composed of many nearly equal slender branches4 ,the greater number of plants have fibrous roots4 ,examples are many common grasses1 wheat1 oats1 corn4 ,the buttercup in ,fig4 #cd has a fibrous root system4 ,many trees have a strong tap-root when very young1 but after a while it ceases to extend strongly and the side roots develop until finally the tap-root character disappears4 ,illustration3 ,,fig4 #cd4--;,a ,,buttercup ,,plant1 with fibrous roots4 ,shape and ,extent of the ,root ,system4--,the depth to which roots extend depends on the kind of plant1 and the nature of the soil4 ,of most plants the roots extend far in all directions and lie comparatively near the surface4 ,the roots usually radiate from a common point just beneath the surface of the ground4 ,the roots grow here and there in search of food1 often extending much farther in all directions than the spread of the top of the plant4 ,roots tend to spread farther in poor soil than in rich soil1 for the same size of plant4 ,the root has no such definite form as the stem has4 ,roots are usually very crooked1 because they are constantly turned aside by obstacles4 ,examine roots in stony soil4 ,the extent of root surface is usually very large1 for the feeding roots are fine and very numerous4 ,an ordinary plant of ,indian corn may have a total length of root 7measured as if the roots were placed end to end7 of several hundred feet4 ,the fine feeding roots are most abundant in the richest part of the soil4 ,they are attracted by the food materials4 ,roots often will completely surround a bone or other morsel4 ,when roots of trees are exposed1 observe that most of them are horizontal and lie near the top of the ground4 ,some roots1 as of willows1 extend far in search of water4 ,they often run into wells and drains1 and into the margins of creeks and ponds4 ,grow plants in a long narrow box1 in one end of which the soil is kept very dry and in the other moist3 observe where the roots grow4 ,buttresses4--,with the increase in diameter1 the upper roots often protrude above the ground and become bracing buttresses4 ,these buttresses are usually largest in trees which always have been exposed to strong winds 7,fig4 #ce74 ,because of growth and thickening1 the roots elevate part of their diameter1 and the washing away of the soil makes them to appear as if having risen out of the ground4 ,illustration3 ,,fig4 #ce4--,,the ,,bracing ,,base ,,of ,a ,,field ,,pine4 ,arial ,roots4--,although roots usually grow underground1 there are some that naturally grow above ground4 ,these usually occur on climbing plants1 the roots becoming supports or fulfilling the office of tendrils4 ,these arial roots usually turn away from the light1 and therefore enter the crevices and dark places of the wall or tree over which the plant climbs4 ,the trumpet creeper 7,fig4 #cf71 true or ,english ivy1 and poison ivy climb by means of roots4 ,illustration3 ,,fig4 #cf4--;,a,,rial ,,roots ,,of ,,trumpet ,,creeper ,,or ,,tecoma4 ,illustration3 ,,fig4 #cg4--;,a,,rial ,,roots ,,of ,,an ,,orchid4 ,in some plants all the roots are arial2 that is1 the plant grows above ground1 and the roots gather food from the air4 ,such plants usually grow on trees4 ,they are known as epiphytes or air-plants4 ,the most familiar examples are some of the tropical orchids1 which are grown in glass-houses 7,fig4 #cg74 ,rootlike organs of dodder and other parasites are discussed in a future chapter4 ,some plants bear arial roots1 that may propagate the plant or may act as braces4 ,they are often called prop-roots4 ,the roots of ,indian corn are familiar 7,fig4 #ch74 ,many ficus trees1 as the banyan of ,india1 send out roots from their branches2 when these roots reach the ground they take hold and become great trunks1 thus spreading the top of the parent tree over large areas4 ,the muscadine grape of the ,southern states often sends down roots from its stems4 ,the mangrove tree of the tropics grows along seashores and sends down roots from the overhanging branches 7and from the fruits7 into the shallow water1 and thereby gradually marches into the sea4 ,the tangled mass behind catches the drift1 and soil is formed4 ,illustration3 ,,fig4 #ch4--;,,indian ,,corn1 showing the brace roots at oo4 ,adventitious ,roots4--,sometimes roots grow from the stem or other unusual places as the result of some accident to the plant1 being located without known method or law4 ,they are called adventitious 7chance7 roots4 ,cuttings of the stems of roses1 figs1 geraniums1 and other plants1 when planted1 send out adventitious roots and form new plants4 ,the ordinary roots1 or soil roots1 are of course not classed as adventitious roots4 ,the adventitious roots arise on occasion1 and not as a normal or regular course in the growth of the plant4 ,no two roots are alike2 that is1 they vary among themselves as stems and leaves do4 ,each kind of plant has its own form or habit of root 7,fig4 #ci74 ,carefully wash away the soil from the roots of any two related plants1 as oats and wheat1 and note the differences in size1 depth1 direction1 mode of branching1 number of fibrils1 color1 and other features4 ,the character of the root system often governs the treatment that the farmer should give the soil in which the plant or crop grows4 ,illustration3 ,,fig4 #ci4--,,roots ,,of ,,barley ,,at ,a ,,and ,,corn ,,at ,b4 ,carefully trace the differences4 ,roots differ not only in their form and habit1 but also in color of tissue1 character of bark or rind1 and other features4 ,it is excellent practice to try to identify different plants by means of their roots4 ,let each pupil bring to school two plants with the roots very carefully dug up1 as cotton1 corn1 potato1 bean1 wheat1 rye1 timothy1 pumpkin1 clover1 sweet pea1 raspberry1 strawberry1 or other common plants4 ,root ,systems of ,weeds4--,some weeds are pestiferous because they seed abundantly1 and others because their underground parts run deep or far and are persistent4 ,make out the root systems in the six worst weeds in your locality4 ,,chapter ,,viii ,,the ,,root4--,,function ,,and ,,structure ,the function of roots is twofold1--to provide support or anchorage for the plant1 and to collect and convey food materials4 ,the first function is considered in ,chapter ,,vii2 we may now give attention in more detail to the second4 ,the feeding surface of the roots is near their ends4 ,as the roots become old and hard1 they serve only as channels through which food passes and as hold-fasts or supports for the plant4 ,the root-hold of a plant is very strong4 ,slowly pull upwards on some plant1 and note how firmly it is anchored in the soil4 ,illustration3 ,,fig4 #dj4--,,wheat ,,growing ,,under ,,different ,,soil ,,treatments4 ,soil deficient in nitrogen2 commercial nitrogen applied to pot #c 7on right74 ,roots have power to choose their food2 that is1 they do not absorb all substances with which they come in contact4 ,they do not take up great quantities of useless or harmful materials1 even though these materials may be abundant in the soil2 but they may take up a greater quantity of some of the plant-foods than the plant can use to advantage4 ,plants respond very quickly to liberal feeding1--that is1 to the application of plant-food to the soil 7,fig4 #dj74 ,the poorer the soil1 the more marked are the results1 as a rule1 of the application of fertilizers4 ,certain substances1 as common salt1 will kill the roots4 ,roots absorb ,substances only in ,solution4--,substances cannot be taken in solid particles4 ,these materials are in solution in the soil water1 and the roots themselves also have the power to dissolve the soil materials to some extent by means of substances that they excrete4 ,the materials that come into the plant through the roots are water and mostly the mineral substances1 as compounds of potassium1 iron1 phosphorus1 calcium1 magnesium1 sulfur1 and chlorine4 ,these mineral substances compose the ash when the plant is burned4 ,the carbon is derived from the air through the green parts4 ,oxygen is derived from the air and the soil water4 ,illustration3 ,,fig4 #da4--,,nodules ,,on ,,roots ,,of ,,red ,,clover4 ,nitrogen enters through the ,roots4--,all plants must have nitrogen2 yet1 although about four fifths of the air is nitrogen1 plants are not able1 so far as we know1 to take it in through their leaves4 ,it enters through the roots in combination with other elements1 chiefly in the form of nitrates 7certain combinations with oxygen and a mineral base74 ,the great family of leguminous plants1 however 7as peas1 beans1 cowpea1 clover1 alfalfa1 vetch71 use the nitrogen contained in the air in the soil4 ,they are able to utilize it through the agency of nodules on their roots 7,figs4 #da1 #db74 ,these nodules contain bacteria1 which appropriate the free or uncombined nitrogen and pass it on to the plant4 ,the nitrogen becomes incorporated in the plant tissue1 so that these crops are high in their nitrogen content4 ,inasmuch as nitrogen in any form is expensive to purchase in fertilizers1 the use of leguminous crops to plow under is a very important agricultural practice in preparing the land for other crops4 ,in order that leguminous crops may acquire atmospheric nitrogen more freely and thereby thrive better1 the land is sometimes sown or inoculated with the nodule-forming bacteria4 ,illustration3 ,,fig4 #db4--,,nodules ,,on ,,vetch4 ,illustration3 ,,fig4 #dc4--,,two ,,kinds ,,of ,,soil ,,that ,,have ,,been ,,wet ,,and ,,then ,,dried4 ,the loamy soil above remains loose and capable of growing plants2 the clay soil below has baked and cracked4 ,roots require moisture in order to serve the plant4 ,the soil water that is valuable to the plant is not the free water1 but the thin film of moisture which adheres to each little particle of soil4 ,the finer the soil1 the greater the number of particles1 and therefore the greater is the quantity of film moisture that it can hold4 ,this moisture surrounding the grains may not be perceptible1 yet the plant can use it4 ,root absorption may continue in a soil which seems to be dust dry4 ,soils that are very hard and 8baked0 7,fig4 #dc7 contain very little moisture or air1--not so much as similar soils that are granular or mellow4 ,proper ,temperature for ,root ,action4--,the root must be warm in order to perform its functions4 ,should the soil of fields or greenhouses be much colder than the air1 the plant suffers4 ,when in a warm atmosphere1 or in a dry atmosphere1 plants need to absorb much water from the soil1 and the roots must be warm if the root-hairs are to supply the water as rapidly as it is needed4 ,if the roots are chilled1 the plant may wilt or die4 ,roots need ,air4--,corn on land that has been flooded by heavy rains loses its green color and turns yellow4 ,besides diluting plant-food1 the water drives the air from the soil1 and this suffocation of the roots is very soon apparent in the general ill health of the plant4 ,stirring or tilling the soil arates it4 ,water plants and bog plants have adapted themselves to their particular conditions4 ,they get their air either by special surface roots1 or from the water through stems and leaves4 ,rootlets4--,roots divide into the thinnest and finest fibrils3 there are roots and there are rootlets4 ,the smallest rootlets are so slender and delicate that they break off even when the plant is very carefully lifted from the soil4 ,illustration3 ,,fig4 #dd4--,,root-,,hairs ,,of ,,the ,,radish4 ,the rootlets1 or fine divisions1 are clothed with the root-hairs 7,figs4 #dd1 #de1 #df74 ,these root-hairs attach to the soil particles1 and a great amount of soil is thus brought into actual contact with the plant4 ,these are very delicate prolonged surface cells of the roots4 ,they are borne for a short distance just back of the tip of the root4 ,rootlet and root-hair differ4 ,the rootlet is a compact cellular structure4 ,the root-hair is a delicate tubular cell 7,fig4 #de71 within which is contained living matter 7protoplasm72 and the protoplasmic lining membrane of the wall governs the entrance of water and substances in solution4 ,being long and tube-like1 these root-hairs are especially adapted for taking in the largest quantity of solutions2 and they are the principal means by which plant-food is absorbed from the soil1 although the surfaces of the rootlets themselves do their part4 ,water plants do not produce an abundant system of root-hairs1 and such plants depend largely on their rootlets4 ,illustration3 ,,fig4 #de4--;,,cross-,,section ,,of ,,root1 enlarged1 showing root-hairs4 ,illustration3 ,,fig4 #df4--,,root-,,hair1 much enlarged1 in contact with the soil particles 7s74 ,air-spaces at a2 water-films on the particles1 as at w4 ,the root-hairs are very small1 often invisible4 ,they1 with the young roots1 are usually broken off when the plant is pulled up4 ,they are best seen when seeds are germinated between layers of dark blotting paper or flannel4 ,on the young roots1 they will be seen as a mold-like or gossamer-like covering4 ,root-hairs soon die3 they do not grow into roots4 ,new ones form as the root grows4 ,osmosis4--,the water with its nourishment goes through the thin walls of the root-hairs and rootlets by the process of osmosis4 ,if there are two liquids of different density on the inside and outside of an organic 7either vegetable or animal7 membrane1 the liquids tend to mix through the membrane4 ,the law of osmosis is that the most rapid flow is toward the denser solution4 ,the protoplasmic lining of the cell wall is such a membrane4 ,the soil water being a weaker solution than the sap in the roots1 the flow is into the root4 ,a strong fertilizer sometimes causes a plant to wither1 or 8burns it40 ,explain4 ,structure of ,roots4--,the root that grows from the lower end of the caulicle is the first or primary root4 ,secondary roots branch from the primary root4 ,branches of secondary roots are sometimes called tertiary roots4 ,do the secondary roots grow from the cortex1 or from the central cylinder of the primary root8 ,trim or peel the cortex from a root and its branches and determine whether the branches still hold to the central cylinder of the main root4 ,internal ,structure of ,roots4--,a section of a root shows that it consists of a central cylinder 7see ,fig4 #de7 surrounded by a layer4 ,this layer is called the cortex4 ,the outer layer of cells in the cortex is called the epidermis1 and some of the cells of the epidermis are prolonged and form the delicate root-hairs4 ,the cortex resembles the bark of the stem in its nature4 ,the central cylinder contains many tube-like canals1 or 8vessels0 that convey water and food 7,fig4 #de74 ,cut a sweet potato across 7also a radish and a turnip7 and distinguish the central cylinder1 cortex and epidermis4 ,notice the hard cap on the tip of roots4 ,roots differ from stems in having no real pith4 ,microscopic ,structure of ,roots4--,near the end of any young root or shoot the cells are found to differ from each other more or less1 according to the distance from the point4 ,this differentiation takes place in the region just back of the growing point4 ,to study growing points1 use the hypocotyl of ,indian corn which has grown about one half inch4 ,make a longitudinal section4 ,note these points 7,fig4 #dg73 7a7 the tapering root-cap beyond the growing point2 7b7 the blunt end of the root proper and the rectangular shape of the cells found there2 7c7 the group of cells in the middle of the first layers beneath the root-cap1--this group is the growing point2 7d7 study the slight differences in the tissues a short distance back of the growing point4 ,there are four regions3 the central cylinder1 made up of several rows of cells in the center 7pl72 the endodermis1 7e7 composed of a single layer on each side which separates the central cylinder from the bark2 the cortex1 or inner bark1 7e7 of several layers outside the endodermis2 and the epidermis1 or outer layer of bark on the outer edges 7d74 ,make a drawing of the section4 ,if a series of the cross-sections of the hypocotyl should be made and studied1 beginning near the growing point and going upward1 it would be found that these four tissues become more distinctly marked1 for at the tip the tissues have not yet assumed their characteristic form4 ,the central cylinder contains the ducts and vessels which convey the sap4 ,illustration3 ,,fig4 #dg4--;,,growing ,,point ,,of ,,root ,,of ,,indian ,,corn4 d1 d1 cells which will form the epidermis2 p1 p1 cells that will form bark2 e1 e1 endodermis2 pl1 cells which will form the axis cylinder2 i1 initial group of cells1 or growing point proper2 c1 root-cap4 ,the ,root-cap4--,note the form of the root-cap shown in the microscopic section drawn in ,fig4 #dg4 ,growing cells1 and especially those which are forming tissue by subdividing1 are very delicate and are easily injured4 ,the cells forming the root-cap are older and tougher and are suited for pushing aside the soil that the root may penetrate it4 ,region of most ,rapid ,growth4--,the roots of a seedling bean may be marked at equal distances by waterproof ink or by bits of black thread tied moderately tight4 ,the seedling is then replanted and left undisturbed for two days4 ,when it is dug up1 the region of most rapid growth in the root can be determined4 ,give a reason why a root cannot elongate throughout its length1--whether there is anything to prevent a young root from doing so4 ,illustration3 ,,fig4 #dh4--,,the ,,marking ,,of ,,the ,,stem ,,and ,,root4 ,in ,fig4 #dh is shown a germinating scarlet runner bean with a short root upon which are marks made with waterproof ink2 and the same root 7,fig4 #di7 is shown after it has grown longer4 ,which part of it did not lengthen at all8 ,which part lengthened slightly8 ,where is the region of most rapid growth8 ,illustration3 ,,fig4 #di4--,,the ,,result4 ,geotropism4--,roots turn toward the earth1 even if the seed is planted with the micropyle up4 ,this phenomenon is called positive geotropism4 ,stems grow away from the earth4 ,this is negative geotropism4 ,illustration3 ,,fig4 #ej4--,,the ,,grasp ,,of ,a ,,plant ,,on ,,the ,,particles ,,of ,,earth4 ,a grass plant pulled in a garden4 ,illustration3 ,,fig4 #ea4--,,plant ,,growing ,,in ,,inverted ,,pot4 ,illustration3 ,,fig4 #eb4--;,,holes ,,in ,,soil ,,made ,,by ,,roots1 now decayed4 ,somewhat magnified4 ,,suggestions 7,chaps4 ,,vii and ,,viii74--#be4 ,tests for food4 ,examine a number of roots1 including several fleshy roots1 for the presence of food material1 making the tests used on seeds4 #bf4 ,study of root-hairs4 ,carefully germinate radish1 turnip1 cabbage1 or other seed1 so that no delicate parts of the root will be injured4 ,for this purpose1 place a few seeds in packing-moss or in the folds of thick cloth or of blotting paper1 being careful to keep them moist and warm4 ,in a few days the seed has germinated1 and the root has grown an inch or two long4 ,notice that1 except at a distance of about a quarter of an inch behind the tip1 the root is covered with minute hairs 7,fig4 #dd74 ,they are actually hairs2 that is1 root-hairs4 ,touch them and they collapse1 they are so delicate4 ,dip one of the plants in water1 and when removed the hairs are not to be seen4 ,the water mats them together along the root and they are no longer evident4 ,root-hairs are usually destroyed when a plant is pulled out of the soil1 be it done ever so carefully4 ,they cling to the minute particles of soil 7,fig4 #df74 ,the hairs show best against a dark background4 #bg4 ,on some of the blotting papers1 sprinkle sand2 observe how the root-hairs cling to the grains4 ,observe how they are flattened when they come in contact with grains of sand4 #bh4 ,root hold of plant4 ,the pupil should also study the root hold4 ,let him carefully pull up a plant4 ,if a plant grow alongside a fence or other rigid object1 he may test the root hold by securing a string to the plant1 letting the string hang over the fence1 and then adding weights to the string4 ,will a stake of similar size to the plant and extending no deeper in the ground have such firm hold on the soil8 ,what holds the ball of earth in ,fig4 #ej8 #bi4 ,roots exert pressure4 ,place a strong bulb of hyacinth or daffodil on firm-packed earth in a pot2 cover the bulb nearly to the top with loose earth2 place in a cool cellar2 after some days or weeks1 note that the bulb has been raised out of the earth by the forming roots4 ,all roots exert pressure on the soil as they grow4 ,explain4 #cj4 ,response of roots and stems to the force of gravity1 or geotropism4 ,plant a fast-growing seedling in a pot so that the plumule extends through the drain hole and suspend the pot with mouth up 7i4e4 in the usual position74 ,or use a pot in which a plant is already growing1 cover with cloth or wire gauze to prevent the soil from falling1 and suspend the pot in an inverted position 7,fig4 #ea74 ,notice the behavior of the stem1 and after a few days remove the soil and observe the position of the root4 #ca4 ,if a pot is laid on one side1 and changed every two days and laid on its opposite side1 the effect on the root and stem will be interesting4 #cb4 ,if a fleshy root is planted wrong end up1 what is the result8 ,try it with pieces of horse-radish root4 #cc4 ,by planting radishes on a slowly revolving wheel the effect of gravity may be neutralized4 #cd4 ,region of root most sensitive to gravity4 ,lay on its side a pot containing a growing plant4 ,after it has grown a few days1 wash away the earth surrounding the roots4 ,which turned downward most decidedly1 the tip of root or the upper part8 #ce4 ,soil texture4 ,carefully turn up soil in a rich garden or field so that you have unbroken lumps as large as a hen's egg4 ,then break these lumps apart carefully with the fingers and determine whether there are any traces or remains of roots 7,fig4 #eb74 ,are there any pores1 holes1 or channels made by roots8 ,are the roots in them still living8 #cf4 ,compare another lump from a clay bank or pile where no plants have been growing4 ,is there any difference in texture8 #cg4 ,grind up this clay lump very fine1 put it in a saucer1 cover with water1 and set in the sun4 ,after a time it will have the appearance shown in the lower saucer in ,fig4 #dc4 ,compare this with mellow garden soil4 ,in which will plants grow best1 even if the plant-food were the same in both8 ,why8 #ch4 ,to test the effect of moisture on the plant1 let a plant in a pot or box dry out till it wilts2 then add water and note the rapidity with which it recovers4 ,vary the experiment in quantity of water applied4 ,does the plant call for water sooner when it stands in a sunny window than when in a cool shady place8 ,prove it4 #ci4 ,immerse a potted plant above the rim of the pot in a pail of water and let it remain there4 ,what is the consequence8 ,why8 #dj4 ,to test the effect of temperature on roots4 ,put one pot in a dish of ice water1 and another in a dish of warm water1 and keep them in a warm room4 ,in a short time notice how stiff and vigorous is the one whose roots are warm1 whereas the other may show signs of wilting4 #da4 ,the process of osmosis4 ,chip away the shell from the large end of an egg so as to expose the uninjured membrane beneath for an area about as large as a dime4 ,with sealing-wax1 chewing-gum1 or paste stick a quill about three inches long to the smaller end of the egg4 ,after the tube is in place1 run a hat pin into it so as to pierce both shell and membrane2 or use a short glass tube1 first scraping the shell thin with a knife and then boring through it with the tube4 ,now set the egg upon the mouth of a pickle jar nearly full of water1 so that the large end with the exposed membrane is beneath the water4 ,after several hours1 observe the tube on top of the egg to see whether the water has forced its way into the egg and increased its volume so that part of its contents are forced up into the tube4 ,if no tube is at hand1 see whether the contents are forced through the hole which has been made in the small end of the egg4 ,explain how the law of osmosis is verified by your result4 ,if the eggshell contained only the membrane1 would water rise into it8 ,if there were no water in the bottle1 would the egg-white pass down into the bottle8 #db4 ,the region of most rapid growth4 ,the pupil should make marks with waterproof ink 7as ,higgins' ink or indelible marking ink7 on any soft growing roots4 ,place seeds of bean1 radish1 or cabbage between layers of blotting paper or thick cloth4 ,keep them damp and warm4 ,when stem and root have grown an inch and a half long each1 with waterproof ink mark spaces exactly one quarter inch apart 7,figs4 #dh1 #di74 ,keep the plantlets moist for a day or two1 and it will be found that on the stem some or all of the marks are more than one quarter inch apart2 on the root the marks have not separated4 ,the root has grown beyond the last mark4 ,,note ,,to ,,teacher4--,the microscopic structure of the root can be determined only by the use of the compound microscope2 but a good general conception of the structure may be had by a careful attention to the text and pictures and to explanations by the teacher1 if such microscopes are not to be had4 ,see note at close of ,chapter ,x4 ,,chapter ,,ix ,,the ,,stem--,,kinds ,,and ,,forms2 ,,pruning ,the ,stem ,system4--,the stem of a plant is the part that bears the buds1 leaves1 flowers1 and fruits4 ,its office is to hold these parts up to the light and air2 and through its tissues the various food-materials and the life-giving fluids are distributed to the growing and working parts4 ,the entire mass or fabric of stems of any plant is called its stem system4 ,it comprises the trunk1 branches1 and twigs1 but not the stalks of leaves and flowers that die and fall away4 ,the stem system may be herbaceous or woody1 annual1 biennial1 or perennial2 and it may assume many sizes and shapes4 ,stems are of ,many ,forms4--,the general way in which a plant grows is called its habit4 ,the habit is the appearance or general form4 ,its habit may be open or loose1 dense1 straight1 crooked1 compact1 straggling1 climbing1 erect1 weak1 strong1 and the like4 ,the roots and leaves are the important functional or working parts2 the stem merely connects them1 and its form is exceedingly variable4 ,kinds of ,stems4--,the stem may be so short as to be scarcely distinguishable4 ,in such cases the crown of the plant--that part just at the surface of the ground--bears the leaves and flowers2 but this crown is really a very short stem4 ,the dandelion1 ,fig4 #cc1 is an example4 ,such plants are often said to be stemless1 however1 in order to distinguish them from plants that have long or conspicuous stems4 ,these so-called stemless plants die to the ground every year4 ,illustration3 ,,fig4 #ec4--,,strict ,,simple ,,stem ,,of ,,mullein4 ,illustration3 ,,fig4 #ed4--,,strict ,,upright ,,stem ,,of ,,narrow-,,leaved ,,dock4 ,illustration3 ,,fig4 #ee4--,,trailing ,,stem ,,of ,,wild ,,morning ,,glory 7,convolvulus arvensis74 ,stems are erect when they grow straight up 7,figs4 #ec1 #ed74 ,they are trailing when they run along on the ground1 as melon1 wild morning-glory 7,fig4 #ee74 ,they are creeping when they run on the ground and take root at places1 as the strawberry4 ,they are decumbent when they lop over to the ground4 ,they are ascending when they lie mostly or in part on the ground but stand more or less upright at their ends2 example1 a tomato4 ,they are climbing when they cling to other objects for support 7,figs4 #cf1 #ef74 ,illustration3 ,,fig4 #ef4--;,a ,,climbing ,,plant 7a twiner74 ,trees in which the main trunk or the 8leader0 continues to grow from its tip are said to be excurrent in growth4 ,the branches are borne along the sides of the trunk1 as in common pines 7,fig4 #eg7 and spruces4 ,excurrent means running out or running up4 ,illustration3 ,,fig4 #eg4--;,,excurrent ,,trunk4 ,a pine4 ,trees in which the main trunk does not continue are said to be deliquescent4 ,the branches arise from one common point or from each other4 ,the stem is lost in the branches4 ,the apple tree1 plum 7,fig4 #eh71 maple1 elm1 oak1 ,china tree1 are familiar examples4 ,deliquescent means dissolving or melting away4 ,illustration3 ,,fig4 #eh4--;,,deliquescent ,,trunk ,,of ,,plum ,,tree4 ,each kind of plant has its own peculiar habit or direction of growth2 spruces always grow to a single stem or trunk1 pear trees are always deliquescent1 morning-glories are always trailing or climbing1 strawberries are always creeping4 ,we do not know why each plant has its own habit1 but the habit is in some way associated with the plant's genealogy or with the way in which it has been obliged to live4 ,the stem may be simple or branched4 ,a simple stem usually grows from the terminal bud1 and side branches either do not start1 or1 if they start1 they soon perish4 ,mulleins 7,fig4 #ec7 are usually simple4 ,so are palms4 ,branched stems may be of very different habit and shape4 ,some stem systems are narrow and erect2 these are said to be strict 7,fig4 #ed74 ,others are diffuse1 open1 branchy1 twiggy4 ,nodes and ,internodes4--,the parts of the stem at which buds grow are called nodes or joints and the spaces between the buds are internodes4 ,the stem at nodes is usually enlarged1 and the pith is usually interrupted4 ,the distance between the nodes is influenced by the vigor of the plant3 how8 ,illustration3 ,,fig4 #ei4--,,rhizome ,,or ,,rootstock4 ,stems vs4 ,roots4--,roots sometimes grow above ground 7,chap4 ,,vii72 so1 also1 stems sometimes grow underground1 and they are then known as subterranean stems1 rhizomes1 or rootstocks 7,fig4 #ei74 ,stems normally bear leaves and buds1 and thereby are they distinguished from roots2 usually1 also1 they contain a pith4 ,the leaves1 however1 may be reduced to mere scales1 and the buds beneath them may be scarcely visible4 ,thus the 8eyes0 on a white potato are cavities with a bud or buds at the bottom 7,fig4 #fj74 ,sweet potatoes have no evident 8eyes0 when first dug 7but they may develop adventitious buds before the next growing-season74 ,the white potato is a stem3 the sweet potato is probably a root4 ,illustration3 ,,fig4 #fj4--,,sprouts ,,arising ,,from ,,the ,,buds1 or eyes1 of a potato tuber4 ,how ,stems elongate4--,roots elongate by growing near the tip4 ,stems elongate by growing more or less throughout the young or soft part or 8between joints0 7,figs4 #dh1 #di74 ,but any part of the stem soon reaches a limit beyond which it cannot grow1 or becomes 8fixed02 and the new parts beyond elongate until they1 too1 become rigid4 ,when a part of the stem once becomes fixed or hard1 it never increases in length3 that is1 the trunk or woody parts never grow longer or higher2 branches do not become farther apart or higher from the ground4 ,stems are modified in form by the particular or incidental conditions under which they grow4 ,the struggle for light is the chief factor in determining the shape and direction of any limb 7,chap4 ,,ii74 ,this is well illustrated in any tree or bush that grows against a building or on the margin of a forest 7,fig4 #d74 ,in a very dense thicket the innermost trees shoot up over the others or they perish4 ,examine any stem and endeavor to determine why it took its particular form4 ,the stem is cylindrical1 the outer part being bark and the inner part being wood or woody tissue4 ,in the dicotyledonous plants1 the bark is usually easily separated from the remainder of the cylinder at some time of the year2 in monocotyledonous plants the bark is not free4 ,growth in thickness takes place inside the covering and not on the very outside of the plant cylinder4 ,it is evident1 then1 that the covering of bark must expand in order to allow of the expansion of the woody cylinder within it4 ,the tissues1 therefore1 must be under constant pressure or tension4 ,it has been determined that the pressure within a growing trunk is often as much as fifty pounds to the square inch4 ,the lower part of the limb in ,fig4 #fa shows that the outer layers of bark 7which are long since dead1 and serve only as protective tissue7 have reached the limit of their expanding capacity and have begun to split4 ,the pupil will now be interested in the bark on the body of an old elm tree 7,fig4 #fb72 and he should be able to suggest one reason why stems remain cylindrical1 and why the old bark becomes marked with furrows1 scales1 and plates4 ,illustration3 ,,fig4 #fa4--;,,cracking ,,of ,,the ,,bark ,,on ,,an ,,elm ,,branch4 ,illustration3 ,,fig4 #fb4--,,piece ,,of ,,bark ,,from ,,an ,,old ,,elm ,,trunk4 ,most woody plants increase in diameter by the addition of an annual layer or 8ring0 on the outside of the woody cylinder1 underneath the bark4 ,the monocotyledonous plants comprise very few trees and shrubs in temperate climates 7the palms1 yuccas1 and other tree-like plants are of this class71 and they do not increase greatly in diameter and they rarely branch to any extent4 ,consult the woodpile for information as to the annual rings4 ,bark-bound ,trees4--,if1 for any reason1 the bark should become so dense and strong that the trunk cannot expand1 the tree is said to be 8bark-bound40 ,such condition is not rare in orchard trees that have been neglected4 ,when good tillage is given to such trees1 they may not be able to overcome the rigidity of the old bark1 and1 therefore1 do not respond to the treatment4 ,sometimes the thinner-barked parts may outgrow in diameter the trunk or the old branches below them4 ,the remedy is to release the tension4 ,this may be done either by softening the bark 7by washes of soap or lye71 or by separating it4 ,the latter is done by slitting the bark-bound part 7in spring71 thrusting the point of a knife through the bark to the wood and then drawing the blade down the entire length of the bark-bound part4 ,the slit is scarcely discernible at first1 but it opens with the growth of the tree1 filling up with new tissue beneath4 ,let the pupil consider the ridges which he now and then finds on trees1 and determine whether they have any significance--whether the tree has ever been released or injured by natural agencies4 ,illustration3 ,,fig4 #fc4--,,proper ,,cutting ,,of ,a ,,branch4 ,the wound will soon be 8healed40 ,the ,tissue covers the ,wounds and 8heals0 them4--,this is seen in ,fig4 #fc1 in which a ring of tissue rolls out over the wound4 ,this ring of healing tissue forms most rapidly and uniformly when the wound is smooth and regular4 ,observe the healing on broken and splintered limbs2 also the difference in rapidity of healing between wounds on strong and weak limbs4 ,there is difference in the rapidity of the healing process in different kinds of trees4 ,compare the apple tree and the peach4 ,this tissue may in turn become bark-bound1 and the healing may stop4 ,on large wounds it progresses more rapidly the first few years than it does later4 ,this roll or ring of tissue is called a callus4 ,the callus grows from the living tissue of the stem just about the wound4 ,it cannot cover long dead stubs or very rough broken branches 7,fig4 #fd74 ,therefore1 in pruning the branches should be cut close to the trunk and made even and smooth2 all long stubs must be avoided4 ,the seat of the wound should be close to the living part of the trunk1 for the stub of the limb that is severed has no further power in itself of making healing tissue4 ,the end of the remaining stub is merely covered over by the callus1 and usually remains a dead piece of wood sealed inside the trunk 7,fig4 #fe74 ,if wounds do not heal over speedily1 germs and fungi obtain foothold in the dying wood and rot sets in4 ,hollow trees are those in which the decay-fungi have progressed into the inner wood of the trunk2 they have been infected 7,fig4 #ff74 ,illustration3 ,,fig4 #fd4--;,,erroneous ,,pruning4 ,illustration3 ,,fig4 #fe4--,,knot ,,in ,a ,,hemlock ,,log4 ,large wounds should be protected with a covering of paint1 melted wax1 or other adhesive and lasting material1 to keep out the germs and fungi4 ,a covering of sheet iron or tin may keep out the rain1 but it will not exclude the germs of decay2 in fact1 it may provide the very moist conditions that such germs need for their growth4 ,deep holes in trees should be treated by having all the decayed parts removed down to the clean wood1 the surfaces painted or otherwise sterilized1 and the hole filled with wax or cement4 ,illustration3 ,,fig4 #ff4--;,a ,,knot ,,hole1 and the beginning of a hollow trunk4 ,stems and roots are living1 and they should not be wounded or mutilated unnecessarily4 ,horses should never be hitched to trees4 ,supervision should be exercised over persons who run telephone1 telegraph1 and electric light wires1 to see that they do not mutilate trees4 ,electric light wires and trolley wires1 when carelessly strung or improperly insulated1 may kill trees 7,fig4 #fg74 ,illustration3 ,,fig4 #fg4--;,,elm ,,tree ,,killed ,,by ,a ,,direct ,,current ,,from ,,an ,,electric ,,railroad ,,system4 ,,suggestions4--,forms of stems4 #dc4 ,are the trunks of trees ever perfectly cylindrical8 ,if not1 what may cause the irregularities8 ,do trunks often grow more on one side than the other8 #dd4 ,slit a rapidly growing limb1 in spring1 with a knife blade1 and watch the result during the season4 #de4 ,consult the woodpile1 and observe the variations in thickness of the annual rings1 and especially of the same ring at different places in the circumference4 ,cross-sections of horizontal branches are interesting in this connection4 #df4 ,note the enlargement at the base of a branch1 and determine whether this enlargement or bulge is larger on long1 horizontal limbs than on upright ones4 ,why does this bulge develop8 ,does it serve as a brace to the limb1 and is it developed as the result of constant strain8 #dg4 ,strength of stems4 ,the pupil should observe the fact that a stem has wonderful strength4 ,compare the proportionate height1 diameter1 and weight of a grass stem with those of the slenderest tower or steeple4 ,which has the greater strength8 ,which the greater height8 ,which will withstand the most wind8 ,note that the grass stem will regain its position even if its top is bent to the ground4 ,note how plants are weighted down after a heavy rain and how they recover themselves4 #dh4 ,split a cornstalk and observe how the joints are tied together and braced with fibers4 ,are there similar fibers in stems of pigweed1 cotton1 sunflower1 hollyhock8 ,illustration3 ,,fig4 #fh4--,,potato4 ,what are roots1 and what stems8 ,has the plant more than one kind of stem8 more than two kinds8 ,explain4 ,,chapter ,x ,,the ,,stem--,,its ,,general ,,structure ,there are two main types of stem structure in flowering plants1 the differences being based on the arrangement of bundles or strands of tissue4 ,these types are endogenous and exogenous 7page #bj74 ,it will require patient laboratory work to understand what these types and structures are4 ,endogenous1 or ,monocotyledonous ,stems4--,examples of endogenous stems are all the grasses1 cane-brake1 sugar-cane1 smilax or green-brier1 palms1 banana1 canna1 bamboo1 lilies1 yucca1 asparagus1 all the cereal grains4 ,for our study1 a cornstalk may be used as a type4 ,illustration3 ,,fig4 #fi4--;,,cross-,,section ,,of ,,cornstalk1 showing the scattered fibro-vascular bundles4 ,slightly enlarged4 ,a piece of cornstalk1 either green or dead1 should be in the hand of each pupil while studying this lesson4 ,fig4 #fi will also be of use4 ,is there a swelling at the nodes8 ,which part of the internode comes nearest to being perfectly round8 ,there is a grooved channel running along one side of the internode3 how is it placed with reference to the leaf8 with reference to the groove in the internode below it8 ,what do you find in each groove at its lower end8 7,in a dried stalk only traces of this are usually seen47 ,does any bud on a cornstalk besides the one at the top ever develop8 ,where do suckers come from8 ,where does the ear grow8 ,cut a cross-section of the stalk between the nodes 7,fig4 #fi74 ,does it have a distinct bark8 ,the interior consists of soft 8pith0 and tough woody parts4 ,the wood is found in strands or fibers4 ,which is more abundant8 ,do the fibers have any definite arrangement8 ,which strands are largest8 ,smallest8 ,the firm smooth rind 7which cannot properly be called a bark7 consists of small wood strands packed closely together4 ,grass stems are hollow cylinders2 and the cornstalk1 because of the lightness of its contents1 is also practically a cylinder4 ,stems of this kind are admirably adapted for providing a strong support to leaves and fruit4 ,this is in accordance with the well-known law that a hollow cylinder is much stronger than a solid cylinder of the same weight of material4 ,cut a thin slice of the inner soft part and hold it up to the light4 ,can you make out a number of tiny compartments or cells8 ,these cells consist of a tissue called parenchyma1 the tissue from which when young all the other tissues arise and differentiate 7,parenchyma parent chyma1 or tissue74 ,the numerous walls of these cells may serve to brace the outer wall of the cylinder2 but their chief function in the young stalk is to give origin to other cells4 ,when alive they are filled with cell sap and protoplasm4 ,illustration3 ,,fig4 #gj4--;,,diagram ,,to ,,show ,,the ,,course ,,of ,,fibro-,,vascular ,,bundles ,,in ,,monocotyledons4 ,trace the woody strands through the nodes4 ,do they ascend vertically8 ,do they curve toward the rind at certain places8 ,compare their course with the strands shown in ,fig4 #gj4 ,the woody strands consist chiefly of tough fibrous cells that give rigidity and strength to the plant1 and of long tubular interrupted canals that serve to convey sap upward from the root and to convey food downward from the leaves to the stem and roots4 ,monocotyledons1 as shown by fossils1 existed before dicotyledons appeared1 and it is thought that the latter were developed from ancestors of the former4 ,it will be interesting to trace the relationship in stem structure4 ,it will first be necessary to learn something of the structure of the wood strand4 ,illustration3 ,,fig4 #ga4--;,,diagram ,,of ,,wood ,,strands ,,or ,,fibro-,,vascular ,,bundles ,,in ,a ,,root1 showing the wood 7x7 and bast 7p7 separated4 ,wood ,strand in ,monocotyledons and ,dicotyledons4--,each wood strand 7or fibro-vascular bundle7 consists of two parts--the bast and the wood proper4 ,the wood is on the side of the strand toward the center of the stem and contains large tubular canals that take the watery sap upward from the roots4 ,the bast is on the side toward the bark and contains fine tubes through which diffuses the dense sap containing digested food from the leaves4 ,in the root 7,fig4 #ga7 the bast and the wood are separate1 so that there are two kinds of strands4 ,illustration3 ,,fig4 #gb4--,,part ,,of ,,cross-,,section ,,of ,,rootstock ,,of ,,asparagus1 showing a few fibro-vascular bundles4 ,an endogenous stem4 ,in monocotyledons1 as already said1 the strands 7or bundles7 are usually scattered in the stem with no definite arrangement 7,figs4 #gb1 #gc74 ,in dicotyledons the strands1 or bundles1 are arranged in a ring4 ,as the dicotyledonous seed germinates1 five bundles are usually formed in its hypocotyl 7,fig4 #gd72 soon five more are interposed between them1 and the multiplication continues1 in tough plants1 until the bundles touch 7,fig4 #gd1 right74 ,the inner parts thus form a ring of wood and the outer parts form the inner bark or bast4 ,a new ring of wood or bast is formed on stems of dicotyledons each year and the age of a cut stem is easily determined4 ,illustration3 a b ,,fig4 #gc4--,,the ,,scattered ,,bundles ,,or ,,strands1 in monocotyledons at a1 and the bundles in a circle in dicotyledons at b4 ,illustration3 ,,fig4 #gd4--;,,dicotyledonous ,,stem ,,of ,,one ,,year ,,at ,,left ,,with ,,five ,,bundles1 and a ,two-year ,stem at ,right4 o1 the pith2 c1 the wood part2 b1 the bast part2 a1 one year's growth4 ,illustration3 ,,fig4 #ge4--;,,fibro-,,vascular ,,bundle ,,of ,,indian ,,corn1 much magnified4 ,a1 annular vessel2 ,a1 annular or spiral vessel2 ,,tt1 thick-walled vessels2 ,w1 tracheids or woody tissue2 ,f1 sheath of fibrous tissue surrounding the bundle2 ,,ft1 fundamental tissue or pith2 ,s1 sieve tissue2 ,p1 sieve plate2 ,c1 companion cell2 l1 intercellular space1 formed by tearing down of adjacent cells2 ,w1 wood parenchyma4 ,illustration3 ,,fig4 #gf4--,,the ,,dicotyledonous ,,bundle ,,or ,,wood ,,strand4 ,upper figure is of moonseed3 c1 cambium2 d1 ducts2 #a1 end of first year's growth2 #b1 end of second year's growth2 bast part at left and wood part at right4 ,lower figure 7from ,wettstein7 is sunflower2 h1 wood-cells2 g1 vessels2 c1 cambium2 p1 fundamental tissue or parenchyma2 b1 bast2 bp1 bast parenchyma2 s1 sieve-tubes4 ,when cross-sections of monocotyledonous and dicotyledonous bundles are examined under the microscope1 it is readily seen why dicotyledonous bundles form rings of wood and monocotyledonous cannot 7,figs4 #ge and #gf74 ,the dicotyledonous bundle 7,fig4 #gf7 has1 running across it1 a layer of brick-shaped cells called cambium1 which cells are a specialized form of the parenchyma cells and retain the power of growing and multiplying4 ,the bundles containing cambium are called open bundles4 ,there is no cambium in monocotyledonous bundles 7,fig4 #ge7 and the bundles are called closed bundles4 ,monocotyledonous stems soon cease to grow in diameter4 ,the stem of a palm tree is almost as large at the top as at the base4 ,as dicotyledonous plants grow1 the stems become thicker each year1 for the delicate active cambium layer forms new cells from early spring until midsummer or autumn1 adding to the wood within and to the bark without4 ,as the growth in spring is very rapid1 the first wood-cells formed are much larger than the last wood-cells formed by the slow growth of the late season1 and the spring wood is less dense and lighter colored than the summer wood2 hence the time between two years' growth is readily made out 7,figs4 #gg and #gh74 ,because of the rapid growth of the cambium in spring and its consequent soft walls and fluid contents1 the bark of trees 8peels0 readily at that season4 ,illustration3 ,,fig4 #gg4--,,white ,,pine ,,stem1 #e years old4 ,the outermost layer is bark4 ,medullary ,rays4--,the first year's growth in dicotyledons forms a woody ring which almost incloses the pith1 and this is left as a small cylinder which does not grow larger1 even if the tree should live a century4 ,it is not quite inclosed1 however1 for the narrow layers of soft cells separating the bundles remain between them 7,fig4 #gh71 forming radiating lines called medullary rays or pith rays4 ,illustration3 ,,fig4 #gh4--;,,arrangement ,,of ,,tissues ,,in ,,two-,,year-,,old ,,stem ,,of ,,moonseed4 p1 pith2 f1 parenchyma4 ,the fibro-vascular bundles1 or wood strands1 are very prominent1 with thin medullary rays between4 ,the ,several ,plant ,cells and their ,functions4--,in the wood there are some parenchyma cells that are still with thin walls1 but have lost the power of division4 ,they are now storage cells4 ,there are also wood fibers which are thick-walled and rigid 7h1 ,fig4 #gf71 and serve to support the sap-canals or wood vessels 7or tracheids7 that are formed by the absorption of the end walls of upright rows of cells2 the canals pass from the roots to the twigs and even to ribs of the leaves and serve to transport the root water4 ,they are recognized 7,fig4 #gi7 by the peculiar thickening of the wall on the inner surface of the tubes1 occurring in the form of spirals4 ,sometimes the whole wall is thickened except in spots called pits 7g1 ,fig4 #gf74 ,these thin spots 7,fig4 #hj7 allow the sap to pass to other cells or to neighboring vessels4 ,illustration3 ,,fig4 #gi4--,,markings ,,in ,,cell ,,walls ,,of ,,wood ,,fibers4 sp1 spiral2 an1 annular2 sc1 scalariform4 ,illustration3 ,,fig4 #hj4--,,pits ,,in ,,the ,,cell ,,wall4 ,longitudinal section of wall at b1 showing pit borders at o1 o4 ,the cambium1 as we have seen1 consists of cells whose function is growth4 ,these cells are thin-walled and filled with protoplasm4 ,during the growing season they are continually adding to the wood within and the bark without2 hence the layer moves outward as it deposits the new woody layer within4 ,illustration3 ,,fig4 #ha4--,,sieve-,,tubes1 s1 s2 p shows a top view of a sieve-plate1 with a companion cell4 c1 at the side2 o shows sieve-plates in the side of the cell4 ,in s1 s the protoplasm is shrunken from the walls by reagents4 ,illustration3 ,,fig4 #hb4--,,thick-,,walled ,,bast ,,cells4 ,the bark consists of inner or fibrous bark or new bast 7these fibers in flax become linen71 the green or middle bark which functions somewhat as the leaves1 and the corky or outer bark4 ,the common word 8bark0 is seen therefore not to represent a homogeneous or simple structure1 but rather a collection of several kinds of tissue1 all separating from the wood beneath by means of cambium4 ,the new bast contains 7#a7 the sieve-tubes 7,fig4 #ha7 which transport the sap containing organic substances1 as sugar and proteids1 from the leaves to the parts needing it 7s1 ,fig4 #gf74 ,these tubes have been formed like the wood vessels1 but they have sieve-plates to allow the dense organic-laden sap to pass with sufficient readiness for purposes of rapid distribution4 7#b7 ,there are also thick-walled bast fibers 7,fig4 #hb7 in the bast that serve for support4 7#c7 ,there is also some parenchyma 7parent tissue7 in the new bast2 it is now in part a storage tissue4 ,sometimes the walls of parenchyma cells in the cortex thicken at the corners and form brace cells 7,fig4 #hc7 7collenchyma7 for support2 sometimes the whole wall is thickened1 forming grit cells or stone cells 7,fig4 #hd2 examples in tough parts of pear1 or in stone of fruits74 ,some parts serve for secretions 7milk1 rosin1 etc47 and are called latex tubes4 ,illustration3 ,,fig4 #hc4--;,,collenchyma ,,in ,,wild ,,jewelweed ,,or ,,touch-,,me-,,not 7,,impatiens74 ,illustration3 ,,fig4 #hd4--;,,grit ,,cells4 ,the outer bark of old shoots consists of corky cells that protect from mechanical injury1 and that contain a fatty substance 7suberin7 impermeable to water and of service to keep in moisture4 ,there is sometimes a cork cambium 7or phellogen7 in the bark that serves to extend the bark and keep it from splitting1 thus increasing its power to protect4 ,transport of the 8,sap40--,we shall soon learn that the common word 8sap0 does not represent a single or simple substance4 ,we may roughly distinguish two kinds of more or less fluid contents3 7#a7 the root water1 sometimes called mineral sap1 that is taken in by the root1 containing its freight of such inorganic substances as potassium1 calcium1 iron1 and the rest2 this root water rises1 we have found1 in the wood vessels1--that is1 in the young or 8sapwood0 7p4 #if72 7#b7 the elaborated or organized materials passing back and forth1 especially from the leaves1 to build up tissues in all parts of the plant1 some of it going down to the roots and root-hairs2 this organic material is transported1 as we have learned1 in the sieve-tubes of the inner bast1--that is1 in the 8inner bark40 ,removing the bark from a trunk in a girdle will not stop the upward rise of the root water so long as the wood remains alive2 but it will stop the passage of the elaborated or food-stored materials to parts below and thus starve those parts2 and if the girdle does not heal over by the deposit of new bark1 the tree will in time starve to death4 ,it will now be seen that the common practice of placing wires or hoops about trees to hold them in position or to prevent branches from falling is irrational1 because such wires interpose barriers over which the fluids cannot pass2 in time1 as the trunk increases in diameter1 the wire girdles the tree4 ,it is much better to bolt the parts together by rods extending through the branches 7,fig4 #he74 ,these bolts should fit very tight in their holes4 ,why8 ,illustration3 ,,fig4 #he4--,,the ,,wrong ,,way ,,to ,,brace ,a ,,tree4 7,see ,fig4 #aah74 ,wood4--,the main stem or trunk1 and sometimes the larger branches1 are the sources of lumber and timber4 ,different kinds of wood have value for their special qualities4 ,the business of raising wood1 for all purposes1 is known as forestry4 ,the forest is to be considered as a crop1 and the crop must be harvested1 as much as corn or rice is harvested4 ,man is often able to grow a more productive forest than nature does4 ,resistance to decay gives value to wood used for shingles 7cypress1 heart of yellow pine7 and for fence posts 7mulberry1 cedar1 post oak1 bois d'arc1 mesquite74 ,hardness and strength are qualities of great value in building4 ,live oak is used in ships4 ,red oak1 rock maple1 and yellow pine are used for floors4 ,the best flooring is sawn with the straight edges of the annual rings upward2 tangential sawn flooring may splinter4 ,chestnut is common in some parts of the country1 being used for ceiling and inexpensive finishing and furniture4 ,locust and bois d'arc 7osage orange7 are used for hubs of wheels2 bois d'arc makes a remarkably durable pavement for streets4 ,ebony is a tropical wood used for flutes1 black piano keys1 and fancy articles4 ,ash is straight and elastic2 it is used for handles for light implements4 ,hickory is very strong as well as elastic1 and is superior to ash for handles1 spokes1 and other uses where strength is wanted4 ,hickory is never sawn into lumber1 but is split or turned4 ,the 8second growth10 which sprouts from stumps1 is most useful1 as it splits readily4 ,fast-growing hickory in rich land is most valuable4 ,the supply of useful hickory is being rapidly exhausted4 ,softness is often important4 ,white pine and sweet gum because of their softness and lightness are useful in box-making4 8,georgia0 or southern pine is harder and stronger than white pine2 it is much used for floors1 ceilings1 and some kinds of cabinet work4 ,white pine is used for window-sash1 doors1 and molding1 and cheaper grades for flooring4 ,hemlock is the prevailing lumber in the east for the framework and clapboarding of buildings4 ,redwood and ,douglas spruce are common building materials on the ,pacific coast4 ,cypress is soft and resists decay and is superior to white pine for sash1 doors1 and posts on the outside of houses4 ,cedar is readily carved and has a unique use in the making of chests for clothes1 as its odor repels moths and other insects4 ,willow is useful for baskets and light furniture4 ,basswood or linden is used for light ceiling and sometimes for cheap floors4 ,whitewood 7incorrectly called poplar7 is employed for wagon bodies and often for house finishing4 ,it often resembles curly maple4 ,beauty of grain and polish gives wood value for furniture1 pianos1 and the like4 ,mahogany and white oak are most beautiful1 although red oak is also used4 ,oak logs which are first quartered and then sawn radially expose the beautiful silver grain 7medullary rays74 ,fig4 #hf shows one mode of quartering4 ,the log is quartered on the lines a1 a1 b1 b2 then succeeding boards are cut from each quarter at #a1 #b1 #c1 etc4 ,the nearer the heart the better the 8grain03 why8 ,ordinary boards are sawn tangentially1 as c1 c4 ,curly pine1 curly walnut1 and bird's-eye maple are woods that owe their beauty of grain to wavy lines or buried knots4 ,merely a stump of curly walnut is worth several hundred dollars4 ,such wood is sliced very thin for veneering and glued over other woods in making pianos and other pieces4 ,if the cause of wavy grain could be found out and such wood grown at will1 the discovery would be very useful4 ,maple is much used for furniture4 ,birch may be colored so as very closely to represent mahogany1 and it is useful for desks4 ,illustration3 ,,fig4 #hf4--,,the ,,making ,,of ,,ordinary ,,boards1 ,,and ,,one ,,way ,,of ,,making 8,,quartered0 ,,boards4 ,special ,products of ,trees4--,cork from the bark of the cork oak in ,spain1 latex from the rubber and sap from the sugar maple trees1 turpentine from pine1 tannin from oak bark1 ,peruvian bark from cinchona1 are all useful products4 ,,suggestions4--,parts of a root and stem through which liquids rise4 #di4 ,pull up a small plant with abundant leaves1 cut off the root so as to leave two inches or more on the plant 7or cut a leafy shoot of squash or other strong-growing coarse plant71 and stand it in a bottle with a little water in the bottom which has been colored with red ink 7eosin74 ,after three hours examine the root2 make cross-sections at several places4 ,has the water colored the axis cylinder8 ,the cortex8 ,what is your conclusion8 ,stand some cut flowers or a leafy plant with cut stem in the same solution and examine as before3 conclusion8 #ej4 ,girdle a twig of a rapidly growing bush 7as willow7 in early spring when growth begins 7a7 by very carefully removing only the bark1 and 7b7 by cutting away also the sapwood4 ,under which condition do the leaves wilt8 ,why8 #ea4 ,stand twigs of willow in water2 after roots have formed under the water1 girdle the twig 7in the two ways7 above the roots4 ,what happens to the roots1 and why8 #eb4 ,observe the swellings on trees that have been girdled or very badly injured by wires or otherwise3 where are these swellings1 and why8 #ec4 ,kinds of wood4 ,let each pupil determine the kind of wood in the desk1 the floor1 the door and window casings1 the doors themselves1 the sash1 the shingles1 the fence1 and in the small implements and furniture in the room2 also what is the cheapest and the most expensive lumber in the community4 #ed4 ,how many kinds of wood does the pupil know1 and what are their chief uses8 ,,note ,,to ,,teacher4--,the work in this chapter is intended to be mainly descriptive1 for the purpose of giving the pupil a rational conception of the main vital processes associated with the stem1 in such a way that he may translate it into his daily thought4 ,it is not intended to give advice for the use of the compound microscope4 ,if the pupil is led to make a careful study of the text1 drawings1 and photographs on the preceding and the following pages1 he will obtain some of the benefit of studying microscope sections without being forced to spend time in mastering microscope technique4 ,if the school is equipped with compound microscopes1 a teacher is probably chosen who has the necessary skill to manipulate them and the knowledge of anatomy and physiology that goes naturally with such work2 and it would be useless to give instruction in such work in a text of this kind4 ,the writer is of the opinion that the introduction of the compound microscope into first courses in botany has been productive of harm4 ,good and vital teaching demands first that the pupil have a normal1 direct1 and natural relation to his subject1 as he commonly meets it1 that the obvious and significant features of the plant world be explained to him and be made a means of training him4 ,the beginning pupil cannot be expected to know the fundamental physiological processes1 nor is it necessary that these processes should be known in order to have a point of view and trained intelligence on the things that one customarily sees4 ,many a pupil has had a so-called laboratory course in botany without having arrived at any real conception of what plants mean1 or without having had his mind opened to any real sympathetic touch with his environment4 ,even if one's knowledge be not deep or extensive1 it may still be accurate as far as it goes1 and his outlook on the subject may be rational4 ,illustration3 ,,fig4 #hg4--,,the ,,many-,,stemmed ,,thickets ,,of ,,mangrove ,,of ,,southernmost ,,seacoasts1 many of the trunks being formed of arial roots4 ,,chapter ,,xi ,,leaves--,,form ,,and ,,position ,leaves may be studied from four points of view1--with reference 7#a7 to their kinds and shapes2 7#b7 their position1 or arrangement on the plant2 7#c7 their anatomy1 or structure2 7#d7 their function1 or the work they perform4 ,this chapter is concerned with the first two categories4 ,illustration3 ,,fig4 #hh4--;,a ,,simple ,,netted-,,veined ,,leaf4 ,illustration3 ,,fig4 #hi4--;,a ,,simple ,,parallel-,,veined ,,leaf4 ,illustration3 ,,fig4 #ij4--;,,compound ,,or ,,branched ,,leaf ,,of ,,brake 7a common fern74 ,kinds4--,leaves are simple or unbranched 7,figs4 #hh1 #hi71 and compound or branched 7,fig4 #ij74 ,the method of compounding or branching follows the mode of veining4 ,the veining1 or venation1 is of two general kinds3 in some plants the main veins diverge1 and there is a conspicuous network of smaller veins2 such leaves are netted-veined4 ,they are characteristic of the dicotyledons4 ,in other plants the main veins are parallel1 or nearly so1 and there is no conspicuous network2 these are parallel-veined leaves 7,figs4 #hi1 #ajb74 ,these leaves are the rule in monocotyledonous plants4 ,the venation of netted-veined leaves is pinnate or feather-like when the veins arise from the side of a continuous midrib 7,fig4 #ia72 palmate or digitate 7hand-like7 when the veins arise from the apex of the petiole 7,figs4 #hh1 #ib74 ,if leaves were divided between the main veins1 the former would be pinnately and the latter digitately compound4 ,illustration3 ,,fig4 #ia4--;,,complete ,,leaves ,,of ,,willow4 ,illustration3 ,,fig4 #ib4--;,,digitate-,,veined ,,peltate ,,leaf ,,of ,,nasturtium4 ,illustration3 ,,fig4 #ic4--,,pinnately ,,compound ,,leaf ,,of ,,ash4 ,it is customary to speak of a leaf as compound only when the parts or branches are completely separate blades1 as when the division extends to the midrib 7,figs4 #ij1 #ic1 #id1 #ie74 ,the parts or branches are known as leaflets4 ,sometimes the leaflets themselves are compound1 and the whole leaf is then said to be bi-compound or twice-compound 7,fig4 #ij74 ,some leaves are three-compound1 four-compound1 or five-compound4 ,decompound is a general term to express any degree of compounding beyond twice-compound4 ,illustration3 ,,fig4 #id4--;,,digitately ,,compound ,,leaf ,,of ,,raspberry4 ,illustration3 ,,fig4 #ie4--,,poison ,,ivy4 ,,leaf ,,and ,,fruit4 ,illustration3 ,,fig4 #if4--,,lobed ,,leaf ,,of ,,sugar ,,maple4 ,leaves that are not divided as far as to the midrib are said to be3 lobed1 if the openings or sinuses are not more than half the depth of the blade 7,fig4 #if72 cleft1 if the sinuses are deeper than the middle2 parted1 if the sinuses reach two thirds or more to the midrib 7,fig4 #ig72 divided1 if sinuses reach nearly or quite to the midrib4 ,the parts are called lobes1 divisions1 or segments1 rather than leaflets4 ,the leaf may be pinnately or digitately lobed1 parted1 cleft1 or divided4 ,a pinnately parted or cleft leaf is sometimes said to be pinnatifid4 ,illustration3 ,,fig4 #ig4--;,,digitately ,,parted ,,leaves ,,of ,,begonia4 ,leaves may have one or all of three parts--blade1 or expanded part2 petiole1 or stalk2 stipules1 or appendages at the base of the petiole4 ,a leaf that has all three of these parts is said to be complete 7,figs4 #ia1 #ajf74 ,the stipules are often green and leaflike and perform the function of foliage1 as in the pea and ,japanese quince 7the latter common in yards74 ,illustration3 ,,fig4 #ih4--,,oblong-,,ovate ,,sessile ,,leaves ,,of ,,tea4 ,leaves and leaflets that have no stalks are said to be sessile 7,figs4 #ih1 #ajc71 i4e4 sitting4 ,find several examples4 ,the same is said of flowers and fruits4 ,the blade of a sessile leaf may partly or wholly surround the stem1 when it is said to be clasping4 ,examples3 aster 7,fig4 #ii71 corn4 ,in some cases the leaf runs down the stem1 forming a wing2 such leaves are said to be decurrent 7,fig4 #ajj74 ,when opposite sessile leaves are joined by their bases1 they are said to be connate 7,fig4 #aja74 ,illustration3 ,,fig4 #ii4--;,,clasping ,,leaf ,,of ,a ,,wild ,,aster4 ,leaflets may have one or all of these three parts1 but the stalks of leaflets are called petiolules and the stipules of leaflets are called stipels4 ,the leaf of the garden bean has leaflets1 petiolules1 and stipels4 ,illustration3 ,,fig4 #ajj4--;,,decurrent ,,leaves ,,of ,,mullein4 ,the blade is usually attached to the petiole by its lower edge4 ,in pinnate-veined leaves1 the petiole seems to continue through the leaf as a midrib 7,fig4 #ia74 ,in some plants1 however1 the petiole joins the blade inside or beyond the margin 7,fig4 #ib74 ,such leaves are said to be peltate or shield-shaped4 ,this mode of attachment is particularly common in floating leaves 7e4g4 the water lilies74 ,peltate leaves are usually digitate-veined4 ,illustration3 ,,fig4 #aja4--,,two ,,pairs ,,of ,,connate ,,leaves ,,of ,,honeysuckle4 ,how to ,tell a ,leaf4--,it is often difficult to distinguish compound leaves from leafy branches1 and leaflets from leaves4 ,as a rule leaves can be distinguished by the following tests3 7#a7 ,leaves are temporary structures1 sooner or later falling4 7#b7 ,usually buds are borne in their axils4 7#c7 ,leaves are usually borne at joints or nodes4 7#d7 ,they arise on wood of the current year's growth4 7#e7 ,they have a more or less definite arrangement4 ,when leaves fall1 the twig that bore them remains2 when leaflets fall1 the main petiole or stalk that bore them also falls4 ,illustration3 ,,fig4 #ajb4--,,linear-,,acuminate ,,leaf ,,of ,,grass4 ,illustration3 ,,fig4 #ajc4--,,short-,,oblong ,,leaves ,,of ,,box4 ,shapes4--,leaves and leaflets are infinitely variable in shape4 ,names have been given to some of the more definite or regular shapes4 ,these names are a part of the language of botany4 ,the names represent ideal or typical shapes2 there are no two leaves alike and very few that perfectly conform to the definitions4 ,the shapes are likened to those of familiar objects or of geometrical figures4 ,some of the commoner shapes are as follows 7name original examples in each class73 ,illustration ,linear1 several times longer than broad1 with the sides nearly or quite parallel4 ,spruces and most grasses are examples 7,fig4 #ajb74 ,in linear leaves1 the main veins are usually parallel to the midrib4 ,illustration ,oblong1 twice or thrice as long as broad1 with the sides parallel for most of their length4 ,fig4 #ajc shows the short-oblong leaves of the box1 a plant that is used for permanent edgings in gardens4 ,illustration ,elliptic differs from the oblong in having the sides gradually tapering to either end from the middle4 ,the ,european beech 7,fig4 #ajd7 has elliptic leaves4 7,this tree is often planted in this country47 ,illustration ,lanceolate1 four to six times longer than broad1 widest below the middle1 and tapering to either end4 ,some of the narrow-leaved willows are examples4 ,most of the willows and the peach have oblong-lanceolate leaves4 ,illustration ,spatulate1 a narrow leaf that is broadest toward the apex4 ,the top is usually rounded4 ,illustration3 ,,fig4 #ajd4--;,,elliptic ,,leaf ,,of ,,purple ,,beech4 ,illustration3 ,,fig4 #aje4--,,ovate ,,serrate ,,leaf ,,of ,,hibiscus4 ,illustration3 ,,fig4 #ajf4--,,leaf ,,of ,,apple1 showing blade1 petiole1 and small narrow stipules4 ,illustration ,ovate1 shaped somewhat like the longitudinal section of an egg3 about twice as long as broad1 tapering from near the base to the apex4 ,this is one of the commonest leaf forms 7,figs4 #aje1 #ajf74 ,illustration ,obovate1 ovate inverted1--the wide part towards the apex4 ,leaves of mullein and leaflets of horse-chestnut and false indigo are obovate4 ,this form is commonest in leaflets of digitate leaves3 why8 ,illustration ,reniform1 kidney-shaped4 ,this form is sometimes seen in wild plants1 particularly in root-leaves4 ,leaves of wild ginger are nearly reniform4 ,illustration ,orbicular1 circular in general outline4 ,very few leaves are perfectly circular1 but there are many that are nearer circular than any other shape 7,fig4 #ajg74 ,illustration3 ,,fig4 #ajg4--,,orbicular ,,lobed ,,leaves4 ,illustration3 ,,fig4 #ajh4--,,truncate ,,leaf ,,of ,,tulip ,,tree4 ,the shape of many leaves is described in combinations of these terms3 as ovate-lanceolate1 lanceolate-oblong4 ,the shape of the base and apex of the leaf or leaflet is often characteristic4 ,the base may be rounded 7,fig4 #ajd71 tapering 7,fig4 #ic71 cordate or heart-shaped 7,fig4 #aje71 truncate or squared as if cut off4 ,the apex may be blunt or obtuse1 acute or sharp1 acuminate or long-pointed1 truncate 7,fig4 #ajh74 ,name examples4 ,the shape of the margin is also characteristic of each kind of leaf4 ,the margin is entire when it is not indented or cut in any way 7,figs4 #ii1 #ajc74 ,when not entire1 it may be undulate or wavy 7,fig4 #ib71 serrate or saw-toothed 7,fig4 #aje71 dentate or more coarsely notched 7,fig4 #ie71 crenate or round-toothed1 lobed1 and the like4 ,give examples4 ,leaves often differ greatly in form on the same plant4 ,observe the different shapes of leaves on the young growths of mulberries 7,fig4 #b7 and wild grapes2 also on vigorous squash and pumpkin vines4 ,in some cases there may be simple and compound leaves on the same plant4 ,this is marked in the so-called ,boston ivy or ampelopsis 7,fig4 #aji71 a vine that is used to cover brick and stone buildings4 ,different degrees of compounding1 even in the same leaf1 may often be found in honey locust and ,kentucky coffee tree4 ,remarkable differences in forms are seen by comparing seed-leaves with mature leaves of any plant 7,fig4 #cj74 ,illustration3 ,,fig4 #aji4--;,,different ,,forms ,,of ,,leaves ,,from ,,one ,,plant ,,of ,,ampelopsis4 ,the ,leaf and its ,environment4--,the form and shape of the leaf often have direct relation to the place in which the leaf grows4 ,floating leaves are usually expanded and flat1 and the petiole varies in length with the depth of the water4 ,submerged leaves are usually linear or thread-like1 or are cut into very narrow divisions3 thereby more surface is exposed1 and possibly the leaves are less injured by moving water4 ,compare the sizes of the leaves on the ends of branches with those at the base of the branches or in the interior of the tree top4 ,in dense foliage masses1 the petioles of the lowermost or undermost leaves tend to elongate--to push the leaf to the light4 ,on the approach of winter the leaf usually ceases to work1 and dies4 ,it may drop1 when it is said to be deciduous2 or it may remain on the plant1 when it is said to be persistent4 ,if persistent leaves remain green during the winter1 the plant is said to be evergreen4 ,give examples in each class4 ,most leaves fall by breaking off at the lower end of the petiole with a distinct joint or articulation4 ,there are many leaves1 however1 that wither and hang on the plant until torn off by the wind2 of such are the leaves of grasses1 sedges1 lilies1 orchids1 and other plants of the monocotyledons4 ,most leaves of this character are parallel-veined4 ,leaves also die and fall from lack of light4 ,observe the yellow and weak leaves in a dense tree top or in any thicket4 ,why do the lower leaves die on house plants8 ,note the carpet of needles under the pines4 ,all evergreens shed their leaves after a time4 ,counting back from the tip of a pine or spruce shoot1 determine how many years the leaves persist4 ,in some spruces a few leaves may be found on branches ten or more years old4 ,arrangement of ,leaves4--,most leaves have a regular position or arrangement on the stem4 ,this position or direction is determined largely by exposure to sunlight4 ,in temperate climates they usually hang in such a way that they receive the greatest amount of light4 ,one leaf shades the other to the least possible degree4 ,if the plant were placed in a new position with reference to light1 the leaves would make an effort to turn their blades4 ,when leaves are opposite the pairs usually alternate4 ,that is1 if one pair stands north and south1 the next pair stands east and west4 ,see the box-elder shoot1 on the left in ,fig4 #aaj4 ,one pair does not shade the pair beneath4 ,the leaves are in four vertical ranks4 ,there are several kinds of alternate arrangement4 ,in the elm shoot1 in ,fig4 #aaj1 the third bud is vertically above the first4 ,this is true no matter which bud is taken as the starting point4 ,draw a thread around the stem until the two buds are joined4 ,set a pin at each bud4 ,observe that two buds are passed 7not counting the last7 and that the thread makes one circuit of the stem4 ,representing the number of buds by a denominator1 and the number of circuits by a numerator1 we have the fraction 1 which expresses the part of the circle that lies between any two buds4 ,that is1 the buds are one half of #cfj degrees apart1 or #ahj degrees4 ,looking endwise at the stem1 the leaves are seen to be #b-ranked4 ,note that in the apple shoot 7,fig4 #aaj1 right7 the thread makes two circuits and five buds are passed3 two-fifths represents the divergence between the buds4 ,the leaves are #e-ranked4 ,illustration3 ,,fig4 #aaj4--,,phyllotaxy ,,of ,,box ,,elder1 ,,elm1 ,,apple4 ,every plant has its own arrangement of leaves4 ,for opposite leaves1 see maple1 box elder1 ash1 lilac1 honeysuckle1 mint1 fuchsia4 ,for #b-ranked arrangement1 see all grasses1 ,indian corn1 basswood1 elm4 ,for #c-ranked arrangement1 see all sedges4 ,for #e-ranked 7which is one of the commonest71 see apple1 cherry1 pear1 peach1 plum1 poplar1 willow4 ,for #h-ranked1 see holly1 osage orange1 some willows4 ,more complicated arrangements occur in bulbs1 house leeks1 and other condensed parts4 ,the buds or 8eyes0 on a potato tuber1 which is an underground stem 7why871 show a spiral arrangement 7,fig4 #aaa74 ,the arrangement of leaves on the stem is known as phyllotaxy 7literally1 8leaf arrangement074 ,make out the phyllotaxy on six different plants nearest the schoolhouse door4 ,in some plants1 several leaves occur at one level1 being arranged in a circle around the stem4 ,such leaves are said to be verticillate1 or whorled4 ,leaves arranged in this way are usually narrow3 why8 ,illustration3 ,,fig4 #aaa4--,,phyllotaxy ,,of ,,the ,,potato ,,tuber4 ,work it out on a fresh long tuber4 ,although a definite arrangement of leaves is the rule in most plants1 it is subject to modification4 ,on shoots that receive the light only from one side or that grow in difficult positions1 the arrangement may not be definite4 ,examine shoots that grow on the under side of dense tree tops or in other partially lighted positions4 ,illustration3 ,,fig4 #aab4--;,,cowpea4 ,describe the leaves4 ,for what is the plant used8 ,,suggestions4--#ee4 ,the pupil should match leaves to determine whether any two are alike4 ,why8 ,compare leaves from the same plant in size1 shape1 color1 form of margin1 length of petiole1 venation1 texture 7as to thickness or thinness71 stage of maturity1 smoothness or hairiness4 #ef4 ,let the pupil take an average leaf from each of the first ten different kinds of plants that he meets and compare them as to the above points 7in ,exercise #ee71 and also name the shapes4 ,determine how the various leaves resemble and differ4 #eg4 ,describe the stipules of rose1 apple1 fig1 willow1 violet1 pea1 or others4 #eh4 ,in what part of the world are parallel-veined leaves the more common8 #ei4 ,do you know of parallel-veined leaves that have lobed or dentate margins8 #fj4 ,what becomes of dead leaves8 #fa4 ,why is there no grass or other undergrowth under pine and spruce trees8 #fb4 ,name several leaves that are useful for decorations4 ,why are they useful8 #fc4 ,what trees in your vicinity are most esteemed as shade trees8 ,what is the character of their foliage8 #fd4 ,why are the internodes so long in water-sprouts and suckers8 #fe4 ,how do foliage characters in corn or sorghum differ when the plants are grown in rows or broadcast8 ,why8 #ff4 ,why may removal of half the plants increase the yield of cotton or sugar-beets or lettuce8 #fg4 ,how do leaves curl when they wither8 ,do different leaves behave differently in this respect8 #fh4 ,what kinds of leaves do you know to be eaten by insects8 ,by cattle8 ,by horses8 ,what kinds are used for human food8 #fi4 ,how would you describe the shape of leaf of peach8 apple8 elm8 hackberry8 maple8 sweet-gum8 corn8 wheat8 cotton8 hickory8 cowpea8 strawberry8 chrysanthemum8 rose8 carnation8 #gj4 ,are any of the foregoing leaves compound8 ,how do you describe the shape of a compound leaf8 #ga4 ,how many sizes of leaves do you find on the bush or tree nearest the schoolroom door8 #gb4 ,how many colors or shades8 #gc4 ,how many lengths of petioles8 #gd4 ,bring in all the shapes of leaves that you can find4 ,,chapter ,,xii ,,leaves--,,structure ,,or ,,anatomy ,besides the framework1 or system of veins found in blades of all leaves1 there is a soft cellular tissue called mesophyll1 or leaf parenchyma1 and an epidermis or skin that covers the entire outside part4 ,illustration3 ,,fig4 #aac4--,,section ,,of ,a ,,leaf1 showing the air spaces4 ,breathing-pore or stoma at a4 ,the palisade cells which chiefly contain the chlorophyll are at b4 ,epidermal cells at c4 ,mesophyll4--,the mesophyll is not all alike or homogeneous4 ,the upper layer is composed of elongated cells placed perpendicular to the surface of the leaf4 ,these are called palisade cells4 ,these cells are usually filled with green bodies called chlorophyll grains4 ,the grain contains a great number of chlorophyll drops imbedded in the protoplasm4 ,below the palisade cells is the spongy parenchyma1 composed of cells more or less spherical in shape1 irregularly arranged1 and provided with many intercellular air cavities 7,fig4 #aac74 ,in leaves of some plants exposed to strong light there may be more than one layer of palisade cells1 as in the ,india-rubber plant and oleander4 ,ivy when grown in bright light will develop two such layers of cells1 but in shaded places it may be found with only one4 ,such plants as iris and compass plant1 which have both surfaces of the leaf equally exposed to sunlight1 usually have a palisade layer beneath each epidermis4 ,epidermis4--,the outer or epidermal cells of leaves do not bear chlorophyll1 but are usually so transparent that the green mesophyll can be seen through them4 ,they often become very thick-walled1 and are in most plants devoid of all protoplasm except a thin layer lining the walls1 the cavities being filled with cell sap4 ,this sap is sometimes colored1 as in the under epidermis of begonia leaves4 ,it is not common to find more than one layer of epidermal cells forming each surface of a leaf4 ,the epidermis serves to retain moisture in the leaf and as a general protective covering4 ,in desert plants the epidermis1 as a rule1 is very thick and has a dense cuticle1 thereby preventing loss of water4 ,there are various outgrowths of the epidermis4 ,hairs are the chief of these4 ,they may be 7#a7 simple1 as on primula1 geranium1 ngelia2 7#b7 once branched1 as on wallflower2 7#c7 compound1 as on verbascum or mullein2 7#d7 disk-like1 as on shepherdia2 7#e7 stellate1 or star-shaped1 as in certain crucifers4 ,in some cases the hairs are glandular1 as in ,chinese primrose of the greenhouses 7,primula ,sinensis7 and certain hairs of pumpkin flowers4 ,the hairs often protect the breathing pores1 or stomates1 from dust and water4 ,stomates 7sometimes called breathing-pores7 are small openings or pores in the epidermis of leaves and soft stems that allow the passage of air and other gases and vapors 7stomate or stoma1 singular2 stomates or stomata1 plural74 ,they are placed near the large intercellular spaces of the mesophyll1 usually in positions least affected by direct sunlight4 ,fig4 #aad shows the structure4 ,there are two guard-cells at the mouth of each stomate1 which may in most cases open or close the passage as the conditions of the atmosphere may require4 ,the guard-cells contain chlorophyll4 ,in ,fig4 #aae is shown a case in which there are compound guard-cells1 that of ivy4 ,on the margins of certain leaves1 as of fuchsia1 impatiens1 cabbage1 are openings known as water-pores4 ,illustration3 ,,fig4 #aad4--;,,diagram ,,of ,,stomate ,,of ,,iris 7,osterhout74 ,illustration3 ,,fig4 #aae4--,,stomate ,,of ,,ivy1 showing compound guard-cells4 ,stomates are very numerous1 as will be seen from the numbers showing the pores to each square inch of leaf surface3 ,lower surface ,upper surface ,peony #ac1gij ,none ,holly #fc1fjj ,none ,lilac #afj1jjj ,none ,mistletoe #bjj #bjj ,tradescantia #b1jjj #b1jjj ,garden ,flag 7iris7 #aa1egb #aa1egb ,the arrangement of stomates on the leaf differs with each kind of plant4 ,fig4 #aaf shows stomates and also the outlines of contiguous epidermal cells4 ,illustration3 ,,fig4 #aaf4--,,stomates ,,of ,,geranium ,,leaf4 ,the function or work of the stomates is to regulate the passage of gases into and out of the plant4 ,the directly active organs or parts are guard-cells1 on either side the opening4 ,one method of opening is as follows3 ,the thicker walls of the guard-cells 7,fig4 #aad7 absorb water from adjacent cells1 these thick walls buckle or bend and part from each other at their middles on either side of the opening1 causing the stomate to open1 when the air gases may be taken in and the leaf gases may pass out4 ,when moisture is reduced in the leaf tissue1 the guard cells part with some of their contents1 the thick walls straighten1 and the faces of the two opposite ones come together1 thus closing the stomate and preventing any water vapor from passing out4 ,when a leaf is actively at work making new organic compounds1 the stomates are usually open2 when unfavorable conditions arise1 they are usually closed4 ,they also commonly close at night1 when growth 7or the utilizing of the new materials7 is most likely to be active4 ,it is sometimes safer to fumigate greenhouses and window gardens at night1 for the noxious vapors are less likely to enter the leaf4 ,dust may clog or cover the stomates4 ,rains benefit plants by washing the leaves as well as by providing moisture to the roots4 ,illustration3 ,,fig4 #aag4--,,lenticels ,,on ,,young ,,shoot ,,of ,,red ,,osier 7,,cornus74 ,lenticels4--,on the young woody twigs of many plants 7marked in osiers1 cherry1 birch7 there are small corky spots or elevations known as lenticels 7,fig4 #aag74 ,they mark the location of some loose cork cells that function as stomates1 for green shoots1 as well as leaves1 take in and discharge gases2 that is1 soft green twigs function as leaves4 ,under some of these twig stomates1 corky material may form and the opening is torn and enlarged3 the lenticels are successors to the stomates4 ,the stomates lie in the epidermis1 but as the twig ages the epidermis perishes and the bark becomes the external layer4 ,gases continue to pass in and out through the lenticels1 until the branch becomes heavily covered with thick1 corky bark4 ,with the growth of the twig1 the lenticel scars enlarge lengthwise or crosswise or assume other shapes1 often becoming characteristic markings4 ,fibro-vascular ,bundles4--,we have studied the fibro-vascular bundles of stems 7,chap4 ,x74 ,these stem bundles continue into the leaves1 ramifying into the veins1 carrying the soil water inwards and bringing1 by diffusion1 the elaborated food out through the sieve-cells4 ,cut across a petiole and notice the hard spots or areas in it2 strip these parts lengthwise of the petiole3 what are they8 ,fall of the ,leaf4--,in most common deciduous plants1 when the season's work for the leaf is ended1 the nutritious matter may be withdrawn1 and a layer of corky cells is completed over the surface of the stem where the leaf is attached4 ,the leaf soon falls4 ,it often falls even before it is killed by frost4 ,deciduous leaves begin to show the surface line of articulation in the early growing season4 ,this articulation may be observed at any time during the summer4 ,the area of the twig once covered by the petioles is called the leaf-scar after the leaf has fallen4 ,in ,chap4 ,,xv are shown a number of leaf-scars4 ,in the plane tree 7sycamore or buttonwood71 the leaf-scar is in the form of a ring surrounding the bud1 for the bud is covered by the hollowed end of the petiole2 the leaf of sumac is similar4 ,examine with a hand lens leaf-scars of several woody plants4 ,note the number of bundle-scars in each leaf-scar4 ,sections may be cut through a leaf-scar and examined with the microscope4 ,note the character of cells that cover the leaf-scar surface4 ,,suggestions4--,to study epidermal hairs3 #ge4 ,for this study1 use the leaves of any hairy or woolly plant4 ,a good hand lens will reveal the identity of many of the coarser hairs4 ,a dissecting microscope will show them still better4 ,for the study of the cell structure1 a compound microscope is necessary4 ,cross-sections may be made so as to bring hairs on the edge of the sections2 or in some cases the hairs may be peeled or scraped from the epidermis and placed in water on a slide4 ,make sketches of the different kinds of hairs4 #gf4 ,it is good practice for the pupil to describe leaves in respect to their covering3 ,are they smooth on both surfaces8 ,or hairy8 ,woolly8 ,thickly or thinly hairy8 ,hairs long or short8 ,standing straight out or lying close to the surface of the leaf8 ,simple or branched8 ,attached to the veins or the plane surface8 ,color8 ,most abundant on young leaves or old8 #gg4 ,place a hairy or woolly leaf under water4 ,does the hairy surface appear silvery8 ,why8 ,other questions3 #gh4 ,why is it good practice to wash the leaves of house plants8 #gi4 ,describe the leaf-scars on six kinds of plants3 size1 shape1 color1 position with reference to the bud1 bundle-scars4 #hj4 ,do you find leaf-scars on monocotyledonous plants--corn1 cereal grains1 lilies1 canna1 banana1 palm1 bamboo1 green brier8 #ha4 ,note the table on page #hh4 ,can you suggest a reason why there are equal numbers of stomates on both surfaces of leaves of tradescantia and flag1 and none on upper surface of other leaves8 ,suppose you pick a leaf of lilac 7or some larger leaf71 seal the petiole with wax and then rub the under surface with vaseline2 on another leaf apply the vaseline to the upper surface2 which leaf withers first1 and why8 ,make a similar experiment with iris or blue flag4 #hb4 ,why do leaves and shoots of house plants turn towards the light8 ,what happens when the plants are turned around8 #hc4 ,note position of leaves of beans1 clover1 oxalis1 alfalfa1 locust1 at night4 ,,chapter ,,xiii ,,leaves--,,function ,,or ,,work ,we have discussed 7in ,chap4 ,,viii7 the work or function of roots and also 7in ,chap4 ,x7 the function of stems4 ,we are now ready to complete the view of the main vital activities of plants by considering the function of the green parts 7leaves and young shoots74 ,sources of ,food4--,the ordinary green plant has but two sources from which to secure food1--the air and the soil4 ,when a plant is thoroughly dried in an oven1 the water passes off2 this water came from the soil4 ,the remaining part is called the dry substance or dry matter4 ,if the dry matter is burned in an ordinary fire1 only the ash remains2 this ash came from the soil4 ,the part that passed off as gas in the burning contained the elements that came from the air2 it also contained some of those that came from the soil--all those 7as nitrogen1 hydrogen1 chlorine7 that are transformed into gases by the heat of a common fire4 ,the part that comes from the soil 7the ash7 is small in amount1 being considerably less than #aj per cent and sometimes less than #a per cent4 ,water is the most abundant single constituent or substance of plants4 ,in a corn plant of the roasting-ear stage1 about #hj per cent of the substance is water4 ,a fresh turnip is over #ij per cent water4 ,fresh wood of the apple tree contains about #de per cent of water4 ,carbon4--,carbon enters abundantly into the composition of all plants4 ,note what happens when a plant is burned without free access of air1 or smothered1 as in a charcoal pit4 ,a mass of charcoal remains1 almost as large as the body of the plant4 ,charcoal is almost pure carbon1 the ash present being so small in proportion to the large amount of carbon that we look on the ash as an impurity4 ,nearly half of the dry substance of a tree is carbon4 ,carbon goes off as a gas when the plant is burned in air4 ,it does not go off alone1 but in combination with oxygen in the form of carbon dioxid gas1 ,,co4 ,the green plant secures its carbon from the air4 ,in other words1 much of the solid matter of the plant comes from one of the gases of the air4 ,by volume1 carbon dioxid forms only a very small fraction of #a per cent of the air4 ,it would be very disastrous to animal life1 however1 if this percentage were much increased1 for it excludes the life-giving oxygen4 ,carbon dioxid is often called 8foul gas40 ,it may accumulate in old wells1 and an experienced person will not descend into such wells until they have been tested with a torch4 ,if the air in the well will not support combustion1--that is1 if the torch is extinguished1--it usually means that carbon dioxid has drained into the place4 ,the air of a closed schoolroom often contains far too much of this gas1 along with little solid particles of waste matters4 ,carbon dioxid is often known as carbonic acid gas4 ,appropriation of the ,carbon4--,the carbon dioxid of the air readily diffuses itself into the leaves and other green parts of the plant4 ,the leaf is delicate in texture1 and when very young the air can diffuse directly into the tissues4 ,the stomates1 however1 are the special inlets adapted for the admission of gases into the leaves and other green parts4 ,through these stomates1 or diffusion-pores1 the outside air enters into the air-spaces of the plant1 and is finally absorbed by the little cells containing the living matter4 ,chlorophyll 78leaf green07 is the agent that secures the energy by means of which carbon dioxid is utilized4 ,this material is contained in the leaf cells in the form of grains 7p4 #hf72 the grains themselves are protoplasm1 only the coloring matter being chlorophyll4 ,the chlorophyll bodies or grains are often most abundant near the upper surface of the leaf1 where they can secure the greatest amount of light4 ,without this green coloring matter1 there would be no reason for the large flat surfaces which the leaves possess1 and no reason for the fact that the leaves are borne most abundantly at the ends of branches1 where the light is most available4 ,plants with colored leaves1 as coleus1 have chlorophyll1 but it is masked by other coloring matter4 ,this other coloring matter is usually soluble in hot water3 boil a coleus leaf and notice that it becomes green and the water becomes colored4 ,plants grown in darkness are yellow and slender1 and do not reach maturity4 ,compare the potato sprouts that have grown from a tuber lying in the dark cellar with those that have grown normally in the bright light4 ,the shoots have become slender and are devoid of chlorophyll2 and when the food that is stored in the tuber is exhausted1 these shoots will have lived useless lives4 ,a plant that has been grown in darkness from the seed will soon die1 although for a time the little seedling will grow very tall and slender3 why8 ,light favors the production of chlorophyll1 and the chlorophyll is the agent in the making of the organic carbon compounds4 ,sometimes chlorophyll is found in buds and seeds1 but in most cases these places are not perfectly dark4 ,notice how potato tubers develop chlorophyll1 or become green1 when exposed to light4 ,photosynthesis4--,carbon dioxid diffuses into the leaf2 during sunlight it is used1 and oxygen is given off4 ,how the carbon dioxid which is thus absorbed may be used in making an organic food is a complex question1 and need not be studied here2 but it may be stated that carbon dioxid and water are the constituents4 ,complex compounds are built up out of simpler ones4 ,chlorophyll absorbs certain light rays1 and the energy thus directly or indirectly obtained is used by the living matter in uniting the carbon dioxid absorbed from the air with some of the water brought up from the roots4 ,the ultimate result usually is starch4 ,the process is obscure1 but sugar is generally one step2 and our first definite knowledge of the product begins when starch is deposited in the leaves4 ,the process of using the carbon dioxid of the air has been known as carbon assimilation1 but the term now most used is photosynthesis 7from two ,greek words1 meaning light and to put together74 ,starch and ,sugar4--,all starch is composed of carbon1 hydrogen1 and oxygen 7,c,h,o74 ,the sugars and the substance of cell walls are very similar to it in composition4 ,all these substances are called carbohydrates4 ,in making fruit sugar from the carbon and oxygen of carbon dioxid and from the hydrogen and oxygen of the water1 there is a surplus of oxygen 7#f parts ,,co #f parts ,h,o ,c,h,o #f ,o74 ,it is this oxygen that is given off into the air during sunlight4 ,digestion4--,starch is in the form of insoluble granules4 ,when such food material is carried from one part of the plant to another for purposes of growth or storage1 it is made soluble before it can be transported4 ,when this starchy material is transferred from place to place1 it is usually changed into sugar by the action of a diastase4 ,this is a process of digestion4 ,it is much like the change of starchy foodstuffs to sugary foods by the saliva4 ,distribution of the ,digested ,food4--,after being changed to the soluble form1 this material is ready to be used in growth1 either in the leaf1 in the stem1 or in the roots4 ,with other more complex products it is then distributed throughout all of the growing parts of the plant2 and when passing down to the root1 it seems to pass more readily through the inner bark1 in plants which have a definite bark4 ,this gradual downward diffusion through the inner bark of materials suitable for growth is the process referred to when the 8descent of sap0 is mentioned4 ,starch and other products are often stored in one growing season to be used in the next season4 ,if a tree is constricted or strangled by a wire around its trunk 7,fig4 #aah71 the digested food cannot readily pass down and it is stored above the girdle1 causing an enlargement4 ,illustration3 ,,fig4 #aah4--,,trunk ,,girdled ,,by ,a ,,wire4 ,see ,fig4 #he4 ,assimilation4--,the food from the air and that from the soil unite in the living tissues4 ,the 8sap0 that passes upwards from the roots in the growing season is made up largely of the soil water and the salts which have been absorbed in the diluted solutions 7p4 #fg74 ,this upward-moving water is conducted largely through certain tubular canals of the young wood4 ,these cells are never continuous tubes from root to leaf2 but the water passes readily from one cell or canal to another in its upward course4 ,the upward-moving water gradually passes to the growing parts1 and everywhere in the living tissues1 it is of course in the most intimate contact with the soluble carbohydrates and products of photosynthesis4 ,in the building up or reconstructive and other processes it is therefore available4 ,we may properly conceive of certain of the simpler organic molecules as passing through a series of changes1 gradually increasing in complexity4 ,there will be formed substances containing nitrogen in addition to carbon1 hydrogen1 and oxygen4 ,others will contain also sulfur and phosphorus1 and the various processes may be thought of as culminating in protoplasm4 ,protoplasm is the living matter in plants4 ,it is in the cells1 and is usually semifluid4 ,starch is not living matter4 ,the complex process of building up the protoplasm is called assimilation4 ,respiration4--,plants need oxygen for respiration1 as animals do4 ,we have seen that plants need the carbon dioxid of the air4 ,to most plants the nitrogen of the air is inert1 and serves only to dilute the other elements2 but the oxygen is necessary for all life4 ,we know that all animals need this oxygen in order to breathe or respire4 ,in fact1 they have become accustomed to it in just the proportions found in the air2 and this is now best for them4 ,when animals breathe the air once1 they make it foul1 because they use some of the oxygen and give off carbon dioxid4 ,likewise1 all living parts of the plant must have a constant supply of oxygen4 ,roots also need it1 for they respire4 ,air goes in and out of the soil by diffusion1 and as the soil is heated and cooled1 causing the air to expand and contract4 ,the oxygen passes into the air-spaces and is absorbed by the moist cell membranes4 ,in the living cells it makes possible the formation of simpler compounds by which energy is released4 ,this energy enables the plant to work and grow1 and the final products of this action are carbon dioxid and water4 ,as a result of the use of this oxygen by night and by day1 plants give off carbon dioxid4 ,plants respire2 but since they are stationary1 and more or less inactive1 they do not need as much oxygen as animals1 and they do not give off so much carbon dioxid4 ,a few plants in a sleeping room need not disturb one more than a family of mice4 ,it should be noted1 however1 that germinating seeds respire vigorously1 hence they consume much oxygen2 and opening buds and flowers are likewise active4 ,transpiration4--,much more water is absorbed by the roots than is used in growth1 and this surplus water passes from the leaves into the atmosphere by an evaporation process known as transpiration4 ,transpiration takes place more abundantly from the under surfaces of leaves1 and through the pores or stomates4 ,a sunflower plant of the height of a man1 during an active period of growth1 gives off a quart of water per day4 ,a large oak tree may transpire #aej gallons per day during the summer4 ,for every ounce of dry matter produced1 it is estimated that #ae to #be pounds of water usually passes through the plant4 ,when the roots fail to supply to the plant sufficient water to equalize that transpired by the leaves1 the plant wilts4 ,transpiration from the leaves and delicate shoots is increased by all of the conditions which increase evaporation1 such as higher temperature1 dry air1 or wind4 ,the stomata open and close1 tending to regulate transpiration as the varying conditions of the atmosphere affect the moisture content of the plant4 ,however1 in periods of drought or of very hot weather1 and especially during a hot wind1 the closing of these stomates cannot sufficiently prevent evaporation4 ,the roots may be very active and yet fail to absorb sufficient moisture to equalize that given off by the leaves4 ,the plant shows the effect 7how874 ,on a hot dry day1 note how the leaves of corn 8roll0 towards afternoon4 ,note how fresh and vigorous the same leaves appear early the following morning4 ,any injury to the roots1 such as a bruise1 or exposure to heat1 drought1 or cold may cause the plant to wilt4 ,water is forced up by root pressure or sap pressure4 7,exercise #ii47 ,some of the dew on the grass in the morning may be the water forced up by the roots2 some of it is the condensed vapor of the air4 ,the wilting of a plant is due to the loss of water from the cells4 ,the cell walls are soft1 and collapse4 ,a toy balloon will not stand alone until it is inflated with air or liquid4 ,in the woody parts of the plant the cell walls may be stiff enough to support themselves1 even though the cell is empty4 ,measure the contraction due to wilting and drying by tracing a fresh leaf on page of notebook1 and then tracing the same leaf after it has been dried between papers4 ,the softer the leaf1 the greater will be the contraction4 ,storage4--,we have said that starch may be stored in twigs to be used the following year4 ,the very early flowers on fruit trees1 especially those that come before the leaves1 and those that come from bulbs1 as crocuses and tulips1 are supported by the starch or other food that was organized the year before4 ,some plants have very special storage reservoirs1 as the potato1 in this case being a thickened stem although growing underground4 7,why a thickened stem8 p4 #hd47 ,it is well to make the starch test on winter twigs and on all kinds of thickened parts1 as tubers and bulbs4 ,carnivorous ,plants4--,certain plants capture insects and other very small animals and utilize them to some extent as food4 ,such are the sundew1 that has on the leaves sticky hairs that close over the insect2 the ,venus's flytrap of the ,southern states1 in which the halves of the leaves close over the prey like the jaws of a steel trap2 and the various kinds of pitcher plants that collect insects and other organic matter in deep1 water-filled1 flask-like leaf pouches 7,fig4 #aai74 ,the sundew and ,venus's flytrap are sensitive to contact4 ,other plants are sensitive to the touch without being insectivorous4 ,the common cultivated sensitive plant is an example4 ,this is readily grown from seeds 7sold by seedsmen7 in a warm place4 ,related wild plants in the south are sensitive4 ,the utility of this sensitiveness is not understood4 ,illustration3 ,,fig4 #aai4--,,the ,,common ,,pitcher ,,plant 7,sarracenia purpurea7 of the ,north1 showing the tubular leaves and the odd1 long-stalked flowers4 ,parts that ,simulate ,leaves4--,we have learned that leaves are endlessly modified to suit the conditions in which the plant is placed4 ,the most marked modifications are in adaptation to light4 ,on the other hand1 other organs often perform the functions of leaves4 ,green shoots function as leaves4 ,these shoots may look like leaves1 in which case they are called cladophylla4 ,the foliage of common asparagus is made up of fine branches3 the real morphological leaves are the minute dry functionless scales at the bases of these branchlets4 7,what reason is there for calling them leaves87 ,the broad 8leaves0 of the florist's smilax are cladophylla3 where are the leaves on this plant8 ,in most of the cacti1 the entire plant body performs the functions of leaves until the parts become cork-bound4 ,leaves are sometimes modified to perform other functions than the vital processes3 they may be tendrils1 as the terminal leaflets of pea and sweet pea2 or spines1 as in barberry4 ,not all spines and thorns1 however1 represent modified leaves3 some of them 7as of hawthorns1 osage orange1 honey locust7 are branches4 ,illustration3 ,,fig4 #abj4--;,,excluding ,,light ,,and ,,co ,,from ,,part ,,of ,a ,,leaf ,illustration3 ,,fig4 #aba4--,,the ,,result4 ,illustration3 ,,fig4 #abb4--,,to ,,show ,,the ,,escape ,,of ,,oxygen4 ,illustration3 ,,fig4 #abc4--,,to ,,illustrate ,a ,,product ,,of ,,respiration4 ,illustration3 ,,fig4 #abd4--,,respiration ,,of ,,thick ,,roots4 ,illustration3 ,,fig4 #abe4--,,to ,,illustrate ,,transpiration4 ,,suggestions4--,to test for chlorophyll4 #hd4 ,purchase about a gill of wood alcohol4 ,secure a leaf of geranium1 clover1 or other plant that has been exposed to sunlight for a few hours1 and1 after dipping it for a minute in boiling water1 put it in a white cup with sufficient alcohol to cover4 ,place the cup in a shallow pan of hot water on the stove where it is not hot enough for the alcohol to take fire4 ,after a time the chlorophyll is dissolved by the alcohol1 which has become an intense green4 ,save this leaf for the starch experiment 7,exercise #he74 ,without chlorophyll1 the plant cannot appropriate the carbon dioxid of the air4 ,starch and photosynthesis4 #he4 ,starch is present in the green leaves which have been exposed to sunlight2 but in the dark no starch can be formed from carbon dioxid4 ,apply iodine to the leaf from which the chlorophyll was dissolved in the previous experiment4 ,note that the leaf is colored purplish brown throughout4 ,the leaf contains starch4 #hf4 ,secure a leaf from a plant which has been in the darkness for about two days4 ,dissolve the chlorophyll as before1 and attempt to stain this leaf with iodine4 ,no purplish brown color is produced4 ,this shows that the starch manufactured in the leaf may be entirely removed during darkness4 #hg4 ,secure a plant which has been kept in darkness for twenty-four hours or more4 ,split a small cork and pin the two halves on opposite sides of one of the leaves1 as shown in ,fig4 #abj4 ,place the plant in the sunlight again4 ,after a morning of bright sunshine dissolve the chlorophyll in this leaf with alcohol2 then stain the leaf with the iodine4 ,notice that the leaf is stained deeply except where the cork was2 there sunlight and carbon dioxid were excluded1 ,fig4 #aba4 ,there is no starch in the covered area4 #hh4 ,plants or parts of plants that have developed no chlorophyll can form no starch4 ,secure a variegated leaf of coleus1 ribbon grass1 geranium1 or of any plant showing both white and green areas4 ,on a day of bright sunshine1 test one of these leaves by the alcohol and iodine method for the presence of starch4 ,observe that the parts devoid of green color have formed no starch4 ,however1 after starch has once been formed in the leaves1 it may be changed into soluble substances and removed1 to be again converted into starch in certain other parts of the living tissues4 ,to test the giving off of oxygen by day4 #hi4 ,make the experiment illustrated in ,fig4 #abb4 ,under a funnel in a deep glass jar containing fresh spring or stream water place fresh pieces of the common waterweed elodea 7or anacharis74 ,have the funnel considerably smaller than the vessel1 and support the funnel well up from the bottom so that the plant can more readily get all of the carbon dioxid available in the water4 ,why would boiled water be undesirable in this experiment8 ,for a home-made glass funnel1 crack the bottom off a narrow-necked bottle by pressing a red-hot poker or iron rod against it and leading the crack around the bottle4 ,invert a test-tube over the stem of the funnel4 ,in sunlight bubbles of oxygen will arise and collect in the test-tube4 ,if a sufficient quantity of oxygen has collected1 a lighted taper inserted in the tube will glow with a brighter flame1 showing the presence of oxygen in greater quantity than in the air4 ,shade the vessel4 ,are bubbles given off8 ,for many reasons it is impracticable to continue this experiment longer than a few hours4 #ij4 ,a simpler experiment may be made if one of the waterweeds ,cabomba 7water-lily family7 is available4 ,tie a lot of branches together so that the basal ends shall make a small bundle4 ,place these in a large vessel of spring water1 and insert a test-tube of water as before over the bundle4 ,the bubbles will arise from the cut surfaces4 ,observe the bubbles on pond scum and waterweeds on a bright day4 ,to illustrate the results of respiration 7,,co74 #ia4 ,in a jar of germinating seeds 7,fig4 #abc7 place carefully a small dish of limewater and cover tightly4 ,put a similar dish in another jar of about the same air space4 ,after a few hours compare the cloudiness or precipitate in the two vessels of limewater4 #ib4 ,or1 place a growing plant in a deep covered jar away from the light1 and after a few hours insert a lighted candle or splinter4 #ic4 ,or1 perform a similar experiment with fresh roots of beets or turnips 7,fig4 #abd7 from which the leaves are mostly removed4 ,in this case1 the jar need not be kept dark2 why8 ,to test transpiration4 #id4 ,cut a succulent shoot of any plant1 thrust the end of it through a hole in a cork1 and stand it in a small bottle of water4 ,invert over this a fruit jar1 and observe that a mist soon accumulates on the inside of the glass4 ,in time drops of water form4 #ie4 ,the experiment may be varied as shown in ,fig4 #abe4 #if4 ,or1 invert the fruit jar over an entire plant1 as shown in ,fig4 #abf1 taking care to cover the soil with oiled paper or rubber cloth to prevent evaporation from the soil4 #ig4 ,the test may also be made by placing the pot1 properly protected1 on balances1 and the loss of weight will be noticed 7,fig4 #abg74 #ih4 ,cut a winter twig1 seal the severed end with wax1 and allow the twig to lie several days2 it shrivels4 ,there must be some upward movement of water even in winter1 else plants would shrivel and die4 #ii4 ,to illustrate sap pressure4 ,the upward movement of sap water often takes place under considerable force4 ,the cause of this force1 known as root pressure1 is not well understood4 ,the pressure varies with different plants and under different conditions4 ,to illustrate3 cut off a strong-growing small plant near the ground4 ,by means of a bit of rubber tube attach a glass tube with a bore of approximately the diameter of the stem4 ,pour in a little water4 ,observe the rise of the water due to the pressure from below 7,fig4 #abh74 ,some plants yield a large amount of water under a pressure sufficient to raise a column several feet2 others force out little1 but under considerable pressure 7less easily demonstrated74 ,the vital processes 7i4e41 the life processes74 #ajj4 ,the pupil having studied roots1 stems1 and leaves1 should now be able to describe the main vital functions of plants3 what is the root function8 stem function8 leaf function8 #aja4 ,what is meant by the 8sap08 #ajb4 ,where and how does the plant secure its water8 oxygen8 carbon8 hydrogen8 nitrogen8 sulfur8 potassium8 calcium8 iron8 phosphorus8 #ajc4 ,where is all the starch in the world made8 ,what does a starch-factory establishment do8 ,where are the real starch factories8 #ajd4 ,in what part of the twenty-four hours do plants grow most rapidly in length8 ,when is food formed and stored most rapidly8 #aje4 ,why does corn or cotton turn yellow in a long rainy spell8 #ajf4 ,if stubble1 corn stalks1 or cotton stalks are burned in the field1 is as much plant-food returned to the soil as when they are plowed under8 #ajg4 ,what process of plants is roughly analogous to perspiration of animals8 #ajh4 ,what part of the organic world uses raw mineral for food8 #aji4 ,why is earth banked over celery to blanch it8 #aaj4 ,is the amount of water transpired equal to the amount absorbed8 #aaa4 ,give some reasons why plants very close to a house may not thrive or may even die4 #aab4 ,why are fruit-trees pruned or thinned out as in ,fig4 #abi8 ,proper balance between top and root4 #aac4 ,we have learned that the leaf parts and the root parts work together4 ,they may be said to balance each other in activities1 the root supplying the top and the top supplying the root 7how874 ,if half the roots were cut from a tree1 we should expect to reduce the top also1 particularly if the tree is being transplanted4 ,how would you prune a tree or bush that is being transplanted8 ,fig4 #acj may be suggestive4 ,illustration3 ,,fig4 #abf4--,,to ,,illustrate ,,transpiration4 ,illustration3 ,,fig4 #abg4--,,loss ,,of ,,water4 ,illustration3 ,,fig4 #abh4--,,to ,,show ,,sap ,,pressure4 ,illustration3 ,,fig4 #abi4--;,,before ,,and ,,after ,,pruning4 ,illustration3 ,,fig4 #acj4--;,,an ,,apple ,,tree1 with suggestions as to pruning when it is set in the orchard4 ,at a is shown a pruned top4 ,,chapter ,,xiv ,,dependent ,,plants ,thus far we have spoken of plants with roots and foliage and that depend on themselves4 ,they collect the raw materials and make them over into assimilable food4 ,they are independent4 ,plants without green foliage cannot make food2 they must have it made for them or they die4 ,they are dependent4 ,a sprout from a potato tuber in a dark cellar cannot collect and elaborate carbon dioxid4 ,it lives on the food stored in the tuber4 ,illustration3 ,,fig4 #aca4--;,a ,,mushroom1 example of a saprophytic plant4 ,this is the edible cultivated mushroom4 ,all plants with naturally white or blanched parts are dependent4 ,their leaves do not develop4 ,they live on organic matter--that which has been made by a plant or elaborated by an animal4 ,the dodder1 ,indian pipe1 beech drop1 coral root among flower-bearing plants1 also mushrooms and other fungi 7,figs4 #aca1 #acb7 are examples4 ,the dodder is common in swales1 being conspicuous late in the season from its thread-like yellow or orange stems spreading over the herbage of other plants4 ,one kind attacks alfalfa and is a bad pest4 ,the seeds germinate in the spring1 but as soon as the twining stem attaches itself to another plant1 the dodder dies away at the base and becomes wholly dependent4 ,it produces flowers in clusters and seeds itself freely 7,fig4 #acc74 ,illustration3 ,,fig4 #acb4--;,a ,,parasitic ,,fungus1 magnified4 ,the mycelium1 or vegetative part1 is shown by the dotted-shaded parts ramifying in the leaf tissue4 ,the rounded haustoria projecting into the cells are also shown4 ,the long fruiting parts of the fungus hang from the under surface of the leaf4 ,parasites and ,saprophytes4--,a plant that is dependent on a living plant or animal is a parasite1 and the plant or animal on which it lives is the host4 ,the dodder is a true parasite2 so are the rusts1 mildews1 and other fungi that attack leaves and shoots and injure them4 ,the threads of a parasitic fungus usually creep through the intercellular spaces in the leaf or stem and send suckers 7or haustoria7 into the cells 7,fig4 #acb74 ,the threads 7or the hyph7 clog the air-spaces of the leaf and often plug the stomates1 and they also appropriate and disorganize the cell fluids2 thus they injure or kill their host4 ,the mass of hyph of a fungus is called mycelium4 ,some of the hyph finally grow out of the leaf and produce spores or reproductive cells that answer the purpose of seeds in distributing the plant 7b1 ,fig4 #acb74 ,illustration3 ,,fig4 #acc4--;,,dodder ,,in ,,fruit4 ,a plant that lives on dead or decaying matter is a saprophyte4 ,mushrooms 7,fig4 #aca7 are examples2 they live on the decaying matter in the soil4 ,mold on bread and cheese is an example4 ,lay a piece of moist bread on a plate and invert a tumbler over it4 ,in a few days it will be moldy4 ,the spores were in the air1 or perhaps they had already fallen on the bread but had not had opportunity to grow4 ,most green plants are unable to make any direct use of the humus or vegetable mold in the soil1 for they are not saprophytic4 ,the shelf-fungi 7,fig4 #acd7 are saprophytes4 ,they are common on logs and trees4 ,some of them are perhaps partially parasitic1 extending the mycelium into the wood of the living tree and causing it to become black-hearted 7,fig4 #acd74 ,illustration3 ,,fig4 #acd4--,,tinder ,,fungus 7,polyporus igniarius7 on beech log4 ,the external part of the fungus is shown below2 the heart-rot injury above4 ,some parasites spring from the ground1 as other plants do1 but they are parasitic on the roots of their hosts4 ,some parasites may be partially parasitic and partially saprophytic4 ,many 7perhaps most7 of these ground saprophytes are aided in securing their food by soil fungi1 which spread their delicate threads over the root-like branches of the plant and act as intermediaries between the food and the saprophyte4 ,these fungus-covered roots are known as mycorrhizas 7meaning 8fungus root074 ,mycorrhizas are not peculiar to saprophytes4 ,they are found on many wholly independent plants1 as1 for example1 the heaths1 oaks1 apples1 and pines4 ,it is probable that the fungous threads perform some of the offices of root-hairs to the host4 ,on the other hand1 the fungus obtains some nourishment from the host4 ,the association seems to be mutual4 ,illustration3 ,,fig4 #ace4--;,,bacteria ,,of ,,several ,,forms1 much magnified4 ,saprophytes break down or decompose organic substances4 ,chief of these saprophytes are many microscopic organisms known as bacteria 7,fig4 #ace74 ,these innumerable organisms are immersed in water or in dead animals and plants1 and in all manner of moist organic products4 ,by breaking down organic combinations1 they produce decay4 ,largely through their agency1 and that of many true but microscopic fungi1 all things pass into soil and gas4 ,thus are the bodies of plants and animals removed and the continuing round of life is maintained4 ,illustration3 ,,fig4 #acf4--;,,american ,,mistletoe ,,growing ,,on ,a ,,walnut ,,branch4 ,some parasites are green-leaved4 ,such is the mistletoe 7,fig4 #acf74 ,they anchor themselves on the host and absorb its juices1 but they also appropriate and use the carbon dioxid of the air4 ,in some small groups of bacteria a process of organic synthesis has been shown to take place4 ,epiphytes4--,to be distinguished from the dependent plants are those that grow on other plants without taking food from them4 ,these are green-leaved plants whose roots burrow in the bark of the host plant and perhaps derive some food from it1 but which subsist chiefly on materials that they secure from air dust1 rain water1 and the air4 ,these plants are epiphytes 7meaning 8upon plants07 or air plants4 ,epiphytes abound in the tropics4 ,certain orchids are among the best known examples 7,fig4 #cg74 ,the ,spanish moss or tillandsia of the ,south is another4 ,mosses and lichens that grow on trees and fences may also be called epiphytes4 ,in the struggle for existence1 the plants probably have been driven to these special places in which to find opportunity to grow4 ,plants grow where they must1 not where they will4 ,,suggestions4--#aad4 ,is a puffball a plant8 ,why do you think so8 #aae4 ,are mushrooms ever cultivated1 and where and how8 #aaf4 ,in what locations are mushrooms and toadstools usually found8 7,there is really no distinction between mushrooms and toadstools4 ,they are all mushrooms47 #aag4 ,what kinds of mildew1 blight1 and rust do you know8 #aah4 ,how do farmers overcome potato blight8 ,apple scab8 ,or any other fungous 8plant disease08 #aai4 ,how do these things injure plants8 #abj4 ,what is a plant disease8 #aba4 ,the pupil should know that every spot or injury on a leaf or stem is caused by something1--as an insect1 a fungus1 wind1 hail1 drought1 or other agency4 ,how many uninjured or perfect leaves are there on the plant growing nearest the schoolhouse steps8 #abb4 ,give formula for ,bordeaux mixture and tell how and for what it is used4 ,,chapter ,,xv ,,winter ,,and ,,dormant ,,buds ,a bud is a growing point1 terminating an axis either long or short1 or being the starting point of an axis4 ,all branches spring from buds4 ,in the growing season the bud is active2 later in the season it ceases to increase the axis in length1 and as winter approaches the growing point becomes more or less thickened and covered by protecting scales1 in preparation for the long resting season4 ,this resting1 dormant1 or winter body is what is commonly spoken of as a 8bud40 ,a winter bud may be defined as an inactive covered growing point1 waiting for spring4 ,structurally1 a dormant bud is a shortened axis or branch1 bearing miniature leaves or flowers or both1 and protected by a covering4 ,cut in two1 lengthwise1 a bud of the horse-chestnut or other plant that has large buds4 ,with a pin separate the tiny leaves4 ,count them4 ,examine the big bud of the rhubarb as it lies under the ground in late winter or early spring2 or the crown buds of asparagus1 hepatica1 or other early spring plants4 ,dissect large buds of the apple and pear 7,figs4 #acg1 #ach74 ,illustration3 ,,fig4 #acg4--;,,bud ,,of ,,apricot1 showing the miniature leaves4 ,illustration3 ,,fig4 #ach4--;,,bud ,,of ,,pear1 showing both leaves and flowers4 ,the latter are the little knobs in the center4 ,the bud is protected by firm and dry scales4 ,these scales are modified leaves4 ,the scales fit close4 ,often the bud is protected by varnish 7see horse-chestnut and the balsam poplars74 ,most winter buds are more or less woolly4 ,examine them under a lens4 ,as we might expect1 bud coverings are most prominent in cold and dry climates4 ,sprinkle water on velvet or flannel1 and note the result and give a reason4 ,all winter buds give rise to branches1 not to leaves alone2 that is1 the leaves are borne on the lengthening axis4 ,sometimes the axis1 or branch1 remains very short1--so short that it may not be noticed4 ,sometimes it grows several feet long4 ,whether the branch grows large or not depends on the chance it has1--position on the plant1 soil1 rainfall1 and many other factors4 ,the new shoot is the unfolding and enlarging of the tiny axis and leaves that we saw in the bud4 ,if the conditions are congenial1 the shoot may form more leaves than were tucked away in the bud4 ,the length of the shoot usually depends more on the lengths of the internodes than on the number of leaves4 ,illustration3 ,,fig4 #aci4--,,leaf-,,scars4--,ailanthus4 ,where ,buds are4--,buds are borne in the axils of the leaves1--in the acute angle that the leaf makes with the stem4 ,when the leaf is growing in the summer1 a bud is forming above it4 ,when the leaf falls1 the bud remains1 and a scar marks the place of the leaf4 ,fig4 #aci shows the large leaf-scars of ailanthus4 ,observe those on the horse-chestnut1 maple1 apple1 pear1 basswood1 or any other tree or bush4 ,sometimes two or more buds are borne in one axil2 the extra ones are accessory or supernumerary buds4 ,observe them in the ,tartarian honeysuckle 7common in yards71 walnut1 butternut1 red maple1 honey locust1 and sometimes in the apricot and peach4 ,if the bud is at the end of a shoot1 however short the shoot1 it is called a terminal bud4 ,it continues the growth of the axis in a direct line4 ,very often three or more buds are clustered at the tip 7,fig4 #adj72 and in this case there may be more buds than leaf scars4 ,only one of them1 however1 is strictly terminal4 ,illustration3 ,,fig4 #adj4--,,terminal ,,bud ,,between ,,two ,,other ,,buds4--,currant4 ,a bud in the axil of a leaf is an axillary or lateral bud4 ,note that there is normally at least one bud in the axil of every leaf on a tree or shrub in late summer and fall4 ,the axillary buds1 if they grow1 are the starting points of new shoots the following season4 ,if a leaf is pulled off early in summer1 what will become of the young bud in its axil8 ,try this4 ,illustration3 ,,fig4 #ada4--;,a ,,gigantic ,,bud4--,cabbage4 ,bulbs and cabbage heads may be likened to buds2 that is1 they are condensed stems1 with scales or modified leaves densely overlapping and forming a rounded body 7,fig4 #ada74 ,they differ from true buds1 however1 in the fact that they are condensations of whole main stems rather than embryo stems borne in the axils of leaves4 ,but bulblets 7as of tiger lily7 may be scarcely distinguishable from buds on the one hand and from bulbs on the other4 ,cut a cabbage head in two1 lengthwise1 and see what it is like4 ,the buds that appear on roots are unusual or abnormal1--they occur only occasionally and in no definite order4 ,buds appearing in unusual places on any part of the plant are called adventitious buds4 ,such usually are the buds that arise when a large limb is cut off1 and from which suckers or water sprouts arise4 ,illustration3 ,,fig4 #adb4--;,,fruit-,,bud ,,of ,,pear4 ,illustration3 ,,fig4 #adc4--,,the ,,opening ,,of ,,the ,,pear ,,fruit-,,bud4 ,illustration3 ,,fig4 #add4--,,opening ,,pear ,,leaf-,,bud4 ,illustration3 ,,fig4 #ade4--,,opening ,,of ,,the ,,pear-,,bud4 ,how ,buds ,open4--,when the bud swells1 the scales are pushed apart1 the little axis elongates and pushes out4 ,in most plants the outside scales fall very soon1 leaving a little ring of scars4 ,with terminal buds1 this ring marks the end of the year's growth3 how8 ,notice peach1 apple1 plum1 willow1 and other plants4 ,in some others1 all the scales grow for a time1 as in the pear 7,figs4 #adb1 #adc1 #add74 ,in other plants the inner bud scales become green and almost leaf-like4 ,see the maple and hickory4 ,sometimes ,flowers come out of the ,buds4--,leaves may or may not accompany the flowers4 ,we saw the embryo flowers in ,fig4 #ach4 ,the bud is shown again in ,fig4 #adb4 ,in ,fig4 #adc it is opening4 ,in ,fig4 #ade it is more advanced1 and the woolly unformed flowers are appearing4 ,in ,fig4 #adf the growth is more advanced4 ,illustration3 ,,fig4 #adf4--;,a ,,single ,,flower ,,in ,,the ,,pear ,,cluster1 as seen at #g ,a4,m4 on the day of its opening4 ,at #aj o'clock it will be fully expanded4 ,illustration3 ,,fig4 #adg4--,,the ,,opening ,,of ,,the ,,flower-,,bud ,,of ,,apricot4 ,illustration3 ,,fig4 #adh4--;,,apricot ,,flower-,,bud1 enlarged4 ,buds that contain or produce only leaves are leaf-buds4 ,those which contain only flowers are flower-buds or fruit-buds4 ,the latter occur on peach1 almond1 apricot1 and many very early spring-flowering plants4 ,the single flower is emerging from the apricot bud in ,fig4 #adg4 ,a longitudinal section of this bud1 enlarged1 is shown in ,fig4 #adh4 ,those that contain both leaves and flowers are mixed buds1 as in pear1 apple1 and most late spring-flowering plants4 ,illustration3 ,,fig4 #adi4--;,,fruit-,,buds ,,and ,,leaf-,,buds ,,of ,,pear4 ,fruit buds are usually thicker or stouter than leaf-buds4 ,they are borne in different positions on different plants4 ,in some plants 7apple1 pear7 they are on the ends of short branches or spurs2 in others 7peach1 red maple7 they are along the sides of the last year's growths4 ,in ,fig4 #adi are shown three fruit-buds and one leaf-bud on ,e1 and leaf-buds on ,a4 ,see also ,figs4 #aej1 #aea1 #aeb1 #aec1 and explain4 ,illustration3 ,,fig4 #aej4--;,,fruit-,,buds ,,of ,,apple ,,on ,,spurs3 a dormant bud at the top4 ,illustration3 ,,fig4 #aea4--;,,cluster ,,of ,,fruit-,,buds ,,of ,,sweet ,,cherry1 with one pointed leaf-bud in center4 ,illustration3 ,,fig4 #aeb4--,,two ,,fruit-,,buds ,,of ,,peach with a leaf-bud between4 ,illustration3 ,,fig4 #aec4--,,opening ,,of ,,leaf-,,buds ,,and ,,flower-,,buds ,,of ,,apple4 8,the burst of spring0 means in large part the opening of the buds4 ,everything was made ready the fall before4 ,the embryo shoots and flowers were tucked away1 and the food was stored4 ,the warm rain falls1 and the shutters open and the sleepers wake3 the frogs peep and the birds come4 ,arrangement of ,buds4--,we have found that leaves are usually arranged in a definite order2 buds are borne in the axils of leaves3 therefore buds must exhibit phyllotaxy4 ,moreover1 branches grow from buds3 branches1 therefore1 should show a definite arrangement2 usually1 however1 they do not show this arrangement because not all the buds grow and not all the branches live4 7,see ,chaps4 ,,ii and ,,iii47 ,it is apparent1 however1 that the mode of arrangement of buds determines to some extent the form of the tree3 compare bud arrangement in pine or fir with that in maple or apple4 ,illustration3 ,,fig4 #aed4--,,oak ,,spray4 ,how are the leaves borne with reference to the annual growths8 ,the uppermost buds on any twig1 if they are well matured1 are usually the larger and stronger and they are the most likely to grow the next spring2 therefore1 branches tend to be arranged in tiers 7particularly well marked in spruces and firs74 ,see ,fig4 #aed and explain it4 ,winter ,buds show what has been the ,effect of ,sunlight4--,buds are borne in the axils of the leaves1 and the size or vigor of the leaf determines to a large extent the size of the bud4 ,notice that1 in most instances1 the largest buds are nearest the tip 7,fig4 #aeg74 ,if the largest ones are not near the tip1 there is some special reason for it4 ,can you state it8 ,examine the shoots on trees and bushes4 ,illustration3 ,,fig4 #aee4--;,,an ,,apple ,,twig4 ,illustration3 ,,fig4 #aef4--,same twig before leaves fell4 ,,suggestions4--,some of the best of all observation lessons are those made on dormant twigs4 ,there are many things to be learned1 the eyes are trained1 and the specimens are everywhere accessible4 #abc4 ,at whatever time of year the pupil takes up the study of branches1 he should look for three things3 the ages of the various parts1 the relative positions of the buds and leaves1 the different sizes of similar or comparable buds4 ,if it is late in spring or early in summer1 he should watch the development of the buds in the axils1 and he should determine whether the strength or size of the bud is in any way related to the size and vigor of the subtending 7or supporting7 leaf4 ,the sizes of buds should also be noted on leafless twigs1 and the sizes of the former leaves may be inferred from the size of the leaf-scar below the bud4 ,the pupil should keep in mind the fact of the struggle for food and light1 and its effects on the developing buds4 #abd4 ,the bud and the branch4 ,a twig cut from an apple tree in early spring is shown in ,fig4 #aee4 ,the most hasty observation shows that it has various parts1 or members4 ,it seems to be divided at the point f into two parts4 ,it is evident that the part from f to h grew last year1 and that the part below f grew two years ago4 ,the buds on the two parts are very unlike1 and these differences challenge investigation4--,in order to understand this seemingly lifeless twig1 it will be necessary to see it as it looked late last summer 7and this condition is shown in ,fig4 #aef74 ,the part from f to h1--which has just completed its growth1--is seen to have its leaves growing singly4 ,in every axil 7or angle which the leaf makes when it joins the shoot7 is a bud4 ,the leaf starts first1 and as the season advances the bud forms in its axil4 ,when the leaves have fallen1 at the approach of winter1 the buds remain1 as seen in ,fig4 #aee4 ,every bud on the last year's growth of a winter twig1 therefore1 marks the position occupied by a leaf when the shoot was growing4--,the part below f1 in ,fig4 #aef1 shows a wholly different arrangement4 ,the leaves are two or more together 7aaaa71 and there are buds without leaves 7bbbb74 ,a year ago this part looked like the present shoot from f to h1--that is1 the leaves were single1 with a bud in the axil of each4 ,it is now seen that some of these bud-like parts are longer than others1 and that the longest ones are those which have leaves4 ,it must be because of the leaves that they have increased in length4 ,the body c has lost its leaves through some accident1 and its growth has ceased4 ,in other words1 the parts at aaaa are like the shoot fh1 except that they are shorter1 and they are of the same age4 ,one grew from the end or terminal bud of the main branch1 and the others from the side or lateral buds4 ,parts or bodies that bear leaves are1 therefore1 branches4--,the buds at bbbb have no leaves1 and they remain the same size that they were a year ago4 ,they are dormant4 ,the only way for a mature bud to grow is by making leaves for itself1 for a leaf will never stand below it again4 ,the twig1 therefore1 has buds of two ages1--those at bbbb are two seasons old1 and those on the tips1 of all the branches 7aaaa1 h71 and in the axil of every leaf1 are one season old4 ,it is only the terminal buds that are not axillary4 ,when the bud begins to grow and to put forth leaves1 it gives rise to a branch1 which1 in its turn1 bears buds4--,it will now be interesting to determine why certain buds gave rise to branches and why others remained dormant4 ,the strongest shoot or branch of the year is the terminal one 7fh74 ,the next in strength is the uppermost lateral one1 and the weakest shoot is at the base of the twig4 ,the dormant buds are on the under side 7for the twig grew in a horizontal position74 ,all this suggests that those buds grew which had the best chance1--the most sunlight and room4 ,there were too many buds for the space1 and in the struggle for existence those that had the best opportunities made the largest growths4 ,this struggle for existence began a year ago1 however1 when the buds on the shoot below f were forming in the axils of the leaves1 for the buds near the tip of the shoot grew larger and stronger than those near its base4 ,the growth of one year1 therefore1 is very largely determined by the conditions under which the buds were formed the previous year4 ,other bud characters4 #abe4 ,it is easy to see the swelling of the buds in a room in winter4 ,secure branches of trees and shrubs1 two to three feet long1 and stand them in vases or jars1 as you would flowers4 ,renew the water frequently and cut off the lower ends of the shoots occasionally4 ,in a week or two the buds will begin to swell4 ,of red maple1 peach1 apricot1 and other very early-flowering things1 flowers may be obtained in ten to twenty days4 #abf4 ,the shape1 size1 and color of the winter buds are different in every kind of plant4 ,by the buds alone botanists are often able to distinguish the kinds of plants4 ,even such similar plants as the different kinds of willows have good bud characters4 #abg4 ,distinguish and draw fruit-buds of apple1 pear1 peach1 plum1 and other trees4 ,if different kinds of maples grow in the vicinity1 secure twigs of the red or swamp maple1 and the soft or silver maple1 and compare the buds with those of the sugar maple and ,norway maple3 ,what do you learn8 ,illustration3 ,,fig4 #aeg4--;,,buds ,,of ,,the ,,hickory4 ,,chapter ,,xvi ,,bud ,,propagation ,we have learned 7in ,chap4 ,,vi7 that plants propagate by means of seeds4 ,they also propagate by means of bud parts1--as rootstocks 7rhizomes71 roots1 runners1 layers1 bulbs4 ,the pupil should determine how any plant in which he is interested naturally propagates itself 7or spreads its kind74 ,determine this for raspberry1 blackberry1 strawberry1 ,june-grass or other grass1 nut-grass1 water lily1 ,may apple or mandrake1 burdock1 ,irish potato1 sweet potato1 buckwheat1 cotton1 pea1 corn1 sugar-cane1 wheat1 rice4 ,plants may be artificially propagated by similar means1 as by layers1 cuttings1 and grafts4 ,the last two we may discuss here4 ,cuttings in ,general4--,a bit of a plant stuck into the ground stands a chance of growing2 and this bit is a cutting4 ,plants have preferences1 however1 as to the kind of a bit which shall be used1 but there is no way of telling what this preference is except by trying4 ,in some instances this preference has not been discovered1 and we say that the plant cannot be propagated by cuttings4 ,most plants prefer that the cutting be made of the soft or growing parts 7called 8wood0 by gardeners71 of which the 8slips0 of geranium and coleus are examples4 ,others grow equally well from cuttings of the hard or mature parts or wood1 as currant and grape2 and in some instances this mature wood may be of roots1 as in the blackberry4 ,in some cases cuttings are made of tubers1 as in the ,irish potato 7,fig4 #fj74 ,pupils should make cuttings now and then4 ,if they can do nothing more1 they can make cuttings of potato1 as the farmer does2 and they can plant them in a box in the window4 ,illustration3 ,,fig4 #aeh4--;,,geranium ,,cutting4 ,illustration3 ,,fig4 #aei4--,,rose ,,cutting4 ,the ,softwood ,cutting4--,the softwood cutting is made from tissue that is still growing1 or at least from that which is not dormant4 ,it comprises one or two joints1 with a leaf attached 7,figs4 #aeh1 #aei74 ,it must not be allowed to wilt4 ,therefore1 it must be protected from direct sunlight and dry air until it is well established2 and if it has many leaves1 some of them should be removed1 or at least cut in two1 in order to reduce the evaporating surface4 ,the soil should be uniformly moist4 ,the pictures show the depth to which the cuttings are planted4 ,for most plants1 the proper age or maturity of wood for the making of cuttings may be determined by giving the twig a quick bend3 if it snaps and hangs by the bark1 it is in proper condition2 if it bends without breaking1 it is too young and soft or too old2 if it splinters1 it is too old and woody4 ,the tips of strong upright shoots usually make the best cuttings4 ,preferably1 each cutting should have a joint or node near its base2 and if the internodes are very short it may comprise two or three joints4 ,the stem of the cutting is inserted one third or more its length in clean sand or gravel1 and the earth is pressed firmly about it4 ,a newspaper may be laid over the bed to exclude the light--if the sun strikes it--and to prevent too rapid evaporation4 ,the soil should be moist clear through1 not on top only4 ,illustration3 ,,fig4 #afj4--;,,cutting-,,box4 ,loose sandy or gravelly soil is used4 ,sand used by masons is good material in which to start most cuttings2 or fine gravel--sifted of most of its earthy matter--may be used4 ,soils are avoided which contain much decaying organic matter1 for these soils are breeding places of fungi1 which attack the soft cutting and cause it to 8damp off10 or to die at or near the surface of the ground4 ,if the cuttings are to be grown in a window1 put three or four inches of the earth in a shallow box or a pan4 ,a soap box cut in two lengthwise1 so that it makes a box four or five inches deep--as a gardener's flat--is excellent 7,fig4 #afj74 ,cuttings of common plants1 as geranium1 coleus1 fuchsia1 carnation1 are kept at a living-room temperature4 ,as long as the cuttings look bright and green1 they are in good condition4 ,it may be a month before roots form4 ,when roots have formed1 the plants begin to make new leaves at the tip4 ,then they may be transplanted into other boxes or into pots4 ,the verbena in ,fig4 #afa is just ready for transplanting4 ,illustration3 ,,fig4 #afa4--,,verbena ,,cutting ,,ready ,,for ,,transplanting4 ,it is not always easy to find growing shoots from which to make the cuttings4 ,the best practice1 in that case1 is to cut back an old plant1 then keep it warm and well watered1 and thereby force it to throw out new shoots4 ,the old geranium plant from the window garden1 or the one taken up from the lawn bed1 may be treated this way 7see ,fig4 #afb74 ,the best plants of geranium and coleus and most window plants are those which are not more than one year old4 ,the geranium and fuchsia cuttings which are made in ,january1 ,february1 or ,march will give compact blooming plants for the next winter2 and thereafter new ones should take their places 7,fig4 #afc74 ,illustration3 ,,fig4 #afb4--,,old ,,geranium ,,plant ,,cut ,,back ,,to ,,make ,,it ,,throw ,,out ,,shoots ,,from ,,which ,,cuttings ,,can ,,be ,,made4 ,illustration3 ,,fig4 #afc4--;,,early ,,winter ,,geranium1 from a spring cutting4 ,the ,hardwood ,cutting4--,best results with cuttings of mature wood are secured when the cuttings are made in the fall and then buried until spring in sand in the cellar4 ,these cuttings are usually six to ten inches long4 ,they are not idle while they rest4 ,the lower end calluses or heals1 and the roots form more readily when the cutting is planted in the spring4 ,but if the proper season has passed1 take cuttings at any time in winter1 plant them in a deep box in the window1 and watch4 ,they will need no shading or special care4 ,grape1 currant1 gooseberry1 willow1 and poplar readily take root from the hardwood4 ,fig4 #afd shows a currant cutting4 ,it has only one bud above the ground4 ,illustration3 ,,fig4 #afd4--;,,currant ,,cutting4 ,the ,graft4--,when the cutting is inserted in a plant rather than in the soil1 it is a graft2 and the graft may grow4 ,in this case the cutting grows fast to the other plant1 and the two become one4 ,when the cutting is inserted in a plant1 it is no longer called a cutting1 but a cion2 and the plant in which it is inserted is called the stock4 ,fruit trees are grafted in order that a certain variety or kind may be perpetuated1 as a ,baldwin or ,ben ,davis variety of apple1 ,seckel or ,bartlett pear1 ,navel or ,st4 ,michael orange4 ,plants have preferences as to the stocks on which they will grow2 but we can find out what their choice is only by making the experiment4 ,the pear grows well on the quince1 but the quince does not thrive on the pear4 ,the pear grows on some of the hawthorns1 but it is an unwilling subject on the apple4 ,tomato plants will grow on potato plants and potato plants on tomato plants4 ,when the potato is the root1 both tomatoes and potatoes may be produced1 although the crop will be very small2 when the tomato is the root1 neither potatoes nor tomatoes will be produced4 ,chestnut will grow on some kinds of oak4 ,in general1 one species or kind is grafted on the same species1 as apple on apple1 pear on pear1 orange on orange4 ,the forming1 growing tissue of the stem 7on the plants we have been discussing7 is the cambium 7,chap4 ,x71 lying on the outside of the woody cylinder beneath the bark4 ,in order that union may take place1 the cambium of the cion and of the stock must come together4 ,therefore the cion is set in the side of the stock4 ,there are many ways of shaping the cion and of preparing the stock to receive it4 ,these ways are dictated largely by the relative sizes of cion and stock1 although many of them are matters of personal preference4 ,the underlying principles are two3 securing close contact between the cambiums of cion and stock2 covering the wounded surfaces to prevent evaporation and to protect the parts from disease4 ,on large stocks the commonest form of grafting is the cleft-graft4 ,the stock is cut off and split2 and in one or both sides a wedge-shaped cion is firmly inserted4 ,fig4 #afe shows the cion2 ,fig4 #aff1 the cions set in the stock2 ,fig4 #afg1 the stock waxed4 ,it will be seen that the lower bud--that lying in the wedge--is covered by the wax2 but being nearest the food supply and least exposed to weather1 it is the most likely to grow3 it will push through the wax4 ,cleft-grafting is practiced in spring1 as growth begins4 ,the cions are cut previously1 when perfectly dormant1 and from the tree which it is desired to propagate4 ,the cions are kept in sand or moss in the cellar4 ,limbs of various sizes may be cleft-grafted1--from one half inch up to four inches in diameter2 but a diameter of one to one and one half inches is the most convenient size4 ,all the leading or main branches of a tree top may be grafted4 ,if the remaining parts of the top are gradually cut away and the cions grow well1 the entire top will be changed over to the new variety4 ,illustration3 ,,fig4 #afe4--;,,cion ,,of ,,apple4 ,illustration3 ,,fig4 #aff4--,,the ,,cion ,,inserted4 ,illustration3 ,,fig4 #afg4--,,the ,,parts ,,waxed4 ,another form of grafting is known as budding4 ,in this case a single bud is used1 and it is slipped underneath the bark of the stock and securely tied 7not waxed7 with soft material1 as bass bark1 corn shuck1 yarn1 or raffia 7the last a commercial palm fiber74 ,budding is performed when the bark of the stock will slip or peel 7so that the bud can be inserted71 and when the bud is mature enough to grow4 ,usually budding is performed in late summer or early fall1 when the winter buds are well formed2 or it may be practiced in spring with buds cut in winter4 ,in ordinary summer budding 7which is the usual mode7 the 8bud0 or cion forms a union with the stock1 and then lies dormant till the following spring1 as if it were still on its own twig4 ,budding is mostly restricted to young trees in the nursery4 ,in the spring following the budding1 the stock is cut off just above the bud1 so that only the shoot from the bud grows to make the future tree4 ,this prevailing form of budding 7shield-budding7 is shown in ,fig4 #afh4 ,illustration3 ,,fig4 #afh4--;,,budding4 ,the 8bud02 the opening to receive it2 the bud tied4 ,,suggestions4--#abh4 ,name the plants that the gardener propagates by means of cuttings4 #abi4 ,by means of grafts4 #acj4 ,the cutting-box may be set in the window4 ,if the box does not receive direct sunlight1 it may be covered with a pane of glass to prevent evaporation4 ,take care that the air is not kept too close1 else the damping-off fungi may attack the cuttings1 and they will rot at the surface of the ground4 ,see that the pane is raised a little at one end to afford ventilation2 and if the water collects in drops on the under side of the glass1 remove the pane for a time4 #aca4 ,grafting wax is made of beeswax1 resin1 and tallow4 ,a good recipe is one part 7as one pound7 of rendered tallow1 two parts of beeswax1 four parts of rosin2 melt together in a kettle2 pour the liquid into a pail or tub of water to solidify it2 work with the hands until it has the color and 8grain0 of taffy candy1 the hands being greased when necessary4 ,the wax will keep any length of time4 ,for the little grafting that any pupil would do1 it is better to buy the wax of a seedsman4 #acb4 ,grafting is hardly to be recommended as a general school diversion1 as the making of cuttings is2 and the account of it in this chapter is inserted chiefly to satisfy the general curiosity on the subject4 #acc4 ,in ,chap4 ,v we had a definition of a plant generation3 what is 8one generation0 of a grafted fruit tree1 as ,le ,conte pear1 ,baldwin1 or ,ben ,davis apple8 #acd4 ,the ,elberta peach originated about #ahhj3 what is meant by 8originated08 #ace4 ,how is the grape propagated so as to come true to name 7explain what is meant by 8coming true078 currant8 strawberry8 raspberry8 blackberry8 peach8 pear8 orange8 fig8 plum8 cherry8 apple8 chestnut8 pecan8 ,,chapter ,,xvii ,,how ,,plants ,,climb ,we have found that plants struggle or contend for a place in which to live4 ,some of them become adapted to grow in the forest shade1 others to grow on other plants1 as epiphytes1 others to climb to the light4 ,observe how woods grapes1 and other forest climbers1 spread their foliage on the very top of the forest tree1 while their long flexile trunks may be bare4 ,there are several ways by which plants climb1 but most climbers may be classified into four groups3 7#a7 scramblers1 7#b7 root climbers1 7#c7 tendril climbers1 7#d7 twiners4 ,scramblers4--,some plants rise to light and air by resting their long and weak stems on the tops of bushes and quick-growing herbs4 ,their stems may be elevated in part by the growing twigs of the plants on which they recline4 ,such plants are scramblers4 ,usually they are provided with prickles or bristles4 ,in most weedy swamp thickets1 scrambling plants may be found4 ,briers1 some roses1 bed-straw or galium1 bittersweet 7,solanum ,dulcamara1 not the ,celastrus71 the tear-thumb polygonums1 and other plants are familiar examples of scramblers4 ,root ,climbers4--,some plants climb by means of true roots4 ,these roots seek the dark places and therefore enter the chinks in walls and bark4 ,the trumpet creeper is a familiar example 7,fig4 #cf74 ,the true or ,english ivy1 which is often grown to cover buildings1 is another instance4 ,still another is the poison ivy4 ,roots are distinguished from stem tendrils by their irregular or indefinite position as well as by their mode of growth4 ,illustration3 ,,fig4 #afi4--,,tendril1 to show where the coil is changed4 ,tendril climbers4--,a slender coiling part that serves to hold a climbing plant to a support is known as a tendril4 ,the free end swings or curves until it strikes some object1 when it attaches itself and then coils and draws the plant close to the support4 ,the spring of the coil also allows the plant to move in the wind1 thereby enabling the plant to maintain its hold4 ,slowly pull a well-matured tendril from its support1 and note how strongly it holds on4 ,watch the tendrils in a wind-storm4 ,usually the tendril attaches to the support by coiling about it1 but the ,virginia creeper and ,boston ivy 7,fig4 #agj7 attach to walls by means of disks on the ends of the tendrils4 ,illustration3 ,,fig4 #agj4--,,tendril ,,of ,,boston ,,ivy4 ,since both ends of the tendril are fixed1 when it finds a support1 the coiling would tend to twist it in two4 ,it will be found1 however1 that the tendril coils in different directions in different parts of its length4 ,in ,fig4 #afi1 showing an old and stretched-out tendril1 the change of direction in the coil occurred at a4 ,in long tendrils of cucumbers and melons there may be several changes of direction4 ,tendrils may represent either branches or leaves4 ,in the ,virginia creeper and grape they are branches2 they stand opposite the leaves in the position of fruit clusters1 and sometimes one branch of a fruit cluster is a tendril4 ,these tendrils are therefore homologous with fruit-clusters1 and fruit-clusters are branches4 ,in some plants tendrils are leaflets 7,chap4 ,,xi74 ,examples are the sweet pea and common garden pea4 ,in ,fig4 #aga1 observe the leaf with its two great stipules1 petiole1 six normal leaflets1 and two or three pairs of leaflet tendrils and a terminal leaflet tendril4 ,the cobea1 a common garden climber1 has a similar arrangement4 ,in some cases tendrils are stipules1 as probably in the green briers 7smilax74 ,the petiole or midrib may act as a tendril1 as in various kinds of clematis4 ,in ,fig4 #agb1 the common wild clematis or 8old man vine10 this mode is seen4 ,illustration3 ,,fig4 #aga4--,,leaves ,,of ,,pea1--very large stipules1 opposite leaflets1 and leaflets represented by tendrils4 ,twiners4--,the entire plant or shoot may wind about a support4 ,such a plant is a twiner4 ,examples are bean1 hop1 morning-glory1 moonflower1 false bittersweet or waxwork 7,celastrus71 some honeysuckles1 wistaria1 ,dutchman's pipe1 dodder4 ,the free tip of the twining branch sweeps about in curves1 much as the tendril does1 until it finds support or becomes old and rigid4 ,each kind of plant usually coils in only one direction4 ,most plants coil against the sun1 or from the observer's left across his front to his right as he faces the plant4 ,examples are bean1 morning-glory4 ,the hop twines from the observer's right to his left1 or with the sun4 ,illustration3 ,,fig4 #agb4--;,,clematis ,,climbing ,,by ,,leaf-,,tendril4 ,,suggestions4--#acf4 ,set the pupil to watch the behavior of any plant that has tendrils at different stages of maturity4 ,a vigorous cucumber plant is one of the best4 ,just beyond the point of a young straight tendril set a stake to compare the position of it4 ,note whether the tendril changes position from hour to hour or day to day4 #acg4 ,is the tip of the tendril perfectly straight8 ,why8 ,set a small stake at the end of a strong straight tendril1 so the tendril will just reach it4 ,watch1 and make drawing4 #ach4 ,if a tendril does not find a support1 what does it do8 #aci4 ,to test the movement of a free tendril1 draw an ink line lengthwise of it1 and note whether the line remains always on the concave side or the convex side4 #adj4 ,name the tendril-bearing plants that you know4 #ada4 ,make similar observations and experiments on the tips of twining stems4 #adb4 ,what twining plants do you know1 and which way do they twine8 #adc4 ,how does any plant that you know get up in the world8 #add4 ,does the stem of a climbing plant contain more or less substance 7weight7 than an erect self-supporting stem of the same height8 ,explain4 ,,chapter ,,xviii ,,the ,,flower--,,its ,,parts ,,and ,,forms ,the function of the flower is to produce seed4 ,it is probable that all its varied forms and colors contribute to this supreme end4 ,these forms and colors please the human fancy and add to the joy of living1 but the flower exists for the good of the plant1 not for the good of man4 ,the parts of the flower are of two general kinds--those that are directly concerned in the production of seeds1 and those that act as covering and protecting organs4 ,the former parts are known as the essential organs2 the latter as the floral envelopes4 ,envelopes4--,the floral envelopes usually bear a close resemblance to leaves4 ,these envelopes are very commonly of two series or kinds--the outer and the inner4 ,the outer series1 known as the calyx1 is usually smaller and green4 ,it usually comprises the outer cover of the flower bud4 ,the calyx is the lowest whorl in ,fig4 #agc4 ,illustration3 ,,fig4 #agc4--;,,flower ,,of ,a ,,buttercup ,,in ,,section4 ,the inner series1 known as the corolla1 is usually colored and more special or irregular in shape than the calyx4 ,it is the showy part of the flower1 as a rule4 ,the corolla is the second or large whorl in ,fig4 #agc4 ,the calyx may be composed of several leaves4 ,each leaf is a sepal4 ,if it is of one piece1 it may be lobed or divided1 in which case the divisions are called calyx-lobes4 ,in like manner1 the corolla may be composed of petals1 or it may be of one piece and variously lobed4 ,a calyx of one piece1 no matter how deeply lobed1 is gamosepalous4 ,a corolla of one piece is gamopetalous4 ,when these series are of separate pieces1 as in ,fig4 #agc1 the flower is said to be polysepalous and polypetalous4 ,sometimes both series are of separate parts1 and sometimes only one of them is so formed4 ,the floral envelopes are homologous with leaves4 ,sepals and petals1 at least when more than three or five1 are in more than one whorl1 and one whorl stands below another so that the parts overlap4 ,they are borne on the expanded or thickened end of the flower stalk2 this end is the torus4 ,in ,fig4 #agc all the parts are seen as attached to the torus4 ,this part is sometimes called the receptacle1 but this word is a common-language term of several meanings1 whereas torus has no other meaning4 ,sometimes one part is attached to another part1 as in the fuchsia 7,fig4 #agd71 in which the petals are borne on the calyx-tube4 ,illustration3 ,,fig4 #agd4--;,,flower ,,of ,,fuchsia ,,in ,,section4 ,subtending ,parts4--,sometimes there are leaf-like parts just below the calyx1 looking like a second calyx4 ,such parts accompany the carnation flower4 ,these parts are bracts 7bracts are small specialized leaves72 and they form an involucre4 ,we must be careful that we do not mistake them for true flower parts4 ,sometimes the bracts are large and petal-like1 as in the great white blooms of the flowering dogwood3 here the real flowers are several1 small and greenish1 forming a small cluster in the center4 ,essential ,organs4--,the essential organs are of two series4 ,the outer series is composed of the stamens4 ,the inner series is composed of the pistils4 ,stamens bear the pollen1 which is made up of grains or spores1 each spore usually being a single plant cell4 ,the stamen is of two parts1 as is readily seen in ,figs4 #agc1 #agd1--the enlarged terminal part or anther1 and the stalk or filament4 ,the filament is often so short as to seem to be absent1 and the anther is then said to be sessile4 ,the anther bears the pollen spores4 ,it is made up of two or four parts 7known as sporangia or spore-cases71 which burst and discharge the pollen4 ,when the pollen is shed1 the stamen dies4 ,the pistil has three parts3 the lowest1 or seed-bearing part1 which is the ovary2 the stigma at the upper extremity1 which is a flattened or expanded surface1 and usually roughened or sticky2 the stalk-like part or style1 connecting the ovary and stigma4 ,sometimes the style is apparently wanting1 and the stigma is said to be sessile on the ovary4 ,these parts are shown in the fuchsia 7,fig4 #agd74 ,the ovary or seed vessel is at a4 ,a long style1 bearing a large stigma1 projects from the flower4 ,see also ,figs4 #age and #agf4 ,illustration3 ,,fig4 #age4--,,the ,,structure ,,of ,a ,,plum ,,blossom4 se1 sepals2 p1 petals2 sta1 stamens2 o1 ovary2 s1 style2 st1 stigma4 ,the pistil consists of the ovary1 style1 and stigma4 ,it contains the seed part4 ,the stamens are tipped with anthers1 in which the pollen is borne4 ,the ovary1 o1 ripens into the fruit4 ,stamens and pistils probably are homologous with leaves4 ,a pistil is sometimes conceived to represent anciently a leaf as if rolled into a tube2 and an anther1 a leaf of which the edges may have been turned in on the midrib4 ,illustration3 ,,fig4 #agf4--,,simple ,,pistils ,,of ,,buttercup1 one in longitudinal section4 ,the pistil may be of one part or compartment1 or of many parts4 ,the different units or parts of which it is composed are carpels4 ,each carpel is homologous with a leaf4 ,each carpel bears one or more seeds4 ,a pistil of one carpel is simple2 of two or more carpels1 compound4 ,usually the structure of the pistil may be determined by cutting horizontally across the lower or seed-bearing part1 as ,figs4 #agg1 #agh explain4 ,a flower may contain a simple pistil 7one carpel71 as the pea 7,fig4 #agg72 several simple pistils 7several separate carpels71 as the buttercup 7,fig4 #agf72 or a compound pistil with carpels united1 as the ,saint ,john's wort 7,fig4 #agh7 and apple4 ,how many carpels in an apple8 ,a peach8 ,an okra pod8 ,a bean pod8 ,the seed cavity in each carpel is called a locule 7,latin locus1 a place74 ,in these locules the seeds are borne4 ,illustration3 ,,fig4 #agg4--,,pistil ,,of ,,garden ,,pea1 the stamens being pulled down in order to disclose it2 also a section showing the single compartment 7compare ,fig4 #ahh74 ,illustration3 ,,fig4 #agh4--;,,compound ,,pistil ,,of ,a ,,st4 ,,john',s ,,wort4 ,it has #e carpels4 ,conformation of the ,flower4--,a flower that has calyx1 corolla1 stamens1 and pistils is said to be complete 7,fig4 #agc72 all others are incomplete4 ,in some flowers both the floral envelopes are wanting3 such are naked4 ,when one of the floral envelope series is wanting1 the remaining series is said to be calyx1 and the flower is therefore apetalous 7without petals74 ,the knotweed 7,fig4 #agi71 smartweed1 buckwheat1 elm are examples4 ,illustration3 ,,fig4 #agi4--,,knotweed1 a very common but inconspicuous plant along hard walks and roads4 ,two flowers1 enlarged1 are shown at the right4 ,these flowers are very small and borne in the axils of the leaves4 ,some flowers lack the pistils3 these are staminate1 whether the envelopes are missing or not4 ,others lack the stamens3 these are pistillate4 ,others have neither stamens nor pistils3 these are sterile 7snowball and hydrangea74 ,those that have both stamens and pistils are perfect1 whether or not the envelopes are missing4 ,those that lack either stamens or pistils are imperfect or diclinous4 ,staminate and pistillate flowers are imperfect or diclinous4 ,illustration3 ,,fig4 #ahj4--,,staminate ,,catkins ,,of ,,oak4 ,the pistillate flowers are in the leaf axils1 and not shown in this picture4 ,illustration3 ,,fig4 #aha4--;,,begonia ,,flowers4 ,staminate at ,a2 pistillate below1 with the winged ovary at ,b4 ,when staminate and pistillate flowers are borne on the same plant1 e4g4 oak 7,fig4 #ahj71 corn1 beech1 chestnut1 hazel1 walnut1 hickory1 pine1 begonia 7,fig4 #aha71 watermelon1 gourd1 pumpkin1 the plant is moncious 78in one house074 ,when they are on different plants1 e4g4 poplar1 cottonwood1 bois d'arc1 willow 7,fig4 #ahb71 the plant is dicious 78in two houses074 ,some varieties of strawberry1 grape1 and mulberry are partly dicious4 ,is the rose either moncious or dicious8 ,illustration3 ,,fig4 #ahb4--;,,catkins ,,of ,a ,,willow4 ,a staminate flower is shown at s1 and a pistillate flower at p4 ,the staminate and pistillate are on different plants4 ,illustration3 ,,fig4 #ahc4--;,,flower ,,of ,,garden ,,nasturtium4 ,separate petal at a4 ,the calyx is produced into a spur4 ,illustration3 ,,fig4 #ahd4--,,the ,,five ,,petals ,,of ,,the ,,pansy1 detached to show the form4 ,illustration3 ,,fig4 #ahe4--;,,flower ,,of ,,catnip4 ,flowers in which the parts of each series are alike are said to be regular 7as in ,figs4 #agc1 #agd1 #age74 ,those in which some parts are unlike other parts of the same series are irregular4 ,their regularity may be in calyx1 as in nasturtium 7,fig4 #ahc72 in corolla 7,figs4 #ahd1 #ahe72 in the stamens 7compare nasturtium1 catnip1 ,fig4 #ahe1 sage72 in the pistils4 ,irregularity is most frequent in the corolla4 ,various ,forms of ,corolla4--,the corolla often assumes very definite or distinct forms1 especially when gamopetalous4 ,it may have a long tube with a wide-flaring limb1 when it is said to be funnelform1 as in morning-glory and pumpkin4 ,if the tube is very narrow and the limb stands at right angles to it1 the corolla is salverform1 as in phlox4 ,if the tube is very short and the limb wide-spreading and nearly circular in outline1 the corolla is rotate or wheel-shaped1 as in potato4 ,a gamopetalous corolla or gamosepalous calyx is often cleft in such way as to make two prominent parts4 ,such parts are said to be lipped or labiate4 ,each of the lips or lobes may be notched or toothed4 ,in #e-membered flowers1 the lower lip is usually #c-lobed and the upper one #b-lobed4 ,labiate flowers are characteristic of the mint family 7,fig4 #ahe71 and the family therefore is called the ,labiat4 7,literally1 labiate means merely 8lipped10 without specifying the number of lips or lobes2 but it is commonly used to designate #b-lipped flowers47 ,strongly #b-parted polypetalous flowers may be said to be labiate2 but the term is oftenest used for gamopetalous corollas4 ,labiate gamopetalous flowers that are closed in the throat 7or entrance to the tube7 are said to be grinning or personate 7personate means masked1 or person-like74 ,snap-dragon is a typical example2 also toadflax or butter-and-eggs 7,fig4 #ahf71 and many related plants4 ,personate flowers usually have definite relations to insect pollination4 ,observe how an insect forces his head into the closed throat of the toadflax4 ,illustration3 ,,fig4 #ahf4--,,personate ,,flower ,,of ,,toadflax4 ,the peculiar flowers of the pea tribes are explained in ,figs4 #ahg1 #ahh4 ,illustration3 ,,fig4 #ahg4--;,,flowers ,,of ,,the ,,common ,,bean1 with one flower opened 7a7 to show the structure4 ,illustration3 ,,fig4 #ahh4--;,,diagram ,,of ,,alfalfa ,,flower ,,in ,,section3 ,c1 calyx2 ,d1 standard2 ,w1 wing2 ,k1 keel2 ,t1 stamen-tube2 ,f1 filament of tenth stamen2 ,x1 stigma2 ,y1 style2 ,o1 ovary2 the dotted lines at ,e show position of stamen tube1 when pushed upward by insects4 ,enlarged4 ,spathe ,flowers4--,in many plants1 very simple 7often naked7 flowers are borne in dense1 more or less fleshy spikes1 and the spike is inclosed in or attended by a leaf1 sometimes corolla-like1 known as a spathe4 ,the spike of flowers is technically known as a spadix4 ,this type of flower is characteristic of the great arum family1 which is chiefly tropical4 ,the commonest wild representatives in the ,north are ,jack-in-the-pulpit1 or ,indian turnip1 and skunk cabbage4 ,in the former the flowers are all diclinous and naked4 ,in the skunk cabbage all the flowers are perfect and have four sepals4 ,the common calla is a good example of this type of inflorescence4 ,illustration3 ,,fig4 #ahi4--;,,head ,,of ,,sunflower4 ,compositous ,flowers4--,the head 7anthodium7 or so-called 8flower0 of sunflower 7,fig4 #ahi71 thistle1 aster1 dandelion1 daisy1 chrysanthemum1 goldenrod1 is composed of several or many little flowers1 or florets4 ,these florets are inclosed in a more or less dense and usually green involucre4 ,in the thistle 7,fig4 #aij7 this involucre is prickly4 ,a longitudinal section discloses the florets1 all attached at bottom to a common torus1 and densely packed in the involucre4 ,the pink tips of these florets constitute the showy part of the head4 ,illustration3 ,,fig4 #aij4--,,longitudinal ,,section ,,of ,,thistle ,,head2 also a ,,floret ,,of ,,thistle4 ,each floret of the thistle 7,fig4 #aij7 is a complete flower4 ,at a is the ovary4 ,at b is a much-divided plumy calyx1 known as the pappus4 ,the corolla is long-tubed1 rising above the pappus1 and is enlarged and #e-lobed at the top1 c4 ,the style projects at e4 ,the five anthers are united about the style in a ring at d4 ,such anthers are said to be syngenesious4 ,these are the various parts of the florets of the ,composit4 ,in some cases the pappus is in the form of barbs1 bristles1 or scales1 and sometimes it is wanting4 ,the pappus1 as we shall see later1 assists in distributing the seed4 ,often the florets are not all alike4 ,the corolla of those in the outer circles may be developed into a long1 straplike1 or tubular part1 and the head then has the appearance of being one flower with a border of petals4 ,of such is the sunflower 7,fig4 #ahi71 aster1 bachelor's button or cornflower1 and field daisy 7,fig4 #baa74 ,these long corolla-limbs are called rays4 ,in some cultivated composites1 all the florets may develop rays1 as in the dahlia and chrysanthemum4 ,in some species1 as dandelion1 all the florets naturally have rays4 ,syngenesious arrangement of anthers is the most characteristic single feature of the composites4 ,illustration3 ,,fig4 #aia4--,,petals ,,arising ,,from ,,the ,,staminal ,,column ,,of ,,hollyhock1 and accessory petals in the corolla-whorl4 ,double ,flowers4--,under the stimulus of cultivation and increased food supply1 flowers tend to become double4 ,true doubling arises in two ways1 morphologically3 7#a7 stamens or pistils may produce petals 7,fig4 #aia72 7#b7 adventitious or accessory petals may arise in the circle of petals4 ,both of these categories may be present in the same flower4 ,in the full double hollyhock the petals derived from the staminal column are shorter and make a rosette in the center of the flower4 ,in ,fig4 #aib is shown the doubling of a daffodil by the modification of stamens4 ,other modifications of flowers are sometimes known as doubling4 ,for example1 double dahlias1 chrysanthemums1 and sunflowers are forms in which the disk flowers have developed rays4 ,the snowball is another case4 ,in the wild snowball the external flowers of the cluster are large and sterile4 ,in the cultivated plant all the flowers have become large and sterile4 ,hydrangea is a similar case4 ,illustration3 ,,fig4 #aib4--,,narcissus ,,or ,,daffodil4 ,single flower at the right4 ,,suggestions4--#ade4 ,if the pupil has been skillfully conducted through this chapter by means of careful study of specimens rather than as a mere memorizing process1 he will be in mood to challenge any flower that he sees and to make an effort to understand it4 ,flowers are endlessly modified in form2 but they can be understood if the pupil looks first for the anthers and ovaries4 ,how may anthers and ovaries always be distinguished8 #adf4 ,it is excellent practice to find the flowers in plants that are commonly known by name1 and to determine the main points in their structure4 ,what are the flowers in ,indian corn8 pumpkin or squash8 celery8 cabbage8 potato8 pea8 tomato8 okra8 cotton8 rhubarb8 chestnut8 wheat8 oats8 #adg4 ,do all forest trees have flowers8 ,explain4 #adh4 ,name all the moncious plants you know4 ,dicious4 #adi4 ,what plants do you know that bloom before the leaves appear8 ,do any bloom after the leaves fall8 #aej4 ,explain the flowers of marigold1 hyacinth1 lettuce1 clover1 asparagus1 garden calla1 aster1 locust1 onion1 burdock1 lily-of-the-valley1 crocus1 ,golden ,glow rudbeckia1 cowpea4 #aea4 ,define a flower4 ,,note ,,to ,,the ,,teacher4--,it cannot be urged too often that the specimens themselves be studied4 ,if this chapter becomes a mere recitation on names and definitions1 the exercise will be worse than useless4 ,properly taught by means of the flowers themselves1 the names become merely incidental and a part of the pupil's language1 and the subject has living interest4 ,,chapter ,,xix ,,the ,,flower--,,fertilization ,,and ,,pollination ,fertilization4--,seeds result from the union of two elements or parts4 ,one of these elements is a cell-nucleus of the pollen-grain4 ,the other element is the cell-nucleus of an egg-cell1 borne in the ovary4 ,the pollen-grain falls on the stigma 7,fig4 #aic74 ,it absorbs the juices exuded by the stigma1 and grows by sending out a tube 7,fig4 #aid74 ,this tube grows downward through the style1 absorbing food as it goes1 and finally reaches the egg-cell in the interior of an ovule in the ovary 7,fig4 #aie71 and fertilization1 or union of a nucleus of the pollen and the nucleus of the egg-cell in the ovule1 takes place4 ,the ovule and embryo within then develops into a seed4 ,the growth of the pollen-tube is often spoken of as germination of the pollen1 but it is not germination in the sense in which the word is used when speaking of seeds4 ,illustration3 ,,fig4 #aic4--;,b1 ,,pollen escaping from anther2 ,a1 pollen germinating on a stigma4 ,enlarged4 ,illustration3 ,,fig4 #aid4--;,a ,,pollen-,,grain ,,and ,,the ,,growing ,,tube4 ,better seeds--that is1 those that produce stronger and more fruitful plants--often result when the pollen comes from another flower4 ,fertilization effected between different flowers is cross-fertilization2 that resulting from the application of pollen to pistils in the same flower is close-fertilization or self-fertilization4 ,it will be seen that the cross-fertilization relationship may be of many degrees--between two flowers in the same cluster1 between those in different clusters on the same branch1 between those on different plants4 ,usually fertilization takes place only between plants of the same species or kind4 ,illustration3 ,,fig4 #aie4--;,,diagram ,,to ,,represent ,,fertilization4 s1 stigma2 st1 style2 ov1 ovary2 o1 ovule2 p1 pollen-grain2 pt1 pollen-tube2 e1 egg-cell2 m1 micropyle4 ,in many cases there is1 in effect1 an apparent selection of pollen when pollen from two or more sources is applied to the stigma4 ,sometimes the foreign pollen1 if from the same kind of plant1 grows1 and fertilization results1 while pollen from the same flower is less promptly effective4 ,if1 however1 no foreign pollen is present1 the pollen from the same flower may finally serve the same purpose4 ,in order that the pollen may grow1 the stigma must be ripe4 ,at this stage the stigma is usually moist and sometimes sticky4 ,a ripe stigma is said to be receptive4 ,the stigma may remain receptive for several hours or even days1 depending on the kind of plant1 the weather1 and how soon pollen is received4 ,watch a certain flower every day to see the anther locules open and the stigma ripen4 ,when fertilization takes place1 the stigma dies4 ,observe1 also1 how soon the petals wither after the stigma has received pollen4 ,pollination4--,the transfer of the pollen from anther to stigma is known as pollination4 ,the pollen may fall of its own weight on the adjacent stigma1 or it may be carried from flower to flower by wind1 insects1 or other agents4 ,there may be self-pollination or cross-pollination1 and of course it must always precede fertilization4 ,usually the pollen is discharged by the bursting of the anthers4 ,the commonest method of discharge is through a slit on either side of the anther 7,fig4 #aic74 ,sometimes it discharges through a pore at the apex1 as in azalea 7,fig4 #aif71 rhododendron1 huckleberry1 wintergreen4 ,in some plants a part of the anther wall raises or falls as a lid1 as in barberry 7,fig4 #aig71 blue cohosh1 ,may apple4 ,the opening of an anther 7as also of a seed-pod7 is known as dehiscence 7de1 from2 hisco1 to gape74 ,when an anther or seed pod opens1 it is said to dehisce4 ,illustration3 ,,fig4 #aif4--;,,anther ,,of ,,azalea1 opening by terminal pores4 ,illustration3 ,,fig4 #aig4--;,,barberry ,,stamen1 with anther opening by lids4 ,most flowers are so constructed as to increase the chances of cross-pollination4 ,we have seen that the stigma may have the power of choosing foreign pollen4 ,the commonest means of necessitating cross-pollination is the different times of maturing of stamens and pistils in the same flower4 ,in most cases the stamens mature first3 the flower is then proterandrous4 ,when the pistils mature first1 the flower is proterogynous4 7,aner1 andr1 is a ,greek root often used1 in combinations1 for stamen1 and gyne for pistil47 ,the difference in time of ripening may be an hour or two1 or it may be a day4 ,the ripening of the stamens and pistils at different times is known as dichogamy1 and flowers of such character are said to be dichogamous4 ,there is little chance for dichogamous flowers to pollinate themselves4 ,many flowers are imperfectly dichogamous--some of the anthers mature simultaneously with the pistils1 so that there is chance for self-pollination in case foreign pollen does not arrive4 ,even when the stigma receives pollen from its own flower1 cross-fertilization may result4 ,the hollyhock is proterandrous4 ,fig4 #aih shows a flower recently expanded4 ,the center is occupied by the column of stamens4 ,in ,fig4 #aii1 showing an older flower1 the long styles are conspicuous4 ,illustration3 ,,fig4 #aih4--;,,flower ,,of ,,hollyhock2 proterandrous4 ,illustration3 ,,fig4 #aii4--,,older ,,flower ,,of ,,hollyhock4 ,some flowers are so constructed as to prohibit self-pollination4 ,very irregular flowers are usually of this kind4 ,with some of them1 the petals form a sac to inclose the anthers and the pollen cannot be shed on the stigma but is retained until a bee forces the sac open2 the pollen is rubbed on the hairs of the bee and transported4 ,regular flowers usually depend mostly on dichogamy and the selective power of the pistil to insure crossing4 ,flowers that are very irregular and provided with nectar and strong perfume are usually pollinated by insects4 ,gaudy colors probably attract insects in many cases1 but perfume appears to be a greater attraction4 ,illustration3 ,,fig4 #bjj4--;,,flower ,,of ,,larkspur4 ,illustration3 ,,fig4 #bja4--;,,envelopes ,,of ,a ,,larkspur4 ,there are five wide sepals1 the upper one being spurred4 ,there are four small petals4 ,the insect visits the flower for the nectar 7for the making of honey7 and may unknowingly carry the pollen4 ,spurs and sacs in the flower are nectaries 7,fig4 #bjj71 but in spurless flowers the nectar is usually secreted in the bottom of the flower cup4 ,this compels the insect to pass by the anther and rub against the pollen before it reaches the nectar4 ,sometimes the anther is a long lever poised on the middle point and the insect bumps against one end and lifts it1 thus bringing the other end of the lever with the pollen sacs down on its back4 ,flowers that are pollinated by insects are said to be entomophilous 78insect loving074 ,fig4 #bjj shows a larkspur4 ,the envelopes are separated in ,fig4 #bja4 ,the long spur at once suggests insect pollination4 ,the spur is a sepal4 ,two hollow petals project into this spur1 apparently serving to guide the bee's tongue4 ,the two smaller petals1 in front1 are peculiarly colored and perhaps serve the bee in locating the nectary4 ,the stamens ensheath the pistils 7,fig4 #bjb74 ,as the insect stands on the flower and thrusts its head into the center1 the envelopes are pushed downward and outward and the pistil and stamens come in contact with its abdomen4 ,since the flower is proterandrous1 the pollen that the pistils receive from the bee's abdomen must come from another flower4 ,note a somewhat similar arrangement in the toadflax or butter-and-eggs4 ,illustration3 ,,fig4 #bjb4--,,stamens ,,of ,,larkspur1 surrounding the pistils4 ,in some cases 7,fig4 #bjc7 the stamens are longer than the pistil in one flower and shorter in another4 ,if the insect visits such flowers1 it gets pollen on its head from the long-stamen flower1 and deposits this pollen on the stigma in the long-pistil flower4 ,such flowers are dimorphous 7of two forms74 ,if pollen from its own flower and from another flower both fall on the stigma1 the probabilities are that the stigma will choose the foreign pollen4 ,illustration3 ,,fig4 #bjc4--;,,dimorphic ,,flowers ,,of ,,primrose4 ,many flowers are pollinated by the wind4 ,they are said to be anemophilous 78wind loving074 ,such flowers produce great quantities of pollen1 for much of it is wasted4 ,they usually have broad stigmas1 which expose large surfaces to the wind4 ,they are usually lacking in gaudy colors and in perfume4 ,grasses and pine trees are typical examples of anemophilous plants4 ,illustration3 ,,fig4 #bjd4--;,,flowers ,,of ,,black ,,walnut3 two pistillate flowers at ,a1 and staminate catkins at ,b4 ,in many cases cross-pollination is insured because the stamens and pistils are in different flowers 7diclinous74 ,moncious and dicious plants may be pollinated by wind or insects1 or other agents 7,fig4 #bjd74 ,they are usually wind-pollinated1 although willows are often1 if not mostly1 insect-pollinated4 ,the ,indian corn is a moncious plant4 ,the staminate flowers are in a terminal panicle 7tassel74 ,the pistillate flowers are in a dense spike 7ear71 inclosed in a sheath or husk4 ,each 8silk0 is a style4 ,each pistillate flower produces a kernel of corn4 ,sometimes a few pistillate flowers are borne in the tassel and a few staminate flowers on the tip of the ear4 ,is self-fertilization possible with the corn8 ,why does a 8volunteer0 stalk standing alone in a garden have only a few grains on the ear8 ,what is the direction of the prevailing wind in summer8 ,if only two or three rows of corn are planted in a garden where prevailing winds occur1 in which direction would they better run8 ,illustration3 ,,fig4 #bje4--;,,common ,,blue ,,violet4 ,the familiar flowers are shown1 natural size4 ,the corolla is spurred4 ,late in the season1 cleistogamous flowers are often borne on the surface of the ground4 ,a small one is shown at a4 ,a nearly mature pod is shown at b4 ,both a and b are one third natural size4 ,although most flowers are of such character as to insure or increase the chances of cross-pollination1 there are some that absolutely forbid crossing4 ,these flowers are usually borne beneath or on the ground1 and they lack showy colors and perfumes4 ,they are known as cleistogamous flowers 7meaning 8hidden flowers074 ,the plant has normal showy flowers that may be insect-pollinated1 and in addition is provided with these simplified flowers4 ,only a few plants bear cleistogamous flowers4 ,hog-peanut1 common blue violet1 fringed wintergreen1 and dalibarda are the best subjects in the ,northern states4 ,fig4 #bje shows a cleistogamous flower of the blue violet at a4 ,above the true roots1 slender stems bear these flowers1 that are provided with a calyx1 and a curving corolla which does not open4 ,inside are the stamens and pistils4 ,late in the season the cleistogamous flowers may be found just underneath the mold4 ,they never rise above ground4 ,the following summer one may find a seedling plant1 in some kinds of plants1 with the remains of the old cleistogamous flower still adhering to the root4 ,cleistogamous flowers usually appear after the showy flowers have passed4 ,they seem to insure a crop of seed by a method that expends little of the plant's energy4 ,the pupil will be interested to work out the fruiting of the peanut 7,fig4 #bjf74 ,unbaked fresh peanuts grow readily and can easily be raised in the ,north in a warm sandy garden4 ,illustration3 ,,fig4 #bjf4--,,pods ,,of ,,peanuts ,,ripening ,,underground4 ,illustration3 ,,fig4 #bjg4--,,struggle ,,for ,,existence ,,among ,,the ,,apple ,,flowers4 ,,suggestions4--#aeb4 ,not all the flowers produce seeds4 ,note that an apple tree may bloom very full1 but that only relatively few apples may result 7,fig4 #bjg74 ,more pollen is produced than is needed to fertilize the flowers2 this increases the chances that sufficient stigmas will receive acceptable pollen to enable the plant to perpetuate its kind4 ,at any time in summer1 or even in fall1 examine the apple trees carefully to determine whether any dead flowers or flower stalks still remain about the apple2 or1 examine any full-blooming plant to see whether any of the flowers fail4 #aec4 ,keep watch on any plant to see whether insects visit it4 ,what kind8 ,when8 ,what for8 #aed4 ,determine whether the calyx serves any purpose in protecting the flower4 ,very carefully remove the calyx from a bud that is normally exposed to heat and sun and rain1 and see whether the flower then fares as well as others4 #aee4 ,cover a single flower on its plant with a tiny paper or muslin bag so tightly that no insect can get in4 ,if the flower sets fruit1 what do you conclude8 #aef4 ,remove carefully the corolla from a flower nearly ready to open1 preferably one that has no other flowers very close to it4 ,watch for insects4 #aeg4 ,find the nectar in any flower that you study4 #aeh4 ,remove the stigma4 ,what happens8 #aei4 ,which of the following plants have perfect flowers3 pea1 bean1 pumpkin1 cotton1 clover1 buckwheat1 potato1 ,indian corn1 peach1 chestnut1 hickory1 watermelon1 sunflower1 cabbage1 rose1 begonia1 geranium1 cucumber1 calla1 willow1 cottonwood1 cantaloupe8 ,what have the others8 #afj4 ,on wind-pollinated plants1 are either anthers or stigmas more numerous8 #afa4 ,are very small colored flowers usually borne singly or in clusters8 #afb4 ,why do rains at blooming time often lessen the fruit crop8 #afc4 ,of what value are bees in orchards8 #afd4 ,the crossing of plants to improve varieties or to obtain new varieties4--,it may be desired to perform the operation of pollination by hand4 ,in order to insure the most definite results1 every effort should be made rightly to apply the pollen which it is desired shall be used1 and rigidly to exclude all other pollen4 7a7 ,the first requisite is to remove the anthers from the flower which it is proposed to cross1 and they must be removed before the pollen has been shed4 ,the flower-bud is therefore opened and the anthers taken out4 ,cut off the floral envelopes with small1 sharp-pointed scissors1 then cut out or pull out the anthers1 leaving only the pistil untouched2 or merely open the corolla at the end and pull out the anthers with a hook or tweezers2 and this method is often the best one4 ,it is best to delay the operation as long as possible and yet not allow the bud to open 7and thereby expose the flower to foreign pollen7 nor the anthers to discharge the pollen4 7b7 ,the flower must next be covered with a paper bag to prevent the access of pollen 7,figs4 #bjh1 #bji74 ,if the stigma is not receptive at the time 7as it usually is not71 the desired pollen is not applied at once4 ,the bag may be removed from time to time to allow of examination of the pistil1 and when the stigma is mature1 which is told by its glutinous or roughened appearance1 the time for pollination has come4 ,if the bag is slightly moistened1 it can be puckered more tightly about the stem of the plant4 ,the time required for the stigma to mature varies from several hours to a few days4 7c7 ,when the stigma is ready1 an unopened anther from the desired flower is crushed on the finger nail or a knife blade1 and the pollen is rubbed on the stigma by means of a tiny brush1 the point of a knife blade1 or a sliver of wood4 ,the flower is again covered with the bag1 which is allowed to remain for several days until all danger of other pollination is past4 ,care must be taken completely to cover the stigmatic surface with pollen1 if possible4 ,the seeds produced by a crossed flower produce hybrids1 or plants having parents belonging to different varieties or species4 #afe4 ,one of the means of securing new forms of plants is by making hybrids4 ,why8 ,illustration3 ,,fig4 #bjh4--;,a ,,paper ,,bag1 with string inserted4 ,illustration3 ,,fig4 #bji4--,,the ,,bag ,,tied ,,over ,a ,,flower4 ,illustration3 ,,fig4 #baj4--;,,fig4 ,the fig is a hollow torus with flowers borne on the inside1 and pollinated by insects that enter at the apex4 ,,chapter ,,xx ,,flower-,,clusters ,origin of the ,flower-cluster4--,we have seen that branches arise from the axils of leaves4 ,sometimes the leaves may be reduced to bracts and yet branches are borne in their axils4 ,some of the branches grow into long limbs2 others become short spurs2 others bear flowers4 ,in fact1 a flower is itself a specialized branch4 ,flowers are usually borne near the top of the plant4 ,often they are produced in great numbers4 ,it results1 therefore1 that flower branches usually stand close together1 forming a cluster4 ,the shape and arrangement of the flower-cluster differ with the kind of plant1 since each plant has its own mode of branching4 ,illustration3 ,,fig4 #baa4--,,terminal ,,flowers ,,of ,,the ,,whiteweed 7in some places called ox-eye daisy74 ,certain definite or well-marked types of flower-clusters have received names4 ,some of these names we shall discuss1 but the flower-clusters that perfectly match the definitions are the exception rather than the rule4 ,the determining of the kinds of flower-clusters is one of the most perplexing subjects in descriptive botany4 ,we may classify the subject around three ideas3 solitary flowers1 centrifugal or determinate clusters1 centripetal or indeterminate clusters4 ,solitary ,flowers4--,in many cases flowers are borne singly2 they are separated from other flowers by leaves4 ,they are then said to be solitary4 ,the solitary flower may be either at the end of the main shoot or axis 7,fig4 #baa71 when it is said to be terminal2 or from the side of the shoot 7,fig4 #bab71 when it is said to be lateral or axillary4 ,illustration3 ,,fig4 #bab4--,,lateral ,,flower ,,of ,,an ,,abutilon4 ,a greenhouse plant4 ,centripetal ,clusters4--,if the flower-bearing axils were rather close together1 an open or leafy flower-cluster might result4 ,if the plant continues to grow from the tip1 the older flowers are left farther and farther behind4 ,if the cluster were so short as to be flat or convex on top1 the outermost flowers would be the older4 ,a flower-cluster in which the lower or outer flowers open first is said to be a centripetal cluster4 ,it is sometimes said to be an indeterminate cluster1 since it is the result of a type of growth which may go on more or less continuously from the apex4 ,the simplest form of a definite centripetal cluster is a raceme1 which is an open elongated cluster in which the flowers are borne singly on very short branches and open from below 7that is1 from the older part of the shoot7 upwards 7,fig4 #bac74 ,the raceme may be terminal to the main branch2 or it may be lateral to it1 as in ,fig4 #bad4 ,racemes often bear the flowers on one side of the stem1 thus forming a single row4 ,when a centripetal flower-cluster is long and dense and the flowers are sessile or nearly so1 it is called a spike 7,fig4 #bae74 ,common examples of spikes are plantain1 mignonette1 mullein4 ,illustration3 ,,fig4 #bac4--,,raceme ,,of ,,currant4 ,terminal or lateral8 ,illustration3 ,,fig4 #bad4--,,lateral ,,racemes 7in fruit7 ,,of ,,barberry4 ,illustration3 ,,fig4 #bae4--,,spike ,,of ,,plantain4 ,a very short and dense spike is a head4 ,clover 7,fig4 #baf7 is a good example4 ,the sunflower and related plants bear many small flowers in a very dense and often flat head4 ,note that in the sunflower 7,fig4 #ahi7 the outside or exterior flowers open first4 ,another special form of spike is the catkin1 which usually has scaly bracts1 the whole cluster being deciduous after flowering or fruiting1 and the flowers 7in typical cases7 having only stamens or pistils4 ,examples are the 8pussies0 of willows 7,fig4 #ahb7 and flower-clusters of oak 7,fig4 #ahj71 walnuts 7,fig4 #bjd71 poplars4 ,illustration3 ,,fig4 #baf4--;,,head ,,of ,,clover ,,blossoms4 ,illustration3 ,,fig4 #bag4--;,,corymb ,,of ,,candy-,,tuft4 ,when a loose1 elongated centripetal flower-cluster has some primary branches simple1 and others irregularly branched1 it is called a panicle4 ,it is a branching raceme4 ,because of the earlier growth of the lower branches1 the panicle is usually broadest at the base or conical in outline4 ,true panicles are not very common4 ,when an indeterminate flower-cluster is short1 so that the top is convex or flat1 it is a corymb 7,fig4 #bag74 ,the outermost flowers open first4 ,centripetal flower-clusters are sometimes said to be corymbose in mode4 ,when the branches of an indeterminate cluster arise from a common point1 like the frame of an umbrella1 the cluster is an umbel 7,fig4 #bah74 ,typical umbels occur in carrot1 parsnip1 caraway and other plants of the parsley family3 the family is known as the ,umbellifer1 or umbel-bearing family4 ,in the carrot and many other ,umbellifer1 there are small or secondary umbels1 called umbellets1 at the end of each of the main branches4 7,in the center of the wild carrot umbel one often finds a single1 blackish1 often aborted flower1 comprising a #a-;flowered umbellet47 ,illustration3 ,,fig4 #bah4--,,remains ,,of ,a ,,last ,,year',s ,,umbel ,,of ,,wild ,,carrot4 ,centrifugal or ,determinate ,clusters4--,when the terminal or central flower opens first1 the cluster is said to be centrifugal4 ,the growth of the shoot or cluster is determinate1 since the length is definitely determined or stopped by the terminal flower4 ,fig4 #bai shows a determinate or centrifugal mode of flower bearing4 ,dense centrifugal clusters are usually flattish on top because of the cessation of growth in the main or central axis4 ,these compact flower-clusters are known as cymes4 ,centrifugal clusters are sometimes said to be cymose in mode4 ,apples1 pears 7,fig4 #bbj71 and elders bear flowers in cymes4 ,some cyme-forms are like umbels in general appearance4 ,a head-like cymose cluster is a glomerule2 it blooms from the top downwards rather than from the base upwards4 ,mixed ,clusters4--,often the cluster is mixed1 being determinate in one part and indeterminate in another part of the same cluster4 ,the main cluster may be indeterminate1 but the branches determinate4 ,the cluster has the appearance of a panicle1 and is usually so called1 but it is really a thyrse4 ,lilac is a familiar example of a thyrse4 ,in some cases the main cluster is determinate and the branches are indeterminate1 as in hydrangea and elder4 ,illustration3 ,,fig4 #bai4--;,,determinate ,,or ,,cymose ,,arrangement4--,wild geranium4 ,illustration3 ,,fig4 #bbj4--;,,cyme ,,of ,,pear4 ,often imperfect4 ,inflorescence4--,the mode or method of flower arrangement is known as the inflorescence4 ,that is1 the inflorescence is cymose1 corymbose1 paniculate1 spicate1 solitary1 determinate1 indeterminate4 ,by custom1 however1 the word 8inflorescence0 has come to be used for the flower-cluster itself in works on descriptive botany4 ,thus a cyme or a panicle may be called an inflorescence4 ,it will be seen that even solitary flowers follow either indeterminate or determinate methods of branching4 ,illustration3 ,,fig4 #bba4--;,,forms ,,of ,,centripetal ,,flower-,,clusters4 #a1 raceme2 #b1 spike2 #c1 umbel2 #d1 head or anthodium2 #e1 corymb4 ,illustration3 ,,fig4 #bbb4--;,,centripetal ,,inflorescence1 continued4 #f1 spadix2 #g1 compound umbel2 #h1 catkin4 ,illustration3 ,,fig4 #bbc4--;,,centrifugal ,,inflorescence4 #a1 cyme2 #b1 scirpioid raceme 7or half cyme74 ,the flower-stem4--,the stem of a solitary flower is known as a peduncle2 also the general stem of a flower-cluster4 ,the stem of the individual flower in a cluster is a pedicel4 ,in the so-called stemless plants the peduncle may arise directly from the ground1 or crown of the plant1 as in dandelion1 hyacinth1 garden daisy2 this kind of peduncle is called a scape4 ,a scape may bear one or many flowers4 ,it has no foliage leaves1 but it may have bracts4 ,,suggestions4--#aff4 ,name six columns in your notebook as follows3 spike1 raceme1 corymb1 umbel1 cyme1 solitary4 ,write each of the following in its appropriate column3 larkspur1 grape1 rose1 wistaria1 onion1 bridal wreath1 banana1 hydrangea1 phlox1 ,china berry1 lily-of-the-valley1 ,spanish dagger 7or yucca71 sorghum1 tuberose1 hyacinth1 mustard1 goldenrod1 peach1 hollyhock1 mullein1 crpe myrtle1 locust1 narcissus1 snapdragon1 peppergrass1 shepherd's purse1 coxcomb1 wheat1 hawthorn1 geranium1 carrot1 elder1 millet1 dogwood1 castor bean2 substitute others for plants that do not grow in your region4 #afg4 ,in the study of flower-clusters1 it is well to choose first those that are fairly typical of the various classes discussed in the preceding paragraphs4 ,as soon as the main types are well fixed in the mind1 random clusters should be examined1 for the pupil must never receive the impression that all flower-clusters follow the definitions in books4 ,clusters of some of the commonest plants are very puzzling1 but the pupil should at least be able to discover whether the inflorescence is determinate or indeterminate4 ,figures #bba to #bbc 7from the ,german7 illustrate the theoretical modes of inflorescence4 ,the numerals indicate the order of opening4 ,,chapter ,,xxi ,,fruits ,the ripened ovary1 with its attachments1 is known as the fruit4 ,it contains the seeds4 ,if the pistil is simple1 or of one carpel1 the fruit also will have one compartment4 ,if the pistil is compound1 or of more than one carpel1 the fruit usually has an equal number of compartments4 ,the compartments in pistil and fruit are known as locules 7from ,latin locus1 meaning 8a place074 ,illustration3 ,,fig4 #bbd4--;,,dentaria1 ,,or ,,tooth-,,wort1 in fruit4 ,the simplest kind of fruit is a ripened #a-loculed ovary4 ,the first stage in complexity is a ripened #b- or many-loculed ovary4 ,very complex forms may arise by the attachment of other parts to the ovary4 ,sometimes the style persists and becomes a beak 7mustard pods1 dentaria1 ,fig4 #bbd71 or a tail as in clematis2 or the calyx may be attached to the ovary2 or the ovary may be embedded in the receptacle1 and ovary and receptacle together constitute the fruit3 or an involucre may become a part of the fruit1 as possibly in the walnut and hickory 7,fig4 #bbe71 and cup of the acorn 7,fig4 #bbf74 ,the chestnut and the beech bear a prickly involucre1 but the nuts1 or true fruits1 are not grown fast to it1 and the involucre can scarcely be called a part of the fruit4 ,a ripened ovary is a pericarp4 ,a pericarp to which other parts adhere has been called an accessory or renforced fruit4 7,page #afi47 ,illustration3 ,,fig4 #bbe4--;,,hickory-,,nut4 ,the nut is the fruit1 contained in a husk4 ,illustration3 ,,fig4 #bbf4--,,live-,,oak ,,acorn4 ,the fruit is the 8seed0 part2 the involucre is the 8cup40 ,illustration3 ,,fig4 #bbg4--,,key ,,of ,,sugar ,,maple4 ,illustration3 ,,fig4 #bbh4--,,key ,,of ,,common ,,american ,,elm4 ,some fruits are dehiscent1 or split open at maturity and liberate the seeds2 others are indehiscent1 or do not open4 ,a dehiscent pericarp is called a pod4 ,the parts into which such a pod breaks or splits are known as valves4 ,in indehiscent fruits the seed is liberated by the decay of the envelope1 or by the rupturing of the envelope by the germinating seed4 ,indehiscent winged pericarps are known as samaras or key fruits4 ,maple 7,fig4 #bbg71 elm 7,fig4 #bbh71 and ash 7,fig4 #ic7 are examples4 ,pericarps4--,the simplest pericarp is a dry1 one-seeded1 indehiscent body4 ,it is known as an akene4 ,a head of akenes is shown in ,fig4 #bbi1 and the structure is explained in ,fig4 #bcj4 ,akenes may be seen in buttercup1 hepatica1 anemone1 smartweed1 buckwheat4 ,illustration3 ,,fig4 #bbi4--;,,akenes ,,of ,,buttercup4 ,illustration3 ,,fig4 #bcj4--;,,akenes ,,of ,,buttercup1 one in longitudinal section4 ,a #a-loculed pericarp which dehisces along the front edge 7that is1 the inner edge1 next the center of the flower7 is a follicle4 ,the fruit of the larkspur 7,fig4 #bca7 is a follicle4 ,there are usually five of these fruits 7sometimes three or four7 in each larkspur flower1 each pistil ripening into a follicle4 ,if these pistils were united1 a single compound pistil would be formed4 ,columbine1 peony1 ninebark1 milkweed1 also have follicles4 ,illustration3 ,,fig4 #bca4--;,,follicle ,,of ,,larkspur4 ,illustration3 ,,fig4 #bcc4--;,,capsule ,,of ,,castor-,,oil ,,bean ,,after ,,dehiscence4 ,illustration3 ,,fig4 #bcb4--;,a ,,bean ,,pod4 ,a #a-loculed pericarp that dehisces on both edges is a legume4 ,peas and beans are typical examples 7,fig4 #bcb72 in fact1 this character gives name to the pea family1--,leguminos4 ,often the valves of the legume twist forcibly and expel the seeds1 throwing them some distance4 ,the word 8pod0 is sometimes restricted to legumes1 but it is better to use it generically for all dehiscent pericarps4 ,a compound pod--dehiscing pericarp of two or more carpels--is a capsule 7,figs4 #bcc1 #bcd1 #bcf1 #bcg74 ,some capsules are of one locule1 but they may have been compound when young 7in the ovary stage7 and the partitions may have vanished4 ,sometimes one or more of the carpels are uniformly crowded out by the exclusive growth of other carpels 7,fig4 #bce74 ,the seeds or parts which are crowded out are said to be aborted4 ,illustration3 ,,fig4 #bcd4--;,,capsule ,,of ,,morning ,,glory4 ,illustration3 ,,fig4 #bce4--,,three-,,carpeled ,,fruit ,,of ,,horse-,,chestnut4 ,two locules are closing by abortion of the ovules4 ,there are several ways in which capsules dehisce or open4 ,when they break along the partitions 7or septa71 the mode is known as septicidal dehiscence 7,fig4 #bcf72 ,in septicidal dehiscence the fruit separates into parts representing the original carpels4 ,these carpels may still be entire1 and they then dehisce individually1 usually along the inner edge as if they were follicles4 ,when the compartments split in the middle1 between the partitions1 the mode is loculicidal dehiscence 7,fig4 #bcg74 ,in some cases the dehiscence is at the top1 when it is said to be apical 7although several modes of dehiscence are here included74 ,when the whole top comes off1 as in purslane and garden portulaca 7,fig4 #bch71 the pod is known as a pyxis4 ,in some cases apical dehiscence is by means of a hole or clefts4 ,illustration3 ,,fig4 #bcf4--,,st4 ,,john',s ,,wort4 ,septicidal4 ,illustration3 ,,fig4 #bcg4--,,loculicidal ,,pod ,,of ,,day-,,lily4 ,the peculiar capsule of the mustard family1 or ,crucifer1 is known as a silique when it is distinctly longer than broad 7,fig4 #bbd71 and a silicle when its breadth nearly equals or exceeds its length4 ,a cruciferous capsule is #b-;carpeled1 with a thin partition1 each locule containing seeds in two rows4 ,the two valves detach from below upwards4 ,cabbage1 turnip1 mustard1 water-cress1 radish1 rape1 shepherd's purse1 sweet alyssum1 wallflower1 honesty1 are examples4 ,illustration3 ,,fig4 #bch4--,,pyxis ,,of ,,portulaca ,,or ,,rose-,,moss4 ,illustration3 ,,fig4 #bci4--;,,berries ,,of ,,gooseberry4 ,remains of calyx at c4 ,illustration3 ,,fig4 #bdj4--;,,berry ,,of ,,the ,,ground ,,cherry ,,or ,,husk ,,tomato1 contained in the inflated calyx4 ,illustration3 ,,fig4 #bda4--,,orange2 example of a berry4 ,the pericarp may be fleshy and indehiscent4 ,a pulpy pericarp with several or many seeds is a berry 7,figs4 #bci1 #bdj1 #bda74 ,to the horticulturist a berry is a small1 soft1 edible fruit1 without particular reference to its structure4 ,the botanical and horticultural conceptions of a berry are1 therefore1 unlike4 ,in the botanical sense1 gooseberries1 currants1 grapes1 tomatoes1 potato-balls1 and even eggplant fruits and oranges 7,fig4 #bda7 are berries2 strawberries1 raspberries1 blackberries are not4 ,illustration3 ,,fig4 #bdb4--,,plum2 example of a drupe4 ,a fleshy pericarp containing one relatively large seed or stone is a drupe4 ,examples are plum 7,fig4 #bdb71 peach1 cherry1 apricot1 olive4 ,the walls of the pit in the plum1 peach1 and cherry are formed from the inner coats of the ovary1 and the flesh from the outer coats4 ,drupes are also known as stone-fruits4 ,illustration3 ,,fig4 #bdc4--;,,fruit ,,of ,,raspberry4 ,illustration3 ,,fig4 #bdd4--;,,aggregate ,,fruit ,,of ,,mulberry2 and a separate fruit4 ,fruits that are formed by the subsequent union of separate pistils are aggregate fruits4 ,the carpels in aggregate fruits are usually more or less fleshy4 ,in the raspberry and blackberry flower1 the pistils are essentially distinct1 but as the pistils ripen they cohere and form one body 7,figs4 #bdc1 #bdd74 ,each of the carpels or pistils in the raspberry and blackberry is a little drupe1 or drupelet4 ,in the raspberry the entire fruit separates from the torus1 leaving the torus on the plant4 ,in the blackberry and dewberry the fruit adheres to the torus1 and the two are removed together when the fruit is picked4 ,accessory ,fruits4--,when the pericarp and some other part grow together1 the fruit is said to be accessory or renforced4 ,an example is the strawberry 7,fig4 #bde74 ,the edible part is a greatly enlarged torus1 and the pericarps are akenes embedded in it4 ,these akenes are commonly called seeds4 ,illustration3 ,,fig4 #bde4--,,strawberry2 fleshy torus in which akenes are embedded4 ,various kinds of renforced fruits have received special names4 ,one of these is the hip1 characteristic of roses4 ,in this case1 the torus is deep and hollow1 like an urn1 and the separate akenes are borne inside it4 ,the mouth of the receptacle may close1 and the walls sometimes become fleshy2 the fruit may then be mistaken for a berry4 ,the fruit of the pear1 apple1 and quince is known as a pome4 ,in this case the five united carpels are completely buried in the hollow torus1 and the torus makes most of the edible part of the ripe fruit1 while the pistils are represented by the core 7,fig4 #bdf74 ,observe the sepals on the top of the torus 7apex of the fruit7 in ,fig4 #bdf4 ,note the outlines of the embedded pericarp in ,fig4 #bdg4 ,illustration3 ,,fig4 #bdf4--,,section ,,of ,,an ,,apple4 ,illustration3 ,,fig4 #bdg4--;,,cross-,,section ,,of ,,an ,,apple4 ,gymnospermous ,fruits4--,in pine1 spruces1 and their kin1 there is no fruit in the sense in which the word is used in the preceding pages1 because there is no ovary4 ,the ovules are naked or uncovered1 in the axils of the scales of the young cone1 and they have neither style nor stigma4 ,the pollen falls directly on the mouth of the ovule4 ,the ovule ripens into a seed1 which is usually winged4 ,because the ovule is not borne in a sac or ovary1 these plants are called gymnosperms 7,greek for 8naked seeds074 ,all the true cone-bearing plants are of this class2 also certain other plants1 as red cedar1 juniper1 yew4 ,the plants are moncious or sometimes dicious4 ,the staminate flowers are mere naked stamens borne beneath scales1 in small yellow catkins which soon fall4 ,the pistillate flowers are naked ovules beneath scales on cones that persist 7,fig4 #bi74 ,gymnospermous seeds may have several cotyledons4 ,,suggestions4--#afh4 ,study the following fruits1 or any five fruits chosen by the teacher1 and answer the questions for each3 ,apple1 peach1 bean1 tomato1 pumpkin4 ,what is its form8 ,locate the scar left by the stem4 ,by what kind of a stem was it attached8 ,is there any remains of the blossom at the blossom end8 ,describe texture and color of surface4 ,divide the fruit into the seed vessel and the surrounding part4 ,has the fruit any pulp or flesh8 ,is it within or without the seed vessel8 ,is the seed vessel simple or subdivided8 ,what is the number of seeds8 ,are the seeds free1 attached to the wall of the vessel1 or to a support in the center8 ,are they arranged in any order8 ,what kind of wall has the seed vessel8 ,what is the difference between a peach stone and a peach seed8 #afi4 ,the nut fruits are always available for study4 ,note the points suggested above4 ,determine what the meat or edible part represents1 whether cotyledons or not4 ,figure #bdh is suggestive4 #agj4 ,mention all the fleshy fruits you know1 tell where they come from1 and refer them to their proper groups4 #aga4 ,what kinds of fruits can you buy in the market1 and to what groups or classes do they belong8 ,of which ones are the seeds only1 and not the pericarps1 eaten8 #agb4 ,an ear of corn is always available for study4 ,what is it--a fruit or a collection of fruits8 ,how are the grains arranged on the cob8 ,how many rows do you count on each of several ears8 ,are all the rows on an ear equally close together8 ,do you find an ear with an odd number of rows8 ,how do the parts of the husk overlap8 ,does the husk serve as protection from rain8 ,can birds pick out the grains8 ,how do insect enemies enter the ear8 ,how and when do weevils lay eggs on corn8 #agc4 ,study a grain of corn4 ,is it a seed8 ,describe the shape of a grain4 ,color4 ,size4 ,does its surface show any projections or depressions8 ,is the seed-coat thin or thick8 ,transparent or opaque8 ,locate the hilum4 ,where is the silk scar8 ,what is the silk8 ,sketch the grain from the two points of view that show it best4 ,where is the embryo8 ,does the grain have endosperm8 ,what is dent corn8 ,flint corn8 ,how many kinds of corn do you know8 ,for what are they used8 ,illustration3 ,,fig4 #bdh4--,,pecan ,,fruit4 ,,note ,,to ,,teacher4--,there are few more interesting subjects to beginning pupils than fruits1--the pods of many kinds1 forms1 and colors1 the berries1 and nuts4 ,this interest may well be utilized to make the teaching alive4 ,all common edible fruits of orchard and vegetable garden should be brought into this discussion 7some of the kinds are explained in 8,lessons with ,plants074 ,of dry fruits1 as pods1 burs1 nuts1 collections may be made for the school museum4 ,fully mature fruits are best for study1 particularly if it is desired to see dehiscence4 ,for comparison1 pistils and partially grown fruits should be had at the same time4 ,if the fruits are not ripe enough to dehisce1 they may be placed in the sun to dry4 ,in the school it is well to have a collection of fruits for study4 ,the specimens may be kept in glass jars4 ,always note exterior of fruit and its parts3 interior of fruit with arrangement and attachment of contents4 ,,chapter ,,xxii ,,dispersal ,,of ,,seeds ,it is to the plant's advantage to have its seeds distributed as widely as possible4 ,it has a better chance of surviving in the struggle for existence4 ,it gets away from competition4 ,many seeds and fruits are of such character as to increase their chances of wide dispersal4 ,the commonest means of dissemination may be classed under four heads3 explosive fruits2 transportation by wind2 transportation by birds2 burs4 ,illustration3 ,,fig4 #bdi4--;,,explosion ,,of ,,the ,,balsam ,,pod4 ,illustration3 ,,fig4 #bej4--;,,explosive ,,fruits ,,of ,,oxalis4 ,an exploding pod is shown at c4 ,the dehiscence is shown at b4 ,the structure of the pod is seen at a4 ,explosive ,fruits4--,some pods open with explosive force and discharge the seeds4 ,even bean and everlasting peas do this4 ,more marked examples are the locust1 witch hazel1 garden balsam 7,fig4 #bdi71 wild jewel-weed or impatiens 7touch-me-not71 violet1 crane's-bill or wild geranium1 bull nettle1 morning glory1 and the oxalis 7,fig4 #bej74 ,the oxalis is common in several species in the wild and cultivation4 ,one of them is known as wood sorrel4 ,fig4 #bej shows the common yellow oxalis4 ,the pod opens loculicidally4 ,the elastic tissue suddenly contracts when dehiscence takes place1 and the seeds are thrown violently4 ,the squirting cucumber is easily grown in a garden 7procure seeds of seedsmen71 and the fruits discharge the seeds with great force1 throwing them many feet4 ,wind ,travelers4--,wind-transported seeds are of two general kinds3 those that are provided with wings1 as the flat seeds of catalpa 7,fig4 #bea7 and cone-bearing trees and the samaras of ash1 elm1 tulip-tree1 ailanthus1 and maple2 and those which have feathery buoys or parachutes to enable them to float in the air4 ,of the latter kind are the fruits of many composites1 in which the pappus is copious and soft4 ,dandelion and thistle are examples4 ,the silk of the milkweed and probably the hairs on the cotton seed have a similar office1 and also the wool of the cat-tail4 ,recall the cottony seeds of the willow and poplar4 ,illustration3 ,,fig4 #bea4--,,winged ,,seeds ,,of ,,catalpa4 ,dispersal by ,birds4--,seeds of berries and of other small fleshy fruits are carried far and wide by birds4 ,the pulp is digested1 but the seeds are not injured4 ,note how the cherries1 raspberries1 blackberries1 ,june-berries1 and others spring up in the fence rows1 where the birds rest4 ,some berries and drupes persist far into winter1 when they supply food to cedar birds1 robins1 and the winter birds4 ,red cedar is distributed by birds4 ,many of these pulpy fruits are agreeable as human food1 and some of them have been greatly enlarged or 8improved0 by the arts of the cultivator4 ,the seeds are usually indigestible4 ,burs4--,many seeds and fruits bear spines1 hooks1 and hairs1 which adhere to the coats of animals and to clothing4 ,the burdock has an involucre with hooked scales1 containing the fruits inside4 ,the clotbur is also an involucre4 ,both are compositous plants1 allied to thistles1 but the whole head1 rather than the separate fruits1 is transported4 ,in some compositous fruits the pappus takes the form of hooks and spines1 as in the 8,spanish bayonets0 and 8pitchforks40 ,fruits of various kinds are known as 8stick tights10 as of the agrimony and hound's-tongue4 ,those who walk in the woods in late summer and fall are aware that plants have means of disseminating themselves 7,fig4 #beb74 ,if it is impossible to identify the burs which one finds on clothing1 the seeds may be planted and specimens of the plant may then be grown4 ,illustration3 ,,fig4 #beb4--,,stealing ,a ,,ride4 ,,suggestions4--#agd4 ,what advantage is it to the plant to have its seeds widely dispersed8 #age4 ,what are the leading ways in which fruits and seeds are dispersed8 #agf4 ,name some explosive fruits4 #agg4 ,describe wind travelers4 #agh4 ,what seeds are carried by birds8 #agi4 ,describe some bur with which you are familiar4 #ahj4 ,are adhesive fruits usually dehiscent or indehiscent8 #aha4 ,do samaras grow on low or tall plants1 as a rule8 #ahb4 ,are the cotton fibers on the seed or on the fruit8 #ahc4 ,name the ways in which the common weeds of your region are disseminated4 #ahd4 ,this lesson will suggest other ways in which seeds are transported4 ,nuts are buried by squirrels for food2 but if they are not eaten1 they may grow4 ,the seeds of many plants are blown on the snow4 ,the old stalks of weeds1 standing through the winter1 may serve to disseminate the plant4 ,seeds are carried by water down the streams and along shores4 ,about woolen mills strange plants often spring up from seed brought in the fleeces4 ,sometimes the entire plant is rolled for miles before the winds4 ,such plants are 8tumbleweeds40 ,examples are ,russian thistle1 hair grass or tumblegrass 7,panicum capillare71 cyclone plant 7,cycloloma platyphyllum71 and white amaranth 7,amarantus albus74 ,about seaports strange plants are often found1 having been introduced in the earth that is used in ships for ballast4 ,these plants are usually known as 8ballast plants40 ,most of them do not persist long4 #ahe4 ,plants are able to spread themselves by means of the great numbers of seeds that they produce4 ,how many seeds may a given elm tree or apple tree or raspberry bush produce8 ,illustration3 ,,fig4 #bec4--,,the ,,fruits ,,of ,,the ,,cat-,,tail ,,are ,,loosened ,,by ,,wind ,,and ,,weather4 ,,chapter ,,xxiii ,,phenogams ,,and ,,cryptogams ,the plants thus far studied produce flowers2 and the flowers produce seeds by means of which the plant is propagated4 ,there are other plants1 however1 that produce no seeds1 and these plants 7including bacteria7 are probably more numerous than the seed-bearing plants4 ,these plants propagate by means of spores1 which are generative cells1 usually simple1 containing no embryo4 ,these spores are very small1 and sometimes are not visible to the naked eye4 ,illustration3 ,,fig4 #bed4--;,,christmas ,,fern4--,dryopteris acrostichoides2 known also as ,aspidium4 ,illustration3 ,,fig4 #bee4--;,,fruiting ,,frond ,,of ,,christmas ,,fern4 ,sori at a4 ,one sorus with its indusium at b4 ,prominent among the spore-propagated plants are ferns4 ,the common ,christmas fern 7so called because it remains green during winter7 is shown in ,fig4 #bed4 ,the plant has no trunk4 ,the leaves spring directly from the ground4 ,the leaves of ferns are called fronds4 ,they vary in shape1 as other leaves do4 ,some of the fronds in ,fig4 #bed are seen to be narrower at the top4 ,if these are examined more closely 7,fig4 #bee71 it will be seen that the leaflets are contracted and are densely covered beneath with brown bodies4 ,these bodies are collections of sporangia or spore-cases4 ,illustration3 ,,fig4 #bef4--;,,common ,,polypode ,,fern4 ,polypodium vulgare4 ,illustration3 ,,fig4 #beg4--,,sori ,,and ,,sporangium ,,of ,,polypode4 ,a chain of cells lies along the top of the sporangium1 which springs back elastically on drying1 thus disseminating the spores4 ,illustration3 ,,fig4 #beh4--,,the ,,brake ,,fruits ,,underneath ,,the ,,revolute ,,edges ,,of ,,the ,,leaf4 ,illustration3 ,,fig4 #bei4--;,,fruiting ,,pinnules ,,of ,,maidenhair ,,fern4 ,the sporangia are collected into little groups1 known as sori 7singular1 sorus7 or fruit-dots4 ,each sorus is covered with a thin scale or shield1 known as an indusium4 ,this indusium separates from the frond at its edges1 and the sporangia are exposed4 ,not all ferns have indusia4 ,the polypode 7,figs4 #bef1 #beg7 does not2 the sori are naked4 ,in the brake 7,fig4 #beh7 and maidenhair 7,fig4 #bei7 the edge of the frond turns over and forms an indusium4 ,the nephrolepis or sword fern of greenhouses is allied to the polypode4 ,the sori are in a single row on either side the midrib 7,fig4 #bfj74 ,the indusium is circular or kidney-shaped and open at one edge or finally all around4 ,the ,boston fern1 ,washington fern1 ,pierson fern1 and others1 are horticultural forms of the common sword fern4 ,in some ferns 7,fig4 #bfa7 an entire frond becomes contracted to cover the sporangia4 ,illustration3 ,,fig4 #bfj4--,,part ,,of ,,frond ,,of ,,sword ,,fern4 ,to the pupil3 ,is this illustration right side up8 ,illustration3 ,,fig4 #bfa4--;,,fertile ,,and ,,sterile ,,fronds ,,of ,,the ,,sensitive ,,fern4 ,the sporangium or spore-case of a fern is a more or less globular body and usually with a stalk 7,fig4 #beg74 ,it contains the spores4 ,when ripe it bursts and the spores are set free4 ,in a moist1 warm place the spores germinate4 ,they produce a small1 flat1 thin1 green1 more or less heart-shaped membrane 7,fig4 #bfb74 ,this is the prothallus4 ,sometimes the prothallus is an inch or more across1 but oftener it is less than a dime in size4 ,although easily seen1 it is commonly unknown except to botanists4 ,prothalli may often be found in greenhouses where ferns are grown4 ,look on the moist stone or brick walls1 or on the firm soil of undisturbed pots and beds2 or spores may be sown in a damp1 warm place4 ,illustration3 ,,fig4 #bfb4--,,prothallus ,,of ,a ,,fern4 ,,enlarged4 ,archegonia at a2 antheridia at b4 ,on the under side of the prothallus two kinds of organs are borne4 ,these are the archegonium 7containing egg-cells7 and the antheridium 7containing sperm-cells74 ,these organs are minute specialized parts of the prothallus4 ,their positions on a particular prothallus are shown at a and b in ,fig4 #bfb1 but in some ferns they are on separate prothalli 7plant dicious74 ,the sperm-cells escape from the antheridium and in the water that collects on the prothallus are carried to the archegonium1 where fertilization of the egg takes place4 ,from the fertilized egg-cell a plant grows1 becoming a 8fern40 ,in most cases the prothallus soon dies4 ,the prothallus is the gametophyte 7from ,greek1 signifying the fertilized plant74 ,the fern plant1 arising from the fertilized egg in the archegonium1 becomes a perennial plant1 each year producing spores from its fronds 7called the sporophyte72 but these spores--which are merely detached special kinds of cells--produce the prothallic phase of the fern plant1 from which new individuals arise4 ,a fern is fertilized but once in its lifetime4 ,the 8fern0 bears the spore1 the spore gives rise to the prothallus1 and the egg-cell of the prothallus 7when fertilized7 gives rise to the fern4 ,a similar alternation of generations runs all through the vegetable kingdom1 although there are some groups of plants in which it is very obscure or apparently wanting4 ,it is very marked in ferns and mosses4 ,in alg 7including the seaweeds7 the gametophyte is the 8plant10 as the non-botanist knows it1 and the sporophyte is inconspicuous4 ,there is a general tendency1 in the evolution of the vegetable kingdom1 for the gametophyte to lose its relative importance and for the sporophyte to become larger and more highly developed4 ,in the seed-bearing plants the sporophyte generation is the only one seen by the non-botanist4 ,the gametophyte stage is of short duration and the parts are small2 it is confined to the time of fertilization4 ,the sporophyte of seed plants1 or the 8plant0 as we know it1 produces two kinds of spores--one kind becoming pollen-grains and the other kind embryo-sacs4 ,the pollen-spores are borne in sporangia1 which are united into what are called anthers4 ,the embryo-sac1 which contains the egg-cell1 is borne in a sporangium known as an ovule4 ,a gametophytic stage is present in both pollen and embryo sac3 fertilization takes place1 and a sporophyte arises4 ,soon this sporophyte becomes dormant1 and is then known as an embryo4 ,the embryo is packed away within tight-fitting coats1 and the entire body is the seed4 ,when the conditions are right the seed grows1 and the sporophyte grows into herb1 bush1 or tree4 ,the utility of the alternation of generations is not understood4 ,the spores of ferns are borne on leaves2 the spores of seed-bearing plants are also borne amongst a mass of specially developed conspicuous leaves known as flowers1 therefore these plants have been known as the flowering plants4 ,some of the leaves are developed as envelopes 7calyx1 corolla71 and others as spore-bearing parts1 or sporophylls 7stamens1 pistils74 ,but the spores of the lower plants1 as of ferns and mosses1 may also be borne in specially developed foliage1 so that the line of demarcation between flowering plants and flowerless plants is not so definite as was once supposed4 ,the one definite distinction between these two classes of plants is the fact that one class produces seeds and the other does not4 ,the seed-plants are now often called spermaphytes1 but there is no single cordinate term to set off those which do not bear seeds4 ,it is quite as well1 for popular purposes1 to use the terms phenogams for the seed-bearing plants and cryptogams for the others4 ,these terms have been objected to in recent years because their etymology does not express literal facts 7phenogam signifying 8showy flowers10 and cryptogam 8hidden flowers071 but the terms represent distinct ideas in classification4 ,the cryptogams include three great series of plants--the ,thallophytes or alg1 lichens1 and fungi2 the ,bryophytes or mosslike plants2 the ,pteridophytes or fernlike plants4 ,illustration3 ,,fig4 #bfc4--;,,diagram ,,to ,,explain ,,the ,,terminology ,,of ,,the ,,frond4 ,,suggestions4--#ahf4 ,the parts of a fern leaf4 ,the primary complete divisions of a frond are called pinn1 no matter whether the frond is pinnate or not4 ,in ferns the word 8pinna0 is used in essentially the same way that leaflet is in the once-compound leaves of other plants4 ,the secondary leaflets are called pinnules1 and in thrice1 or more1 compound fronds1 the last complete parts or leaflets are ultimate pinnules4 ,the diagram 7,fig4 #bfc7 will aid in making the subject clear4 ,if the frond were not divided to the midrib1 it would be simple1 but this diagram represents a compound frond4 ,the general outline of the frond1 as bounded by the dotted line1 is ovate4 ,the stipe is very short4 ,the midrib of a compound frond is known as the rachis4 ,in a decompound frond1 this main rachis is called the primary rachis4 ,segments 7not divided to the rachis7 are seen at the tip1 and down to h on one side and to m on the other4 ,pinn are shown at i1 k1 l1 o1 n4 ,the pinna o is entire2 n is crenate-dentate2 i is sinuate or wavy1 with an auricle at the base2 k and l are compound4 ,the pinna k has twelve entire pinnules4 7,is there ever an even number of pinnules on any pinna87 ,pinna l has nine compound pinnules1 each bearing several entire ultimate pinnules4 ,the spores4--#ahg4 ,lay a mature fruiting frond of any fern on white paper1 top side up1 and allow it to remain in a dry1 warm place4 ,the spores will discharge on the paper4 #ahh4 ,lay the full-grown 7but not dry7 cap of a mushroom or toadstool bottom down on a sheet of clean paper1 under a ventilated box in a warm1 dry place4 ,a day later raise the cap4 ,,chapter ,,xxiv ,,studies ,,in ,,cryptogams ,the pupil who has acquired skill in the use of the compound microscope may desire to make more extended excursions into the cryptogamous orders4 ,the following plants have been chosen as examples in various groups4 ,ferns are sufficiently discussed in the preceding chapter4 ,,bacteria ,if an infusion of ordinary hay is made in water and allowed to stand1 it becomes turbid or cloudy after a few days1 and a drop under the microscope will show the presence of minute oblong cells swimming in the water perhaps by means of numerous hair-like appendages1 that project through the cell wall from the protoplasm within4 ,at the surface of the dish containing the infusion the cells are non-motile and are united in long chains4 ,each of these cells or organisms is a bacterium 7plural1 bacteria74 7,fig4 #ace47 ,bacteria are very minute organisms1--the smallest known1--consisting either of separate oblong or spherical cells1 or of chains1 plates1 or groups of such cells1 depending on the kind4 ,they possess a membrane-like wall which1 unlike the cell walls of higher plants1 contains nitrogen4 ,the presence of a nucleus has not been definitely demonstrated4 ,multiplication is by the fission of the vegetative cells2 but under certain conditions of drought1 cold1 or exhaustion of the nutrient medium1 the protoplasm of the ordinary cells may become invested with a thick wall1 thus forming an endospore which is very resistant to extremes of environment4 ,no sexual reproduction is known4 ,bacteria are very widely distributed as parasites and saprophytes in almost all conceivable places4 ,decay is largely caused by bacteria1 accompanied in animal tissue by the liberation of foul-smelling gases4 ,certain species grow in the reservoirs and pipes of water supplies1 rendering the water brackish and often undrinkable4 ,some kinds of fermentation 7the breaking down or decomposing of organic compounds1 usually accompanied by the formation of gas7 are due to these organisms4 ,other bacteria oxidize alcohol to acetic acid1 and produce lactic acid in milk and butyric acid in butter4 ,bacteria live in the mouth1 stomach1 intestines1 and on the surface of the skin of animals4 ,some secrete gelatinous sheaths around themselves2 others secrete sulfur or iron1 giving the substratum a vivid color4 ,were it not for bacteria1 man could not live on the earth1 for not only are they agents in the process of decay1 but they are concerned in certain healthful processes of plants and animals4 ,we have learned in ,chap4 ,,viii how bacteria are related to nitrogen-gathering4 ,bacteria are of economic importance not alone because of their effect on materials used by man1 but also because of the disease-producing power of certain species4 ,pus is caused by a spherical form1 tetanus or lock-jaw by a rod-shaped form1 diphtheria by short oblong chains1 tuberculosis or 8consumption0 by more slender oblong chains1 and typhoid fever1 cholera1 and other diseases by other forms4 ,many diseases of animals and plants are caused by bacteria4 ,disease-producing bacteria are said to be pathogenic4 ,the ability to grow in other nutrient substances than the natural one has greatly facilitated the study of these minute forms of life4 ,by the use of suitable culture media and proper precautions1 pure cultures of a particular disease-producing bacterium may be obtained with which further experiments may be conducted4 ,milk provides an excellent collecting place for bacteria coming from the air1 from the coat of the cow and from the milker4 ,disease germs are sometimes carried in milk4 ,if a drop of milk is spread on a culture medium 7as agar71 and provided with proper temperature1 the bacteria will multiply1 each one forming a colony visible to the naked eye4 ,in this way1 the number of bacteria originally contained in the milk may be counted4 ,bacteria are disseminated in water1 as the germ of typhoid fever and cholera2 in milk and other fluids2 in the air2 and on the bodies of flies1 feet of birds1 and otherwise4 ,bacteria are thought by many to have descended from alg by the loss of chlorophyll and decrease in size due to the more specialized acquired saprophytic and parasitic habit4 ,,alg ,the alg comprise most of the green floating 8scum0 which covers the surfaces of ponds and other quiet waters4 ,the masses of plants are often called 8frog spittle40 ,others are attached to stones1 pieces of wood1 and other objects submerged in streams and lakes1 and many are found on moist ground and on dripping rocks4 ,aside from these1 all the plants commonly known as seaweeds belong to this category2 these latter are inhabitants of salt water4 ,the simplest forms of alg consist of a single spherical cell1 which multiplies by repeated division or fission4 ,many of the forms found in fresh water are filamentous1 i4e4 the plant body consists of long threads1 either simple or branched4 ,such a plant body is termed a thallus4 ,this term applies to the vegetative body of all plants that are not differentiated into stem and leaves4 ,such plants are known as thallophytes 7p4 #aha74 ,all alg contain chlorophyll1 and are able to assimilate carbon dioxid from the air4 ,this distinguishes them from the fungi4 ,nostoc4--,on wet rocks and damp soil dark1 semitransparent irregular or spherical gelatinous masses about the size of a pea are often found4 ,these consist of a colony of contorted filamentous alg embedded in the jelly-like mass4 ,the chain of cells in the filament is necklace-like4 ,each cell is homogeneous1 without apparent nucleus1 and blue-green in color1 except one cell which is larger and clearer than the rest4 ,the plant therefore belongs to the group of blue-green alg4 ,the jelly probably serves to maintain a more even moisture and to provide mechanical protection4 ,multiplication is wholly by the breaking up of the threads4 ,occasionally certain cells of the filament thicken to become resting-spores1 but no other spore formation occurs4 ,illustration3 ,,fig4 #bfd4--;,,filament ,,of ,,oscillatoria1 showing one dead cell where the strand will break4 ,oscillatoria4--,the blue-green coatings found on damp soil and in water frequently show under the microscope the presence of filamentous alg composed of many short homogeneous cells 7,fig4 #bfd74 ,if watched closely1 some filaments will be seen to wave back and forth slowly1 showing a peculiar power of movement characteristic of this plant4 ,multiplication is by the breaking up of the threads4 ,there is no true spore formation4 ,illustration3 ,,fig4 #bfe4--,strand of ,spirogyra1 showing the chlorophyll bands4 ,there is a nucleus at a4 ,how many cells1 or parts of cells1 are shown in this figure8 ,,spirogyra4--,one of the most common forms of the green alg is spirogyra 7,fig4 #bfe74 ,this plant often forms the greater part of the floating green mass 7or 8frog spittle07 on ponds4 ,the threadlike character of the thallus can be seen with the naked eye or with a hand lens1 but to study it carefully a microscope magnifying two hundred diameters or more must be used4 ,the thread is divided into long cells by cross walls which1 according to the species1 are either straight or curiously folded 7,fig4 #bff74 ,the chlorophyll is arranged in beautiful spiral bands near the wall of each cell4 ,from the character of these bands the plant takes its name4 ,each cell is provided with a nucleus and other protoplasm4 ,the nucleus is suspended near the center of the cell 7a1 ,fig4 #bfe7 by delicate strands of protoplasm radiating toward the wall and terminating at certain points in the chlorophyll band4 ,the remainder of the protoplasm forms a thin layer lining the wall4 ,the interior of the cell is filled with cell-sap4 ,the protoplasm and nucleus cannot be easily seen1 but if the plant is stained with a dilute alcoholic solution of eosin they become clear4 ,spirogyra is propagated vegetatively by the breaking off of parts of the threads1 which continue to grow as new plants4 ,resting-spores1 which may remain dormant for a time1 are formed by a process known as conjugation4 ,two threads lying side by side send out short projections1 usually from all the cells of a long series 7,fig4 #bff74 ,the projections or processes from opposite cells grow toward each other1 meet1 and fuse1 forming a connecting tube between the cells4 ,the protoplasm1 nucleus1 and chlorophyll band of one cell now pass through this tube1 and unite with the contents of the other cell4 ,the entire mass then becomes surrounded by a thick cellulose wall1 thus completing the resting-spore1 or zygospore 7z1 ,fig4 #bff74 ,illustration3 ,,fig4 #bff4--;,,conjugation ,,of ,,spirogyra4 ,ripe zygospores on the left2 a1 connecting tubes4 ,illustration3 ,,fig4 #bfg4--,,strand1 ,,or ,,filament ,,of ,,zygnema1 freed from its gelatinous covering4 ,zygnema is an alga closely related to spirogyra and found in similar places4 ,its life history is practically the same1 but it differs from spirogyra in having two star-shaped chlorophyll bodies 7,fig4 #bfg7 in each cell1 instead of a chlorophyll-bearing spiral band4 ,illustration3 ,,fig4 #bfh4--,,thread ,,of ,,vaucheria ,,with ,o,,gonia ,,and ,,antheridia4 ,vaucheria is another alga common in shallow water and on damp soil4 ,the thallus is much branched1 but the threads are not divided by cross walls as in spirogyra4 ,the plants are attached by means of colorless root-like organs which are much like the root hairs of the higher plants3 these are rhizoids4 ,the chlorophyll is in the form of grains scattered through the thread4 ,vaucheria has a special mode of asexual reproduction by means of swimming spores or swarm-spores4 ,these are formed singly in a short enlarged lateral branch known as the sporangium4 ,when the sporangium bursts1 the entire contents escape1 forming a single large swarm-spore1 which swims about by means of numerous lashes or cilia on its surface4 ,the swarm spores are so large that they can be seen with the naked eye4 ,after swimming about for some time they come to rest and germinate1 producing a new plant4 ,the formation of resting-spores of vaucheria is accomplished by means of special organs1 ogonia 7o1 ,fig4 #bfh7 and antheridia 7a1 ,fig4 #bfh74 ,both of these are specially developed branches from the thallus4 ,the antheridia are nearly cylindrical1 and curved toward the ogonia4 ,the upper part of an antheridium is cut off by a cross wall1 and within it numerous ciliated sperm-cells are formed4 ,these escape by the ruptured apex of the antheridium4 ,the ogonia are more enlarged than the antheridia1 and have a beak-like projection turned a little to one side of the apex4 ,they are separated from the thallus thread by a cross wall1 and contain a single large green cell1 the egg-cell4 ,the apex of the ogonium is dissolved1 and through the opening the sperm-cells enter4 ,fertilization is thus accomplished4 ,after fertilization the egg-cell becomes invested with a thick wall and is thus converted into a resting-spore1 the ospore4 ,fucus4--,these are rather large specialized alg belonging to the group known as brown seaweeds and found attached by a disk to the rocks of the seashore just below high tide 7,fig4 #bfi74 ,they are firm and strong to resist wave action and are so attached as to avoid being washed ashore4 ,they are very abundant alg4 ,in shape the plants are long1 branched1 and multicellular1 with either flat or terete branches4 ,they are olive-brown4 ,propagation is by the breaking off of the branches4 ,no zospores are produced1 as in many other seaweeds2 and reproduction is wholly sexual4 ,the antheridia1 bearing sperm-cells1 and the ogonia1 each bearing eight egg-cells1 are sunken in pits or conceptacles4 ,these pits are aggregated in the swollen lighter colored tips of some of the branches 7s1 s1 ,fig4 #bfi74 ,the egg-cells and sperm-cells escape from the pits and fertilization takes place in the water4 ,the matured eggs1 or spores1 reproduce the fucus plant directly4 ,illustration3 ,,fig4 #bfi4--;,,fucus4 ,fruiting branches at s1 s4 ,on the stem are two air-bladders4 ,illustration3 ,,fig4 #bgj4--,,nitella4 ,nitella4--,this is a large branched and specialized fresh-water alga found in tufts attached to the bottom in shallow ponds 7,fig4 #bgj74 ,between the whorls of branches are long internodes consisting of a single cylindrical cell1 which is one of the largest cells known in vegetable tissue4 ,under the microscope the walls of this cell are found to be lined with a layer of small stationary chloroplastids1 within which layer the protoplasm1 under favorable circumstances1 will be found in motion1 moving up one side and down the other 7in rotation74 ,note the clear streak up the side of the cell and its relation to the moving current4 ,,fungi ,some forms of fungi are familiar to every one4 ,mushrooms and toadstools1 with their varied forms and colors1 are common in fields1 woods1 and pastures4 ,in every household the common molds are familiar intruders1 appearing on old bread1 vegetables1 and even within tightly sealed fruit jars1 where they form a felt-like layer dusted over with blue1 yellow1 or black powder4 ,the strange occurrence of these plants long mystified people1 who thought they were productions of the dead matter upon which they grew1 but now we know that a mold1 as any other plant1 cannot originate spontaneously2 it must start from something which is analogous to a seed4 ,the 8seed0 in this case is a spore4 ,a spore may be produced by a vegetative process 7growing out from the ordinary plant tissues71 or it may be the result of a fertilization process4 ,favorable conditions for the growth of fungi4--,place a piece of bread under a moist bell jar and another in an uncovered place near by4 ,sow mold on each4 ,note the result from day to day4 ,moisten a third piece of bread with weak copper sulfate 7blue vitriol7 or mercuric chlorid solution1 sow mold1 cover with bell jar1 note results1 and explain4 ,expose pieces of different kinds of food in a damp atmosphere and observe the variety of organisms appearing4 ,fungi are saprophytes or parasites1 and must be provided with organic matter on which to grow4 ,they are usually most abundant in moist places and wet seasons4 ,illustration3 ,,fig4 #bga4--,,mucor ,,mucedo1 showing habit4 ,illustration3 ,,fig4 #bgb4--,,spores ,,of ,,mucor1 some germinating4 ,mold4--,one of these molds 7,mucor mucedo71 which is very common on all decaying fruits and vegetables1 is shown in ,fig4 #bga1 somewhat magnified4 ,when fruiting1 this mold appears as a dense mass of long white hairs1 often over an inch high1 standing erect from the fruit or vegetable on which it is growing4 ,the life of this mucor begins with a minute rounded spore 7a1 ,fig4 #bgb71 which lodges on the decaying material4 ,when the spore germinates1 it sends out a delicate thread that grows rapidly in length and forms very many branches that soon permeate every part of the substance on which the plant grows 7b1 ,fig4 #bgb74 ,one of these threads is termed a hypha4 ,all the threads together form the mycelium of the fungus4 ,the mycelium disorganizes the material in which it grows1 and thus the mucor plant 7,fig4 #bga7 is nourished4 ,it corresponds physiologically to the roots and stems of other plants4 ,when the mycelium is about two days old1 it begins to form the long fruiting stalks which we first noticed4 ,to study them1 use a compound microscope magnifying about two hundred diameters4 ,one of the stalks1 magnified1 is shown in a1 ,fig4 #bgd4 ,it consists of a rounded head1 the sporangium1 sp1 supported on a long1 delicate stalk1 the sporangiophore4 ,the stalk is separated from the sporangium by a wall which is formed at the base of the sporangium4 ,this wall1 however1 does not extend straight across the thread1 but it arches up into the sporangium like an inverted pear4 ,it is known as the columella1 c4 ,when the sporangium is placed in water1 the wall immediately dissolves and allows hundreds of spores1 which were formed in the cavity within the sporangium1 to escape1 b4 ,all that is left of the fruit is the stalk1 with the pear-shaped columella at its summit1 c4 ,the spores that have been set free by the breaking of the sporangium wall are now scattered by the wind and other agents4 ,those that lodge in favorable places begin to grow immediately and reproduce the fungus4 ,the others soon perish4 ,illustration3 ,,fig4 #bgc4--,,mucor1 showing formation of zygospore on the right2 germinating zygospore on the left4 ,illustration3 ,,fig4 #bgd4--,,mucor4 a1 sporangium2 b1 sporangium bursting2 c1 columella4 ,the mucor may continue to reproduce itself in this way indefinitely1 but these spores are very delicate and usually die if they do not fall on favorable ground1 so that the fungus is provided with another means of carrying itself over unfavorable seasons1 as winter4 ,this is accomplished by means of curious thick-walled resting-spores or zygospores4 ,the zygospores are formed on the mycelium buried within the substance on which the plant grows4 ,they originate in the following way3 ,two threads that lie near together send out short branches1 which grow toward each other and finally meet 7,fig4 #bgc74 ,the walls at the ends1 a1 then disappear1 allowing the contents to flow together4 ,at the same time1 however1 two other walls are formed at points farther back1 b1 b1 separating the short section1 c1 from the remainder of the thread4 ,this section now increases in size and becomes covered with a thick1 dark brown wall ornamented with thickened tubercles4 ,the zygospore is now mature and1 after a period of rest1 it germinates1 either producing a sporangium directly or growing out as mycelium4 ,the zygospores of the mucors form one of the most interesting and instructive objects among the lower plants4 ,they are1 however1 very difficult to obtain4 ,one of the mucors 7,sporodinia grandis7 may be frequently found in summer growing on toadstools4 ,this plant usually produces zygospores that are formed on the arial mycelium4 ,the zygospores are large enough to be recognized with a hand lens4 ,the material may be dried and kept for winter study1 or the zygospores may be prepared for permanent microscopic mounts in the ordinary way4 ,illustration3 ,,fig4 #bge4--,,yeast ,,plants4 ,yeast4--,this is a very much reduced and simple fungus1 consisting normally of isolated spherical or elliptical cells 7,fig4 #bge7 containing abundant protoplasm and probably a nucleus1 although the latter is not easily observed4 ,it propagates rapidly by budding1 which consists of the gradual extrusion of a wart-like swelling that is sooner or later cut off at the base by constriction1 thus forming a separate organism4 ,although simple in structure1 the yeast is found to be closely related to some of the higher groups of fungi as shown by the method of spore formation4 ,when grown on special substances like potato or carrot1 the contents of the cell may form spores inside of the sac-like mother cell1 thus resembling the sac-fungi to which blue mold and mildews belong4 ,the yeast plant is remarkable on account of its power to induce alcoholic fermentation in the media in which it grows4 ,there are many kinds of yeasts4 ,one of them is found in the common yeast cakes4 ,in the process of manufacture of these cakes1 the yeast cells grow to a certain stage1 and the material is then dried and fashioned into small cakes1 each cake containing great numbers of the yeast cells4 ,when the yeast cake is added to dough1 and proper conditions of warmth and moisture are provided1 the yeast grows rapidly and breaks up the sugar of the dough into carbon dioxid and alcohol4 ,this is fermentation4 ,the gases escape and puff up the dough1 causing the bread to rise4 ,in this loosened condition the dough is baked2 if it is not baked quickly enough1 the bread 8falls40 ,shake up a bit of yeast cake in slightly sweetened water3 the water soon becomes cloudy from the growing yeasts4 ,parasitic fungi4--,most of the molds are saprophytes4 ,many other fungi are parasitic on living plants and animals 7,fig4 #bhe74 ,some of them have complicated life histories1 undergoing many changes before the original spore is again produced4 ,the willow mildew and the common rust of wheat will serve to illustrate the habits of parasitic fungi4 ,the willow mildew 7,uncinula salicis74--,this is one of the sac fungi4 ,it forms white downy patches on the leaves of willows 7,fig4 #bgf74 ,these patches consist of numerous interwoven threads that may be recognized under the microscope as the mycelium of the fungus4 ,the mycelium in this case lives on the surface of the leaf and nourishes itself by sending short branches into the cells of the leaf to absorb food materials from them4 ,illustration3 ,,fig4 #bgf4--;,,colonies ,,of ,,willow ,,mildew4 ,illustration3 ,,fig4 #bgg4--,,summer-,,spores ,,of ,,willow ,,mildew4 ,illustration3 ,,fig4 #bgh4--,,perithecium ,,of ,,willow ,,mildew4 ,illustration3 ,,fig4 #bgi4--,,section ,,through ,,perithecium ,,of ,,willow ,,mildew4 ,numerous summer-spores are formed of short1 erect branches all over the white surface4 ,one of these branches is shown in ,fig4 #bgg4 ,when it has grown to a certain length1 the upper part begins to segment or divide into spores which fall and are scattered by the wind4 ,those falling on other willows reproduce the fungus there4 ,this process continues all summer1 but in the later part of the season provision is made to maintain the mildew through the winter4 ,if some of the white patches are closely examined in ,july or ,august1 a number of little black bodies will be seen among the threads4 ,these little bodies are called perithecia1 shown in ,fig4 #bgh4 ,to the naked eye they appear as minute specks1 but when seen under a magnification of #bjj diameters they present a very interesting appearance4 ,they are hollow spherical bodies decorated around the outside with a fringe of crook-like hairs4 ,the resting-spores of the willow mildew are produced in sacs or asci inclosed within the leathery perithecia4 ,figure #bgi shows a cross-section of a perithecium with the asci arising from the bottom4 ,the spores remain securely packed in the perithecia4 ,they do not ripen in the autumn1 but fall to the ground with the leaf1 and there remain securely protected among the dead foliage4 ,the following spring they mature and are liberated by the decay of the perithecia4 ,they are then ready to attack the unfolding leaves of the willow and repeat the work of the summer before4 ,illustration3 ,,fig4 #bhj4--,,sori ,,containing ,,teleutospores ,,of ,,wheat ,,rust4 ,the wheat rust4--,the development of some of the rusts1 as the common wheat rust 7,puccinia graminis71 is even more interesting and complicated than that of the mildews4 ,wheat rust is also a true parasite1 affecting wheat and a few other grasses4 ,the mycelium here cannot be seen by the unaided eye1 for it consists of threads which are present within the host plant1 mostly in the intercellular spaces4 ,these threads also send short branches1 or haustoria 7,fig4 #acb71 into the neighboring cells to absorb nutriment4 ,illustration3 ,,fig4 #bha4--,,teleutospore ,,of ,,wheat ,,rust4 ,the resting-spores of wheat rust are produced in late summer1 when they may be found in black lines breaking through the epidermis of the wheat stalk 7black-rust stage74 ,they are formed in masses1 called sori 7,fig4 #bhj71 from the ends of numerous crowded mycelial strands just beneath the epidermis of the host4 ,the individual spores are very small and can be well studied only with a microscope of high power 7 about #djj74 ,they are brown two-celled bodies with a thick wall 7,fig4 #bha74 ,since they are the resting or winter-spores1 they are termed teleutospores 78completed spores074 ,usually they do not fall1 but remain in the sori during winter4 ,the following spring each cell of the teleutospore puts forth a rather stout thread1 which does not grow more than several times the length of the spore and terminates in a blunt extremity4 ,this germ tube1 promycelium1 now becomes divided into four cells by cross walls1 which are formed from the top downwards4 ,each cell gives rise to a short1 pointed branch which1 in the course of a few hours1 forms at its summit a single spore called a sporidium4 ,this in turn germinates and produces a mycelium4 ,in ,fig4 #bhb a germinating teleutospore is drawn to show the promycelium1 p1 divided into four cells1 each producing a short branch with a little sporidium1 s4 ,illustration3 ,,fig4 #bhb4--;,,germinating ,,teleutospore ,,of ,,wheat ,,rust4 ,illustration3 ,,fig4 #bhc4--,,leaf ,,of ,,barberry ,,with ,,cluster-,,cups4 ,illustration3 ,,fig4 #bhd4--,,section ,,through ,a ,,cluster-,,cup ,,on ,,barberry ,,leaf4 ,a most remarkable circumstance in the life history of the wheat rust is the fact that the mycelium produced by the sporidium can live only in barberry leaves1 and it follows that if no barberry bushes are in the neighborhood the sporidia finally perish4 ,those which happen to lodge on a barberry bush germinate immediately1 producing a mycelium that enters the barberry leaf and grows within its tissues4 ,very soon the fungus produces a new kind of spores on the barberry leaves4 ,these are called cidiospores4 ,they are formed in long chains in little fringed cups1 or cidia1 which appear in groups on the lower side of the leaf 7,fig4 #bhc74 ,these orange or yellow cidia are termed cluster-cups4 ,in ,fig4 #bhd is shown a cross-section of one of the cups1 outlining the long chains of spores1 and the mycelium in the tissues4 ,the cidiospores are formed in the spring1 and after they have been set free1 some of them lodge on wheat or other grasses1 where they germinate immediately4 ,the germ-tube enters the leaf through a stomate1 whence it spreads among the cells of the wheat plant4 ,in summer one-celled reddish uredospores 78blight spores10 red-rust stage7 are produced in a manner similar to the teleutospores4 ,these are capable of germinating immediately1 and serve to disseminate the fungus during the summer on other wheat plants or grasses4 ,late in the season1 teleutospores are again produced1 completing the life cycle of the plant4 ,illustration3 ,,fig4 #bhe4--;,,how ,a ,,parasitic ,,fungus ,,works4 ,anthracnose on a bean pod entering the bean beneath4 7,whetzel47 ,many rusts besides ,puccinia graminis produce different spore forms on different plants4 ,the phenomenon is called hetercism1 and was first shown to exist in the wheat rust4 ,curiously enough1 the peasants of ,europe had observed and asserted that barberry bushes cause wheat to blight long before science explained the relation between the cluster-cups on barberry and the rust on wheat4 ,the true relation was actually demonstrated1 as has since been done for many other rusts on their respective hosts1 by sowing the cidiospores on healthy wheat plants and thus producing the rust4 ,the cedar apple is another rust1 producing the curious swellings often found on the branches of red cedar trees4 ,in the spring the teleutospores ooze out from the 8apple0 in brownish yellow masses4 ,it has been found that these attack various fruit trees1 producing cidia on their leaves4 ,fig4 #bhe explains how a parasitic fungus works4 ,puffballs1 mushrooms1 toadstools1 and shelf fungi4--,these represent what are called the higher fungi1 because of the size and complexity of the plant body as well as from the fact that they seem to stand at the end of one line of evolution4 ,the mycelial threads grow together in extensive strands in rotten wood or in the soil1 and send out large complex growths of mycelium in connection with which the spores are borne4 ,these arial parts are the only ones we ordinarily see1 and which constitute the 8mushroom0 part 7,fig4 #aca74 ,only asexual spores 7basidiospores7 are produced1 and on short stalks 7basidia7 7,fig4 #bhf74 ,in the puffballs the spores are inclosed and constitute a large part of the 8smoke40 ,in the mushrooms and toadstools they are borne on gills1 and in the shelf fungi 7,fig4 #acd7 on the walls of minute pores of the underside4 ,the mycelium of these shelf fungi frequently lives and grows for a long time concealed in the substratum before the visible fruit bodies are sent out4 ,practically all timber decay is caused by such growth1 and the damage is largely done before the fruiting bodies appear4 ,for other accounts of mushrooms1 see ,chap4 ,,xiv4 ,illustration3 ,,fig4 #bhf4--,,part ,,of ,,gill ,,of ,,the ,,cultivated ,,mushroom4 tr1 trama tissue2 sh1 hymenium2 b1 basidium2 st1 sterigma2 sp1 spore4 7,atkinson47 ,,lichens ,lichens are so common everywhere that the attention of the student is sure to be drawn to them4 ,they grow on rocks1 trunks of trees 7,fig4 #bhg71 old fences1 and on the earth4 ,they are thin1 usually gray ragged objects1 apparently lifeless4 ,their study is too difficult for beginners1 but a few words of explanation may be useful4 ,illustration3 ,,fig4 #bhg4--,,lichen ,,on ,,an ,,oak ,,trunk4 7,a species of ,physcia47 ,lichens were formerly supposed to be a distinct or separate division of plants4 ,they are now known to be organisms1 each species of which is a constant association of a fungus and an alga4 ,the thallus is ordinarily made up of fungous mycelium or tissue within which the imprisoned alga is definitely distributed4 ,the result is a growth unlike either component4 ,this association of alga and fungus is usually spoken of as symbiosis1 or mutually helpful growth1 the alga furnishing some things1 the fungus others1 and both together being able to accomplish work that neither could do independently4 ,by others this union is considered to be a mild form of parasitism1 in which the fungus profits at the expense of the alga4 ,as favorable to this view1 the facts are cited that each component is able to grow independently1 and that under such conditions the algal cells seem to thrive better than when imprisoned by the fungus4 ,lichens propagate by means of soredia1 which are tiny parts separated from the body of the thallus1 and consisting of one or more algal cells overgrown with fungus threads4 ,these are readily observed in many lichens4 ,they also produce spores1 usually ascospores1 which are always the product of the fungus element1 and which reproduce the lichen by germinating in the presence of algal cells1 to which the hyph immediately cling4 ,lichens are found in the most inhospitable places1 and1 by means of acids which they secrete1 they attack and slowly disintegrate even the hardest rocks4 ,by making thin sections of the thallus with a sharp razor and examining under the compound microscope1 it is easy to distinguish the two components in many lichens4 ,,liverworts ,the liverworts are peculiar flat green plants usually found on wet cliffs and in other moist1 shady places4 ,they frequently occur in greenhouses where the soil is kept constantly wet4 ,one of the commonest liverworts is ,marchantia polymorpha1 two plants of which are shown in ,figs4 #bhh1 #bhi4 ,the plant consists of a ribbon-like thallus that creeps along the ground1 becoming repeatedly forked as it grows4 ,the end of each branch is always conspicuously notched4 ,there is a prominent midrib extending along the center of each branch of the thallus4 ,on the under side of the thallus1 especially along the midrib1 there are numerous rhizoids which serve the purpose of roots1 absorbing nourishment from the earth and holding the plant in its place4 ,the upper surface of the thallus is divided into minute rhombic areas that can be seen with the naked eye4 ,each of these areas is perforated by a small breathing pore or stomate that leads into a cavity just beneath the epidermis4 ,this space is surrounded by chlorophyll-bearing cells1 some of which stand in rows from the bottom of the cavity 7,fig4 #bij74 ,the delicate assimilating tissue is thus brought in close communication with the outer air through the pore in the thick1 protecting epidermis4 ,illustration3 ,,fig4 #bhh4 ,,fig4 #bhi4 ,,plants ,,of ,,marchantia4 ,illustration3 ,,fig4 #bij4--,,section ,,of ,,thallus ,,of ,,marchantia4 ,stomate at a4 ,at various points on the midrib are little cups containing small green bodies4 ,these bodies are buds or gemm which are outgrowths from the cells at the bottom of the cup4 ,they become loosened and are then dispersed by the rain to other places1 where they take root and grow into new plants4 ,the most striking organs on the thallus of marchantia are the peculiar stalked bodies shown in ,figs4 #bhh1 #bhi4 ,these are termed archegoniophores and antheridiophores or receptacles4 ,their structure and function are very interesting1 but their parts are so minute that they can be studied only with the aid of a microscope magnifying from #ajj to #djj times4 ,enlarged drawings will guide the pupil4 ,illustration3 ,,fig4 #bia4--,,section ,,through ,,antheridiophore ,,of ,,marchantia1 showing antheridia4 ,one antheridium more magnified4 ,the antheridiophores are fleshy1 lobed disks borne on short stalks 7,fig4 #bia74 ,the upper surface of the disk shows openings scarcely visible to the naked eye4 ,however1 a section of the disk1 such as is drawn in ,fig4 #bia1 shows that the pores lead into oblong cavities in the receptacle4 ,from the base of each cavity there arises a thick1 club-shaped body1 the antheridium4 ,within the antheridium are formed many sperm-cells which are capable of swimming about in water by means of long lashes or cilia attached to them4 ,when the antheridium is mature1 it bursts and allows the ciliated sperm cells to escape4 ,the archegoniophores are also elevated on stalks 7,fig4 #bhi74 ,instead of a simple disk1 the receptacle consists of nine or more finger-like rays4 ,along the under side of the rays1 between delicately fringed curtains1 peculiar flask-like bodies1 or archegonia1 are situated4 ,the archegonia are not visible to the naked eye4 ,they can be studied only with the microscope 7 about #djj74 ,one of them much magnified is represented in ,fig4 #bib4 ,its principal parts are the long neck1 a1 and the rounded venter1 b1 inclosing a large free cell--the egg-cell4 ,illustration3 ,,fig4 #bib4--;,,archegonium ,,of ,,marchantia4 ,illustration3 ,,fig4 #bic4--;,,archegoniophore1 ,,with ,,sporogonia1 ,,of ,,marchantia4 ,we have seen that the antheridium at maturity discharges its sperm-cells4 ,these swim about in the water provided by the dew and rain4 ,some of them finally find their way to the archegonia and egg-cells1 the latter being fertilized1 as pollen fertilizes the ovules of higher plants4 ,after fertilization the egg-cell develops into the spore capsule or sporogonium4 ,the mature spore capsules may be seen in ,fig4 #bic4 ,they consist of an oval spore-case on a short stalk1 the base of which is imbedded in the tissue of the receptacle1 from which it derives the necessary nourishment for the development of the sporogonium4 ,at maturity the sporogonium is ruptured at the apex1 setting free the spherical spores together with numerous filaments having spirally thickened walls 7,fig4 #bid74 ,these filaments are called elaters4 ,when drying1 they exhibit rapid movements by means of which the spores are scattered4 ,the spores germinate and again produce the thallus of marchantia4 ,illustration3 ,,fig4 #bid4--,,spores ,,and ,,elaters ,,of ,,marchantia4 ,illustration3 ,,fig4 #bie4--,,polytrichum ,,commune4 f1f1 fertile plants1 one on the left in fruit1 m1 antheridial plant4 ,illustration3 ,,fig4 #bif4--,,section ,,of ,,leaf ,,of ,,polytrichum ,,commune4 ,,mosses 7,bryophyta7 ,if we have followed carefully the development of marchantia1 the study of one of the mosses will be comparatively easy4 ,the mosses are more familiar plants than the liverworts4 ,they grow on trees1 stones1 and on the soil both in wet and dry places4 ,one of the common larger mosses1 known as ,polytrichum commune1 may serve as an example1 ,fig4 #bie4 ,this plant grows on rather dry knolls1 mostly in the borders of open woods1 where it forms large beds4 ,in dry weather these beds have a reddish brown appearance1 but when moist they form beautiful green cushions4 ,this color is due1 in the first instance1 to the color of the old stems and leaves1 and1 in the second instance1 to the peculiar action of the green living leaves under the influence of changing moisture-conditions4 ,the inner or upper surface of the leaf is covered with thin1 longitudinal ridges of delicate cells which contain chlorophyll4 ,these cells are shown in cross-section in ,fig4 #bif1 as dots or granules4 ,all the other tissue of the leaf consists of thick-walled1 corky cells which do not allow moisture to penetrate4 ,when the air is moist the green leaves spread out1 exposing the chlorophyll cells to the air1 but in dry weather the margins of the leaves roll inward1 and the leaves fold closely against the stem1 thus protecting the delicate assimilating tissue4 ,the antheridia and archegonia of polytrichum are borne in groups at the ends of the branches on different plants 7many mosses bear both organs on the same branch74 ,they are surrounded by involucres of characteristic leaves termed perichtia or perichtal leaves4 ,multicellular hairs known as paraphyses are scattered among the archegonia and antheridia4 ,the involucres with the organs borne within them are called receptacles1 or1 less appropriately1 8moss flowers40 ,as in marchantia1 the organs are very minute and must be highly magnified to be studied4 ,illustration3 ,,fig4 #big4--,,section ,,through ,a ,,receptacle ,,of ,,polytrichum ,,commune1 showing paraphyses and antheridia4 ,the antheridia are borne in broad cup-like receptacles on the antheridial plants 7,fig4 #big74 ,they are much like the antheridia of marchantia1 but they stand free among the paraphyses and are not sunk in cavities4 ,at maturity they burst and allow the sperm cells or spermatozoids to escape4 ,in polytrichum1 when the receptacles have fulfilled their function1 the stem continues to grow from the center of the cup 7m1 ,fig4 #bie74 ,the archegonia are borne in other receptacles on different plants4 ,they are like the archegonia of marchantia except that they stand erect on the end of the branch4 ,the sporogonium which develops from the fertilized egg is shown in a1 b1 ,fig4 #bie4 ,it consists of a long1 brown stalk bearing the spore-case at its summit4 ,the base of the stalk is imbedded in the end of the moss stem by which it is nourished4 ,the capsule is entirely inclosed by a hairy cap1 the calyptra1 b4 ,the calyptra is really the remnant of the archegonium1 which1 for a time1 increases in size to accommodate and protect the young growing capsule4 ,it is finally torn loose and carried up on the spore-case4 ,the mouth of the capsule is closed by a circular lid1 the operculum1 having a conical projection at the center4 ,the operculum soon drops1 or it may be removed1 displaying a fringe of sixty-four teeth guarding the mouth of the capsule4 ,this ring of teeth is known as the peristome4 ,in most mosses the teeth exhibit peculiar hygroscopic movements2 i4e4 when moist they bend outwards1 and upon drying curve in toward the mouth of the capsule4 ,this motion1 it will be seen1 serves to disperse the spores gradually over a long period of time4 ,not the entire capsule is filled with spores4 ,there are no elaters1 but the center of the capsule is occupied by a columnar strand of tissue1 the columella1 which expands at the mouth into a thin1 membranous disk1 closing the entire mouth of the capsule except the narrow annular chink guarded by the teeth4 ,in this moss the points of the teeth are attached to the margin of the membrane1 allowing the spores to sift out through the spaces between them4 ,when the spores germinate they form a green1 branched thread1 the protonema4 ,this gives rise directly to moss plants1 which appear as little buds on the thread4 ,when the moss plants have sent their little rhizoids into the earth1 the protonema dies1 for it is no longer necessary for the support of the little plants1 and the moss plants grow independently4 ,funaria is a moss very common on damp1 open soil4 ,it forms green patches of small fine leaves from which arise long brown stalks terminated by curved capsules 7,fig4 #bih74 ,the structure is similar to that of polytrichum1 except the absence of plates on the under side of the leaves1 the continuous growth of the stem1 the curved capsule1 double peristome1 moncious rather than dicious receptacles1 and nearly glabrous unsymmetrical calyptra4 ,illustration3 ,,fig4 #bih4--;,,funaria ,,hygroscopica4 ,,equisetums1 ,,or ,,horsetails 7,pteridophyta7 ,there are about twenty-five species of equisetum1 constituting the only genus of the unique family ,equisetace4 ,among these ,e4 arvense 7,fig4 #bii7 is common on clayey and sandy soils4 ,in this species the work of nutrition and that of spore production are performed by separate shoots from an underground rhizome4 ,the fertile branches appear early in spring4 ,the stem1 which is #c to #f inches high1 consists of a number of cylindrical1 furrowed internodes1 each sheathed at the base by a circle of scale leaves4 ,the shoots are of a pale yellow color4 ,they contain no chlorophyll1 and are nourished by the food stored in the rhizome 7,fig4 #bii74 ,the spores are formed on specially developed fertile leaves or sporophylls which are collected into a spike or cone at the end of the stalk 7a1 ,fig4 #bii74 ,a single sporophyll is shown at b4 ,it consists of a short stalk expanded into a broad1 mushroom-like head4 ,several large sporangia are borne on its under side4 ,the spores formed in the sporangia are very interesting and beautiful objects when examined under the microscope 7 about #bjj74 ,they are spherical1 green bodies1 each surrounded by two spiral bands attached to the spore at their intersection1 s4 ,these bands exhibit hygroscopic movements by means of which the spores become entangled1 and are held together4 ,this is of advantage to the plant1 as we shall see4 ,all the spores are alike1 but some of the prothallia grow to a greater size than the others4 ,the large prothallia produce only archegonia while the smaller ones produce antheridia4 ,both of these organs are much like those of the ferns1 and fertilization is accomplished in the same way4 ,since the prothallia are usually dicious1 the special advantage of the spiral bands1 holding the spores together so that both kinds of prothallia may be in close proximity1 will be easily understood4 ,as in the fern1 the fertilized egg-cell develops into an equisetum plant4 ,illustration3 ,,fig4 #bii4--;,,equisetum ,,arvense4 st1 sterile shoot2 f1 fertile shoot showing the spike at a2 b1 sporophyll1 with sporangia2 s1 spore4 ,the sterile shoots 7st1 ,fig4 #bii7 appear much later in the season4 ,they give rise to repeated whorls of angular or furrowed branches4 ,the leaves are very much reduced scales1 situated at the internodes4 ,the stems are provided with chlorophyll and act as assimilating tissue1 nourishing the rhizome and the fertile shoots4 ,nutriment is also stored in special tubers developed on the rhizome4 ,other species of equisetum have only one kind of shoot--a tall1 hard1 leafless1 green shoot with the spike at its summit4 ,equisetum stems are full of silex1 and they are sometimes used for scouring floors and utensils2 hence the common name 8scouring rush40 ,,iso,,tes 7,pteridophyta7 ,isotes or quillwort is usually found in water or damp soil on the edges of ponds and lakes4 ,the general habit of the plant is seen in ,fig4 #cjj1 a4 ,it consists of a short1 perennial stem bearing numerous erect1 quill-like leaves with broad sheathing bases4 ,the plants are commonly mistaken for young grasses4 ,illustration3 ,,fig4 #cjj4--;,,iso,,tes1 showing habit of plant at a2 b1 base of leaf1 showing sporangium1 velum1 and ligule4 ,isotes bears two kinds of spores1 large roughened ones1 the macrospores1 and small ones or microspores4 ,both kinds are formed in sporangia borne in an excavation in the expanded base of the leaf4 ,the macrospores are formed on the outer and the microspores on the inner leaves4 ,a sporangium in the base of a leaf is shown at b4 ,it is partially covered by a thin membrane1 the velum4 ,the minute triangular appendage at the upper end of the sporangium is called the ligule4 ,the spores are liberated by the decay of the sporangia4 ,they form rudimentary prothallia of two kinds4 ,the microspores produce prothallia with antheridia1 while the macrospores produce prothallia with archegonia4 ,fertilization takes place as in the mosses or liverworts1 and the fertilized egg-cell1 by continued growth1 gives rise again to the isotes plant4 ,,club-,,mosses 7,pteridophyta7 ,the club-mosses are low trailing plants of moss-like looks and habit1 although more closely allied to ferns than to true mosses4 ,except one genus in ,florida1 all our club mosses belong to the genus ,lycopodium4 ,they grow mostly in woods1 having #a-nerved evergreen leaves arranged in four or more ranks4 ,some of them make long strands1 as the ground pine1 and are much used for ,christmas decorations4 ,the spores are all of one kind or form1 borne in #a-;celled sporangia that open on the margin into two valves4 ,the sporangia are borne in some species 7,fig4 #cja7 as small yellow bodies in the axils of the ordinary leaves near the tip of the shoot2 in other species 7,fig4 #cjb7 they are borne in the axils of small scales that form a catkin-like spike4 ,the spores are very numerous1 and they contain an oil that makes them inflammable4 ,about #ajj species of lycopodium are known4 ,the plants grown by florists under the name of lycopodium are of the genus ,selaginella1 more closely allied to isotes1 bearing two kinds of spores 7microspores and macrospores74 ,illustration3 ,,fig4 #cja4--;,a ,,lycopodium ,,with ,,sporangia ,,in ,,the ,,axils ,,of ,,the ,,foliage ,,leaves4 7,lycopodium lucidulum74 ,illustration3 ,,fig4 #cjb4--;,a ,,club-,,moss 7,lycopodium complanatum74 ,,animal ,,biology ,,chapter ,i ,,the ,,principles ,,of ,,biology ,biology 7,greek1 bios1 life2 logos1 discourse7 means the science of life4 ,it treats of animals and plants4 ,that branch of biology which treats of animals is called zoology 7,gr4 zoon1 animal2 logos1 discourse74 ,the biological science of botany 7,gr4 botane1 plant or herb7 treats of plants4 ,living things are distinguished from the not living by a series of processes1 or changes 7feeding1 growth1 development1 multiplication1 etc471 which together constitute what is called life4 ,these processes are called functions4 ,both plants and animals have certain parts called organs which have each a definite work1 or function2 hence animals and plants are said to be organized4 ,for example1 men and most animals have a certain organ 7the mouth7 for taking in nourishment2 another 7the food tube71 for its digestion4 ,because of its organization1 each animal or plant is said to be an organism4 ,living things constitute the organic kingdom4 ,things without life and not formed by life constitute the inorganic1 or mineral1 kingdom4 ,mark ,i for inorganic and ,o for organic after the proper words in this list3 granite1 sugar1 lumber1 gold1 shellac1 sand1 coal1 paper1 glass1 starch1 copper1 gelatine1 cloth1 air1 potatoes1 alcohol1 oil1 clay4 ,which of these things are used for food by animals8 ,conclusion8 ,energy in the ,organic ,world4--,we see animals exerting energy2 that is1 we see them moving about and doing work4 ,plants are never seen acting that way2 yet they need energy in order to form their tissues1 grow1 and raise themselves in the air4 ,source of ,plant ,energy4--,we notice that green plants thrive only in the light1 while animal growth is largely independent of light4 ,in fact1 in the salt mines of ,poland there are churches and villages below the ground1 and children are born1 become adults1 and live all their lives below ground1 without seeing the sun4 7,that these people are not very strong is doubtless due more to want of fresh air and other causes than want of sunlight47 ,illustration3 ,,fig4 #a4--,,surfaces ,,of ,a ,,leaf1 ,,magnified4 ,illustration3 ,,fig4 #b4--;,a ,,leaf ,,storing ,,energy ,,in ,,sunlight4 ,the need of plants for sunlight shows that they must obtain something from the sun4 ,this has been found to be energy4 ,this enables them to lift their stems in growth1 and form the various structures called tissues which make up their stems and leaves4 7,see ,part ,i1 ,chap4 ,,xiii47 ,it is noticed that they take in food and water from the soil through their roots4 ,experiments also show that green plants take in through pores 7,fig4 #a71 on the under side of their leaves1 a gas composed of carbon and oxygen1 and called carbon dioxid4 ,the energy in the sunlight enables the plant to separate out the carbon of the carbon dioxid and build mineral and water and carbon into organic substances4 ,the oxygen of the carbon dioxid is set free and returns to the air 7,fig4 #b74 ,starch1 sugar1 oil1 and woody fiber are examples of substances thus formed4 ,can you think of any fuel not due to plants8 ,how ,animals obtain ,energy4--,you have noticed that starch1 oil1 etc41 will burn1 or oxidize1 that is1 unite with the oxygen of the air2 thus the sun's energy1 stored in these substances1 is changed back to heat and motion4 ,the oxidation of oil or sugar may occur in a furnace2 it may also occur in the living substance of the active animal4 ,illustration3 ,,fig4 #c4--;,colorless plants1 as ,,mushrooms1 give off no oxygen4 ,a ,,green ,,leaf1 even after it is cut1 gives off oxygen 7,o7 if kept in the sun4 ,fortunately for the animals the plants oxidize very little of the substances built up by them1 since they do not move about nor need to keep themselves warm4 ,we notice that animals are constantly using plant substances for food1 and constantly drawing the air into their bodies4 ,if the sunlight had not enabled the green plant to store up these substances and set free the oxygen 7,fig4 #c71 animals would have no food to eat nor air to breathe2 hence we may say that the sunlight is indirectly the source of the life and energy of animals4 ,mushrooms and other plants without green matter cannot set oxygen free 7,fig4 #c74 ,experiment to show the ,cause of ,burning1 or ,oxidation4--,obtain a large glass bottle 7a pickle jar71 a short candle1 and some matches4 ,light the candle and put it on a table near the edge1 and cover it with the glass jar4 ,the flame slowly smothers and goes out4 ,why is this8 ,is the air now in the jar different from that which was in it before the candle was lighted8 ,some change must have taken place or the candle would continue to burn4 ,to try whether the candle will burn again under the jar without changing the air1 slide the jar to the edge of the table and let the candle drop out4 ,light the candle and slip it up into the jar again1 the jar being held with its mouth a little over the edge of the table to receive the candle 7,fig4 #e74 ,the flame goes out at once4 ,evidently the air in the jar is not the same as the air outside4 ,take up the jar and wave it to and fro a few times1 so as to remove the old air and admit fresh air4 ,the candle now burns in it with as bright a flame as at first4 ,so we conclude that the candle will not continue to burn unless there is a constant supply of fresh air4 ,the gas formed by the burning is carbon dioxid4 ,it is the gas from which plants extract carbon4 7,see ,plant ,biology1 ,chap4 ,v47 ,one test for the presence of this gas is that it forms a white1 chalky cloud in lime water2 another is that it smothers a fire4 ,experiment to show that ,animals give off ,carbon ,dioxid4--,place a cardboard over the mouth of a bottle containing pure air4 ,take a long straw1 the hollow stem of a weed1 a glass tube1 or a sheet of stiff paper rolled into a tube1 and pass the tube into the bottle through a hole in the cardboard4 ,without drawing in a deep breath1 send one long breath into the bottle through the tube1 emptying the lungs by the breath as nearly as possible 7,fig4 #d74 ,next invert the bottle on the table as in the former experiment1 afterward withdrawing the cardboard4 ,move the bottle to the edge of the table and pass the lighted candle up into it 7,fig4 #e74 ,does the flame go out as quickly as in the former experiment8 ,if you breathe through a tube into clear lime water1 the water turns milky4 ,the effect of the breath on the candle and on the lime water shows that carbon dioxid is continually leaving our bodies in the breath4 ,illustration3 ,,fig4 #d4--;,breathing into a bottle4#a ,illustration3 ,,fig4 #e4--,testing the air in the bottle4#a #a ,from ,coleman's 8,physiology for ,beginners10 ,macmillan ,co41 ,n4,y4 ,oxidation and ,deoxidation4--,the union of oxygen with carbon and other substances1 which occurs in fires and in the bodies of animals1 is called oxidation4 ,the separation of the oxygen from carbon such as occurs in the leaves of plants is called deoxidation4 ,the first process sets energy free1 the other process stores it up4 ,animals give off carbon dioxid from their lungs or gills1 and plants give off oxygen from their leaves4 ,but plants need some energy in growing1 so oxidation also occurs in plants1 but to a far less extent than in animals4 ,at night1 because of the absence of sunlight1 no deoxidation is taking place in the plant1 but oxidation and growth continue2 so at night the plant actually breathes out some carbon dioxid4 ,the deepest part of the lungs contains the most carbon dioxid4 ,why was it necessary to empty the lungs as nearly as possible in the experiment with the candle8 ,why would first drawing a deep breath interfere with the experiment8 ,why does closing the draught of a stove1 thus shutting off part of the air1 lessen the burning8 ,why does a 8firefly0 shine brighter at each breath8 ,why is the pulse and breathing faster in a fever8 ,very slow in a trance8 ,the key for understanding any animal is to find how it gets food and oxygen1 and how it uses the energy thus obtained to grow1 move1 avoid its enemies1 and get more food4 ,because it moves1 it needs senses to guide it4 ,the key for understanding a plant is to find how it gets food and sunlight for its growth4 ,it makes little provision against enemies2 its food is in reach1 so it needs no senses to guide it4 ,the plant is built on the plan of having the nutritive activities near the surface 7e4g4 absorption by roots2 gas exchange in leaves74 ,the animal is built on the plan of having its nutritive activities on the inside 7e4g4 digestion2 breathing74 ,cell and ,protoplasm4--,both plants and animals are composed of small parts called cells4 ,cells are usually microscopic in size4 ,they have various shapes1 as spherical1 flat1 cylindrical1 fiber-like1 star-shaped4 ,the living substance of cells is called protoplasm4 ,it is a stiff1 gluey fluid1 albuminous in its nature4 ,every cell has a denser spot or kernel called a nucleus1 and in the nucleus is a still smaller speck called a nucleolus4 ,most cells are denser and tougher on the outside1 and are said to have a cell wall1 but many cells are naked1 or without a wall4 ,hence the indispensable part of a cell is not the wall but the nucleus1 and a cell may be defined as a bit of protoplasm containing a nucleus4 ,this definition includes naked cells as well as cells with walls4 ,one-celled ,animals4--,there are countless millions of animals and plants the existence of which was not suspected until the invention of the microscope several centuries ago4 ,they are one-celled1 and hence microscopic in size4 ,it is believed that the large animals and plants are descended from one-celled animals and plants4 ,in fact1 each individual plant or animal begins life as a single cell1 called an egg cell1 and forms its organs by the subdivision of the egg cell into many cells4 ,an egg cell is shown in ,fig4 #f1 and the first stages in the development of an egg cell are shown in ,fig4 #g4 ,illustration3 ,,fig4 #f4--;,egg cell of mammal with yolk4 ,illustration3 ,,fig4 #g4--;,egg cell subdivides into many cells forming a sphere 7morula7 containing a liquid4 ,a dimple forms and deepens to form the next stage 7gastrula74 ,the animals to be studied in the first chapter are one-celled animals4 ,to understand them we must learn how they eat1 breathe1 feel1 and move4 ,they are called ,protozoans 7,greek protos1 first2 zoon1 life74 ,all other animals are composed of many cells and are called ,metazoans 7,greek meta1 beyond or after74 ,the cells composing the mucous membrane in man are shown in ,fig4 #h4 ,the cellular structure of the leaf of a many-celled plant is illustrated in ,fig4 #a4 7,see also ,chap4 ,i1 ,human ,biology47 ,illustration3 ,,fig4 #h4--,,mucous ,,membrane formed of one layer of cells4 ,a few cells secrete mucus4 ,method of ,classifying ,animals4--,the various animals display differences more or less marked4 ,the question arises1 are not some of them more closely related than others8 ,we conclude that they are1 since the difference between some animals is very slight1 while the difference between others is quite marked4 ,to show the different steps in classifying an animal1 we will take an example1--the cow4 ,even little children learn to recognize a cow1 although individual cows differ somewhat in form1 size1 color1 etc4 ,the varieties of cows1 such as short-horn1 ,jersey1 etc41 all form one species of animals1 having the scientific name taurus4 ,let us include in a larger group the animals closest akin to a cow4 ,we see a cat1 a bison1 and a dog2 rejecting the cat and the dog1 we see that the bison has horns1 hoofs1 and other similarities4 ,we include it with the cow in a genus called ,bos1 calling the cow ,bos taurus1 and the bison1 ,bos bison4 ,the sacred cow of ,india 7,bos indicus7 is so like the cow and buffalo as also to belong in the genus ,bos4 ,why is not the camel1 which1 like ,bos bison1 has a hump1 placed in the genus ,bos8 7,fig4 #cij47 ,the ,old ,world buffaloes1--most abundant in ,africa and ,india1--the antelopes1 sheep1 goats1 and several other genera are placed with the genus ,bos in a family called the hollow horns4 ,this family1 because of its even number of toes and the habit of chewing the cud1 resembles the camel family1 the deer family1 and several other families4 ,these are all placed together in the next higher systematic unit called an order1 in this case1 the order of ruminants4 ,the ruminants1 because they are covered with hair and nourish the young with milk1 are in every essential respect related to the one-toed horses1 the beasts of prey1 the apes1 etc4 ,hence they are all placed in a more inclusive division of animals1 the class called mammals4 ,all mammals have the skeleton1 or support of the body1 on the inside1 the axis of which is called the vertebral column4 ,this feature also belongs to the classes of reptiles1 amphibians1 and fishes4 ,it is therefore consistent to unite these classes by a general idea or conception into a great branch of animals called the vertebrates4 ,returning from the general to the particular by successive steps1 state the branch1 class1 order1 family1 genus1 and species to which the cow belongs4 ,the ,eight ,branches or ,sub-kingdoms4--,the simplest classification divides the whole animal kingdom into eight branches1 named and characterized as follows1 beginning with the lowest3 ,i4 ,,protozoans4 ,one-celled4 ,,ii4 ,,sponges4 ,many openings4 ,,iii4 ,,polyps4 ,circular2 cup-like2 having only one opening which is both mouth and vent4 ,,iv4 ,,echinoderms4 ,circular2 rough-skinned2 two openings4 ,v4 ,,mollusks4 ,no skeleton2 usually with external shell4 ,,vi4 ,,vermes4 ,elongate body1 no jointed legs4 ,,vii4 ,,arthropods4 ,external jointed skeleton2 jointed legs4 ,,viii4 ,,vertebrates4 ,internal jointed skeleton with axis or backbone4 ,,chapter ,,ii ,,protozoa 7,one-celled ,animals7 ,,the ,,ameba ,,suggestions4--,amebas live on the slime found on submerged stems and leaves in standing water1 or in the ooze at the bottom4 ,water plants may be crowded into a glass dish and allowed to decay1 and after about two weeks the ameba may be found in the brown slime scraped from the plants4 ,an ameba culture sometimes lasts only three days4 ,the most abundant supply ever used by the writer was from a bottle of water where some oats were germinating4 ,use or inch objective1 and cover with a thin cover glass4 ,teachers who object to the use of the compound microscope in a first course should require a most careful study of the figures4 ,illustration3 ,,fig4 #i4--;,,ameba ,,proteus1 much enlarged4 ,illustration3 ,,fig4 #aj4--;,,ameba4 cv1 contractile vacuole2 ec1 ectoplasm2 en1 endoplasm2 n1 nucleus2 ps1 pseudopod2 ps1 pseudopod forming2 ectoplasm protrudes and endoplasm flows into it4 ,form and ,structure4--,the ameba 7also spelled amba7 looks so much like a clear drop of jelly that a beginner cannot be certain that he has found one until it moves4 ,it is a speck of protoplasm 7,fig4 #i71 with a clear outer layer1 the ectoplasm2 and a granular1 internal part1 the endoplasm4 ,is there a distinct line between them8 7,fig4 #aj47 ,note the central portion and the slender prolongations or pseudopods 7,greek1 false feet74 ,does the endoplasm extend into the pseudopods8 7,fig4 #aj47 ,are the pseudopods arranged with any regularity8 ,sometimes it is possible to see a denser appearing portion1 called the nucleus2 also a clear space1 the contractile vacuole 7,fig4 #aj74 ,movements4--,sometimes while the pseudopods are being extended and contracted1 the central portion remains in the same place 7this is motion74 ,usually only one pseudopod is extended1 and the body flows into it2 this is locomotion 7,fig4 #aa74 ,there is a new foot made for each step4 ,illustration3 ,,fig4 #aa4--,the same ameba seen at different times4 ,feeding4--,if the ameba crawls near a food particle1 the pseudopod is pressed against it1 or a depression occurs 7,fig4 #ab71 and the particle is soon embedded in the endoplasm4 ,often a clear space called a food vacuole is noticed around the food particle4 ,this is the water that is taken in with the particle 7,fig4 #ab74 ,the water and the particle are soon absorbed and assimilated by the endoplasm4 ,illustration3 ,,fig4 #ab4--,,the ,,ameba taking food4 ,excretion4--,if a particle of sand or other indigestible matter is taken in1 it is left behind as the ameba moves on4 ,there is a clear space called the contractile vacuole1 which slowly contracts and disappears1 then reappears and expands 7,figs4 #i and #aj74 ,this possibly aids in excreting oxidized or useless material4 ,circulation in the ameba consists of the movement of its protoplasmic particles4 ,it lacks special organs of circulation4 ,feeling4--,jarring the glass slide seems to be felt1 for it causes the activity of the ameba to vary4 ,it does not take in for food every particle that it touches4 ,this may be the beginning of taste1 based upon mere chemical affinity4 ,the pseudopods aid in feeling4 ,reproduction4--,sometimes an ameba is seen dividing into two parts4 ,a narrowing takes place in the middle2 the nucleus also divides1 a part going to each portion 7,fig4 #ac74 ,the mother ameba finally divides into two daughter amebas4 ,sex is wanting4 ,illustration3 ,,fig4 #ac4--;,,ameba1 dividing4 ,source of the ,ameba's ,energy4--,we thus see that the ameba moves without feet1 eats without a mouth1 digests without a stomach1 feels without nerves1 and1 it should also be stated1 breathes without lungs1 for oxygen is absorbed from the water by its whole surface4 ,its movements require energy2 this1 as in all animals1 is furnished by the uniting of oxygen with the food4 ,carbon dioxid and other waste products are formed by the union2 these pass off at the surface of the ameba and taint the water with impurities4 ,questions4--,why will the ameba die in a very small quantity of water1 even though the water contains enough food8 ,why will it die still quicker if air is excluded from contact with the drop of water8 ,the ameba never dies of old age4 ,can it be said to be immortal8 ,according to the definition of a cell 7,chapter ,i71 is the ameba a unicellular or multicellular animal8 ,cysts4--,if the water inhabited by a protozoan dries up1 it encysts1 that is1 it forms a tough skin called a cyst4 ,upon return of better conditions it breaks the cyst and comes out4 ,encysted protozoans may be blown through the air3 this explains their appearance in vessels of water containing suitable food but previously free from protozoans4 ,,the ,,slipper ,,animalcule ,,or ,,paramecium ,suggestions4--,stagnant water often contains the paramecium as well as the ameba2 or they may be found in a dish of water containing hay or finely cut clover1 after the dish has been allowed to stand in the sun for several days4 ,a white film forming on the surface is a sign of their presence4 ,they may even be seen with the unaided eye as tiny white particles by looking through the side of the dish or jar4 ,use at first a or in4 objective4 ,restrict their movements by placing cotton fibers beneath the cover glass2 then examine with or objective4 ,otherwise1 study figures4 ,shape and ,structure4--,the paramecium's whole body1 like the ameba's1 is only one cell4 ,it resembles a slipper in shape1 but the pointed end is the hind end1 the front end being rounded 7,fig4 #ad74 ,the paramecium is propelled by the rapid beating of numerous fine1 threadlike appendages on its surface1 called cilia 7,latin1 eyelashes7 7,figs474 ,the cilia1 like the pseudopods of the ameba1 are merely prolongations of the cell protoplasm1 but they are permanent4 ,the separation between the outer ectoplasm and the interior granular endoplasm is more marked than in the ameba 7,fig4 #ad74 ,illustration3 ,,fig4 #ad4--,,paramecium1 showing cilia1 c4 ,two contractile vacuoles1 cv2 the macronucleus1 mg2 two micronuclei1 mi2 the gullet 771 a food ball forming and ten food balls in their course from gullet to vent1 a4 ,illustration3 ,,fig4 #ae4 ,nucleus and ,vacuoles4--,there is a large nucleus called the macronucleus1 and beside it a smaller one called the micronucleus4 ,they are hard to see4 ,about one third of the way from each end is a clear1 pulsating space 7bb4 ,fig4 #ae7 called the pulsating vacuole4 ,these spaces contract until they disappear1 and then reappear1 gradually expanding4 ,tubes lead from the vacuoles which probably serve to keep the contents of the cell in circulation4 ,illustration3 ,,fig4 #af4--,,two ,,paramecia exchanging parts of their nuclei4 ,feeding4--,a depression1 or groove1 is seen on one side1 this serves as a mouth 7,figs474 ,a tube which serves as a gullet leads from the mouth-groove to the interior of the cell4 ,the mouth-groove is lined with cilia which sweep food particles inward4 ,the particles accumulate in a mass at the inner end of the gullet1 become separated from it as a food ball 7,fig4 #ad71 and sink into the soft protoplasm of the body4 ,the food balls follow a circular course through the endoplasm1 keeping near the ectoplasm4 ,reproduction4--,this1 as in the ameba1 is by division1 the constriction being in the middle1 and part of the nucleus going to each half4 ,sometimes two individuals come together with their mouth-grooves touching and exchange parts of their nuclei 7,fig4 #af74 ,they then separate and each divides to form two new individuals4 ,we thus see that the paramecium1 though of only one cell1 is a much more complex and advanced animal than the ameba4 ,the tiny paddles1 or cilia1 the mouth-groove1 etc41 have their special duties similar to the specialized organs of the many-celled animals to be studied later4 ,illustration3 ,,fig4 #ag4--,,vorticella 7or bell animalcule71 two extended1 one withdrawn4 ,illustration3 ,,fig4 #ah4--;,euglena4 ,illustration3 ,,fig4 #ai4--,,shell ,,of ,a ,,radiolarian4 ,if time and circumstances allow a prolonged study1 several additional facts may be observed by the pupil1 e4g4 ,does the paramecium swim with the same end always foremost1 and same side uppermost8 ,can it move backwards8 ,avoid obstacles8 ,change shape in a narrow passage8 ,does refuse matter leave the body at any particular place8 ,trace movement of the food particles4 ,draw the paramecium4 ,which has more permanent parts1 the ameba or paramecium8 ,name two anatomical similarities and three differences2 four functional similarities and three differences4 ,the ameba belongs in the class of protozoans called ,rhizopoda 8root footed40 ,other classes of ,protozoans are the ,infusorians1 which have many waving cilia 7,fig4 #ag7 or one whip-like flagellum 7,fig4 #ah71 and the ,foraminifers which possess a calcareous shell pierced with holes4 ,much chalky limestone has been formed of their shells4 ,these and the radiolarians1 which have flinty shells 7,fig4 #ai71 are often placed in the class rhizopoda4 ,to which class does the paramecium belong8 ,protozoans furnish a large amount of food to the higher animals4 ,to the ,teacher4 ,if plant1 animal1 and human biology are to be given in one year as planned1 and full time allowed for practical work1 the portions of the text in small type1 as ,chapter ,,iii1 may be omitted or merely read and discussed4 ,any two of the three parts forming the course may be used for a year's course by using all of the text and spending more time on practical and field work4 ,,chapter ,,iii ,,sponges ,,suggestions4--,in many parts of the ,united ,states1 fresh-water sponges may1 by careful searching1 be found growing on rocks and logs in clear water4 ,they are brown1 creamy1 or greenish in color1 and resemble more a cushion-like plant than an animal4 ,they have a characteristic gritty feel4 ,they soon die after removal to an aquarium4 ,a number of common small bath sponges may be bought and kept for use in studying the skeleton of an ocean sponge4 ,these sponges should not have large holes in the bottom2 if so1 too much of the sponge has been cut away4 ,a piece of marine sponge preserved in alcohol or formalin may be used for showing the sponge with its flesh in place4 ,microscopic slides may be used for showing the spicules4 ,illustration3 ,,fig4 #ba4--;,,fresh-,,water ,,sponge4 ,illustration3 ,,fig4 #bb4--,,section of fresh-water sponge 7enlarged74 ,the small fresh-water sponge 7,fig4 #ba7 lacks the more or less vase-like form typical of sponges4 ,it is a rounded mass growing upon a rock or log4 ,as indicated by the arrows1 where does water enter the sponge8 ,this may be tested by putting coloring matter in the water near the living sponge4 ,where does the water come out8 7,fig4 #bb47 ,does it pass through ciliated chambers in its course8 ,is the surface of the sponge rough or smooth8 ,do any of the skeletal spicules show on the surface8 7,fig4 #ba47 ,does the sponge thin out near its edge8 ,illustration3 ,,fig4 #bc4--;,,eggs and ,,spicules of fresh-water sponge 7enlarged74 ,the egg of this sponge is shown in ,fig4 #bc4 ,it escapes from the parent sponge through the osculum1 or large outlet4 ,as in most sponges1 the first stage after the egg is ciliated and free-swimming4 ,marine ,sponges4--,the grantia 7,fig4 #bd7 is one of the simplest of marine sponges4 ,what is the shape of grantia8 ,what is its length and diameter8 ,how does the free end differ from the fixed end8 ,are the spicules projecting from its body few or many8 ,illustration3 ,,fig4 #bd4--;,grantia4 ,where is the osculum1 or large outlet8 ,with what is this surrounded8 ,the osculum opens from a central cavity called the cloaca4 ,the canals from the pores lead to the cloaca4 ,buds are sometimes seen growing out from the sponge near its base4 ,these are young sponges formed asexually4 ,later they become detached from the parent sponge4 ,illustration3 ,,fig4 #be4--,plan of a sponge4 ,commercial 8,sponge40--,what part of the complete animal remains in the bath sponge8 ,slow growing sponges grow more at the top and form tall1 simple1 tubular or vase-like animals4 ,fast growing sponges grow on all sides at once and form a complicated system of canals1 pores1 and oscula4 ,which of these habits of growth do you think belonged to the bath sponge8 ,is there a large hole in the base of your specimen8 ,if so1 this is because the cloaca was reached in trimming the lower part where it was attached to a rock4 ,test the elasticity of the sponge when dry and when wet by squeezing it4 ,is it softer when wet or dry8 ,is it more elastic when wet or dry8 ,how many oscula does your specimen have8 ,how many inhalent pores to a square inch8 ,using a probe 7a wire with knob at end1 or small hat pin71 try to trace the canals from the pores to the cavities inside4 ,do the fibers of the sponge appear to interlace1 or join1 according to any system8 ,do you see any fringe-like growths on the surface which show that new tubes are beginning to form8 ,was the sponge growing faster at the top1 on the sides1 or near the bottom8 ,burn a bit of the sponge2 from the odor1 what would you judge of its composition8 ,is the inner cavity more conspicuous in a simple sponge or in a compound sponge like the bath sponge8 ,is the bath sponge branched or lobed8 ,compare a number of specimens 7,figs4 #bf1 #bg1 #bh7 and decide whether the common sponge has a typical shape4 ,what features do their forms possess in common8 ,illustration3 ,,fig4 #bf4--;,bath ,sponge4 ,illustration3 ,,fig4 #bg4--;,bath ,sponge4 ,illustration3 ,,fig4 #bh4--;,bath ,sponge4 ,sponges are divided into three classes1 according as their skeletons are flinty 7silicious71 limy 7calcareous71 or horny4 ,some of the silicious sponges have skeletons that resemble spun glass in their delicacy4 ,flint is chemically nearly the same as glass4 ,the skeleton shown in ,fig4 #bi is that of a glass sponge which lives near the ,philippine ,islands4 ,illustration3 ,,fig4 #bi4--,skeleton of a glass sponge4 ,the horny sponges do not have spicules in their skeletons1 as the flinty and limy sponges have1 but the skeleton is composed of interweaving fibers of spongin1 a durable substance of the same chemical nature as silk 7,figs4 #cj and #ca74 ,illustration3 ,,fig4 #cj4--;,a horny sponge4 ,illustration3 ,,fig4 #ca4--,section of horny sponge4 ,the limy sponges have skeletons made of numerous spicules of lime4 ,the three-rayed spicule is the commonest form4 ,the commercial sponge1 seen as it grows in the ocean1 appears as a roundish mass with a smooth1 dark exterior1 and having about the consistency of beef liver4 ,several large openings 7oscula71 from which the water flows1 are visible on the upper surface4 ,smaller holes 7inhalent pores--many of them so small as to be indistinguishable7 are on the sides4 ,if the sponge is disturbed1 the smaller holes1 and perhaps the larger ones1 will close4 ,the outer layer of cells serves as a sort of skin4 ,since so much of the sponge is in contact with water1 most of the cells do their own breathing1 or absorption of oxygen and giving off of carbon dioxid4 ,nutriment is passed on from the surface cells to nourish the rest of the body4 ,reproduction4--,egg-cells and sperm-cells are produced by certain cells along the canals4 ,the egg-cell1 after it is fertilized by the sperm-cell1 begins to divide and form new cells1 some of which possess cilia4 ,the embryo sponge passes out at an osculum4 ,by the vibration of the cilia1 it swims about for a while4 ,it afterwards settles down with the one end attached to the ocean floor and remains fixed for the rest of its life4 ,the other end develops oscula4 ,some of the cilia continue to vibrate and create currents which bring food and oxygen4 ,the cilia in many species are found only in cavities called ciliated chambers4 7,figs4 #bb1 #cb47 ,there are no distinct organs in the sponge and there is very little specialization of cells4 ,the ciliated cells and the reproductive cells are the only specialized cells4 ,the sponges were for a long time considered as colonies of separate one-celled animals classed as protozoans4 ,they are1 without doubt1 many-celled animals4 ,if a living sponge is cut into pieces1 each piece will grow and form a complete sponge4 ,that the sponge is not a colony of one-celled animals1 each like an ameba1 but is a many-celled animal1 will be realized by examining ,fig4 #cb1 which shows a bit of sponge highly magnified4 ,a sponge may be conceived as having developed from a one-celled animal as follows3 ,several one-celled animals happened to live side by side2 each possessed a thread-like flagellum 7,e1 ,fig4 #cb7 or whip-lash for striking the water4 ,by lashing the water1 they caused a stronger current 7,fig4 #be7 than protozoans living singly could cause4 ,thus they obtained more food and multiplied more rapidly than those living alone4 ,the habit of working together left its impress on the cells and was transmitted by inheritance4 ,illustration3 ,,fig4 #cb4--,microscopic plan of ciliated chamber4 ,each cell lining the chamber has a nucleus1 a whip-lash1 and a collar around base of whip-lash4 ,question3 ,state two uses of whip-lash4 ,cell joined to cell formed a ring2 ring joined to ring formed a tube which was still more effective than a ring in lashing the water into a current and bringing fresh food 7particles of dead plants and animals7 and oxygen4 ,no animals eat sponges2 possibly because spicules1 or fibers1 are found throughout the flesh1 or because the taste and odor is unpleasant enough to protect them4 ,small animals sometimes crawl into them to hide4 ,one species grows upon shells inhabited by hermit crabs4 ,moving of the shell from place to place is an advantage to them1 while they conceal the crab and thus protect it4 ,special ,report3 ,sponge 8,fisheries40 7,localities2 how sponges are taken1 cleaned1 dried1 shipped1 and sold47 ,,chapter ,,iv ,,polyps 7,,cuplike ,,animals7 ,,the ,,hydra1 ,,or ,,fresh ,,water ,,polyp ,illustration3 ,,fig4 #cc4--;,a ,,hydra4 ,,suggestions4--,except in the drier regions of the ,united ,states1 the hydra can usually be found by careful search in fresh water ponds not too stagnant4 ,it is found attached to stones1 sticks1 or leaves1 and has a slender1 cylindrical body from a quarter to half an inch long1 varying in thickness from that of a fine needle to that of a common pin4 ,the green hydra and the brown hydra1 both very small1 are common species1 though hydras are often white or colorless4 ,they should be kept in a large glass dish filled with water4 ,they may be distinguished by the naked eye but are not studied satisfactorily without a magnifying glass or microscope4 ,place a living specimen attached to a bit of wood in a watch crystal filled with water1 or on a hollowed slip1 or on a slip with a bit of weed to support the cover glass1 and examine with hand lens or lowest power of microscope4 ,prepared microscopical sections1 both transverse and longitudinal1 may be bought of dealers in microscopic supplies4 ,one is shown in ,fig4 #ci4 ,is the hydra's body round or two-sided8 7,fig4 #ce47 ,what is its general shape8 ,does one individual keep the same shape8 7,fig4 #cd47 ,how does the length of the threadlike tentacles compare with the length of the hydra's body8 ,about how many tentacles are on a hydra's body8 ,do all have the same number of tentacles8 ,are the tentacles knotty or smooth8 7,fig4 #ce47 ,the hydra is usually extended and slender2 sometimes it is contracted and rounded4 ,in which of these conditions is the base 7the foot7 larger around than the rest of the body8 7,fig4 #cd47 ,smaller8 ,how many openings into the body are visible8 ,is there a depression or an eminence at the base of the tentacles8 ,for what is the opening on top of the body probably used8 ,why are the tentacles placed at the top of the hydra's body8 ,does the mouth have the most convenient location possible8 ,illustration3 ,,fig4 #cd4--;,forms assumed by ,hydra4 ,illustration3 ,,fig4 #ce4--;,,hydra 7much enlarged74 ,the conical projection bearing the mouth is called hypostome 7,fig4 #cd74 ,the mouth opens into the digestive cavity4 ,is this the same as the general body cavity1 or does the stomach have a wall distinct from the body cavity8 ,how far down does the body cavity extend8 ,does it extend up into the tentacles8 7,fig4 #ci47 ,if a tentacle is touched1 what happens8 ,is the body ever bent8 ,which is more sensitive1 the columnar body or the tentacles8 ,in searching for hydras would you be more likely to find the tentacles extended or drawn in8 ,is the hypostome ever extended or drawn in8 7,fig4 #cd47 ,locomotion4--,the round surface1 or disk1 by which the hydra is attached1 is called its foot4 ,can you move on one foot without hopping8 ,the hydra moves by alternately elongating and rounding the foot4 ,can you discover other ways by which it moves8 ,does the hydra always stand upon its foot8 ,illustration3 ,,fig4 #cf4--,,nettling ,,cell4 ,,ii4 discharged1 and ,i4 not discharged4 ,lasso ,cells4--,upon the tentacles 7,fig4 #ce7 are numerous cells provided each with a thread-like process 7,fig4 #cf7 which lies coiled within the cell1 but which may be thrown out upon a water flea1 or other minute animal that comes in reach4 ,the touch of the lasso paralyzes the prey 7,fig4 #cg74 ,these cells are variously called lasso cells1 nettling cells1 or thread cells4 ,the thread is hollow and is pushed out by the pressure of liquid within4 ,when the pressure is withdrawn the thread goes back as the finger of a glove may be turned back into the glove by turning the finger outside in4 ,when a minute animal1 or other particle of food comes in contact with a tentacle1 how does the tentacle get the food to the mouth8 ,by bending and bringing the end to the mouth1 or by shortening and changing its form1 or in both ways8 7,fig4 #cd1 ,c47 ,do the neighboring tentacles seem to bend over to assist a tentacle in securing prey8 7,fig4 #cd1 ,c47 ,illustration3 ,,fig4 #cg4--;,,hydra capturing a water flea4 ,digestion4--,the food particles break up before remaining long in the stomach1 and the nutritive part is absorbed by the lining cells1 or endoderm 7,fig4 #ci74 ,the indigestible remnants go out through the mouth4 ,the hydra is not provided with a special vent4 ,why could the vent not be situated at the end opposite the mouth8 ,circulation and ,respiration4--,does water have free access to the body cavity8 ,does the hydra have few or nearly all of its cells exposed to the water in which it lives8 ,from its structure1 decide whether it can breathe like a sponge or whether special respiratory cells are necessary to supply it with oxygen and give off carbon dioxid4 ,blood vessels are unnecessary for transferring oxygen and food from cell to cell4 ,illustration3 ,,fig4 #ch4--;,,hydras on pondweed4 ,reproduction4--,do you see any swellings upon the side of the hydra8 7,fig4 #cd1 ,a47 ,if the swelling is near the tentacles1 it is a spermary2 if near the base it is an ovary4 ,a sperm coalesces with or fertilizes the ovum after the ovum is exposed by the breaking of the ovary wall4 ,sometimes the sperm from one hydra unites with the ovum of another hydra4 ,this is called cross-fertilization4 ,the same term is applied to the process in plants when the male element1 or pollen1 of the flower unites with the ovules1 or female element1 of the flower on another plant4 ,the hydra1 like most plants and some other animals1 is hermaphrodite1 that is to say1 both sperms and ova are produced by one individual4 ,in the autumn1 eggs are produced with hard shells to withstand the cold until spring4 ,sexual reproduction takes place when food is scarce4 ,asexual generation 7by budding7 is common with the hydra when food supply is abundant4 ,after the bud grows to a certain size1 the outer layer of cells at the base of the bud constricts and the young hydra is detached4 ,compare the sponge and the hydra in the following respects3--many celled1 or one celled2 obtaining food2 breathing2 tubes and cavities2 openings2 reproduction2 locomotion4 ,which ranks higher among the metazoa8 ,the metazoa1 or many celled animals1 include all animals except which branch8 ,illustration3 ,,fig4 #ci4--,longitudinal section of hydra 7microscopic and diagrammatic74 ,figure #ci is a microscopic view of a vertical section of a hydra to show the structure of the body wall4 ,there is an outer layer called the ectoderm1 and an inner layer called the endoderm4 ,there is also a thin supporting layer 7black in the figure7 called the mesoglea4 ,the mesoglea is the thinnest layer4 ,are the cells larger in the endoderm or the ectoderm8 ,do both layers of cells assist in forming the reproductive bud8 ,the ectoderm cells end on the inside in contractile tails which form a thin line and have the effect of muscle fibers4 ,they serve the hydra for its remarkable changes of shape4 ,when the hydra is cut in pieces1 each piece makes a complete hydra1 provided it contains both endoderm and ectoderm4 ,in what ways does the hydra show 8division of labor08 ,answer this by explaining the classes of cells specialized to serve a different purpose4 ,which cells of the hydra are least specialized8 ,in what particulars is the plan of the hydra different from that of a simple sponge8 ,an ingenious naturalist living more than a century ago1 asserted that it made no difference to the hydra whether the ectoderm or the endoderm layer were outside or inside1--that it could digest equally well with either layer4 ,he allowed a hydra to swallow a worm attached to a thread1 and then by gently pulling in the thread1 turned the hydra inside out4 ,more recently a ,japanese naturalist showed that the hydra could easily be turned inside out1 but he also found that when left to itself it soon reversed matters and returned to its natural condition1 that the cells are really specialized and each layer can do its own work and no other4 ,habits4--,the hydra's whole body is a hollow bag1 the cavity extending even into the tentacles4 ,the tentacles may increase in number as the hydra grows but seldom exceed eight4 ,the hydra has more active motion than locomotion4 ,it seldom moves from its place1 but its tentacles are constantly bending1 straightening1 contracting1 and expanding4 ,the body is also usually in motion1 bending from one side to another4 ,when the tentacles approach the mouth with captured prey1 the mouth 7invisible without a hand lens7 opens widely1 showing five lobes or lips1 and the booty is soon tucked within4 ,a hydra can swallow an animal larger in diameter than itself4 ,the endoderm cells have ameboid motion1 that is1 they extend pseudopods4 ,they also resemble amebas in the power of intra-cellular digestion2 that is1 they absorb the harder particles of food and digest them afterwards1 rejecting the indigestible portions4 ,some of these cells have flagella 7see ,fig4 #ci7 which keep the fluid of the cavity in constant motion4 ,sometimes the hydra moves after the manner of a small caterpillar called a 8measuring worm10 that is1 it takes hold first by the foot1 then by the tentacles1 looping its body at each step4 ,sometimes the body goes end over end in slow somersaults4 ,the length of the extended hydra may reach one half inch4 ,when touched1 both tentacles and body contract until it looks to the unaided eye like a round speck of jelly4 ,this shows sensibility1 and a few small star-shaped cells are believed to be nerve cells1 but the hydra has not a nervous system4 ,hydras show their liking for light by moving to the side of the vessel or aquarium whence the light comes4 ,illustration3 ,,fig4 #dj4--;,,hydroid ,,colony1 with nutritive 7,p7 reproductive 7,m7 and defensive 7,s7 hydranths4 ,the ,branch ,polyps 7sometimes called ,clenterata74--,the hydra is the only fresh water representative of this great branch of the animal kingdom4 ,this branch is characterized by its members having only one opening to the body4 ,the polyps also include the salt water animals called hydroids1 jellyfishes1 and coral polyps4 ,illustration3 ,,fig4 #da4--8,,portuguese ,,man-,o'-,,war0 7compare with ,fig4 #dj74 ,a floating hydroid colony with long1 stinging 7and sensory7 streamers4 ,troublesome to bathers in ,gulf of ,mexico4 ,notice balloon-like float4 ,hydroids4--,figure #dj shows a hydroid1 or group of hydra-like growths1 one of which eats and digests for the group1 another defends by nettling cells1 another produces eggs4 ,each hydra-like part of a hydroid is called a hydranth4 ,sometimes the buds on the hydra remain attached so long that a bud forms upon the first bud4 ,thus three generations are represented in one organism4 ,such growths show us that it is not always easy to tell what constitutes an individual animal4 ,illustration3 ,,fig4 #db4--,the formation of many free swimming jellyfishes from one fixed hydra-like form4 ,the saucer-like parts 7h7 turn over after they separate and become like ,fig4 #dc or #dd4 ,letters show sequence of diagrams4 ,hydroids may be conceived to have been developed by the failure of budding hydras to separate from the parent1 and by the gradual formation of the habit of living together and assisting each other4 ,when each hydranth of the hydroid devoted itself to a special function of digestion1 defense1 or reproduction1 this group lived longer and prospered2 more eggs were formed1 and the habits of the group were transmitted to a more numerous progeny than were the habits of a group where members worked more independently of each other4 ,as the sponge is the first1 lowest1 and simplest example of the devotion of special cells to special purposes1 the hydroid is the first1 lowest1 and simplest example of the occurrence of organs1 that is of special parts of the body 7groups of cells7 set aside for a special work4 ,how many mature hydranths are seen in the hydroid shown in ,fig4 #dj8 ,why are the defensive hydranths on the outside of the colony8 ,which hydranths have no tentacles8 ,why not8 ,jellyfish4--,alternation of ,generations4--,medusa4--,with some species of hydroids1 a very curious thing happens4--,the hydranth that is to produce the eggs falls off and becomes independent of the colony4 ,more surprising still1 its appearance changes entirely and instead of being hydra-like1 it becomes the large and complex creature called jellyfish 7,fig4 #dc74 ,but the egg of the jellyfish produces a small hydra-like animal which gives rise by budding to a hydroid1 and the cycle is complete4 ,illustration3 ,,fig4 #dc4--;,a ,,jellyfish4 ,illustration3 ,,fig4 #dd4--;,a ,,jellyfish 7medusa74 ,the bud 7or reproductive hydranth7 of the hydroid does not produce a hydroid1 but a jellyfish2 the egg of the jellyfish does not produce a jellyfish1 but a hydroid4 ,this is called by zoologists1 alternation of generations4 ,a complete individual is the life from the germination of one egg to the production of another4 ,so that an 8individual0 consists of a hydroid colony fixed in one place together with all the jellyfish produced from its buds1 and which may now be floating miles away from it in the ocean4 ,bathers in the surf are sometimes touched and stung by the long1 streamer-like tentacles of the jellyfish4 ,these1 like the tentacles of the hydra1 have nettling cells 7,fig4 #da74 ,the umbrella-shaped free swimming jellyfish is called a medusa 7,fig4 #dd74 ,coral ,polyps4--,some of the salt water relatives of the hydra produce buds which remain attached to the parent without1 however1 becoming different from the parent in any way4 ,the coral polyps and corallines are examples of colonies of this kind1 possessing a common stalk which is formed as the process of multiplication goes on4 ,in the case of coral polyps1 the separate animals and the flesh connecting them secrete within themselves a hard1 limy1 supporting structure known as coral4 ,in some species1 the coral1 or stony part1 is so developed that the polyp seems to be inserted in the coral1 into which it withdraws itself for partial protection 7,fig4 #de74 ,illustration3 ,,fig4 #de4--;,,coral ,,polyps 7tentacles1 a multiple of six74 ,notice hypostome4 ,the corallines secrete a smooth stalk which affords no protection1 but they also secrete a coating or sheath which incloses both themselves and the stalk4 ,the coating has apertures through which the polyps protrude in order to feed when no danger is near 7,fig4 #df74 ,the red 8corals0 used for jewelry are bits of stalks of corallines4 ,the corallines 7,figs4 #dg1 #dh7 are not so abundant nor so important as the coral polyps 7,figs4 #de1 #di74 ,illustration3 ,,fig4 #df4--,,red ,,coralline with crust and polyps 7eight tentacles74 ,illustration3 ,,fig4 #dg4--,,sea ,,fan 7a coralline74 ,colonies of coral polyps grow in countless numbers in the tropical seas4 ,the coral formed by successive colonies of polyps accumulates and builds up many islands and important additions to continents4 ,the ,florida 8keys10 or islands1 and the southern part of the mainland of ,florida were so formed4 ,illustration3 ,,fig4 #dh4--,,organ ,,pipe 8,coral0 7a coralline74 ,the ,sea ,anemone1 like the coral polyp1 lives in the sea1 but like the fresh water hydra1 it deposits no limy support for its body4 ,the anemone is much larger than the hydra and most coral polyps1 many species attaining a height of several inches4 ,it does not form colonies4 ,when its arms are drawn in1 it looks like a large knob of shiny but opaque jelly4 ,polyps used to be called zoophytes 7plant-animals71 because of their flower-like appearance 7,figs4 #ej1 #ea74 ,illustration3 ,,fig4 #di4--,,upright ,,cut through coral polyp #d4 ms1 mouth2 mr1 gullet2 ls1 ls1 fleshy partitions 7mesenteries7 extending from outer body wall to gullet 7to increase absorbing surface72 s1 s1 shorter partitions2 mb1 fb1 stony support 7of lime1 called coral72 t1 tentacles4 ,illustration3 ,,fig4 #ej4--,,sea ,,anemone4 ,illustration3 ,,fig4 #ea4--,,sea ,,anemones4 ,,chapter ,v ,,echinoderms 7,,spiny ,,animals7 ,,the ,,starfish ,,suggestions4 ,since the echinoderms are aberrant though interesting forms not in the regular line of development of animals1 this chapter may be omitted if it is desired to shorten the course4--,the common starfish occurs along the ,atlantic coast4 ,it is captured by wading along the shore when the tide is out4 ,it is killed by immersion in warm1 fresh water4 ,specimens are usually preserved in #d per cent formalin4 ,dried starfish and sea urchins are also useful4 ,a living starfish kept in a pail of salt water will be instructive4 ,illustration3 ,,fig4 #eb4--,starfish on a rocky shore4 ,illustration3 ,,fig4 #ec4--,,plan of starfish2 ,,iii1 madreporite4 ,external ,features4--,starfish are usually brown or yellow4 ,why8 7,see ,fig4 #eb47 ,has it a head or tail8 ,right and left sides8 ,what is the shape of the disk1 or part which bears the five arms or rays8 7,fig4 #ec47 ,does the body as a whole have symmetry on two sides of a line 7bilateral symmetry71 or around a point 7radial symmetry78 ,do the separate rays have bilateral symmetry8 ,the skeleton consists of limy plates embedded in the tough skin 7,fig4 #ed74 ,is the skin rough or smooth8 ,hard or soft8 ,are the projections 7or spines7 in the skin long or short8 ,the skin is hardened by the limy plates1 except around the mouth1 which is at the center of the lower side and surrounded by a membrane4 ,which is rougher1 the mouth side1 7oral side7 or the opposite 7aboral side78 ,which side is more nearly flat8 ,the vent is at or near the center of the disk on the aboral surface4 ,it is usually very small and sometimes absent4 ,why a vent is not of much use will be understood after learning how the starfish takes food4 ,illustration3 ,,fig4 #ed4--,,limy ,,plates in portion of a ray4 ,illustration3 ,,fig4 #ee4--,starfish 7showing ,,madreporite74 ,an organ peculiar to animals of this branch1 and called the madreporic plate1 or madreporite1 is found on the aboral surface between the bases of two rays 7,fig4 #ee74 ,it is wartlike1 and usually white or red4 ,this plate is a sieve2 the small openings keep out sand but allow water to filter through4 ,illustration3 ,,fig4 #ef4--,,water tube ,system of starfish4 m1 madreporite2 stc1 stone canal2 ap1 ampulla4 ,movements3 the ,water-tube ,system4--,the water1 which is filtered through the perforated madreporite1 is needed to supply a system of canals 7,fig4 #ef74 ,the madreporite opens into a canal called the stone canal1 the wall of which is hardened by the same kind of material as that found in the skin4 ,the stone canal leads to the ring canal which surrounds the mouth 7,fig4 #ef74 ,the ring canal sends radial canals into each ray to supply the double row of tube feet found in the groove at the lower side of each ray 7,fig4 #eg74 ,because of their arrangement in rows1 the feet are also called ambulacral feet 7,latin ambulacra1 8forest walks074 ,there is a water holder 7ampulla71 or muscular water bulb at the base of each tube foot 7,fig4 #eh74 ,these contract and force the water into the tube feet and extend them4 ,the cuplike ends of the tubes cling to the ground by suction4 ,the feet contain delicate muscles by which they contract and shorten4 ,thus the animal pulls itself slowly along1 hundreds of feet acting together4 ,the tube feet1 for their own protection1 may contract and retire into the groove1 the water which extended them being sent back into the ampulla4 ,this system of water vessels 7or water-vascular system7 of the echinodermata is characteristic of them2 i4e4 is not found elsewhere in the animal kingdom4 ,the grooves and the plates on each side of them occupy the ambulacral areas4 ,the rows of spines on each side of the grooves are freely movable4 7,what advantage87 ,the spines on the aboral surface are not freely movable4 ,illustration3 ,,fig4 #eg4--,starfish1 from below2 tube feet extended4 ,illustration3 ,,fig4 #eh4--,,section ,,of ,,one ,,ray and central portion of starfish4 f#a1 f#b1 f#c1 tube feet more or less extended2 au1 eye spot2 k1 gills2 da1 stomach2 m1 madreporite2 st1 stone canal2 p1 ampulla2 ei1 ovary4 ,respiration4--,the system of water vessels serves the additional purpose of bringing water containing oxygen into contact with various parts of the body1 and the starfish was formerly thought to have no special respiratory organs4 ,however there are holes in the aboral wall through which the folds of the delicate lining membrane protrude4 ,these are now supposed to be gills 7k1 ,fig4 #eh74 ,the nervous system is so close to the aboral surface that much of it is visible without dissection4 ,its chief parts are a nerve ring around the mouth1 which sends off a branch along each ray4 ,these branches may be seen by separating the rows of tube feet4 ,they end in a pigmented cell at the end of each ray called the eye-spot4 ,the food of starfish consists of such animals as crabs1 snails1 and oysters4 ,when the prey is too large to be taken into the mouth1 the starfish turns its stomach inside out over the prey 7,fig4 #ei74 ,after the shells separate1 the stomach is applied to the soft digestible parts4 ,after the animal is eaten1 the stomach is retracted4 ,this odd way of eating is very economical to its digestive powers1 for only that part of the food which can be digested and absorbed is taken into the body4 ,only the lower part of the stomach is wide and extensible4 ,the upper portion 7next to the aboral surface7 is not so wide4 ,this portion receives the secretion from five pairs of digestive glands1 a pair of which is situated in each ray4 ,jaws and teeth are absent4 7,why87 ,the vent is sometimes wanting4 ,why8 ,illustration3 ,,fig4 #ei4--,starfish eating a sea snail4 b1 stomach everted4 ,reproduction4--,there is a pair of ovaries at the base of each ray of the female starfish 7,fig4 #eh74 ,the spermaries of the male have the same position and form as the ovaries1 but they are lighter colored1 usually white4#b #b ,the sperm cells and egg cells are poured out into the water by the adults1 and the sperm cell1 which1 like all sperm cells1 has a vibratory1 tail-like flagellum to propel it1 reaches and fertilizes the egg cell4 ,regeneration after ,mutilation4--,if a starfish loses one or more rays1 they are replaced by growth4 ,only a very ignorant oyster-man1 angry at the depredations of starfish upon his oyster beds1 would chop starfish to pieces1 as this only serves to multiply them4 ,this power simulates multiplication by division in the simplest animals4 ,steps in ,advance of ,lower ,branches4--,the starfish and other echinodermata have a more developed nervous system1 sensory organs1 and digestion1 than forms previously studied2 most distinctive of all1 they have a body cavity distinct from the food cavity4 ,the digestive glands1 reproductive glands1 and the fluid which serves imperfectly for blood1 are in the body cavity4 ,there is no heart or blood vessels4 ,the motions of the stomach and the bending of the rays give motion to this fluid in the body cavity4 ,it cannot be called blood1 but it contains white blood corpuscles4 ,illustration3 ,,fig4 #fj4--,young starfish crawling upon their mother4 7,challenger ,reports47 ,the starfish when first hatched is an actively swimming bilateral animal1 but it soon becomes starlike 7,fig4 #fj74 ,the limy plates of the starfish belong neither to the outer nor inner layer 7endoderm and ectoderm7 of the body wall1 but to a third or middle layer 7mesoderm72 for echinoderms1 like the polyps1 belong to the three-layered animals4 ,in this its skeleton differs from the shell of a crawfish1 which is formed by the hardening of the skin itself4 ,protective ,coloration4--,starfish are brown or yellow4 ,this makes them inconspicuous on the brown rocks or yellow sands of the seashore4 ,this is an example of protective coloration4 ,,the ,,sea ,,urchin ,external ,features4--,what is the shape of the body8 ,what kind of symmetry has it8 ,do you find the oral 7or mouth7 surface8 ,the aboral surface8 ,where is the body flattened8 ,what is the shape of the spines8 ,what is their use8 ,how are the tube feet arranged8 ,where do the rows begin and end8 ,would you think a sea urchin placed upside down in water1 could right itself less or more readily than a starfish8 ,what advantage in turning would each have that the other would not have8 ,the name sea urchin has no reference to a mischievous boy1 but means sea hedgehog 7,french oursin1 hedgehog71 the name being suggested by its spines4 ,comparison of ,starfish and ,sea ,urchin4--,the water system of the sea urchin1 consisting of madreporite1 tubes1 and water bulbs1 or ampull1 is similar to that of the starfish4 ,the tube feet and locomotion are alike4 ,there is no need for well-developed respiratory organs in either animal1 as the whole body1 inside and out1 is bathed in water4 ,the method of reproduction is the same4 ,illustration3 ,,fig4 #fa4--;,a ,,sea ,,urchin crawling up the glass front wall of an aquarium 7showing mouth spines and tube feet74 ,illustration3 ,,fig4 #fb4--;,a ,,sea ,,urchin with spines removed1 the limy plates showing the knobs on which the spines grew4 ,illustration3 ,,fig4 #fc4--,,section ,,of ,,sea ,,urchin with soft parts removed1 showing the jaws which bear the teeth protruding in ,fig4 #fb4 ,the starfish eats animal food4 ,the food of the sea urchin is almost exclusively vegetable1 hence it needs teeth 7,fig4 #fb1 #fc72 its food tube is longer than that of a starfish1 just as the food tube of a sheep1 whose food digests slowly1 is much longer than that of a dog4 ,illustration3 ,,fig4 #fd4--,,the ,,sea ,,otter1 an urchin with mouth 7o7 and vent 7,a7 on same side of body4 ,the largest species of sea urchins are almost as big as a child's head1 but this size is unusual4 ,the spines are mounted on knobs1 and the joint resembles a ball-and-socket joint1 and allow as wide range of movement4 ,some sea urchins live on sandy shores1 other species live upon the rocks4 ,the sand dollars are lighter colored4 7,why87 ,they are usually flatter and have lighter1 thinner walls1 for there is danger of sinking into the sand4 ,the five-holed sand cake or sand dollar has its weight still further diminished by the holes1 which also allow it to rise more easily through the water4 ,the flattened lower surface of both starfish and sea urchin causes the body to remain still while the tube feet are stretching forward for another step4 ,,other ,,echinoderms ,the sea cucumbers1 or holothurians1 resemble the sea urchin in many respects1 but their bodies are elongated1 and the limy plates are absent or very minute4 ,the mouth is surrounded by tentacles 7,fig4 #fe74 ,illustration3 ,,fig4 #fe4--,,sea ,,cucumbers4 ,illustration3 ,,fig4 #ff4--;,a ,,brittle ,,star4 ,the brittle stars resemble the starfish in form1 but their rays are very slender1 more distinct from the disk1 and the tube feet are on the edges of the rays1 not under them 7,fig4 #ff74 ,the crinoids are the most ancient of the echinoderms4 7,figs4 #fg1 #fh47 ,their fossils are very abundant in the rocks4 ,they inhabited the geological seas1 and it is believed that the other echinoderms descended from them4 ,a few now inhabit the deep seas4 ,some species are fixed by stems when young1 and later break away and become free-swimming1 others remain fixed throughout life4 ,the four classes of the branch echinoderms are ,starfish 7asteroids71 ,sea urchins 7echinoids71 ,sea cucumbers 7holothurians71 and ,sea lilies 7crinoids74 ,illustration3 ,,fig4 #fg4--;,,crinoid1 arms closed4 ,illustration3 ,,fig4 #fh4--;,,disk ,,of ,,crinoid from above1 showing mouth in center and vent near it1 at right 7arms removed74 ,comparative ,review ,make a table like this as large as the page of the notebook will allow1 and fill in without guessing4 ,,ameba ,,sponge ,,hydra ,,coral ,,starfish ,,polyp ---------------------------------------- ----------------------- ,is body round1 two- sided1 or irregular ---------------------------------------- ----------------------- ,what organs of sense ---------------------------------------- ----------------------- ,openings into body ---------------------------------------- ----------------------- ,hard or supporting parts of body ---------------------------------------- ----------------------- ,how food is taken ---------------------------------------- ----------------------- ,how move ---------------------------------------- ----------------------- ,how breathe ,,chapter ,,vi ,,worms ,,suggestions3--,earthworms may be found in the daytime after a heavy rain1 or by digging or turning over planks1 logs1 etc41 in damp places4 ,they may be found on the surface at night by searching with a lantern4 ,live specimens may be kept in the laboratory in a box packed with damp 7not wet7 loam and dead leaves4 ,they may be fed on bits of fat meat1 cabbage1 onion1 etc41 dropped on the surface4 ,when studying live worms1 they should be allowed to crawl on damp paper or wood4 ,an earthworm placed in a glass tube with rich1 damp soil1 may be watched from day to day4 ,external ,features4--,is the body bilateral8 ,is there a dorsal and ventral surface8 ,can you show this by a test with a live worm8 ,do you know of an animal with dorsal and ventral surface1 but not bilateral8 ,illustration3 ,,fig4 #fi4--;,an ,earthworm4 ,can you make out a head8 ,a head end8 ,a neck8 ,touch the head and test whether it can be made to crawl backwards4 ,which end is more tapering8 ,is the mouth at the tip of the head end or on the upper or lower surface8 ,how is the vent situated8 ,its shape8 ,as the worm lies on a horizontal surface1 is the body anywhere flattened8 ,are there any very distinct divisions in the body8 ,do you see any eyes8 ,experiment to find whether the worm is sensitive 7#a7 to touch1 7#b7 to light1 7#c7 to strong odors1 7#d7 to irritating liquids4 ,does it show a sense of taste8 ,the experiments should show whether it avoids or seeks a bright light1 as a window2 also whether any parts of the body are especially sensitive to touch1 or all equally sensitive4 ,what effect when a bright light is brought suddenly near it at night8 ,is red blood visible through the skin8 ,can you notice any pulsations in a vessel along the back8 ,do all earthworms have the same number of divisions or rings8 ,compare the size of the rings or segments4 ,can it crawl faster on glass or on paper8 ,illustration3 ,,fig4 #gj4--,,mouth ,,and ,,set4 ,illustration3 ,,fig4 #ga4--;,,earthworm1 mouth end above4 ,a magnifying glass will show on most species tiny bristle-like projections called set4 ,how are the set arranged8 7d1 ,fig4 #gj47 ,how many on one ring of the worm8 ,how do they point8 ,does the worm feel smoother when it is pulled forward or backward between the fingers8 ,why8 ,are set on the lower surface8 ,upper surface8 ,the sides8 ,what is the use of the set8 ,are they useful below ground8 ,does the worm move at a uniform rate8 ,what change in form occurs as the front part of the body is pushed forward8 ,as the hinder part is pulled onward8 ,how far does it go at each movement8 ,at certain seasons a broad band1 or ring1 appears1 covering several segments and making them seem enlarged 7,fig4 #ga74 ,this is the clitellum1 or reproductive girdle4 ,is this girdle nearer the mouth or the tail8 ,draw the exterior of an earthworm4 ,dorsal and ,ventral ,surfaces4--,the earthworm always crawls with the same surface to the ground2 this is called the ventral surface1 the opposite surface is the dorsal surface4 ,this is the first animal studied to which these terms are applicable4 ,what are the ventral and dorsal surfaces of a fish1 a frog1 a bird1 a horse1 a man8 ,the name 8worm0 is often carelessly applied to various crawling things in general4 ,it is properly applied1 however1 only to segmented animals without jointed appendages4 ,although a caterpillar crawls1 it is not a worm for several reasons4 ,it has six jointed legs1 and it is not a developed animal1 but only an early stage in the life of a moth or butterfly4 ,a 8grubworm0 also has jointed legs 7,fig4 #afg74 ,it does not remain a grub1 but in the adult stage is a beetle4 ,a worm never develops into another animal in the latter part of its life2 its set are not jointed4 ,illustration3 ,,fig4 #gb4--;,,food ,,tube of earthworm4 7,top view47 ,illustration3 ,,fig4 #gc4--;,,food ,,tube ,,and ,,blood ,,vessels of earthworm showing the ring-like hearts4 7,side view47 ,the ,food ,tube4--,the earthworm has no teeth1 and the food tube1 as might be inferred from the form of the body1 is simple and straight4 ,on account of slight variation in size and structure1 its parts are named the pharynx 7muscular71 gullet1 crop1 gizzard 7muscular71 and the long intestine extending through the last three fourths of its body 7,fig4 #gb74 ,the functions of the parts of the food tube are indicated by their names4 ,illustration3 ,,fig4 #gd4 ,circulation4--,there is a large dorsal blood vessel above the food tube 7,fig4 #gc74 ,from the front portion of this tube arise several large tubular rings or 8hearts0 which are contractile and serve to keep the blood circulating4 ,they lead to a ventral vessel below the food tube 7,fig4 #gd74 ,the blood is red1 but the coloring matter is in the liquid1 not in the blood cells4 ,nervous ,system4--,between the ventral blood vessels is a nerve cord composed of two strands 7see ,fig4 #ge74 ,there is a slight swelling1 or ganglion1 on each strand1 in each segment 7,fig4 #ge74 ,the strands separate near the front end of the worm1 and a branch goes up each side of the gullet and enters the two pear-shaped cerebral ganglia1 or 8brain0 7,fig4 #ge74 ,illustration3 ,,fig4 #ge4--;,,ganglia ,,near ,,mouth and part of nerve chain of earthworm4 ,food4--,the earthworm eats earth containing organic matter1 the inorganic part passing through the vent in the form of circular casts found in the morning at the top of the earthworm's hole4 ,what else does it eat8 ,the earth worm needs no teeth1 as it excretes through the mouth an alkaline fluid which softens and partly digests the food before it is eaten4 ,when this fluid is poured out upon a green leaf1 the leaf at once turns brown4 ,the starch in the leaf is also acted upon4 ,the snout aids in pushing the food into the mouth4 ,kidneys4--,since oxidation is occurring in its tissues1 and impurities are forming1 there must be some way of removing impurities from the tissues4 ,the earthworm does not possess one-pair organs like the kidneys of higher animals to serve this purpose1 but it has numerous pairs of small tubular organs called nephridia which serve the purpose4 ,each one is simply a tube with several coils 7,fig4 #gf74 ,there is a pair on the floor of each segment 7,fig4 #gf74 ,each nephridium has an inner open end within the body cavity1 and its outer end opens by a pore on the surface between the set 7,fig4 #gh74 ,the nephridia absorb waste water from the liquid in the celom1 or body cavity surrounding the food tube1 and convey it to the outside4 ,illustration3 ,,fig4 #gf4--,,two ,,pairs ,,of ,,nephridia4 ,respiration4--,the skin of the earthworm is moist1 and the blood capillaries approach so near to the surface of the body that the oxygen is constantly passing in from the air1 and carbon dioxid passing out2 hence it is constantly breathing through all parts of its skin4 ,it needs no lungs nor special respiratory organs of any kind4 ,illustration3 ,,fig4 #gg4--,sperm 7sp7 and egg glands 7es7 of earthworm4 ,reproduction4--,when one individual animal produces both sperm cells and egg cells1 it is said to be hermaphrodite4 ,this is true of the earthworm4 ,the egg cell is always fertilized1 however1 not by the sperm cells of the same worm1 but by sperm cells formed by another worm4 ,the openings of these ova or egg glands consist of two pairs of small pores found on the ventral surface of the fourteenth and fifteenth segments in most species 7see ,fig4 #gg74 ,there are also two pairs of small receptacles for temporarily holding the foreign sperm cells4 ,one pair of the openings from these receptacles is found 7with difficulty7 in the wrinkle behind the ninth segment 7,fig4 #gg71 and the other pair behind the tenth segment4 ,the sperm glands are in front of the ovaries 7,fig4 #gg71 but the sperm ducts are longer than the oviducts1 and open behind them 7,figs4 #gg1 #gh74 ,the worms exchange sperm cells1 but not egg cells4 ,the reproductive girdle1 or clitellum1 already spoken of1 forms the case which is to hold the eggs 7see ,fig4 #ga74 ,when the sperm cells have been exchanged1 and the ova are ready for fertilization1 the worm draws itself backward from the collarlike case or clitellum so that it slips over the head4 ,as it passes the fifteenth and sixteenth segments1 it collects the ova1 and as it passes the ninth and tenth segments1 it collects the sperm cells previously received by touching another worm4 ,the elastic1 collar-like clitellum closes at the ends after it has slipped over the worm's head1 forming a capsule4 ,the ova are fertilized in this capsule1 and some of them hatch into worms in a few days4 ,these devour the eggs which do not hatch4 ,the eggs develop into complete but very small worms before the worms escape from the capsule4 ,illustration3 ,,fig4 #gh4--,side view showing set1 nephridia pores1 and reproductive openings4 ,habits4--,the earthworm is omnivorous4 ,it will eat bits of meat as well as leaves and other vegetation4 ,it has also the advantage1 when digging its hole1 of eating the earth which must be excavated4 ,every one has noticed the fresh 8casts0 piled up at the holes in the morning4 ,as the holes are partly filled by rains1 the casts are most abundant after rains4 ,the chief enemies of the earthworm are moles and birds4 ,the worms work at night and retire so early in the morning that it takes a very early bird to catch a worm4 ,perhaps the nearest to an intelligent act the earthworm accomplishes is to conceal the mouth of its hole by plugging it with a pebble or bit of leaf4 ,they hibernate1 going below danger of frost in winter4 ,in dry weather they burrow several feet deep4 ,the muscular coat beneath1 and much thicker than the skin1 consists of two layers3 an outer layer runs around the body just beneath the skin1 and an inner1 thicker layer of fibers runs lengthwise4 ,the worm crawls by shortening the longitudinal muscles4 ,as the bristles 7set7 point backward1 they prevent the front part of the body from slipping back1 so the hinder part is drawn forward4 ,next1 the circular muscles contract1 and the bristles preventing the hind part from slipping back1 the fore portion is pushed forward4 ,is the worm thicker when the hinder part is being pulled up or when the fore part is being thrust forward8 ,does the earthworm pull or push itself along1 or does it do both8 ,occasionally it travels backward1 e4g4 it sometimes goes backward into its hole4 ,then the bristles are directed forward4 ,the right and left halves of the body are counterparts of each other1 hence the earthworm is bilaterally symmetrical4 ,the lungs and gills of animals must always be kept moist4 ,the worm cannot live long in dry air1 for respiration in the skin ceases when it cannot be kept moist1 and the worm smothers4 ,long immersion in water is injurious to them1 perhaps because there is far less oxygen in water than in the air4 ,darwin wrote a book called 8,vegetable ,mold and ,earthworms40 ,he estimated that there were fifty thousand earthworms to the acre on farm land in ,england1 and that they bring up eighteen tons of soil in an acre each year4 ,as the acids of the food tube act upon the mineral grains that pass through it1 the earthworm renders great aid in forming soil4 ,by burrowing it makes the soil more porous and brings up the subsoil4 ,although without eyes1 the worm is sensitive to light falling upon its anterior segments4 ,when the light of a lantern suddenly strikes it at night1 it crawls quickly to its burrow4 ,its sense of touch is so keen that it can detect a light puff of breath4 ,which of the foods kept in a box of damp earth disappeared first8 ,what is indicated as to a sense of taste8 ,why is the bilateral type of structure better adapted for development and higher organization than the radiate type of the starfish8 ,the earthworm's body is a double tube2 the hydra's body is a single tube2 which plan is more advantageous1 and why8 ,would any other color do just as well for an earthworm8 ,why1 or why not8 ,the sandworm 7,nereis7 lives in the sand of the seashore1 and swims in the sea at night 7,fig4 #gi74 ,it is more advanced in structure than the earthworm1 as it has a distinct head 7,fig4 #hj71 eyes1 two teeth1 two lips1 and several pairs of antenn1 and two rows of muscular projections which serve as feet4 ,it is much used by fishermen for bait4 ,if more easily obtained1 it may be studied instead of the earthworm4 ,illustration3 ,,fig4 #gi4--,,sand ,,worm 7,nereis74 ,there are four classes in the branch ,vermes3 #a7 the earthworms1 including sandworms and leeches2 #b7 the roundworms1 including trichina1 hairworms1 and vinegar eels2 #c7 flatworms1 including tapeworm and liver fluke2 #d7 rotifers1 which are mere specks in size4 ,illustration3 ,,fig4 #hj4--;,,head ,,of ,,sandworm 7enlarged74 ,the tapeworm is a flatworm which has lost most of its organs on account of its parasitic life4 ,its egg is picked up by an herbivorous animal when grazing4 ,the embryo undergoes only partial development in the body of the herbivorous animal1 e4g4 an ox4 ,the next stage will not develop until the beef is eaten by a carnivorous animal1 to whose food canal it attaches itself and soon develops a long chain of segments called a 8tape40 ,each segment absorbs fluid food through its body wall4 ,as the segments at the older end mature1 each becomes full of germs1 and the segments become detached and pass out of the canal1 to be dropped and perhaps picked up by an herbivorous animal and repeat the life cycle4 ,the trichina is more dangerous to human life than the tapeworm4 ,it gets into the food canal in uncooked pork 7bologna sausage1 for example71 multiplies there1 migrates into the muscles1 causing great pain1 and encysts there1 remaining until the death of the host4 ,it is believed to get into the bodies of hogs again when they eat rats1 which in turn have obtained the cysts from carcasses4 ,summary of the ,biological ,process4--,an earthworm is a living machine which does work 7digging and crawling2 seizing1 swallowing1 and digesting food2 pumping blood2 growing and reproducing74 ,to do the work it must have a continual supply of energy4 ,the energy for its work is set free by the protoplasm 7in its microscopic cells7 undergoing a destructive chemical change 7oxidation74 ,the waste products from the breaking down of the protoplasm must be continually removed 7excretion74 ,the broken-down protoplasm must be continually replaced if life is to continue 7the income must exceed the outgo if the animal is still growing74 ,the microscopic cells construct more protoplasm out of food and oxygen 7assimilation7 supplied them by the processes of nutrition 7eating1 digesting1 breathing1 circulating74 ,this protoplasm in turn oxidizes and releases more energy to do work1 and thus the cycle of life proceeds4 ,,chapter ,,vii ,,crustaceans ,,crawfish ,,suggestions4--,in regions where crawfish are not found1 a live crab may be used4 ,locomotion and behavior may be studied by providing a tub of water1 or better1 a large glass jar such as a broad candy jar4 ,for suggestions on study of internal structure1 see p4 #eh4 ,habitat4--,do you often see crawfish1 or crayfish1 moving about1 even in water where they are known to be abundant8 ,what does your answer suggest as to the time when they are probably most active8 ,why do you never see one building its chimney1 even where crawfish holes are abundant8 ,is the chimney always of the same color as the surface soil8 ,are the crawfish holes only of use for protection8 ,in what kind of spots are crawfish holes always dug8 ,why8 ,what becomes of crawfish when the pond or creek dries up8 ,how deep are the holes8 ,how large are the lumps of mud of which the chimney is built8 ,how does it get them out of the hole8 ,why is the mud built into a chimney instead of thrown away8 7,what would happen to a well with its mouth no higher than the ground87 ,why are crawfish scarce in rocky regions1 as ,new ,england8 ,how does the color of the crawfish compare with its surroundings8 ,is its color suited to life in clear or muddy water8 ,define protective coloration4 ,habits4--,does the crawfish walk better in water or out of it8 ,why8 ,does it use the legs with the large claws to assist in walking8 ,do the swimmerets 7under the abdomen7 move fast or slow8 7,observe it from below in a large jar of clear water47 ,what propels it backward8 ,forward8 ,does the crawfish move at a more uniform rate when swimming backward or forward8 ,why8 ,in which way can it swim more rapidly8 ,do the big legs with claws offer more resistance to the water while it is swimming backward or forward8 ,how does it hold the tail after the stroke1 while it is darting backward through the water8 ,hold a crawfish with its tail submerged and its head up4 ,can the tail strike the water with much force8 ,allow it to grasp a pencil3 can it sustain its own weight by its grip8 ,feeding4--,offer several kinds of food to a crawfish that has not been alarmed or teased4 ,does it prefer bread1 meat1 or vegetables8 ,how does it get the food to its mouth8 ,does it eat rapidly or slowly8 ,does it tear the food with the big pincers8 ,can it gnaw with the small appendages near the mouth8 ,breathing4--,does the crawfish breathe with gills or lungs8 ,place a few drops of ink near the base of the hind legs of a crawfish resting quietly in shallow water4 ,where is the ink drawn in8 ,where does it come out8 ,to explain the cause and purpose of this motion1 place a crawfish in a large glass jar containing water1 and see the vibratory motion of the parts under the front portion of the body4 ,there is a gill paddle1 or gill bailer1 under the shell on each side of the body that moves at the same rate4 ,senses4--,crawfish are best caught with a piece of meat or beef's liver tied to a string4 ,do they always lose hold as soon as they are lifted above the water8 ,what do you conclude as to the alertness of their senses8 ,does the covering of its body suggest the possession of a delicate or dull sense of touch8 ,of what motions are the eyes capable8 ,touch one of the eyes4 ,the result8 ,can a crawfish see in all directions8 ,to test this1 place a crawfish on a table and try whether you can move to a place where you can see the crawfish without seeing its eyes4 ,what are the advantages and disadvantages of having the eyes on stalks8 ,illustration3 ,,fig4 #ha4--;,,crawfish 7dorsal surface74 ,illustration3 ,,fig4 #hb4 ,touch the body and the several appendages of the crawfish4 ,where does it seem most sensitive to touch8 ,which can reach farther1 the antenn or the big claws8 ,why are short feelers needed as well as long ones8 ,make a loud and sudden noise without jarring the crawfish4 ,is it affected by sound8 ,external ,anatomy 7,figs4 #ha1 #hb1 #hc1 #hd74--;,is the body of the crawfish rounded out 7convex7 everywhere1 or is any part of its surface either flat or rounded in 7concave78 ,what color has the crawfish8 ,is this color of any use to the crawfish8 ,illustration3 ,,fig4 #hc4--,,lateral ,,view ,,of ,,crawfish4 ,illustration3 ,,fig4 #hd4--;,,fourth ,,abdominal ,,segment ,,of ,,crawfish with swimmeret4 ,make out the two distinct regions or divisions of the body 7,fig4 #ha74 ,the anterior 7front7 region is called the head-chest or cephalothorax1 and the posterior 7rear7 region is called the tail4 ,which region is larger8 ,why8 ,which is flexible8 ,why8 ,is the covering of the body hard or soft8 ,what is the advantage of such a covering8 ,what are its disadvantages8 ,how is the covering modified at the joints to permit motion8 ,tail4--,how many joints1 or segments1 on the tail8 7,figs4 #ha1 #hc47 ,does the hard covering of each segment slip under or over the segment behind it when the abdomen is straight8 ,does this lessen friction while swimming forward8 ,is there a pair of swimmerets to each segment of the abdomen8 7,figs4 #hb1 #hf47 ,notice that each swimmeret has a main stalk 7protopod71 an outer branch 7exopod71 and an inner branch 7endopod7 7,fig4 #hd74 ,are the stalk and the branches each in one piece or jointed8 ,the middle part of the tail fin is called the telson4 ,by finding the position of the vent1 decide whether the food tube goes into the telson 7,fig4 #hb74 ,should it be called an abdominal segment8 ,are the side pieces of the tail fin attached to the telson or to the sixth segment8 ,do these side pieces correspond to swimmerets8 ,do they likewise have the ,y-shaped structure8 7,fig4 #hf47 ,if the swimmerets on the first abdominal segment are large1 the specimen is a male4 ,if they are small1 it is a female4 ,which sex is shown in ,fig4 #hb8 ,fig4 #hf8 ,carapace4--,the covering of the head chest 7cephalothorax7 is called the carapace4 ,has it free edges8 ,the gills are on the sides of the body and are covered by the carapace 7,fig4 #hg74 ,the projection in front is called the rostrum1 meaning beak4 ,does the rostrum project beyond the eyes8 ,there is a transverse groove across the carapace which may be said to divide the head from the abdomen4 ,where does this groove end at the sides8 ,illustration3 ,,fig4 #he4--a1 mandible2 #b1 #c1 maxill2 #d1 #e1 #f1 maxillipeds4 ,legs4--,how many legs has the crawfish8 ,how many are provided with large claws8 ,small claws8 ,is the outer claw hinged in each of the large grasping pincers8 ,the inner claw8 ,illustration3 ,,fig4 #hf4--;,,crawfish 7ventral surface74 ,appendages for ,taking ,food4--,if possible to watch a living crawfish eating1 notice whether it places the food directly into the mouth with the large claws4 ,bend the large claws under and see if they will reach the mouth4 ,attached just in front of the legs the crawfish has three pairs of finger-like appendages1 called foot jaws 7maxillipeds71 with which it passes the food from the large pincers to its mouth 7,figs4 #he1 #hf74 ,they are in form and use more like fingers than feet4 ,in front of the foot jaws are two pairs of thin jaws 7maxill7 and in front of the thin jaws are a pair of stout jaws 7mandibles7 7,fig4 #he74 ,do the jaws move sidewise or up and down8 ,which of the jaws has a jointed finger 7palp7 attached to it8 ,do all of the appendages for taking food have both exopod and endopod branches on a basal stalk or protopod8 ,which of the appendages have a scalloped edge8 ,how would you know from looking at the crawfish that it is not merely a scavenger8 ,why are there no pincers on the hind feet8 ,illustration3 ,,fig4 #hg4--;,gill cover removed and gills exposed4 ,mp1 gill bailer4 ,sense ,organs4--,find the antenn1 or long feelers 7,figs4 #hb1 #ij74 ,are the antenn attached above or below the eyes8 7,fig4 #hg47 ,illustration3 ,,fig4 #hh4--,,lengthwise ,,section ,,of ,,male ,,crawfish4 c1 heart2 ,ac1 artery to head2 ,aa1 artery to abdomen2 ,km1 stomach2 ,d1 intestine2 ,l1 liver2 ,t1 spermary2 ,go1 opening of sperm duct2 ,g1 brain2 ,n1 nerve chain4 ,find the pair of antennules1 or small feelers4 ,are their divisions like or unlike each other8 ,compare the length of the antennules and the antenn4 ,compare the flexibility of the antenn with that of the other appendages4 ,observe the position of the eyes 7,figs4 #ha1 #hh74 ,how long are the eyestalks8 ,is the stalk flexible or stiff8 ,touch the eye4 ,where is the joint which enables the stalk to move8 ,is the outer covering of the eye hard or soft8 ,a mounted preparation of the transparent covering 7cornea7 of the eye1 seen with lower power of microscope1 reveals that the cornea is made up of many divisions1 called facets4 ,each facet is the front of a very small eye1 hundreds of which make up the whole eye1 which is therefore called a compound eye4 ,the elongated openings to the ear sacs are located each on the upper side of the base of a small feeler just below the eye4 ,respiratory ,system4--,the respiratory organs are gills located on each side of the thorax in a space between the carapace and body 7,fig4 #hg74 ,the gills are white1 curved1 and feathery4 ,is the front gill the largest or the smallest8 ,the gills overlap each other2 which is the outermost gill8 ,on the second maxilla is a thin1 doubly curved plate called a gill bailer 7,fig4 #he74 ,the second maxilla is so placed that the gill bailer comes at the front end of the gill chamber4 ,the bailer paddles continually1 bringing the water forward out of the gill4 ,the gills are attached below at the base of the legs4 ,are the gills thick or thin8 ,how far upward do they go8 ,does the backward motion in swimming aid or hinder the passage of the water through the gills8 ,does a crawfish1 when at rest on the bottom of a stream1 have its head up or down stream8 ,why8 ,openings4--,the slitlike vent is on the under side of the telson 7,figs4 #hb1 #hh74 ,the mouth is on the under side of the thorax behind the mandibles4 ,at the base of the long antenn are the openings from the green glands1 two glands in the head which serve as kidneys 7,fig4 #hi74 ,the openings of the reproductive organs are on the third pair of legs in the female1 and the fifth pair of legs in the male 7,fig4 #hh74 ,the eggs are carried on the swimmerets4 ,illustration3 ,,fig4 #hi4--,level lengthwise section showing h1 heart4 d1 green gland4 le1 liver4 kie1 gills4 kh1 gill cavity4 ma1 stomach4 7,after ,huxley47 ,internal ,structure4--,,suggestions4 ,if studied by dissection1 it will be necessary to have several crawfish for each pupil1 one for gaining general knowledge1 and others for studying the systems in detail4 ,specimens should have lain in alcohol for several days4 ,illustration3 ,,fig4 #ij4--,,section ,,of ,,crawfish showing stomach s1 liver li1 and vent a4 ,the ,food ,tube4--,is the stomach in the head portion of the cephalothorax or in the thoracic portion8 7,figs4 #hh1 #hi74 ,is the stomach large or small8 ,what is its general shape8 ,does the gullet lead upward or backward8 ,is it long or short8 7,fig4 #hh47 ,the mid tube1 which is the next portion of the food tube1 is smaller than the stomach4 ,on each side of it are openings from the bile ducts which bring the secretion from the digestive gland1 sometimes called the liver4 ,does this gland extend the whole length of the thorax8 ,is it near the floor or the top of the cavity8 ,the third and last portion of the food tube is the intestine4 ,it extends from the thorax to the vent4 ,is it large or small8 ,straight or curved8 ,the powerful flexor muscles of the tail lie in the abdomen below the intestines4 ,compare the size of these muscles with the extensor muscle above the intestine 7,fig4 #ij74 ,why this difference8 ,does the food tube extend into the telson8 ,locate the vent 7,fig4 #ij74 ,the ,circulation4--,the blood is a liquid containing white corpuscles4 ,it lacks red corpuscles and is colorless4 ,the heart is in the upper part of the thorax4 ,it is surrounded by a large1 thin bag1 and thus it is in a chamber 7called the pericardial sinus74 ,the blood from the pulmonary veins enters this sinus before it enters the heart4 ,the origin of this pericardial sinus by the fusing of veins is shown in ,fig4 #acj4 ,does one artery1 or do several arteries1 leave the heart8 ,there is a larger dorsal artery lying on the intestine and passing back to the telson2 there are three arteries passing forward close to the dorsal surface 7,figs4 #hi1 #ia74 ,one large artery 7the sternal7 passes directly downward 7,figs4 #hh1 #ia71 and sends a branch forward and another backward near the ventral surface4 ,the openings into the heart from the sinus have valvular lips which prevent a backward flow of blood into the sinus4 ,hence1 when the heart contracts1 the blood is sent out into the several arteries4 ,the arteries take a supply of fresh blood to the eyes1 stomach1 muscles1 liver1 and the various organs4 ,after it has given oxygen to the several organs and taken up carbon dioxid1 it returns by veins to pass through the gills on each side1 where it gives out the useless gas and takes up oxygen from the water4 ,it is then led upward by veins into the pericardial sinus again4 ,a double nerve chain of ganglia supplies nerve force to the various nerves 7,fig4 #ib74 ,this main nerve chain lies along the ventral surface below the food tube 7,fig4 #ij71 except one pair of ganglia which lie above the esophagus or gullet 7,fig4 #hh71 and are called the supra-esophageal ganglia1 or brain4 ,illustration3 ,,fig4 #ia4--,showing heart and main blood vessels4 ,illustration3 ,,fig4 #ib4 ,crustacea4--,because of the limy crust which covers the crawfish and its kindred1 they are placed in the class called ,crustacea4 ,illustration3 ,,fig4 #ic4--;,,crab ,,from ,,below4 ,illustration3 ,,fig4 #id4--;,,hermit ,,crab1 using shell of sea snail for a house4 ,decapods4--,all crustacea which have ten feet belong in the order called decapoda 7ten-footed74 ,this order includes the crabs1 lobsters1 shrimp1 etc4 ,the crabs and lobsters are of considerable importance because of use as food4 ,small boys sometimes catch crawfish1 and in some instances are known to cook and eat them for amusement1 the only part cooked being the muscular tail4 ,the crab's tail is small and flat and held under the body 7,fig4 #ic74 ,illustration3 ,,fig4 #ie4--;,,development ,,of ,a ,,crab4 a1 nauplius just after hatching2 b1 c1 d1 zoa2 e1 megalops2 f1 adult4 ,question3 ,which stage is most like a crayfish8 ,compare with metamorphoses of insects4 ,since the limy covering to serve the purpose of protection is not soft enough to be alive and growing1 it is evident that the crustacea are hampered in their growth by their crusty covering4 ,during the first year the crawfish sheds its covering1 or molts three times1 and once each year thereafter4 ,it grows very fast for a few days just after molting1 while the covering is soft and extensible4 ,since it is at the mercy of birds1 fish1 and other enemies while in this soft and defenseless condition1 it stays hidden until the covering hardens4 ,hence it cannot eat much1 but probably by the absorption of water the tissues grow2 that is1 enlarge4 ,in the intervening periods1 when growth is impossible1 it develops2 that is1 the tissues and organs change in structure and become stronger4 8,soft-shelled crab0 is a popular dish1 but there is no species by that name1 this being only a crab just after molting which has been found by fishermen in spite of its hiding4 ,general ,questions4--,how do crawfish choose their food8 ,how long can they live out of water8 ,why do their gills remain moist out of water longer than a fish8 ,how do they breathe out of water8 ,are they courageous or cowardly animals8 ,when they lose appendages when fighting or molting1 they are readily reproduced1 but the part molts several times in regaining its size4 ,have you seen crawfish with one claw smaller than the other8 ,explain4 ,compare the crawfish and crab 7,figs4 #ha1 #ic1 and #ie7 in the following particulars3 shape1 body1 eyes1 legs1 abdomen1 habitat1 movement4 ,,key ,,to ,,the ,,four ,,classes ,,in ,,branch ,,arthropods #a4 ,,insects #c body divisions1 #f legs #b4 ,,arachnids #b body divisions1 #h legs #c4 ,,myriapods many body divisions1 many legs #d4 ,,crustaceans gill breathers1 skeleton 7external7 limy ,by the aid of the key and of figures #if-aje1 classify the following ,arthropods3 tick1 thousand-leg centipede1 king crab1 pill bug1 spider1 scorpion1 beetle4 ,illustration3 ,,fig4 #if4--,,pill ,,bug4 ,illustration3 ,,fig4 #ig4--,,lady ,,beetle4 ,illustration3 ,,fig4 #ih4--,,scorpion4 ,illustration3 ,,fig4 #ii4--,,tick before and after feeding4 ,illustration3 ,,fig4 #ajj4--;,,centipede4 ,illustration3 ,,fig4 #aja4--,,one ,,segment ,,of ,,centipede with one pair of legs4 ,illustration3 ,,fig4 #ajb4--,,one ,,segment ,,of ,,thousand ,,legs with two pairs of legs4 ,illustration3 ,,fig4 #ajc4--,,thousand ,,legs4 ,illustration3 ,,fig4 #ajd4--;,a ,,spider4 ,illustration3 ,,fig4 #aje4--,,king ,,crab4 ,illustrated ,study4 ,,classification ,,of ,,arthropods4 ,key on p4 #fa4 ,,chapter ,,viii ,,insects ,,the ,,grasshopper ,,suggestions4--,collect grasshoppers1 both young and full-grown1 and keep alive in broad bottles or tumblers and feed on fresh grass or lettuce4 ,when handling a live grasshopper1 never hold it by its legs1 as the joints are weak4 ,to keep them for some time and observe their molts1 place sod in the bottom of a box and cover the box with mosquito netting or wire gauze4 ,what is the general shape of its body8 7,fig4 #ajf47 ,where is the body thickest8 ,is it bilaterally symmetrical1 that is1 are the two sides of the body alike8 ,is the skeleton1 or hard part of the body1 internal or external8 ,is the skeleton as stiff and thick as that of a crawfish8 ,what is the length of your specimen8 ,its color8 ,why does it have this coloration8 ,in what ways does the grasshopper resemble the crawfish8 ,differ from it8 ,illustration3 ,,fig4 #ajf4--;,a ,,grasshopper4 ,the ,three ,regions of the ,body4--,the body of the grasshopper is divided into three regions1--the head1 thorax1 and abdomen4 ,which of these three divisions has no distinct subdivisions8 ,the body of the grasshopper1 like that of the earthworm1 is made of ringlike segments4 ,are the segments most distinct in the head1 thorax1 or abdomen8 ,which region is longest8 ,shortest8 ,strongest8 ,why8 ,which region bears the chief sense organs8 ,the appendages for taking food8 ,the locomotory appendages8 ,which division of the body is most active in breathing8 ,the ,abdomen4--,about how many segments or rings in the abdomen8 ,do all grasshoppers have the same number of rings8 7,answer for different species and different individuals of the same species47 ,the first segment and the last two are incomplete rings4 ,does the flexibility of the abdomen reside in the rings1 or the joints between the rings8 ,is there merely a thin1 soft line between the rings1 or is there a fold of the covering8 ,does one ring slip into the ring before it or behind it when the abdomen is bent8 ,as the grasshopper breathes1 does each ring enlarge and diminish in size8 ,each ring is divided into two parts by folds4 ,does the upper half-ring overlap the lower half-ring1 or the reverse8 ,with magnifying glass1 find a small slit1 called a spiracle1 or breathing hole1 on each side of each ring just above the side groove 7,fig4 #ajf74 ,a tube leads from each spiracle4 ,while the air is being taken in1 do the two portions of the rings move farther apart8 ,when they are brought together again1 what must be the effect8 ,in pumping the air1 the abdomen may be said to work like a bellows4 ,bellows usually have folds to allow motion4 ,is the comparison correct8 ,how many times in a minute does the grasshopper take in air8 ,if it is made to hop vigorously around the room and the breathing is again timed1 is there any change8 ,illustration3 ,,fig4 #ajg4--;,a ,,grasshopper ,,dissected4 ,find the ears on the front wall of the first abdominal ring 7,fig4 #ajg74 ,they may be seen by slightly pressing the abdomen so as to widen the chink between it and the thorax4 ,the ears are merely glistening1 transparent membranes1 oval in form4 ,a nerve leads from the inner surface of each membrane4 ,state any advantage or disadvantage in having the ears located where they are4 ,ovipositor4--,if the specimen is a female1 it has an egg-placer or ovipositor1 consisting of four blunt projections at the end of the abdomen 7,fig4 #ajg74 ,if it is a male1 there are only two appendages4 ,these are above the end of the abdomen1 and smaller than the parts of the ovipositor4 ,females are larger and more abundant than males4 ,in laying the eggs1 the four blunt points are brought tightly together and then forced into the ground and opened 7,fig4 #ajh74 ,by repeating this1 a pit is made almost as deep as the abdomen is long4 ,what sex is shown in ,fig4 #ajf8 ,fig4 #ajg8 ,draw a side view of the grasshopper4 ,illustration3 ,,fig4 #ajh4--;,,grasshopper ,,laying ,,eggs4 7,riley47 ,thorax4--,this1 the middle portion of the body1 consists of three segments or rings 7,fig4 #ajg74 ,is the division between the rings most apparent above or below8 ,which two of the three rings are more closely united8 ,the front ring 7prothorax7 of the thorax has no rings4 ,is it larger above or below8 ,does it look more like a collar or a cape8 7,fig4 #ajf47 ,a spiracle is found on the second ring 7mesothorax1 or middle thorax7 just above the second pair of legs4 ,there is another in the soft skin between the prothorax and mesothorax just under the large cape or collar4 ,the last ring of the thorax is called the metathorax 7rear thorax74 ,how many legs are attached to each ring of the thorax8 ,can a grasshopper walk8 ,run8 ,climb8 ,jump8 ,fly8 ,do any of the legs set forward8 7,see ,fig4 #ajf47 ,outward8 ,backward8 ,can you give reasons for the position of each pair8 7,suggestion3 ,what is the use of each pair87 ,if an organ is modified so that it is suited to serve some particular purpose or function1 it is said to be specialized4 ,are any of the legs specialized so that they serve for a different purpose than the other legs8 ,the leg of a grasshopper 7as of all insects7 is said to have five parts1 all the small parts after the first four parts being counted as one part and called the foot4 ,are all the legs similar1 that is1 do the short and long joints in all come in the same order8 ,numbered in order from the body1 which joint of the leg is the largest1--the first1 second1 third1 or fourth8 ,which joint is the shortest8 ,the slenderest8 ,which joint has a number of sharp points or spines on it8 ,find by experiment whether these spines are of use in walking 7,fig4 #ajf74 ,jumping8 ,climbing8 ,in what order are the legs used in walking8 ,how many legs support the body at each step8 ,illustration3 ,,fig4 #aji4--;,,how ,a ,,grasshopper ,,walks4 ,illustration3 ,,fig4 #aaj4--;,,how ,a ,,spider ,,walks4 ,all animals that have ears have ways of communicating by sounds4 ,why would it be impossible for the grasshopper to have a voice1 even if it had vocal cords in its throat8 ,the male grasshoppers of many species make a chirping1 or stridulation1 by rubbing the wing against the leg4 ,look on the inner side 7why not outer side87 of the largest joint of the hind leg for a row of small spines visible with the aid of a hand lens 7,fig4 #aaa74 ,the sound is produced by the outer wings rubbing against the spines4 ,have you noticed whether the sound is produced while the insect is still or in motion8 ,why8 ,the male grasshoppers of some species1 instead of having spines1 rub the under side of the front wing on the upper side of the hind wing4 ,illustration3 ,,fig4 #aaa4--;,a1 ,,row ,,of ,,spines1 z1 used in chirping4 ,b1 the same more enlarged4 ,wings4--,to what is the first pair of wings attached8 ,the second pair8 ,why are the wings not attached to the prothorax8 ,why are the wings attached so near the dorsal line of the body8 ,why are the second and third rings of the thorax more solidly joined than the first and second rings8 ,compare the first and second pairs of wings in shape1 size1 color1 thickness1 and use 7,fig4 #aab74 ,how are the second wings folded so as to go under the first wings8 ,about how many folds in each8 ,illustration3 ,,fig4 #aab4--;,,grasshopper ,,in ,,flight4 ,draw a hind wing opened out4 ,head4--,what is the shape of the head viewed from the front1 the side1 and above8 ,make sketches4 ,what can you say of a neck8 ,is the head movable in all directions8 ,what is the position of the large eyes8 ,like the eyes of the crawfish1 they are compound1 with many facets4 ,but the grasshopper has also three simple eyes1 situated one in the middle of the forehead and one just above each antenna4 ,they are too small to be seen without a hand lens4 ,how does the grasshopper's range of vision compare with that of the crawfish8 ,are the antenn flexible8 ,what is their shape8 ,position8 ,are they segmented8 ,touch an antenna1 a wing1 a leg1 and the abdomen in succession4 ,which seems to be the most sensitive to touch8 ,the antenn are for feeling2 in some species of insects they are also the organs of hearing4 ,illustration3 ,,fig4 #aac4 ,the mouth parts of a grasshopper are highly specialized4 ,they should be compared with the mouth parts of a beetle shown in ,fig4 #aac1 since the mouth parts of these two insects correspond closely4 ,if the grasshopper is fed with a blade of fresh grass1 the function of each mouth part may be plainly seen4 ,it is almost impossible to understand these functions by studying a dead specimen1 but a fresh specimen is much better than a dry one4 ,illustration3 ,,fig4 #aad4--;a1 ,,food ,,tube ,,of ,,beetle4 b1 gizzard2 d1 intestine2 c1 biliary vessels4 ,see ,fig4 #abg4 ,the upper lip1 or labrum1 is seen in front4 ,is it tapering or expanded8 ,in what direction is it movable8 ,the dark pointed biting jaws 7mandibles7 are next4 ,are they curved or straight8 ,sharp or blunt pointed8 ,notched or smooth8 ,do they work up and down1 or sideways8 ,the holding jaws 7maxill71 each with two jaw fingers 7maxillary palpi7 are behind the chewing jaws4 ,why8 ,the lower lip 7labium7 has a pair of lip fingers 7labial palpi7 upon it4 ,the brown tongue1 usually bathed in saliva1 is seen in the lower part of the mouth4 ,since the grasshopper has no lips1 or any way of producing suction1 it must lap the dew in drinking4 ,does it merely break off bits of a grass blade1 or does it chew8 ,the heart1 circulation1 nervous system1 digestive and respiratory organs of the grasshopper agree mainly with the general description of the organs of insects given in the next section4 ,microscopic ,objects4--,these may be bought ready mounted1 or may be examined fresh4 ,a portion of the covering of the large eye may be cut off and the dark layer on the inside of the covering scraped off to make it transparent4 ,what is the shape of the facets8 ,can you make any estimate of their number8 ,a portion of the transparent hind wing may be used1 and the 8veins0 in it studied4 ,a thin bit of an abdominal segment containing a spiracle will show the structure of these important organs4 ,illustration3 ,,fig4 #aae4--;,,egg ,,and ,,molts ,,of ,a ,,grasshopper4 ,growth of the ,grasshopper4--,some species hibernate in sheltered places and lay eggs in the spring1 but adult species are scarce at that season4 ,most species lay the eggs in the fall2 these withstand the cold and hatch out in the spring4 ,those hatched from one set of eggs sometimes stay together for a few days4 ,they eat voraciously1 and as they grow1 the soft skin becomes hardened by the deposit of horny substance called chitin4 ,this prevents further growth until the insect molts1 the skin first splitting above the prothorax4 ,after hatching1 there are five successive periods of growth4 ,at which molt do the very short wings first appear8 7,fig4 #aae47 ,after the last molt the animal is complete1 and changes no more in size for the rest of its life4 ,there has been an attempt among writers to restrict the term grasshopper to the long-winged1 slender species1 and to call the shorter winged1 stouter species locusts according to old ,english usage4 ,illustration3 ,,fig4 #aaf4--;,,cockroach4 ,illustration3 ,,fig4 #aag4--,,praying ,,mantis1 or devil's horse4 ,illustration3 ,,fig4 #aah4--;,,cricket4 ,illustration3 ,,fig4 #aai4--,,mole ,,cricket4 ,economic ,importance of ,grasshoppers4--,great injury is often done to vegetation by grasshoppers2 however1 the millions of tiny but ravenous eaters hatched in early spring are usually soon thinned out by the birds4 ,the migratory locusts constitute a plague when they appear1 and they have done so since ancient times4 ,the ,rocky ,mountain locusts flying eastward have darkened the sky1 and where they settled to the earth ate almost every green thing4 ,in #ahgd-e they produced almost a famine in ,kansas1 ,nebraska1 and other ,western states4 ,the young hatched away from the mountains were not healthy1 and died prematurely1 and their devastations came to an end4 ,of course the migrations may occur again4 ,packard calculates that the farmers of the ,west lost #bjj1jjj1jjj because of their ravages in #ahgd-e4 ,illustration3 ,,fig4 #abj4--;,,front ,,leg ,,of ,,mole ,,cricket4 #c4 ,the cockroaches 7,fig4 #aaf71 kindred of the grasshoppers1 are household pests that have migrated almost everywhere that ships go4 ,the praying mantis 7,fig4 #aag71 or devil's horse1 also belongs to this order4 ,it is beneficial1 since it destroys other insects4 ,which of its legs are specialized8 ,the walking stick 7,fig4 #aba7 and cricket 7,fig4 #aah71 like most members of the order1 are vegetarian4 ,illustration3 ,,fig4 #aba4--;,,four ,,walking ,,stick ,,insects4 ,are grasshoppers more common in fields and meadows1 or in wooded places8 ,how many different colors have you seen on grasshoppers8 ,which colors are most common8 ,grasshoppers are very scarce in ,europe as they love dry1 warm countries4 ,why do locusts migrate8 ,give an instance in ancient times4 ,how long do most grasshoppers live8 ,does a grasshopper spread its wings before it flies8 ,does it jump and fly together8 ,can it select the place for alighting8 ,,note ,,to ,,teacher4--,field work in ,zoology should be systematic4 ,every trip has a definite region and definite line of study in view1 but every animal seen should be noted4 ,the habitat1 adaptation by structure and habits to the environment1 relations to other animals1 classification of animals seen1 should be some of the ideas guiding the study4 ,the excursions may be divided somewhat as follows1 according as opportunities offer3 ,upland woods1 lowland woods1 upland pastures1 fields1 swamps1 a fresh-water lake1 a pond1 lower sea beach1 higher sea beach1 sand hills along shore1 roadside1 garden1 haunts of birds1 insect visits to flowers1 ground insects1 insects in logs4 ,an alphabetical letter file may be used for filing individual field observations4 ,these should be placed before the class orally or in writing4 ,if accepted as reliable 7repeated and revised if necessary71 the observations should be filed away and credit given the student on a regular scale4 ,thus will grading and marks be placed to encourage intelligent study of nature rather than book or laboratory cram4 ,one per cent to be added to the final grade may be credited for every species of pupa1 every rare insect 7with an observed fact as to its habits7 brought in1 every bird migration observed1 every instance of protective coloration1 mimicry 7p4 #adf71 outwitting of enemy1 instance of injurious insects1 and how to combat them1 etc4 ,sharp eyes and clear reasoning will then count as much on school grades as a memory for words or mechanical following of laboratory directions4 ,on scale of #ajj1 class work #ej1 examination #be1 field work #be4 ,collecting ,insects4--,in cities and towns insects1 varying with the season1 are attracted by electric lights4 ,beetles and bugs will be found under the lights1 moths on posts near the lights1 grasshoppers and crickets and other insects in the grass near by4 ,a lamp placed by a window brings many specimens4 ,in the woods and in rocky places insects are found under logs and stones1 and under the bark of dead trees4 ,in open places1 prairies1 meadows1 and old fields with grass and flowers1 it will be easy to find grasshoppers1 butterflies1 and some beetles4 ,ponds and streams are usually rich in animal forms1 such as bugs and beetles1 which swim on or under the surface1 and larv of dragon flies crawling on the bottom4 ,dragon flies and other insects that lay eggs on the water are found flying in the air above4 7,in the spring1 newly hatched crawfish1 tadpoles1 and the eggs of frogs and toads should also be collected1 if found47 ,moths may be caught at night by daubing molasses or sirup made from brown sugar upon the trunks of several trees1 and visiting the trees at intervals with a lantern4 ,an insect net for catching butterflies and for dredging ponds may be made by bending a stout wire into a circle one foot in diameter1 leaving enough straight wire to fasten with staples on an old broomstick4 ,to the frame is fastened a flour sack1 or cone made of a piece of mosquito netting4 ,butterflies and moths should be promptly killed1 or they will beat their wings to pieces4 ,the quickest method is by dropping several drops of gasoline upon the ventral 7under7 side of the thorax and abdomen4 7,caution3 ,gasoline should never be used near an open fire1 or lamp1 as explosions and deaths result from the flame being led through the gasoline-saturated air to the vessel containing it47 ,a cigar box and a bottle with a notched cork may be used for holding specimens4 ,cigar boxes may be used for holding collections of dried insects4 ,cork or ribbed packing paper may be fixed in the bottom for supporting the insect pins4 ,moth balls or tobacco may be placed in each box to keep out the insect pests which infest collections4 ,it is pleasant and profitable to take to the fields a small book like this one1 or even ,comstock's 8,manual of ,insects10 or ,kellogg's 8,american ,insects10 and study the insects and their habits where they are found4 ,captured insects which1 in either the larval or perfect stage1 are injurious to vegetation1 should always be killed after studying their actions and external features1 even if the internal structure is not to be studied4 ,beneficial insects1 such as ladybugs1 ichneumon flies1 bees1 mantis 7devil's horse71 dragon flies1 etc41 should be set free uninjured4 ,,anatomy ,,and ,,general ,,characteristics ,,of ,,the ,,class ,,insecta ,the body of an insect 7e4g4 a wasp1 ,fig4 #abb7 is divided by means of two marked narrowings into three parts3 the head 7,k71 chest 7,b71 and abdomen 7,h74 ,illustration3 ,,fig4 #abb4--;,a ,,wasp4 ,the head is a freely movable capsule bearing four pairs of appendages4 ,hence it is regarded as having been formed by the union of four rings1 since the ancestor of the insects is believed to have consisted of similar rings1 each ring bearing a pair of unspecialized legs4 ,the early grub or caterpillar stage of insects is believed to resemble somewhat the ancestral form4 ,the typical mouth parts of an insect 7,fig4 #abc71 named in order from above1 are 7#a7 an upper lip 7labrum1 ol7 7#b7 a pair of biting jaws 7mandibles1 ok7 7#c7 a pair of grasping jaws 7maxill1 ,a1 ,b71 and 7#d7 a lower lip 7labium1 m1 a1 b74 ,the grasping jaws bear two pairs of jointed jaw fingers 7maxillary palpi1 ,d1 ,c71 and the lower lip bears a pair of similar lip fingers 7labial palpi1 d74 ,the biting jaws move sideways2 they usually have several pointed notches which serve as teeth4 ,why should the grasping jaws be beneath the chewing jaws8 ,why is it better for the lower lip to have fingers than the upper lip8 ,why are the fingers 7or palpi7 jointed8 7,watch a grasshopper or beetle eating47 ,why does an insect need grasping jaws8 ,illustration3 ,,fig4 #abc4--,,mouth ,,parts ,,of ,,beetle4 ,illustration3 ,,fig4 #abd4--;,,external ,,parts ,,of ,a ,,beetle4 ,the chest1 or thorax1 consists of three rings 7,fig4 #abd7 called the front thorax 7prothorax71 middle thorax 7mesothorax7 and hind thorax 7metathorax71 or first1 second1 and third rings4 ,the first ring bears the first pair of legs1 the second ring bears the second pair of legs and the upper or front wings1 and the third ring bears the third pair of legs and the under or hind wings4 ,illustration3 ,,fig4 #abe4--,,leg ,,of ,,insect4 ,the six feet of insects are characteristic of them1 since no other animals have that number1 the spider having eight1 the crawfish and crabs having ten1 the centipedes still more1 while the birds and beasts have less than six4 ,hence the insects are sometimes called the ,six-,footed class 7,hexapoda74 ,the insects are the only animals that have the body in three divisions4 ,man1 beasts1 and birds have only two divisions 7head and trunk72 worms are not divided4 ,define the class insecta by the two facts characteristic of them 7i4e4 possessed by them alone71 viz43 ,insects are animals with and 4 ,why would it be ambiguous to include 8hard outer skeleton0 in this definition8 ,to include 8bilateral symmetry08 8,segmented body08 ,the definition of a class must include all the individuals of the class1 and exclude all the animals that do not belong to the class4 ,the leg of an insect 7,fig4 #abe7 has five joints 7two short joints1 two long1 and the foot74 ,named in order from above1 they are 7#a7 the hip 7coxa71 7#b7 thigh ring 7trochanter71 7#c7 thigh 7femur71 7#d7 the shin 7tibia71 7#e7 the foot1 which has five parts4 ,which of the five joints of a wasp's leg 7,fig4 #abb7 is thickest8 ,slenderest8 ,shortest8 ,one joint 7which87 of the foot 7,fig4 #abb7 is about as long as the other four joints of the foot combined4 ,is the relative length of the joints of the leg the same in grasshoppers1 beetles1 etc41 as in the wasp 7,figs478 ,figure #abe is a diagram of an insect's leg cut lengthwise4 ,the leg consists of thick-walled tubes 7o1 n7 with their ends held together by thin1 easy-wrinkling membranes which serve as joints4 ,thus motion is provided for at the expense of strength4 ,when handling live insects they should never be held by the legs1 as the legs come off very easily4 ,does the joint motion of insects most resemble the motion of hinge joints or ball-and-socket joints8 ,answer by tests of living insects4 ,there are no muscles in the foot of an insect4 ,the claw is moved by a muscle 7m7 in the thigh with which it is connected by the long tendon 7z1 s1 t1 v74 ,in which part are the breathing muscles8 ,as the wings are developed from folds of the dorsal skin1 the wing has two layers1 an upper and a lower layer4 ,these inclose the so-called 8nerves0 or ribs of the wing1 each of which consists of a blood tube inclosed in an air tube4 ,illustration3 ,,fig4 #abf4--;,,foot ,,of ,,fly1 with climbing pads4 ,the abdomen in various species consists of from five to eleven overlapping rings with their foldlike joints between them4 ,does each ring overlap the ring in front or the one behind it8 ,the food tube 7,fig4 #abg7 begins at the mouth1 which usually contains salivary glands 7#d1 ,fig4 #abg74 ,what is the color of the grasshopper's saliva8 ,the food tube expands first into a croplike enlargement2 next to this is the stomach 7#f1 ,fig4 #abg71 which resembles the gizzard in birds1 as its inner wall is furnished with chitinous teeth 7b1 ,fig4 #aad74 ,these reduce the food fragments that were imperfectly broken up by the biting jaws before swallowing4 ,glands comparable to the liver of higher animals open into the food tube where the stomach joins the small intestine4 ,at the junction of the small and large intestine 7#i7 are a number of fine tubes 7#h7 which correspond to kidneys and empty their secretion into the large intestine4 ,illustration3 ,,fig4 #abg4--,,viscera ,,of ,,grasshopper4 ,key in text4 ,compare with ,fig4 #aad4 ,illustration3 ,,fig4 #abh4--;,,air ,,tubes ,,of ,,insect4 ,the breathing organs of the insects are peculiar to them 7see ,fig4 #abh74 ,they consist of tubes which are kept open by having in their walls continuous spirals of horny material called chitin4 ,most noticeable are the two large membranous tubes filled with air and situated on each side of the body4 ,do these tubes extend through the thorax8 7,fig4 #abh47 ,the air reaches these two main tubes by a number of pairs of short windpipes1 or tracheas1 which begin at openings 7spiracles74 ,in which division are the spiracles most numerous8 7,fig4 #abh47 ,which division is without spiracles8 ,could an insect be drowned1 i4e4 smothered1 by holding its body under water8 ,could it be drowned by immersing all of it but its head8 ,the motion of the air through the breathing tubes is caused by a bellowslike motion of the abdomen4 ,this is readily observed in grasshoppers1 beetles1 and wasps4 ,as each ring slips into the ring in front of it1 the abdomen is shortened1 and the impure air1 laden with carbon dioxid1 is forced out4 ,as the rings slip out1 the abdomen is extended and the fresh air comes in1 bringing oxygen4 ,illustration3 ,,fig4 #abi4--;,,insect',s ,,heart 7plan74 ,illustration3 ,,fig4 #acj4--;,,diagrams ,,of ,,evolution ,,of ,,pericardial ,,sac around insect's heart from a number of veins 7,lankester74 ,illustration3 ,,fig4 #aca4--,,position ,,of ,,insect',s ,,heart1 food tube1 and nerve chain4 ,the ,circulation4--,near the dorsal surface of the abdomen 7,fig4 #aca7 extends the long1 slender heart 7,fig4 #abi74 ,the heart has divisions separated by valvelike partitions4 ,the blood comes into each of the heart compartments through a pair of openings4 ,the heart contracts from the rear toward the front1 driving the blood forward4 ,the blood contains bodies corresponding to the white corpuscles of human blood1 but lacks the red corpuscles and the red color4 ,the blood is sent even to the wings4 ,the ribs on the wings consist of blood tubes inclosed in air tubes1 so that the blood vessels are surrounded by air1 and the purification of the blood is taking place throughout the course of the circulation4 ,hence the imperfect circulation is no disadvantage4 ,the perfect provision for supplying oxygen explains the remarkable activity of which insects are capable and their great strength1 which1 considering their size1 is unequaled by any other animals4 ,illustration3 ,,fig4 #acb4--,,nervous ,,system ,,of ,,bee4 ,the ,nervous ,system4--,the heart in backboned animals1 e4g4 man1 is ventral and the chief nerve trunk is dorsal4 ,as already stated1 the heart of an insect is dorsal2 its chief nerve chain1 consisting of a double row of ganglia1 is near the ventral surface 7,fig4 #aca74 ,all the ganglia are below the food tube except the first pair in the head1 which are above the gullet4 ,this pair may be said to correspond somewhat to the brain of backboned animals2 the nerves from the eyes and feelers lead to it4 ,with social insects1 as bees and ants1 it is large and complex 7,fig4 #acb74 ,in a typical insect they are the largest ganglia4 ,illustration3 ,,fig4 #acc4--;,,feeler of a beetle4 ,the ,senses4--,the sense of smell of most insects is believed to be located in the feelers4 ,the organ of hearing is variously located in different insects4 ,where is it in the grasshopper8 ,the organs of sight are highly developed1 and consist of two compound eyes on the side of the head and three simple eyes on the top or front of the head between the compound eyes4 ,the simple eye has nerve cells1 pigments1 and a lens resembling the lens in the eyes of vertebrates 7,fig4 #acd74 ,the compound eye 7,fig4 #ace7 has thousands of facets1 usually hexagonal1 on its surface1 the facets being the outer ends of cones which have their inner ends directed toward the center of the eye4 ,it is probable that the large1 or compound1 eyes of insects only serve to distinguish bright objects from dark objects4 ,the simple eyes afford distinct images of objects within a few inches of the eye4 ,in general1 the sight of insects1 contrary to what its complex sight organs would lead us to expect1 is not at all keen4 ,yet an insect can fly through a forest without striking a twig or branch4 ,is it better for the eyes that are immovable in the head to be large or small8 ,which has comparatively larger eyes1 an insect or a beast8 ,illustration3 ,,fig4 #acd4--;,diagram of simple eye of insect4 ,l1 lens2 ,n1 optic nerve4 ,illustration3 ,,fig4 #ace4--;,,compound ,,eye ,,of ,,insect4 #a1 hexagonal facets of crystalline cones4 #f1 blood vessel in optic nerve4 ,inherited ,habit1 or ,instinct4--,insects and other animals inherit from their parents their particular form of body and of organs which perform the different functions4 ,for example1 they inherit a nervous system with a structure similar to that of their parents1 and hence with a tendency to repeat similar impulses and acts4 ,repeated acts constitute a habit1 and an inherited habit is called an instinct4 ,moths1 for example1 are used to finding nectar in the night-blooming flowers1 most of which are white4 ,the habit of going to white flowers is transmitted in the structure of the nervous system2 so we say that moths have an instinct to go to white objects2 it is sometimes more obscurely expressed by saying they are attracted or drawn thereby4 ,instincts are not ,infallible4--,they are trustworthy in only one narrow set of conditions4 ,now that man makes many fires and lights at night1 the instinct just mentioned often causes the death of the moth4 ,the instinct to provide for offspring is necessary to the perpetuation of all but the simplest animals4 ,the dirt dauber1 or mud wasp1 because of inherited habit1 or instinct1 makes the cell of the right size1 lays the egg1 and provides food for offspring that the mother will never see4 ,it seals stung and semiparalyzed spiders in the cell with the egg4 ,if you try the experiment of removing the food before the cell is closed1 the insect will bring more spiders2 if they are removed again1 a third supply will be brought2 but if taken out the third time1 the mud wasp will usually close the cell without food1 and when the egg hatches the grub will starve4 ,the ,development of ,insects4--,the growth and molting of the grasshopper from egg to adult has been studied4 ,all insects do not develop exactly by this plan4 ,some hatch from the egg in a condition markedly different from the adult4 ,the butterfly's egg produces a wormlike caterpillar which has no resemblance to the butterfly4 ,after it grows it forms an inclosing case in which it spends a quiet period of development and comes out a butterfly4 ,this change from caterpillar to butterfly is called the metamorphosis4 ,the life of an insect is divided into four stages3 7#a7 egg1 7#b7 larva1 7#c7 pupa1 and 7#d7 imago1 or perfect insect 7,figs4 #acf1 #acg1 #ach74 ,illustration3 ,,fig4 #acf4--,measuring worm1 the larva of a moth4 ,illustration3 ,,fig4 #acg4--,pupa of a mosquito4 ,illustration3 ,,fig4 #ach4--,,the ,,four ,,stages ,,of ,a ,,botfly1 all enlarged4 a1 egg on hair of horse 7bitten off and swallowed72 b1 larva2 c1 larva with hooks for holding to lining of stomach2 d1 pupal stage1 passed in the earth2 e1 adult horse fly4 ,the egg stage is one of development1 no nourishment being absorbed4 ,the larval stage is one of voracious feeding and rapid growth4 ,in the pupa stage no food is taken and there is no growth in size1 but rapid development takes place4 ,in the perfect stage food is eaten1 but no growth in size takes place4 ,in this stage the eggs are produced4 ,when there is very little resemblance between the larva and imago1 and the pupa is quiescent1 the metamorphosis1 or change1 is said to be complete4 ,when1 as with the grasshopper1 no very marked change takes place between the larva and imago 7that is to say1 during the pupa stage1 which is active71 the metamorphosis is said to be incomplete4 ,by studying the illustrations and specimens1 and by thinking of your past observations of insects1 determine which of the insects in the following list have a complete metamorphosis3 beetle1 house fly1 grasshopper1 butterfly1 cricket1 wasp4 ,,table ,,for ,,classifying ,,insects 7class ,insecta7 ,,into ,,orders ,,order ,a ,biting ,insects2 mouth parts for grasping and biting ,b ,wingless2 changes 7metamorphosis7 ,,no ,,wings incomplete 7,aptera7 ,b ,under wings thinner than upper wings1 and ,,fan ,,wings fold like a fan beneath them2 changes 7,orthoptera7 incomplete ,b ,upper wings hard and thick1 protecting ,,sheath ,,wings under wings1 which fold both lengthwise and 7,coleoptera7 crosswise beneath them2 changes incomplete ,b ,all four wings nearly alike1 finely veined1 transparent ,c ,hind wings smaller than fore1 two or ,,nerve ,,wings three filaments attached to abdomen1 7,neuroptera7 antenn long2 changes complete ,c ,hind wings not smaller than fore2 no ,,false ,,nerve ,,wings filaments on abdomen1 antenn 7,pseudoneuroptera7 inconspicuous2 changes incomplete ,a ,sucking ,insects2 mouth parts for sucking or licking ,b ,basal half of upper wing usually leathery1 ,,half ,,wings other half of wing transparent2 lower lips 7,hemiptera7 transformed into a tube2 true bugs ,b ,four wings covered by scales1 holding-jaws ,,scaly ,,wings 7maxill7 elongated to form a sucking tube 7,lepidoptera7 coiled under head2 changes complete ,b ,four wings1 membranous1 hind wings hook to ,,joined ,,wings fore wings in flight2 mouth parts for both 7,hymenoptera7 biting and sucking2 abdomen with sting2 changes complete ,b ,two wings1 mandibles rudimentary1 mouth a ,,two ,,wings soft beak 7,diptera7 ,b ,no wings1 mandibles rudimentary1 mouth a ,,lost ,,wings horny beak 7,siphonoptera7 ,illustration3 ,,fig4 #aci4--,,may ,,fly4 ,what order 7see table78 ,illustration3 ,,fig4 #adj4--,,silver ,,scale4 7,order87 ,exercise in the ,use of the ,table or ,key4--,write the name of the order after each of the following names of insects3-- ,wasp 7,fig4 #abb7 ,weevil 7,fig4 #afc7 ,squash bug 7,fig4 #ahd7 ,ant lion 7,fig4 #agj7 ,dragon fly 7,fig4 #agg7 ,ichneumon fly 7,fig4 #aei7 ,house fly 7,fig4 #agb7 ,flea 7,fig4 #agc7 ,silver scale or earwig 7,fig4 #adj7 ,codling moth 7,fig4 #ada7 ,botfly 7,fig4 #ach7 ,moths and ,butterflies4--,order 8 ,why 7p4 #hb78 ,the presence of scales on the wings is a never-failing test of a moth or butterfly4 ,the wings do not fold at all4 ,they are so large and the legs so weak and delicate that the butterfly keeps its balance with difficulty when walking4 ,the maxill are developed to form the long sucking proboscis4 ,how do they fit together to form a tube8 7,see ,fig4 #adg47 ,the proboscis varies from a fraction of an inch in the 8miller0 to five inches in some tropical moths1 which use it to extract nectar from long tubular flowers4 ,when not in use1 it is held coiled like a watch spring under the head 7,fig4 #adh74 ,the upper lip 7labrum71 under lip 7labium71 and lip fingers 7labial palpi7 are very small1 and the mandibles small or wanting 7,fig4 #adf74 ,the metamorphosis is complete1 the contrast between the caterpillar or larva of the moth and butterfly and the adult form being very great4 ,the caterpillar has the three pairs of jointed legs typical of insects2 these are found near the head 7,fig4 #ada74 ,it has also from three to five pairs of fleshy unjointed proplegs1 one pair of which is always on the last segment4 ,how many pairs of proplegs has the silkworm caterpillar8 7,fig4 #adc47 ,the measuring worm1 or looper8 7,fig4 #acf47 ,the pupa has a thin shell4 ,can you see external signs of the antenn1 wings1 and legs in this stage8 7,fig4 #adc47 ,the pupa is concealed by protective coloration1 and is sometimes inclosed in a silken cocoon which was spun by the caterpillar before the last molt4 ,hairy caterpillars usually produce butterflies1 and the naked ones usually produce moths4 ,hairy ones are uncomfortable for birds to eat4 ,the naked and brightly marked ones 7warning coloration7 often contain an acrid and distasteful fluid4 ,the injuries from lepidoptera are done in the caterpillar stage4 ,the codling moth 7,fig4 #ada7 destroys apples to the value of #f1jjj1jjj annually4 ,the clothes moth 7,fig4 #aga7 is a household pest4 ,the tent caterpillar denudes trees of their leaves4 ,the only useful caterpillar is the silkworm 7,fig4 #adc74 ,in ,italy and ,japan many of the country dwellings have silk rooms where thousands of these caterpillars are fed and tended by women and children4 ,why is the cabbage butterfly so called8 ,why can it not eat cabbage8 ,why does sealing clothes in a paper bag prevent the ravages of the clothes moth8 ,flight of ,lepidoptera4--,which appears to use more exertion to keep afloat1 a bird or a butterfly8 ,explain why4 ,of all flying insects which would more probably be found highest up mountains8 ,how does the butterfly suddenly change direction of flight8 ,does it usually fly in a straight or zigzag course8 ,advantage of this8 ,why is zigzag flight unnecessary to moths8 ,bright colors are protective1 as lepidoptera are in greatest danger when at rest on flowers4 ,are the brightest colors on upper or under side of wings of butterfly8 ,why8 7,think of the colors in a flower47 ,why is it better for moths to hold their wings flat out when at rest8 ,where are moths during the day8 ,how can you test whether the color of the wings is given by the scales8 ,state how moths and butterflies differ in respect to3 body1 wings1 feelers1 habits2 abundance of scales4 ,insects and ,flowers4--,we are indebted to insects for the bright colors and sweet honey of flowers4 ,flowers need insects to carry their pollen to other flowers1 as cross-fertilization produces the best seeds4 ,the insects need the nectar of the flowers for food1 and the bright colors and sweet odors are the advertisements of the flowers to attract insects4 ,there were no flowers in the world before flying insects were developed4 ,moths1 butterflies1 and bees carry most pollen 7see ,plant ,biology1 ,chap4 ,,vi74 ,comparative ,study4--,make a table like this1 occupying entire page of notebook1 leaving no margins1 and fill in accurately3-- ,,fly ,,dragon ,,beetle ,,bee ,,grass- ,,butter- pp4 #ib1 ,,fly1 pp4 #ij1 pp4 #hh1 ,,hopper ,,fly #ic p4 #ic #ia #hi ---------------------------------------- ------------------------ ,number and kind of wings ---------------------------------------- ------------------------ ,descrip- tion of legs ---------------------------------------- ------------------------ ,antenn 7length1 shape1 joints7 ---------------------------------------- ------------------------ ,biting or sucking mouth parts ---------------------------------------- ------------------------ ,complete or incomplete metamor- phosis ,illustration3 ,,fig4 #ada4--;,,codling ,,moth1 from egg to adult4 7,see ,farmers' ,bulletin1 p4 #ie47 ,illustration3 ,,fig4 #adb4--;,,cabbage ,,butterfly1 male and female1 larva and pupa4 ,illustration3 ,,fig4 #adc4--,,life ,,history ,,of ,,silkworm4 ,illustration3 ,,fig4 #add4--,,scales ,,from ,,butterflies' ,,wings1 as seen under microscope4 ,,to ,,the ,,teacher3 ,these illustrated studies require slower and more careful study than the text4 ,one1 or at most two1 studies will suffice for a lesson4 ,the questions can be answered by studying the figures4 ,weak observers will often fail and they should not be told1 but should try again until they succeed4 ,illustration3 ,,fig4 #ade4--,,scales ,,on ,,moth',s ,,wing4 ,illustration3 ,,fig4 #adf4--;,,head ,,of ,,butterfly4 ,illustration3 ,,fig4 #adg4--,,section ,,of ,,proboscis of butterfly showing lapping joint and dovetail joint4 ,illustration3 ,,fig4 #adh4--;,,head ,,of ,,butterfly 7side view74 ,,figs4 #ada-adh4 ,illustrated ,study of ,lepidoptera4--,study the stages in the development of codling moth1 silkworm moth1 and cabbage butterfly4 ,where does each lay its eggs8 ,what does the larva of each feed upon8 ,describe the pupa of each4 ,describe the adult forms4 ,find the spiracles and prolegs on the silkworm4 ,compare antenn of moth and butterfly4 ,which has larger body compared to size of wings8 ,describe the scales from a butterfly's wings as seen under microscope 7#add74 ,how are the scales arranged on moth's wing 7#ade78 ,by what part is scale attached to wing8 ,do the scales overlap8 ,study butterfly's head and proboscis 7,figs4 #adf-adh74 ,what shape is compound eye8 ,are the antenn jointed8 ,is the proboscis jointed8 ,why not call it a tongue8 7,see text47 ,which mouth parts have almost disappeared8 ,what is the shape of cut ends of halves of proboscis8 ,how are the halves joined to form a tube8 ,if you saw a butterfly on a flower1 for what purpose would you think it was there8 ,what1 if you saw it on a leaf8 ,how many spots on fore wing of female cabbage butterfly8 7,fig4 #abd1 above47 ,does the silkworm chrysalis fill its cocoon8 ,eggs may be obtained from ,u4 ,s4 ,dept4 of ,agriculture4 ,illustration3 ,,fig4 #adi4 ,illustration3 ,,fig4 #aej4 ,illustration3 ,,fig4 #aea4 ,illustration3 ,,fig4 #aeb4 ,illustration3 ,,fig4 #aec4 ,illustration3 ,,fig4 #aed4 ,illustration3 ,,fig4 #aee4 ,illustration3 ,,fig4 #aef4 ,illustration3 ,,fig4 #aeg4 ,illustration3 ,,fig4 #aeh4--;,anatomy of bee4 ,,figs4 #adi-afa4 ,illustrated ,study of ,bees and their ,kindred4--,head of worker 7,fig4 #adi73 o1 upper lip2 ok1 chewing jaws2 uk1 grasping jaws2 kt1 jaw finger2 lt1 lip finger2 z1 tongue4 ,how do heads of drone 7#aej7 and queen 7#aea7 differ as to mouth1 size of the two compound eyes1 size and position of the three simple eyes8 ,is the head of a worker more like head of drone or head of queen8 ,judging by the head1 which is the queen1 drone1 and worker in ,figs4 #aed-aef8 ,which of the three is largest8 ,smallest8 ,broadest8 ,figure #aeb shows hind leg of worker4 ,what surrounds the hollow1 us1 which serves as pollen basket8 ,the point1 fh1 is a tool for removing wax which is secreted 7c1 ,fig4 #aeg7 between rings on abdomen4 ,in ,fig4 #aeh1 find relative positions of heart1 v1 food tube1 and nerve chain4 ,is crop1 ,j1 in thorax or abdomen8 ,in this nectar is changed to honey1 that it may not spoil4 ,compare nerve chain in ,fig4 #acb4 ,illustration3 ,,fig4 #aei4--;,ichneumon fly4 ,illustration3 ,,fig4 #afj4 ,illustration3 ,,fig4 #afa4--,wasp using pebble4 ,from ,peckham's 8,solitary ,wasps10 ,houghton1 ,mifflin ,co4 ,compare the cells of bumble bee 7,fig4 #aec7 with those of hive bee4 ,they differ not only in shape but in material1 being made of web instead of wax1 and they usually contain larv instead of honey4 ,only a few of the queens among bumble bees and wasps survive the winter4 ,how do ants and honey bees provide for the workers also to survive the winter8 ,name all the social insects that you can think of4 ,do they all belong to the same order8 ,the ichneumon fly shown enlarged in ,fig4 #aei lays its eggs under a caterpillar's skin4 ,what becomes of the eggs8 ,the true size of the insect is shown by the cross lines at a4 ,the eggs are almost microscopic in size4 ,the pup shown 7true size7 on caterpillar are sometimes mistaken for eggs4 ,the same mistake is made about the pupa cases of ants4 ,ichneumon flies also use tree-borers as 8hosts0 for their eggs and larva4 ,is this insect a friend of man8 ,the digging wasp 7,figs4 #afj and #afa7 supplies its larva with caterpillars and closes the hole1 sometimes using a stone as pounding tool4 ,among the few other uses of tools among lower animals are the elephant's use of a branch for a fly brush1 and the ape's use of a walking stick4 ,this wasp digs with fore feet like a dog and kicks the dirt out of the way with its hind feet4 ,are the wings of bees and wasps more closely or less closely veined than the wings of dragon flies8 7,fig4 #agg47 ,for an interesting account of the order 8,joined-wings0 7bees and their kindred7 see ,comstock's 8,ways of the ,six-footed10 ,ginn ,co4 ,illustrated ,study of ,beetles4 ,illustration3 ,,fig4 #afb4--;,diving beetle 7,dysticus71 with larva1 a4 ,illustration3 ,,fig4 #afc4--,weevil4 ,illustration3 ,,fig4 #afd4 ,illustration3 ,,fig4 #afe4 ,illustration3 ,,fig4 #aff4--;,click beetle4 ,illustration3 ,,fig4 #afg4--,,may ,,beetle4 ,illustration3 ,,fig4 #afh4 ,illustration3 ,,fig4 #afi4--;,colorado beetle 7potato bug74 ,illustrated ,study of ,beetles 7,figs4 #afb-afi74--,write the life history of the ,colorado beetle1 or potato bug 7,fig4 #afi71 stating where the eggs are laid and describing the form and activities of each stage 7the pupal stage1 b1 is passed in the ground74 ,do the same for the ,,may ,,beetle 7,figs4 #afg-afh74 7,it is a larva--the white grub--for three years2 hogs root them up47 ,beetles1 like moths1 may be trapped with a lantern set above a tub of water4 ,where does a ,scarab or sacred beetle of the ,egyptians1 also called tumble bug 7,fig4 #afd71 lay its eggs 7,fig4 #afe78 ,why8 ,how does the click beetle1 or jack snapper 7,fig4 #aff71 throw itself into the air8 ,for what purpose8 ,the large proboscis of the weevil 7,fig4 #afc7 is used for piercing a hole in which an egg is laid in grain of corn1 boll of cotton1 acorn1 chestnut1 plum1 etc4 ,how are the legs and body of the diving beetle suited for swimming 7,fig4 #afb78 ,describe its larva4 ,what is the shape of the lady bug 7,fig4 #ig78 ,it feeds upon plant lice 7,fig4 #ahe74 ,is any beetle of benefit to man8 ,illustration3 ,,fig4 #agj4--,life history of ant lion4 ,illustrated ,study of ,ant ,lion1 or ,doodle ,bug 7,fig4 #agj74--;,find the pitfall 7what shape872 the larva 7describe it72 the pupa case 7ball covered with web and sand72 the imago4 ,compare imago with dragon fly 7,fig4 #agg74 ,how does ant lion prevent ant from climbing out of pitfall 7see ,fig4 #agj78 ,what is on edge of nearest pitfall8 ,explain4 ,ant lions may be kept in a box half filled with sand and fed on ants4 ,how is the pitfall dug8 ,what part of ant is eaten8 ,how is unused food removed8 ,how long is it in the larval state8 ,pupal state8 ,keep net over box to prevent adult from flying away when it emerges4 ,illustration3 ,,fig4 #aga4 ,illustration3 ,,fig4 #agb4--,metamorphosis of house fly 7enlarged74 ,illustration3 ,,fig4 #agc4--,metamorphosis of flea4 ,illustration3 ,,fig4 #agd4--,louse4 ,illustration3 ,,fig4 #age4--;,bed bug4 #e4 ,illustration3 ,,fig4 #agf4--,life history of mosquito4 ,illustrated ,study of ,insect ,pests 7,figs4 #aga-agf74--,why does the clothes moth 7#aga7 lay its eggs upon woolen clothing8 ,how does the larva conceal itself8 ,the larva can cut through paper and cotton1 yet sealing clothes in bags of paper or cotton protects them4 ,explain4 ,the house fly eats liquid sweets4 ,it lays its eggs in horse dung4 ,describe its larval and pupal forms4 ,banishing horses from city would have what beneficial effect8 ,describe the louse and its eggs1 which are shown attached to a hair1 natural size and enlarged4 ,describe the bed bug4 ,benzine poured in cracks kills bed bugs4 ,do bed bugs bite or suck8 ,why are they wingless8 ,describe the larva1 f1 pupa1 g1 and the adult flea1 all shown enlarged4 ,its mandibles1 b1 b1 are used for piercing4 ,to kill fleas lather dog or cat completely and let lather remain on five minutes before washing4 ,eggs are laid and first stages passed in the ground4 ,how does the mosquito lay its eggs in the water without drowning 7#agf78 ,why are the eggs always laid in still water8 ,which part of the larva 7wiggletail7 is held to the surface in breathing8 ,what part of the pupa 7called tumbler1 or bull head7 is held to the surface in breathing8 ,give differences in larva and pupa4 ,where does pupa change to perfect insect8 ,describe mouth parts of male mosquito 7at left7 and female 7at right74 ,only female mosquitoes suck blood4 ,males suck juice of plants4 ,malarial mosquito alights with hind end of body raised at an angle4 ,for figure see ,human ,biology1 ,chap4 ,x4 ,why does killing fish and frogs increase mosquitoes8 #a oz4 of kerosene for #ae ft4 of surface of water1 renewed monthly1 prevents mosquitoes4 ,what is the use to the squash bug 7,fig4 #ahd7 of having so bad an odor8 ,illustration3 ,,fig4 #agg4 ,,fig4 #agg4 ,illustrated ,study of ,dragon ,fly4--#c shows dragon fly laying its eggs in water while poised on wing4 ,describe the larval form 7water tiger74 ,the extensible tongs are the maxill enlarged4 ,the pupa 7#a7 is active and lives in water4 ,where does transformation to adult take place 7#e78 ,why are eyes of adult large8 its legs small8 ,compare front and hind wings4 ,do the eyes touch each other8 ,why is a long abdomen useful in flight8 ,why would long feelers be useless8 ,what is the time of greatest danger in the development of the dragon fly8 ,what other appropriate name has this insect8 ,why should we never kill a dragon fly8 ,illustration3 ,,fig4 #agh4--,the tarantula4 ,illustration3 ,,fig4 #agi4--,trap-door spider4 ,illustration3 ,,fig4 #ahj4 ,illustration3 ,,fig4 #aha4--;,anatomy of spider4 ,illustration3 ,,fig4 #ahb4--,laying egg4 ,illustration3 ,,fig4 #ahc4--;,foot of spider4 ,illustrated ,study of ,spiders 7,figs4 #agh-ahc74--,the tarantula1 like most spiders1 has eight simple eyes 7none compound74 ,find them 7,fig4 #agh74 ,how do spiders and insects differ in body8 ,number of legs8 ,which have more joints to legs8 ,does trap-door spider hold the door closed 7,fig4 #agi78 ,how many pairs of spinnerets for spinning web has a spider 7,spw1 #ahj78 ,foot of spider has how many claws8 ,how many combs on claws for holding web8 ,spiders spin a cocoon for holding eggs4 ,from what part of abdomen are eggs laid 7,e1 #ahb2 #b1 #aha78 ,find spider's air sacs1 lu1 ,fig4 #aha2 spinning organs1 sp2 fang1 kf2 poison gland1 g2 palpi1 kt2 eyes1 au2 nerve ganglia1 og1 ug2 sucking tube1 sr2 stomach1 d2 intestine1 ma2 liver1 le2 heart1 h1 7black72 vent1 a4 ,give two reasons why a spider is not an insect4 ,how does it place its feet at each step 7,fig4 #aaj78 ,does the size of its nerve ganglia indicate great or little intelligence8 ,why do you think first part of body corresponds to both head and thorax of insects8 ,illustration3 ,,fig4 #ahd4--,squash bug1 or stink bug4 ,the following ,farmer's ,bulletins are available for free distribution to those interested1 by the ,u4 ,s4 ,department of ,agriculture1 ,washington1 ,d4,c43-- ,farmer's ,bulletin ,no4 #dg1 ,insects affecting the ,cotton ,plant2 ,no4 #ei1 ,bee ,keeping2 ,no4 #gj1 ,the ,principal ,insect ,enemies of the ,grape2 ,no4 #hj1 ,the ,peach ,twig ,borer2 ,no4 #ii1 ,three ,insect ,enemies of ,shade ,trees2 ,no4 #abj1 ,the ,principal ,insects affecting the ,tobacco ,plant2 ,no4 #abg1 ,important ,insecticides2 ,no4 #acb1 ,the ,principal ,insect ,enemies of ,growing ,wheat2 ,no4 #ade1 ,carbon ,bisulphid as an ,insecticide2 ,no4 #adf1 ,insecticides and ,fungicides2 ,no4 #aeb1 revised1 ,mange in ,cattle2 ,no4 #aec1 ,orchard ,enemies in the ,pacific ,northwest2 ,no4 #aee1 ,how ,insects affect ,health in ,rural ,districts2 ,no4 #aei1 ,scab in ,sheep2 ,no4 #afe1 ,silkworm ,culture2 ,no4 #aga1 ,the ,control of the ,codling ,moth2 ,no4 #agb1 ,scale ,insects and ,mites on ,citrus ,trees2 ,no4 #aif1 ,usefulness of the ,toad2 ,no4 #bji1 ,controlling the ,boll ,weevil in ,cotton ,seed and at ,ginneries2 ,no4 #baa1 ,the ,use of ,paris ,green in controlling the ,cotton ,boll ,weevil2 ,no4 #bab1 ,the ,cotton ,bollworm2 ,no4 #baf1 ,the ,control of the ,boll ,weevil2 ,no4 #bbc1 ,miscellaneous ,cotton ,insects in ,texas2 ,no4 #bdg1 ,the ,control of the ,codling ,moth and ,apple ,scab4 ,illustration3 ,,fig4 #ahe4--;,female plant louse1 with and without wings 7enlarged74 ,the following bulletins of the ,bureau of ,entomology may be obtained from the same source at the prices affixed3 ,bulletin ,no4 #be 7old series71 ,destructive ,locusts1 #ae;c42 ,no4 #a 7new series71 ,the ,honey ,bee1 #ae;c42 ,no4 #c1 ,the ,san ,jos ,scale1 #aj;c42 ,no4 #d1 ,the ,principal ,household ,insects of the ,u4 ,s41 #aj;c42 ,no4 #aa1 ,the ,gypsy ,moth in ,america1 #e;c42 ,no4 #ad1 ,the ,periodical ,cicada1 #ae;c42 ,no4 #ae1 ,the ,chinch ,bug1 #aj;c42 ,no4 #af1 ,the ,hessian ,fly1 #aj;c42 ,nos4 #ai1 #bc1 and #cc1 ,insects ,injurious to ,vegetables1 #aj;c4 each2 ,no4 #be1 ,notes on ,mosquitoes of the ,u4 ,s41 #aj;c42 ,no4 #db1 ,some ,insects attacking the ,stems of ,growing ,wheat1 ,rye1 ,barley1 and ,oats1 #e;c42 ,no4 #ej1 ,the ,cotton ,bollworm1 #be;c42 ,no4 #ea1 ,the ,mexican ,boll ,weevil1 #be;c4 ,bureau of ,plant ,industry--,bulletin ,no4 #hh1 ,weevil-resisting ,adaptations of the ,cotton ,plant1 #aj;c4 ,this gives an instructive account of the struggle of a plant for existence against an insect enemy4 ,illustration3 ,,fig4 #ahf4--;,gall fly 7enlarged7 and oak gall with larva1 and one from which a developed insect has escaped4 ,illustration3 ,,fig4 #ahg4--,,plan ,,of ,,mouth ,,parts ,,of ,,the ,,insect ,,orders4 ,a1 straight wings1 nerve wings1 false nerve wings2 ,b1 joined wings2 ,c1 scaly wings2 ,d1 half wings2 ,e1 two wings4 ol1 upper lip2 ok1 biting jaws2 uk1 holding jaws2 ul1 under lip2 kt1 jaw fingers2 lt1 lip fingers4 ,illustration ,illustration3 ,pearl divers4 ,,chapter ,,ix ,,mollusks ,,the ,,fresh-,,water ,,mussel ,,suggestions4--,the mussel is usually easy to procure from streams and lakes by raking or dredging4 ,in cities the hard-shelled clam1 or quahog1 is for sale at the markets1 and the following descriptions apply to the anodon1 unio1 or quahog1 with slight changes in regard to the siphons4 ,mussels can be kept alive for a long time in a tub with sand in the bottom4 ,pairs of shells should be at hand for study4 ,external ,features4--,the shell is an elongated oval1 broader and blunter at one end 7,fig4 #ahh74 ,why does the animal close its shell8 ,does it open the shell8 ,why8 ,does it thrust the foot forward and pull up to it1 or thrust the foot back and push8 7,mussels and clams have no bones47 ,does it go with the blunt or the more tapering end of the shell forward8 7,fig4 #ahh47 ,can a mussel swim8 ,why1 or why not8 ,lay the shells1 fitted together1 in your hand with the hinge side away from you and the blunt end to the left 7,fig4 #ahh74 ,is the right or the left shell uppermost8 ,which is the top1 or dorsal1 side8 ,which is the front1 or anterior1 end8 ,is the straight edge at the top or the bottom8 ,our word 8valve0 is derived from a word meaning shell1 because the ,romans used shells for valves in pumps4 ,is the mussel a univalve or a bivalve8 ,which kind is the oyster8 ,the snail8 ,does the mussel have bilateral symmetry8 ,can you find a horny covering1 or epidermis1 over the limy shell of a fresh specimen8 ,why is it necessary8 ,does water dissolve lime8 ,horn8 ,find a bare spot4 ,does any of the shell appear to be missing there8 ,the bare projection on each shell is called the umbo4 ,is the umbo near the ventral or the dorsal line8 ,the posterior or anterior end8 ,is the surface of the umbones worn8 ,do the umbones rub against the sand as the mussel plows its way along8 ,how are the shells held together8 ,where is the ligament attached8 7,fig4 #ahi47 ,is it opposite the umbones or more to the front or rear8 7,fig4 #ahi47 ,is the ligament of the same material as the shell8 ,is the ligament in a compressed condition when the shell is open or when it is closed8 7,fig4 #ahi47 ,when is the muscle relaxed8 ,illustration3 ,,fig4 #ahh4--;,,anodon1 or fresh-water mussel4 ,illustration3 ,,fig4 #ahi4--;,,diagram ,,of ,,shell open and closed1 showing muscle1 m1 and ligament1 b4 ,illustration3 ,,fig4 #aij4--,,mussel crawling in sand4 ,notice the lines on the outside of the shell 7,figs4 #ahh and #aij74 ,what point do they surround8 ,they are lines of growth4 ,was each line once the margin of the shell8 ,if the shell should increase in size1 what would the present margin become8 7,fig4 #aia47 ,does growth take place on the margin only8 ,did the shell grow thicker as it grew larger8 ,where is it thinnest8 ,draw the outside of the shell from the side4 ,draw a dorsal view4 ,by the drawings write the names of the margins of the shell 7p4 #ih7 and of other parts learned1 using lines to indicate the location of the parts4 ,study the surface of the shell inside and out4 ,the inside is called mother-of-pearl4 ,is it of lime8 ,is the deeper layer of the shell of lime8 7,when weak hydrochloric acid or strong vinegar is dropped on limy substances1 a gas1 carbon dioxid1 bubbles up47 ,compare the thickness of the epidermal layer1 the middle chalky layer1 and the inner1 pearly layer4 ,illustration3 ,,fig4 #aia4--;,,diagram4 ,change of points of attachment of muscles as mussel enlarges4 7,morgan47 ,anatomy of the ,mussel4--,what parts protrude at any time beyond the edge of the shell8 7,fig4 #aij47 ,the shell is secreted by two folds of the outer layer of the soft body of the mussel4 ,these large1 flaplike folds hang down on each side1 and are called the mantle4 ,the two great flaps of the mantle hang down lower than the rest of the body and line the shell which it secretes 7,fig4 #aib74 ,the epidermis of the mantle secretes the shell just as the epidermis of the crawfish secretes its crust4 ,can you find the pallial line1 or the line to which the mantle extended on each shell when the animal was alive8 ,a free portion of the mantle extended like a fringe below the pallial line4 ,illustration3 ,,fig4 #aib4--;,,cross ,,section ,,of ,,mussel4 7,diagram1 after ,parker47 ,the shells were held together by two large adductor muscles4 ,the anterior adductor 7,fig4 #aic7 is near the front end1 above the foot4 ,the posterior adductor is toward the rear end1 but not so near the end as the anterior4 ,can you find both muscle scars in the shells8 ,are they nearer the ventral or dorsal surface8 ,the points of attachment traveled downward and farther apart as the animal grew 7see ,fig4 #aia74 ,higher than the larger scars are small scars1 or impressions1 where the protractor and retractor muscles that extend and draw in the foot were attached4 ,illustration3 ,,fig4 #aic4--;,,anatomy ,,of ,,mussel4 7,beddard47 ,the muscular foot extends downward in the middle1 halfway between the shells 7,fig4 #aic74 ,on each side of the foot and behind it hang down the two pairs of gills1 the outer pair and the inner pair 7,fig4 #aib74 ,they may be compared to four ,v-shaped troughs with their sides full of holes4 ,the water enters the troughs through the holes and overflows above4 ,is there a marked difference in the size of the two pairs of gills8 ,a kind of chamber for the gills is made by the joining of the mantle flaps below1 along the ventral line4 ,the mantle edges are separated at two places1 leaving openings called exhalent and inhalent siphons4 ,fresh water with its oxygen1 propelled by cilia at the opening and on the gills1 enters through the lower or inhalent siphon1 passes between the gills1 and goes to an upper passage1 leaving the gill chamber by a slit which separates the gills from the foot4 ,for this passage1 see arrow 7,fig4 #aid74 ,the movement of the water is opposite to the way the arrow points4 ,after going upward and backward1 the water emerges by the exhalent siphon4 ,the gills originally consisted of a great number of filaments4 ,these are now united1 but not completely so1 and the gills still have a perforated or lattice structure4 ,thus they present a large surface for absorbing oxygen from the water4 ,illustration3 ,,fig4 #aid4--,,mussel4 ,a1 left shell and mantle flap removed4 ,b1 section through body4 ,question3 ,guided by other figures1 identify the parts to which lines are drawn4 ,the mouth is in front of the foot1 between it and the anterior adductor muscle 7,fig4 #aid74 ,on each side of the mouth are the labial palps1 which are lateral lips 7,fig4 #aie74 ,they have cilia which convey the food to the mouth after the inhalent siphon has sent food beyond the gill chamber and near to the mouth4 ,thus both food and oxygen enter at the inhalent siphon4 ,the foot is in the position of a lower lip1 and if regarded as a greatly extended lower lip1 the animal may be said to have what is to us the absurd habit of using its lower lip as a foot4 ,the foot is sometimes said to be hatchet-shaped 7,fig4 #aie74 ,do you see any resemblance8 ,does the foot penetrate deep or shallow into the sand8 7,fig4 #aij47 ,why1 or why not8 ,illustration3 ,,fig4 #aie4--,,mussel4 ,from below4 ,level cut across both shells4 ,se1 palp2 ,p1 foot2 ,o1 mouth2 ,g1 liver2 ,gg1 ,vg1 ,pg1 ganglia4 ,illustration3 ,,fig4 #aif4--;,,heart ,,of ,,mussel1 with intestine passing through it4 ,illustration3 ,,fig4 #aig4 ,the food tube of the mussel is comparatively simple4 ,behind the mouth it enlarges into a swelling called the stomach 7,fig4 #aic74 ,the bile ducts of the neighboring liver empty into the stomach4 ,the intestine makes several turns in the substance of the upper part of the foot1 and then passing upward1 it runs approximately straight to the vent 7or anus71 which is in the wall of the exhalent siphon4 ,the intestine not only runs through the pericardial cavity 7celome7 surrounding the heart1 but through the ventricle of the heart itself 7,fig4 #aif74 ,the kidneys consist of tubes which open into the pericardial chamber above and into the gill chamber below 7,neph41 ,fig4 #aic74 ,the tubes are surrounded by numerous blood vessels 7,fig4 #aih7 and carry off the waste matter from the blood4 ,the nervous system consists of three pairs of ganglia and nerves 7,fig4 #aig74 ,the ganglia are distinguishable because of their orange color4 ,the pedal ganglia on the front of the foot are easily seen also2 the visceral ganglia on the posterior adductor muscle may be seen without removing the mussel from the shell 7,fig4 #aic74 ,the reproductive organs open into the rear portion of the gill cavity 7,fig4 #aic74 ,the sperms1 having been set free in the water1 are drawn into the ova by the same current that brings the food4 ,the eggs are hatched in the gills4 ,after a while the young mussels go out through the siphon4 ,summary4--,in the gills 7,fig4 #aih7 the blood gains what8 ,loses what8 ,from the digestive tube the blood absorbs nourishment4 ,in the kidneys the blood is partly purified by the loss of nitrogenous waste4 ,illustration3 ,,fig4 #aih4--;,,diagram ,,of ,,mussel ,,cut ,,across1 showing mantle1 ma2 gills1 kie2 foot1 f2 heart1 h2 intestine1 ed4 ,the cilia of the fringes on the inhalent1 or lower1 siphon1 vibrate continually and drive water and food particles into the mouth cavity4 ,food particles that are brought near the labial palps are conveyed by them to the mouth4 ,as the water passes along the perforated gills1 its oxygen is absorbed2 the mantle also absorbs oxygen from the water as it passes4 ,the water1 as stated before1 goes next through a passage between the foot and palp into the cavity above the gills and on out through the exhalent siphon4 ,by stirring the water1 or placing a drop of ink near the siphons of a mussel kept in a tub1 the direction of its flow may be seen4 ,the pulsations of the heart are plainly visible in a living mollusk4 ,habits of the ,mussel4--,is it abundant in clear or muddy water2 swift1 still1 or slightly moving water8 ,describe its track or furrow4 ,what is its rate of travel8 ,can you distinguish the spots where the foot was attached to the ground8 ,how long is one 8step0 compared to the length of the shell8 ,the animal usually has the valves opened that it may breathe and eat4 ,the hinge ligament acts like the case spring of a watch1 and holds the valves open unless the adductor muscles draw them together 7,fig4 #ahi74 ,when the mussel first hatches from the egg1 it has a triangular shell4 ,it soon attaches itself to some fish and thus travels about2 after two months it drops to the bottom again4 ,other ,mollusca4--,the oyster's shells are not an exact pair1 the shell which lies upon the bottom being hollowed out to contain the body1 and the upper shell being flat4 ,can you tell by examining an oyster shell which was the lower valve8 ,does it show signs of having been attached to the bottom8 ,the young oyster1 like the young mussel1 is free-swimming4 ,like the arthropoda1 most mollusks undergo a metamorphosis to reach the adult stage 7,fig4 #aii74 ,illustration3 ,,fig4 #aii4--,,oyster4 ,c1 mouth2 a1 vent2 g1 g1 ganglia2 mt1 mantle2 b1 gill4 ,illustration3 ,,fig4 #bjj4--,,trochus4 ,illustration3 ,,fig4 #bja4--;,,cypr,a4 7,univalve1 with a long opening to shell47 ,examine the shells of clams1 snails1 scallops1 and cockles4 ,make drawings of their shells4 ,the slug is very similar to the snail except that it has no shell4 ,if the shell of the snail shown in ,fig4 #bjb were removed1 there would be left a very good representation of a slug4 ,economic ,importance of ,mollusca4--,several species of clams are eaten4 ,one of them is the hard-shell clam 7quahog7 found on the ,atlantic coast from ,cape ,cod to ,texas4 ,its shell is white4 ,it often burrows slightly beneath the surface4 ,the soft-shell clam is better liked as food4 ,it lives along the shores of all northern seas4 ,it burrows a foot beneath the surface and extends its siphons through the burrow to the surface when the tide is in1 and draws into its shell the water containing animalcules and oxygen4 ,oysters to the value of many millions of dollars are gathered and sold every year4 ,the most valuable oyster fisheries of the ,united ,states are in ,chesapeake ,bay4 ,the young oysters1 or 8spat10 after they attach themselves to the bottom in shallow water1 are transplanted4 ,new oyster beds are formed in this way4 ,the beds are sometimes strewn with pieces of rock1 broken pottery1 etc41 to encourage the oysters to attach themselves4 ,the dark spot in the fleshy body of the oyster is the digestive gland1 or liver4 ,the cut ends of the tough adductor muscles are noticeable in raw oysters4 ,the starfish is very destructive in oyster beds4 ,pearls are deposited by bivalves around some irritating particle that gets between the shell and the mantle4 ,the pearl oyster furnishes most of the pearls2 sometimes pearls of great value are obtained from fresh-water mussels in the ,united ,states4 ,name articles that are made partly or wholly of mother-of-pearl4 ,illustration3 ,,fig4 #bjb4--;,a ,,snail4 l1 mouth2 vf1 hf1 feelers2 e1 opening of egg duct2 fu1 foot2 ma1 mantle2 lu1 opening to lung2 a1 vent4 ,study of a ,live ,snail or ,slug4--,is its body dry or moist8 ,do land snails and slugs have lungs or gills8 ,why8 ,how many pairs of tentacles has it8 ,what is their relative length and position8 ,the eyes are dark spots at bases of tentacles of snail and at the tips of the rear tentacles of slug4 ,touch the tentacles4 ,what happens8 ,do the tentacles simply stretch1 or do they turn inside out as they are extended8 ,is the respiratory opening on the right or left side of the body8 ,on the mantle fold or on the body8 7,figs4 #bjb-c-d47 ,how often does the aperture open and close8 ,illustration3 ,,fig4 #bjc4--;,a ,,slug4 ,illustration3 ,,fig4 #bjd4--;,,circulation ,,and ,,respiration ,,in ,,snail4 a1 mouth2 b1 b1 foot2 c1 vent2 d1 d1 lung2 h1 heart4 ,blood vessels are black4 7,perrier47 ,place the snail in a moist tumbler4 ,does the whole under surface seem to be used in creeping8 ,does the creeping surface change shape as the snail creeps8 ,do any folds or wrinkles seem to move either toward the front or rear of its body8 ,is enough mucus left to mark the path traveled8 ,the fold moves to the front1 adheres1 and smooths out as the slug or snail is pulled forward4 ,cephalopods4--,the highest and best developed mollusks are the cephalopods1 or 8head-footed0 mollusks4 ,surrounding the mouth are eight or ten appendages which serve both as feet and as arms4 ,these appendages have two rows of sucking disks by which the animal attaches itself to the sea bottom1 or seizes fish or other prey with a firm grip4 ,the commonest examples are the squid1 with a long body and ten arms1 and the octopus1 or devilfish1 with a short body and eight arms4 ,cephalopods have strong biting mouth parts and complex eyes somewhat resembling the eyes of backboned1 or vertebrate1 animals4 ,the large and staring eyes add to the uncanny1 terrifying appearance4 ,illustration3 ,,fig4 #bje4--;,a ,,squid4 ,the sepia or 8ink0 discharged through the siphon of the squid makes a dark cloud in the water and favors its escape from enemies almost as much as its swiftness 7,fig4 #bje74 ,the squid sometimes approaches a fish with motion so slow as to be imperceptible1 and then suddenly seizes it1 and quickly kills it by biting it on the back behind the head4 ,the octopus is more sluggish than the squid4 ,large species called devilfish sometimes have a spread of arms of twenty-five feet4 ,the pearly nautilus 7,fig4 #bjf7 and the female of the paper argonaut 7,fig4 #bjg7 are examples of cephalopods that have shells4 ,the cuttlefish is closely related to the squid4 ,illustration3 ,,fig4 #bjf4--,,pearly ,,nautilus4 7,shell sawed through to show chambers used when it was smaller1 and siphuncle1 ,s1 connecting them4 ,tentacles1 ,t47 ,illustration3 ,,fig4 #bjg4--,,paper ,,argonaut 7female74 7i4e4 the animal is three times as long and broad as figure74 ,illustration3 ,,fig4 #bjh4--,,paper ,,argonaut 7male74 4 ,general ,questions4--,the living parts of the mussel are very soft1 the name mollusca having been derived from the ,latin word mollis1 soft4 ,why is it that the softest animals1 the mollusks1 have the hardest coverings8 ,to which class of mollusks is the name acephala 7headless7 appropriate8 ,lamellibranchiata 7platelike gills78 ,why is a smooth shell suited to a clam and a rough shell suited to an oyster8 ,why are the turns of a snail's shell so small near the center8 ,why does the mussel have no use for head1 eyes1 or projecting feelers8 ,in what position of the valves of a mussel is the hinge ligament in a stretched condition8 ,how does the shape of the mussel's gills insure that the water current and blood current are brought in close contact8 ,the three classes of mollusks are3 the pelecypoda 7hatchet-footed72 gastropoda 7stomach-footed72 and cephalopoda 7head-footed74 ,give an example of each class4 ,comparison of ,mollusks4 ,,mussel ,,snail ,,squid ----------------------------------- ,shell ----------------------------------- ,head ----------------------------------- ,body ----------------------------------- ,foot ----------------------------------- ,gills ----------------------------------- ,eyes ,comparative ,review4--7,to occupy an entire page in notebook47 ,,grass- ,,hopper ,,spider ,,crayfish ,,centipede ,,mussel ---------------------------------------- ---------------------- ,bilateral or radiate ---------------------------------------- --------------------- ,appendages for locomotion ---------------------------------------- --------------------- ,names of divisions of body ---------------------------------------- --------------------- ,organs and method of breathing ---------------------------------------- --------------------- ,locomotion ,,chapter ,x ,,fishes ,illustration ,,suggestions4--,the behavior of a live fish in clear water1 preferably in a glass vessel or an aquarium1 should be studied4 ,a skeleton may be prepared by placing a fish in the reach of ants4 ,skeletons of animals placed on ant beds are cleaned very thoroughly4 ,the study of the perch1 that follows1 will apply to almost any common fish4 ,movements and ,external ,features4--,what is the general shape of the body of a fish8 ,how does the dorsal1 or upper1 region differ in form from the ventral8 ,is there a narrow part or neck where the head joins the trunk8 ,where is the body thickest8 ,what is the ratio between the length and height8 7,fig4 #bji47 ,are the right and left sides alike8 ,is the symmetry of the fish bilateral or radial8 ,the body of the fish may be divided into three regions1--the head1 trunk1 and tail4 ,the trunk begins with the foremost scales2 the tail is said to begin at the vent1 or anus4 ,which regions bear appendages8 ,is the head movable independently of the trunk1 or do they move together8 ,state the advantage or disadvantage in this4 ,is the body depressed 7flattened vertically7 or compressed 7flattened laterally78 ,do both forms occur among fishes8 7,see figures on pages #abc1 #abd47 ,how is the shape of the body advantageous for movement8 ,can a fish turn more readily from side to side1 or up and down8 ,why8 ,is the head wedge-shaped or conical8 ,are the jaws flattened laterally or vertically8 ,the fish swims in the water1 the bird swims in the air4 ,account for the differences in the shape of their bodies4 ,illustration3 ,,fig4 #bji4--,,white ,,perch 7,morone ,americana74 ,is the covering of the body like the covering of any animal yet studied8 ,the scales are attached in little pockets1 or folds1 in the skin4 ,observe the shape and size of scales on different parts of the body4 ,what parts of the fish are without scales8 ,examine a single scale2 what is its shape8 ,do you see concentric lines of growth on a scale8 ,sketch a few of the scales to show their arrangement4 ,what is the use of scales8 ,why are no scales needed on the head8 ,how much of each scale is hidden8 ,is there a film over the scale8 ,are the colors in the scale or on it8 ,the ,fins4--,are the movements of the fish active or sluggish8 ,can it remain stationary without using its fins8 ,can it move backward8 ,how are the fins set in motion8 ,what is the color of the flesh1 or muscles1 of a fish8 ,count the fins4 ,how many are in pairs8 7,fig4 #bji47 ,how many are vertical8 ,how many are on the side8 ,how many are on the middle line8 ,are the paired or unpaired fins more effective in balancing the fish8 ,in turning it from side to side8 ,in raising and lowering the fish8 ,in propelling it forward8 ,how are some of the fins useful to the fish besides for balancing and swimming8 ,the hard spines supporting the fins are called the fin rays4 ,the fin on the dorsal line of the fish is called the dorsal fin4 ,are its rays larger or smaller than the rays of the other fins8 ,the perch is sometimes said to have two dorsal fins1 since it is divided into two parts4 ,the fin forming the tail is called the tail fin1 or caudal fin4 ,are its upper and lower corners alike in all fishes8 7,fig4 #bbh47 ,on the ventral side1 just behind the vent1 is the ventral fin1 also called the anal fin4 ,the three fins mentioned are unpaired fins4 ,of the four-paired fins1 the pair higher on the sides 7and usually nearer the front7 are the pectoral fins4 ,the pair nearer the ventral line are the pelvic fins4 ,they are close together1 and in many fish are joined across the ventral line4 ,the ventral fins are compared to the legs1 and the pectoral fins to the arms1 of higher vertebrates4 7,fig4 #bdd47 ,compare fins of fish1 pages #abc1 #abd4 ,make a drawing of the fish seen from the side1 omitting the scales unless your drawing is very large4 ,are the eyes on the top or sides of the head1 or both8 ,can a fish shut its eyes8 ,why1 or why not8 ,is the eyeball bare1 or covered by a membrane8 ,is the covering of the eyeball continuous with the skin of the head8 ,is there a fold or wrinkle in this membrane or the surrounding skin8 ,has the eye a pupil8 ,an iris8 ,is the eye of the fish immovable1 slightly movable1 or freely movable8 ,can it look with both eyes at the same object8 ,is the range of vision more upward or downward8 ,to the front or side8 ,in what direction is vision impossible8 ,can a fish close its eyes in sleep8 ,does the eyeball appear spherical or flattened in front8 ,the ball is really spherical1 the lens is very convex1 and fish are nearsighted4 ,far sight would be useless in a dense medium like water4 ,illustration3 ,,fig4 #baj4--;,,blackboard ,,outline ,,of ,,fish4 ,in what direction are the nostrils from the eyes8 7,fig4 #baa47 ,there are two pairs of nostrils1 but only one pair of nasal cavities1 with two nostrils opening into each4 ,there are no nasal passages to the mouth1 as the test with a probe shows that the cavities do not open into the mouth4 ,what two functions has the nose in man8 ,what function has it in the fish8 ,illustration3 ,,fig4 #baa4--;,,head ,,of ,,carp4 ,there are no external ears4 ,the ear sacs are embedded in the bones of the skull4 ,is hearing acute or dull8 ,when fishing1 is it more necessary not to talk or to step lightly1 so as not to jar the boat or bank8 ,what is the use of the large openings found at the back of the head on each side8 7,fig4 #baa47 ,under the skin at the sides of the head are thin membrane bones formed from the skin2 they aid the skin in protection4 ,just under these membrane bones are the gill covers1 of true bone4 ,which consists of more parts1 the membranous layer1 or the true bony layer in the gill cover8 7,figs4 #baa and #bab47 ,illustration3 ,,fig4 #bab4--,,skeleton ,,of ,,perch4 ,is the mouth large or small8 ,are the teeth blunt or pointed8 ,near the outer edge1 or far in the mouth8 7,fig4 #bab47 ,does the fish have lips8 ,are the teeth in one continuous row in either jaw8 ,in the upper jaw there are also teeth on the premaxillary bones4 ,these bones are in front of the maxillary bones1 which are without teeth4 ,teeth are also found in the roof of the mouth1 and the tongue bears horny appendages similar to teeth4 ,are the teeth of the fish better suited for chewing or for grasping8 ,why are teeth on the tongue useful8 ,watch a fish eating3 does it chew its food8 ,can a fish taste8 ,test by placing bits of brown paper and food in a vessel or jar containing a live fish4 ,is the throat1 or gullet1 of the fish large or small8 ,the skeleton of a fish is simpler than the skeleton of other backboned animals4 ,study ,fig4 #bab or a prepared skeleton4 ,at first glance1 the skeleton appears to have two vertebral columns4 ,why8 ,what bones does the fish have that correspond to bones in the human skeleton8 ,are the projections 7processes7 from the vertebr long or short8 ,the ribs are attached to the vertebr of the trunk1 the last rib being above the vent4 ,the tail begins at the vent4 ,are there more tail vertebr or trunk vertebr8 ,are there any neck 7cervical7 vertebr 7i4e4 in front of those that bear ribs78 ,the first few ribs 7how many87 are attached to the central body of the vertebr4 ,the remaining ribs are loosely attached to processes on the vertebr4 ,the ribs of bony fishes are not homologous with the ribs of the higher vertebrates4 ,in most fishes there are bones called intermuscular bones attached to the first ribs 7how many in the perch87 which are possibly homologous to true ribs2 that is1 true ribs in the higher vertebrates may have been developed from such beginnings4 ,illustration3 ,,fig4 #bac4 ,which1 if any1 of the fin skeletons 7,fig4 #bad7 are not attached to the general skeleton8 ,which fin is composed chiefly of tapering1 pointed rays8 ,which fins consist of rays which subdivide and widen toward the end8 ,which kind are stiff1 and which are flexible8 ,which of the fin rays are segmented1 or in two portions8 ,the outer segment is called the radial1 the inner the basal segment4 ,which segments are longer8 ,there is one basal segment that lacks a radial segment2 find it 7,fig4 #bab74 ,illustration3 ,,fig4 #bad4--,,soft-,,rayed ,,and ,,spiny-,,rayed ,,fins4 ,what is the advantage of the backbone plan of structure over the armor-plate plan8 ,you have seen the spool-like body of the vertebra in canned salmon4 ,is it concave1 flat1 or convex at the ends8 ,illustration3 ,,fig4 #bae4--;,,carp1 with right gill cover removed to show gills4 ,illustration3 ,,fig4 #baf4--,,skeleton ,,around ,,throat ,,of ,,fish4 ,the gills are at the sides of the head 7,fig4 #bae7 under the opercula1 or gill covers4 ,what is the color of the gills8 ,do the blood vessels appear to be very near the surface of the gills1 or away from the surface8 ,what advantage in this8 ,are the gills smooth or wrinkled8 7,fig4 #bae47 ,what advantage8 ,the bony supports of the gills1 called the gill arches1 are shown in ,fig4 #baf 7k to k74 ,how many arches on each side8 ,the gill arches have projections on their front sides1 called gill rakers1 to prevent food from being washed through the clefts between the arches4 ,the fringes on the rear of the gill arches are called the gill filaments 7a1 ,fig4 #baf74 ,these filaments support the thin and much-wrinkled borders of the gills1 for the gills are constructed on the plan of exposing the greatest possible surface to the water4 ,compare the plan of the gills and the human lungs4 ,the gill opening on each side is guarded by seven rays 7kh1 ,fig4 #baf7 along the hinder border of the gill cover4 ,these rays grow from the tongue bone4 7,zu1 ,fig4 #baf4 ,this is a rear view47 ,illustration3 ,,fig4 #bag4--;,,circulation ,,in ,,gills4 ,illustration3 ,,fig4 #bah4--,,nostrils1 ,,mouth1 ,,and ,,gill ,,openings ,,of ,,sting-,,ray4 ,watch a live fish and determine how the water is forced between the gills4 ,is the mouth opened and closed in the act of breathing8 ,are the openings behind the gill covers opened and closed8 ,how many times per minute does fresh water reach the gills8 ,do the mouth and gill covers open at the same time8 ,why must the water in contact with the gills be changed constantly8 ,why does a fish usually rest with its head up stream8 ,how may a fish be kept alive for a time after it is removed from the water8 ,why does drying of the gills prevent breathing8 ,if the mouth of a fish were propped open1 and the fish returned to the water1 would it suffocate8 ,why1 or why not8 ,illustration3 ,,fig4 #bai4--;,,gill ,,openings ,,of ,,eel4 ,food ,tube4--,the gullet is short and wide4 ,the stomach is elongated 7,fig4 #bbj74 ,there is a slight constriction1 or narrowing1 where it joins the intestine4 ,is the intestine straight1 or does it lie in few or in many loops8 7,fig4 #bbj47 ,the liver has a gall bladder and empties into the intestine through a bile duct4 ,is the liver large or small8 ,simple or lobed8 ,the spleen 7mi1 ,fig4 #bbj7 lies in a loop of the intestine4 ,the last part of the intestine is straight and is called the rectum4 ,is it of the same size as the other portions of the intestine8 ,the fish does not possess a pancreas1 the most important digestive gland of higher vertebrates4 ,illustration3 ,,fig4 #bbj4--;,,anatomy ,,of ,,carp4 7,see also colored figure #d47 bf1 barbels on head 7for feeling72 h1 ventricle of heart2 as1 aortic bulb for regulating flow to gills2 vk1 venous sinus2 ao1 dorsal aorta2 ma1 stomach2 l1 liver2 gb1 gall cyst2 mi1 spleen2 d1 small intestine2 md1 large intestine2 a1 vent2 s1 s1 swim bladder2 ni1 ni1 kidney2 hl1 ureter2 hb1 bladder2 ro1 eggs 7roe72 mhe1 opening of ducts from kidney and ovary4 ,questions3 ,are the kidneys dorsal or ventral8 ,the swim bladder8 ,why8 ,why is the swim bladder double8 ,does blood enter gills above or below8 ,the ovary lies between the intestine and the air bladder4 ,in ,fig4 #bbj it is shown enlarged and filled with egg masses called roe4 ,it opens by a pore behind the vent4 ,the silver lining of the body cavity is called the peritoneum4 7,see ,chap4 ,,vii1 ,human ,biology47 ,is the air bladder simple or partly divided in the perch8 ,in the carp8 7,fig4 #bbj47 ,is it above or below the center of the body8 ,why8 ,the air bladder makes the body of the fish about as light as water that it may rise and sink with little effort4 ,when a fish dies1 the gases of decomposition distend the bladder and the abdomen1 and the fish turns over4 ,why8 ,where are the kidneys8 7,fig4 #bbj47 ,their ends unite close under the spinal column4 ,the ureters1 or tubes1 leading from them1 unite1 and after passing a small urinary bladder1 lead to a tiny urinary pore just behind the opening from the ovary4 7,colored figure #d47 ,the ,circulation4--,the fish1 unlike other vertebrates1 has its breathing organs and its heart in its head4 ,the gills have already been described4 ,the heart of an air-breathing vertebrate is near its lungs4 ,why8 ,the heart of a fish is near its gills for the same reason4 ,the heart has one auricle and one ventricle4 7,colored figure #a47 ,illustration3 ,,fig4 #bba4--,,plan ,,of ,,circulation4 ,ab1 arteries to gills2 ,ba1 aortic bulb2 ,v1 ventricle4 ,blood returning to the heart comes through several veins into a sinus1 or antechamber1 whence it passes down through a valve into the auricle2 from the auricle it goes forward into the ventricle4 ,the ventricle sends it into an artery1 not directly1 but through a bulb 7as1 ,fig4 #bbj71 which serves to maintain a steady flow1 without pulse beats1 into the large artery 7aorta7 leading to the gills4 ,the arteries leading from the gills join to form a dorsal aorta 7,ao1 ,fig4 #bba71 which passes backward1 inclosed by the lower processes of the spinal column4 ,after going through the capillaries of the various organs1 the blood returns to the heart through veins4 ,the color of the blood is given by red corpuscles4 ,these are nucleated1 oval1 and larger than the blood corpuscles of other vertebrates4 ,the blood of the fish is slightly above the temperature of the water it inhabits4 ,illustration3 ,,fig4 #bbb4--;,,brain ,,of ,,perch1 from above4 n1 end of nerve of smell2 au1 eye2 v1 z1 m1 fore1 mid1 and hind brain2 h1 spinal bulb2 r1 spinal cord4 ,notice the general shape of the brain 7,fig4 #bbb74 ,are its subdivisions distinct or indistinct8 ,are the lobes in pairs8 ,the middle portion of the brain is the widest1 and consists of the two optic lobes4 ,from these lobes the optic nerves pass beneath the brain to the eyes 7,sn1 ,fig4 #bbc74 ,in front of the optic lobes lie the two cerebral lobes1 or the cerebrum4 ,the small olfactory lobes are seen 7,fig4 #bbd7 in front of the cerebrum4 ,the olfactory nerves may be traced to the nostrils4 ,back of the optic lobes 7mid brain7 is the cerebellum 7hind brain71 and back of it is the medulla oblongata1 or beginning of the spinal cord4 ,illustration3 ,,fig4 #bbc4--;,,brain ,,of ,,perch1 side view4 ,illustration3 ,,fig4 #bbd4--;,,brain ,,of ,,perch1 from below4 ,taking the eyeball for comparison1 is the whole brain as large as one eyeball8 7,fig4 #bbb47 ,judging from the size of the parts of the brain1 which is more important with the fish1 thinking or perception8 ,which is the most important sense8 ,the scales along a certain line on each side of the fish1 called the lateral line1 are perforated over a series of lateral line sense organs1 supposed to be the chief organs of touch 7see ,fig4 #bji74 ,illustration3 ,,fig4 #bbe4--,,the ,,stickleback4 ,instead of depositing the eggs on the bottom1 it makes a nest of water plants--the only fish that does so--and bravely defends it4 ,questions4--,which of the fins of the fish have a use which corresponds to the keel of a boat8 ,the rudder8 ,a paddle for sculling8 ,an oar8 ,state several reasons why the head of the fish must be very large1 although the brain is very small4 ,does all the blood go to the gills just after leaving the heart8 ,make a list of the different species of fish found in the waters of your neighborhood2 in the markets of your town4 ,illustration3 ,,fig4 #bbf4--;,,artificial ,,fecundation4 ,the egg-cells and sperm-cells are pressed out into a pan of water4 ,illustration3 ,,fig4 #bbg4--,,newly ,,hatched ,,trout1 with yolk-sac adhering1 eyes large1 and fins mere folds of the skin4 7,enlarged47 ,reproduction4--,the female fish deposits the unfertilized eggs1 or ova1 in a secluded spot on the bottom4 ,afterward the male fish deposits the sperms in the same place 7see ,fig4 #bbe74 ,the eggs1 thus unprotected1 and newly hatched fish as well1 are used for food by fish of the same and other species4 ,to compensate for this great destruction1 most fish lay 7spawn7 many thousands of eggs1 very few of which reach maturity4 ,higher vertebrates 7e4g4 birds7 have1 by their superior intelligence1 risen above this wasteful method of reproduction4 ,some kinds of marine fish1 notably cod1 herring1 and salmon1 go many miles up fresh rivers to spawn4 ,it is possible that this is because they were originally fresh-water species2 yet they die if placed in fresh water except during the spawning season4 ,they go because of instinct1 which is simply an inherited habit4 ,rivers may be safer than the ocean for their young4 ,they are worn and exhausted by the journey1 and never survive to lay eggs the second time4 ,illustration3 ,,fig4 #bbh4--;,a ,,shark 7,acanthias vulgaris74 ,the air bladder is developed from the food tube in the embryo fish1 and is homologous with lungs in the higher vertebrates4 ,are their functions the same8 ,fish that feed on flesh have a short intestine4 ,those that eat plants have a long intestine4 ,which kind of food is more quickly digested8 ,there are mucous glands in the skin of a fish which supply a secretion to facilitate movement through the water2 hence a freshly caught fish1 before the secretion has dried1 feels very slippery4 ,the air bladder1 although homologous to lungs1 is not a breathing organ in common fishes4 ,it is filled by the formation of gases from the blood1 and can be made smaller by the contraction of muscles along the sides of the body2 this causes the fish to sink4 ,in the gar and other ganoids1 the air bladder contains blood vessels1 is connected with the gullet1 and is used in breathing4 ,organs serving the same purpose in different animals are said to be analogous4 ,to what in man are the gills of the fish analogous8 ,organs having a like position and origin are said to be homologous4 ,the air bladders of a fish are homologous with the lungs of man2 but since they have not the same use they are not analogous4 ,how does the tail of a shark or a gar differ from the tail of common fishes8 7,fig4 #bbh47 ,do you know of fish destitute of scales8 ,do you know of fish with whiplike feelers on the head8 7,figs47 ,why are most fishes white on the under side8 ,comparative ,review4--7,copy table on one page or two facing pages of notebook47 ,,is ,,there ,,digestive ,a ,,head8 ,,method ,,of ,,organs ,,and ,,re- ,a ,,neck8 ,,feeding ,,digestion ,,production ,,senses ---------------------------------------- ------------------------ ,ameba ---------------------------------------- ------------------------ ,sponge ---------------------------------------- ------------------------ ,hydra ---------------------------------------- ------------------------ ,starfish ---------------------------------------- ------------------------ ,earthworm ---------------------------------------- ------------------------ ,wasp ---------------------------------------- ------------------------ ,mussel ---------------------------------------- ------------------------ ,fish ,illustration3 ,,fig4 #bbi4--;,,drawing ,,the ,,seine4 ,illustration3 ,,fig4 #bcj4--,,sunfish4 ,,fig4 #bca4--,,tunny4 ,,fig4 #bcb4--,,swordfish4 ,,fig4 #bcc4--,,swellfish4 ,,fig4 #bcd4--,,turbot4 ,,fig4 #bce4--;,,carp4 ,,fig4 #bcf4--;,,herring4 ,,fig4 #bcg4--,,speckled ,,trout4 ,,fig4 #bch4--,,perch4 ,,fig4 #bci4--,,salmon4 ,seven ,food ,fish4 ,three ,curious ,fish4 ,,special ,,reports4 7,encyclopedia1 texts1 dictionary47 ,illustration3 ,,fig4 #bdj4--,,sea ,,horse 7hippocampus71 with incubating pouch1 ,brt4 ,,fig4 #bda4--;,,band ,,fish4 ,,fig4 #bdb4--,,torpedo4 ,electrical organs at right and left of brain4 ,,fig4 #bdc4--,,lantern ,,fish 7,linophryne lucifer74 7,after ,collett47 ,,fig4 #bdd4--,,lung ,,fish of ,australia 7,ceratodus miolepis74 ,,fig4 #bde4--,,trunk ,,fish4 ,,fig4 #bdf4--,,seaweed ,,fish4 7,phyllopteryx eques74 ,remarkable ,fish4 ,,special ,,reports4 7,encyclopedia1 texts1 dictionary47 ,,key ,,to ,,the ,,branches1 ,,or ,,sub-,,kingdoms ,a ,one-celled ,animals 7,protozoans7 ,i4 ,,protozoans ,a ,many-celled ,animals 7,metazoans7 ,b ,,radiate 7around a center74 ,without head2 all aquatic1 resembling plants1 and often fixed to bottom ,c ,walls of body serving as digestive organs ,d ,many openings1 no tentacles ,,ii4 ,,sponges 7,porifera7 ,d ,one opening1 which is both mouth and ,,iii4 ,,polyps vent2 tentacles for seizing prey 7,clenterata7 ,c ,digestive tube distinct from body wall1 ,,iv4 ,,echinoderms spiny skin ,b ,,bilateral4 ,with anterior and posterior end2 dorsal and ventral surface ,c ,body of successive segments2 legs ,v4 ,,vermes without joints ,c ,external skeleton of successive rings2 ,,vi4 ,,arthropods jointed legs ,c ,body soft2 no skeleton2 usually bearing ,,vii4 ,,mollusks a limy shell ,c ,internal jointed skeleton1 attached to ,,viii4 ,,vertebrates an axis or vertebral column ,examples4--,tell the branch to which each of the following animals belongs3 crayfish1 earthworm1 thousand leg1 white grub1 sea anemone1 ameba1 tapeworm1 caterpillar1 beetle1 sparrow1 snake1 oyster1 starfish1 fish4 ,be prepared to state the reason for each classification4 ,the classes in the branch vertebrata are3 #a4 ,fishes 7pisces74 #b4 ,frogs and ,salamanders 7batrachia74 #c4 ,reptiles 7reptilia74 #d4 ,birds 7aves74 #e4 ,mammals 7mammalia74 ,illustration3 ,,fig4 #bdg4--;,a ,,snail4 7,which branch8 ,why87 ,,chapter ,,xi ,,batrachia ,the theory of evolution teaches that animal life began in a very simple form in the sea1 and that afterward the higher sea animals lost their gills and developed lungs and legs and came out to live upon the land2 truly a marvelous procedure1 and incredible to many1 although the process is repeated every spring in countless instances in pond and brook4 ,in popular language1 every cold-blooded vertebrate breathing with lungs is called a reptile4 ,the name reptile is properly applied only to lizards1 snakes1 turtles1 and alligators4 ,the common mistake of speaking of frogs and salamanders as reptiles arises from considering them only in their adult condition4 ,reptiles hatch from the egg as tiny reptiles resembling the adult forms2 frogs and salamanders1 as every one knows1 leave the egg in the form of tadpoles 7,fig4 #bdh74 ,the fact that frogs and salamanders begin active life as fishes1 breathing by gills1 serves to distinguish them from other cold-blooded animals1 and causes naturalists to place them in a separate class1 called batrachia 7twice breather7 or amphibia 7double life74 ,,tadpoles ,,suggestions4--,tadpoles may be studied by placing a number of frog's eggs in a jar of water1 care being taken not to place a large number of eggs in a small amount of water4 ,when they hatch1 water plants 7e4g4 green alg7 should be added for food4 ,the behavior of frogs may be best studied in a tub of water4 ,a toad in captivity should be given a cool1 moist place1 and fed well4 ,a piece of meat placed near a toad may attract flies1 and the toad may be observed while catching them1 but the motion is so swift as to be almost imperceptible4 ,live flies may be put into a glass jar with a toad4 ,toads do not move about until twilight1 except in cloudy1 wet weather4 ,they return to ponds and brooks in spring at the time for laying eggs4 ,this time for both frogs and toads is shown by trilling4 ,all frogs1 except tree frogs1 remain in or near the water all the year4 ,illustration3 ,,fig4 #bdh4--,,metamorphoses ,,of ,,the ,,frog1 numbered in order4 ,do eggs hatch and tadpoles grow more rapidly in a jar of water kept in a warm place or in a cold place8 ,in pond water or drinking water8 ,can the tadpoles be seen to move in the eggs before hatching8 ,when do the external gills show8 7,fig4 #bdh47 ,what parts may be described in a tadpole8 ,what is the shape of the tail8 ,compare the tadpole with the fish as to 7#a7 general shape1 7#b7 covering1 7#c7 fins1 7#d7 tail1 7#e7 gills4 ,do the external gills disappear before or after any rudiments of limbs appear8 7#f1 #g1 ,fig4 #bdh47 ,can you locate the gills after they become internal8 7,fig4 #bdi47 ,illustration3 ,,fig4 #bdi4--,,tadpole1 from below1 showing intestine and internal gills4 7,enlarged47 ,in what state of growth are the legs when the tadpole first goes to the surface to breathe8 ,which legs appear first8 ,what advantage is this8 ,what becomes of the tail8 ,is the tail entirely gone before the frog first leaves the water8 ,are tadpoles habitually in motion or at rest8 ,is the intestine visible through the skin8 7,fig4 #bdi47 ,is it straight or coiled8 ,remembering why some fish have larger intestines than others1 and that a cow has a long intestine and a cat a short one1 state why a tadpole has a relatively longer intestine than a frog4 ,compare the mouth1 jaws1 eyes1 skin1 body1 and habits of tadpole and frog4 ,,frogs ,prove that frogs and toads are beneficial to man4 ,did you ever know of a frog or toad destroying anything useful1 or harming any one1 or causing warts8 ,how many pupils in class ever had warts8 ,had they handled frogs before the warts came8 ,frogs are interesting1 gentle1 timid animals4 ,why are they repulsive to some people8 ,environment4--,where are frogs found in greatest numbers8 ,what occurs when danger threatens them8 ,what enemies do they have8 ,what color1 or tint1 is most prominent on a frog8 ,does the color 8mimic0 or imitate its surroundings8 ,what is the color of the under side of the body8 7,fig4 #bej47 ,why is there greater safety in that color8 ,what enemies would see water frogs from below8 ,do tree frogs mimic the bark8 ,the leaves8 ,can a frog stay under water for an indefinite time8 ,why1 or why not8 ,what part of a frog is above the surface when it floats or swims in a tub of water8 ,why8 ,do frogs croak in the water or on the bank8 ,why do they croak after a rain8 ,do toads croak8 ,are the eggs laid in still or flowing water8 ,in a clear place or among sticks and stems8 ,singly1 or in strings or in masses8 7,fig4 #bdh47 ,describe an egg4 ,why do frogs dig into the mud in autumn in cold climates8 ,why do they not dig in mud at the bottom of a pond8 ,why is digging unnecessary in the ,gulf states8 ,describe the position of the frog when still 7,fig4 #bej74 ,what advantage in this position8 ,does the frog use its fore legs in swimming or jumping8 ,its hind legs8 ,how is the frog fitted for jumping8 ,compare it in this respect with a jumping insect2 a jumping mammal4 ,how is it fitted for swimming8 ,is the general build of its body better fitted for swimming or jumping8 ,how far can a frog jump8 ,illustration3 ,,fig4 #bej4--,,painted ,,frog 7,chorophilus ornatus71 of ,mexico4 ,external ,features4--,the frog may be said to have two regions in its body1 the head and trunk4 ,a neck hardly exists1 as there is only one vertebra in front of the shoulders 7,fig4 #beb71 although most vertebrates have seven neck 7cervical7 vertebr4 ,there are no tail 7caudal7 vertebr1 even in the tadpole state of frogs and toads4 ,the head appears triangular in shape when viewed from what direction8 ,the head of a frog is more pointed than the head of a toad4 ,is the skull a closed case of broad bones or an open structure of narrow bones8 7,fig4 #beb47 ,describe the mouth4 ,observe the extent of the mouth opening 7,fig4 #bea74 ,are teeth present in the upper jaw8 ,the lower jaw8 ,are the teeth sharp1 or dull8 ,does the frog chew its food8 ,is the tongue slender or thick8 7,fig4 #bea47 ,is it attached to the front or the back of the mouth8 ,in what direction does the free end extend when the tongue lies flat8 ,is the end pointed or lobed8 ,how far out will the tongue stretch8 ,for what is it used8 ,why is it better for the teeth to be in the upper jaw rather than in the lower jaw8 ,that the teeth are of little service is shown by the fact that the toad with similar habits of eating has no teeth4 ,will a toad catch and swallow a bullet or pebble rolled before it8 ,the toad is accustomed to living food1 hence prefers a moving insect to a still one4 ,illustration3 ,,fig4 #bea4--;,,head ,,of ,,frog4 ,the ,senses4--,compare the eyes with the eyes of a fish in respect to position and parts4 ,are the eyes protruding or deep-set8 ,touch the eye of a live frog4 ,can it be retracted8 ,what is the shape of the pupil8 ,the color of the iris8 ,is the eye bright or dull8 ,what probably gave rise to the superstition that a toad had a jewel in its head8 ,is there a third eyelid8 ,are the upper and lower eyelids of the same thickness8 ,with which lid does it wink8 ,close its eye8 ,observe the large oval ear drum or tympanum4 ,what is its direction from the eye8 7,fig4 #bea47 ,the mouth8 ,is there a projecting ear8 ,does the frog hear well8 ,what reason for your answer8 ,as in the human ear1 a tube 7the ,eustachian tube7 leads from the mouth to the inner side of the tympanum4 ,how many nostrils8 7,fig4 #bea47 ,are they near together or separated8 ,large or small8 ,a bristle passed into the nostril comes into the mouth not far back in the roof4 ,why must it differ from a fish in this8 ,how do the fore and hind legs differ8 ,how many toes on the fore foot or hand8 ,on the hind foot8 ,on which foot is one of the toes rudimentary8 ,why is the fore limb of no assistance in propelling the body in jumping8 ,do the toes turn in or out8 7,fig4 #bej47 ,how does the frog give direction to the jump8 ,what would be the disadvantage of always jumping straight forward when fleeing8 ,which legs are more useful in alighting8 ,illustration3 ,,fig4 #beb4--,,skeleton ,,of ,,frog4 ,divisions of the ,limbs4--,distinguish the upper arm1 forearm1 and hand in the fore limb 7,figs4 #beb and #bec74 ,compare with skeleton of man 7,fig4 #cii74 ,do the arms of a man and a frog both have one bone in the upper arm and two in the forearm8 ,both have several closely joined bones in the wrist and five separate bones in the palm4 ,do any of the frog's fingers have three joints8 ,compare also the leg of manand the hind leg of the frog 7,figs4 #bec and #cii74 ,does the thigh have one bone in each8 ,the shank of man has two bones1 shin and splint bone4 ,do you see a groove near the end in the shank bone of a frog 7,fig4 #beb71 indicating that it was formed by the union of a shin and splint bone8 ,the first two of the five bones of the ankle are elongated1 giving the hind leg the appearance of having an extra joint 7,fig4 #bec74 ,the foot consists of six digits1 one of which1 like the thumb on the fore limb1 is rudimentary4 ,the five developed toes give the five digits of the typical vertebrate foot4 ,besides the five bones corresponding to the instep1 the toes have two1 three1 or four bones each4 ,how is the hind foot specialized for swimming8 ,which joint of the leg contains most muscle8 7,fig4 #bed47 ,find other bones of the frog analogous in position and similar in form to bones in the human skeleton4 ,illustration3 ,,fig4 #bec4--,,skeleton ,,of ,,frog4 ,illustration3 ,,fig4 #bed4--,,leg ,,muscles ,,of ,,frog4 ,is the skin of a frog tight or loose8 ,does it have any appendages corresponding to scales1 feathers1 or hair of other vertebrates8 ,is the skin rough or smooth8 ,the toad is furnished with glands in the skin which are sometimes swollen2 they form a bitter secretion1 and may be1 to some extent1 a protection4 ,yet birds and snakes do not hesitate to swallow toads whole4 ,show how both upper and under surfaces of frog illustrate protective coloration4 ,all batrachians have large and numerous blood vessels in the skin by which gases are exchanged with the air1 the skin being almost equal to a third lung4 ,that the skin may function in this way1 it must not become dry4 ,using this fact1 account for certain habits of toads as well as frogs4 ,if a frog is kept in the dark or on a dark surface1 its skin will become darker than if kept in the light or on a white dish4 ,try this experiment1 comparing two frogs4 ,this power of changing color is believed to be due to the diminution in size of certain pigment cells by contraction1 and enlargement from relaxation4 ,this power is possessed to a certain degree not only by batrachians but also by many fishes and reptiles4 ,the chameleon1 or green lizard of the ,gulf states1 surpasses all other animals in this respect 7,fig4 #bhj74 ,what advantage from this power8 ,illustration3 ,,fig4 #bee4--;,,digestive ,,canal ,,of ,,frog4 ,mh1 mouth2 ,z1 tongue pulled outward2 ,s1 opening to larynx2 ,oe1 gullet2 ,m1 stomach2 ,d1 intestine2 ,p1 pancreas2 ,l1 liver2 ,g1 gall bladder2 ,r1 rectum2 ,hb1 bladder2 ,cl1 cloaca2 ,a1 vent4 ,digestive ,system4--,the large mouth cavity is connected by a short throat with the gullet1 or esophagus 7,fig4 #bee74 ,a slit called the glottis opens from the throat into the lungs 7,fig4 #bee74 ,is the gullet long or short8 ,broad or narrow8 ,is the stomach short or elongated8 ,is the division distinct between the stomach and gullet1 and stomach and intestine8 ,is the liver large or small8 ,is it simple or lobed8 ,the pancreas lies between the stomach and the first bend of the intestines 7,fig4 #bee74 ,what is its shape8 ,a bile duct connects the liver with the small intestine 7,dc1 ,fig4 #bee74 ,it passes through the pancreas1 from which it receives several pancreatic ducts4 ,after many turns1 the small intestine joins the large intestine4 ,the last part of the large intestine is called the rectum 7,latin1 straight74 ,the last part of the rectum is called the cloaca 7,latin1 a drain71 and into it the ducts from the kidneys and reproductive glands also open4 ,the kidneys are large1 elongated1 and flat4 ,they lie under the dorsal wall4 ,the urinary bladder is also large4 ,does the salamander have a similar digestive system8 7,fig4 #bef47 ,why are the liver and lungs 7,fig4 #bef7 longer in a salamander than in a frog8 ,illustration3 ,,fig4 #bef4--;,,anatomy ,,of ,,salamander4 #a;a1 heart2 #b1 lungs2 #c;a1 stomach2 #c;b1 intestine2 #c;c1 large intestine2 #d1 liver2 #h1 egg masses2 #aj1 bladder2 #aa1 vent4 ,respiration4--,how many lungs8 ,are they simple or lobed8 7,fig4 #bef47 ,a lung cut open is seen to be baglike1 with numerous ridges on its inner surface4 ,this increases the surface with which the air may come in contact4 ,in the walls of the lungs are numerous capillaries4 ,does the frog breathe with mouth open or closed8 ,does the frog have any ribs for expanding the chest8 ,what part of the head expands and contracts8 ,is this motion repeated at a slow or rapid rate8 ,regularly or irregularly8 ,there are valves in the nostrils for opening and closing them4 ,is there any indication of opening and closing as the throat expands and contracts8 ,the mouth and throat 7pharynx7 are filled with air each time the throat swells1 and the exchange of gases 7which gases87 takes place continually through their walls and the walls of the lungs4 ,at intervals the air is forced through the glottis into the lungs4 ,after a short time it is expelled from the lungs by the muscular abdominal walls1 which press upon the abdominal organs1 and so upon the lungs4 ,immediately the air is forced back into the lungs1 so that they are kept filled4 ,in some species the lungs regularly expand at every second contraction of the throat4 ,this is shown by a slight outward motion at the sides4 ,does the motion of the throat cease when the frog is under water8 ,why would the frog be unable to breathe 7except through the skin7 if its mouth were propped open8 ,why does the fact that the breathing is so slow as to almost cease when hibernating1 aid the frog in going through the winter without starving8 7,chap4 ,i47 ,why must frogs and toads keep their skins moist8 ,which looks more like a clod8 ,why8 ,the ,heart and ,circulation4--,what is the shape of the heart8 7,fig4 #beg47 ,observe the two auricles in front and the conical ventricle behind them4 ,the great arterial trunk from the ventricle passes forward beyond the auricles2 it divides into two branches which turn to the right and left 7,fig4 #beg74 ,each branch immediately subdivides into three arteries 7,fig4 #beg71 one going to the head1 one to the lungs and skin1 and a third1 the largest1 passes backward in the trunk1 where it is united again to its fellow4 7,colored ,fig4 #b47 ,both of the pulmonary veins1 returning to the heart with pure blood from the lungs1 empty into the left auricle4 ,veins with the impure blood from the body empty into the right auricle4 ,both the auricles empty into the ventricles1 but the pure and impure blood are prevented from thoroughly mixing by ridges on the inside of the ventricle4 ,only in an animal with a four-chambered heart does pure blood from the lungs pass unmixed and pure to all parts of the body1 and only such animals are warm-blooded4 ,the purer 7i4e4 the more oxygenated7 the blood1 the greater the oxidation and warmth4 ,the red corpuscles in a frog's blood are oval and larger than those of man4 ,are all of them nucleated8 7,fig4 #beh47 ,the flow of blood in the web of a frog's foot is a striking and interesting sight4 ,it may be easily shown by wrapping a small frog in a wet cloth and laying it with one foot extended upon a glass slip on the stage of a microscope4 ,illustration3 ,,fig4 #beg4--,,plan ,,of ,,frog',s ,,circulation4 ,venous system is black2 the arterial1 white4 ,,au1 auricles2 ,v1 ventricle2 ,l1 lung2 ,,liv1 liver4 ,aorta has one branch to right1 another to left1 which reunite below4 ,right branch only persists in birds1 left branch in beasts and man4 ,illustration3 ,,fig4 #beh4--;,,frog',s ,,blood 7magnified #bejj areas74 ,red cells oval1 nucleated1 and larger than human blood cells4 ,nuclei of two white cells visible near center4 7,peabody47 ,illustration3 ,,fig4 #bei4--;,,brain ,,of ,,frog4 ,illustration3 ,,fig4 #bfj4--,,nervous ,,system ,,of ,,frog4 ,the brain of the frog 7,fig4 #bei7 is much like that of a fish 7,fig4 #bbd74 ,the olfactory1 cerebral1 and optic lobes1 cerebellum and medulla are in the same relative position1 although their relative sizes are not the same4 ,compared with the other parts1 are the olfactory lobes more or less developed than in a fish8 ,the cerebral hemispheres8 ,the optic lobes8 ,the cerebellum8 ,there is a cavity in the brain4 ,it is readily exposed on the under surface of the medulla by cutting the membrane1 which is there its only covering 7,fig4 #bei74 ,illustration3 ,,fig4 #bfa4--,position of legs in tailless 7,a7 and tailed 7,b7 amphibian4 ,frogs and toads are beneficial 7why87 and do not the slightest injury to any interest of man4 ,if toads are encouraged to take up their abode in a garden1 they will aid in ridding it of insects4 ,a house may be made in a shady corner with four bricks1 or better still1 a hole a foot deep may be dug to furnish them protection from the heat of the day4 ,a toad's muzzle is not so tapering as a frog's 7why871 its feet are not so fully webbed 7why871 and its skin is not so smooth 7why874 ,in case of doubt open the mouth and rub the finger along the upper jaw2 a frog has sharp teeth1 a toad none at all4 ,the tadpoles of frogs1 toads1 and salamanders are much alike4 ,in toad's spawn the eggs lie in strings inclosed in jelly2 frogs spawn is in masses 7,fig4 #bdh74 ,any batrachian may easily be passed around the class after placing it in a tumbler with gauze or net tied over top4 ,it should be kept in a box with two inches of moist earth on the bottom4 ,if no live insects are obtainable for feeding a toad1 bits of moist meat may be dangled from the end of a string4 ,if tadpoles are placed in a pool or tub in a garden1 the toads hatched will soon make destructive garden insects become a rarity4 ,does a frog or a salamander have the more primitive form of body8 ,why do you think so8 ,salamanders are sometimes called mud puppies4 ,the absurd belief that salamanders are poisonous is to be classed with the belief that toads cause warts4 ,the belief among the ancients that salamanders ate fire arose perhaps from seeing them coming away from fires that had been built over their holes on river banks by travelers4 ,their moist skin protected them until the fire became very hot4 ,describe the 8mud puppy0 shown in ,fig4 #bfb4 ,in the ,west the pouched gopher1 or rat 7,fig4 #cga71 is sometimes absurdly called a salamander4 ,illustration3 ,,fig4 #bfb4--;,,blind ,,salamander 7,proteus anguinus74 4 ,found in caves and underground streams in ,balkans4 ,gills external1 tail finlike1 legs small4 ,,chapter ,,xii ,,reptilia 7,,reptiles7 ,this class is divided into four orders which have such marked differences of external form that there is no difficulty in distinguishing them4 ,these orders are represented by ,lizards1 ,snakes1 ,turtles1 and ,alligators4 ,of these1 only the forms of lizards and alligators have similar proportions1 but there is a marked difference in their size1 lizards being1 in general1 the smallest1 and alligators the largest of the reptiles4 ,illustration3 ,,fig4 #bfc4--;,a ,,salamander4 ,illustration3 ,,fig4 #bfd4--;,a ,,lizard4 ,comparison of ,lizards and ,salamanders4--,to make clear the difference between reptiles and batrachians1 it will be well to compare the orders in the two classes which resemble each other in size and shape2 namely1 lizards and salamanders 7,figs4 #bfc and #bfd74 ,state in a tabular form their differences in skin1 toe1 manner of breathing1 development from egg1 shape of tail1 habitat1 habits4 ,each has an elongated body1 two pairs of limbs1 and a long tail1 yet they are easily distinguished4 ,are the differences suggested above valid for the other batrachians 7frogs7 and other reptiles 7e4g4 turtles78 ,trace the same differences between the toad or frog 7,fig4 #bej7 and the 8horned toad10 which is a lizard 7,fig4 #bfe74 ,illustration3 ,,fig4 #bfe4--8;,,horned ,,toad0 ,,lizard1 of the ,southwest 7,phrynosoma cornita74 4 ,,study ,,of ,a ,,turtle ,,or ,,tortoise ,,suggestions4--,because of the ease with which a tortoise or turtle may be caught and their movements and habits studied1 it is suggested that one of these be studied as an example of reptiles4 ,besides a live specimen1 a skeleton of one species and the shells of several species should be available4 ,illustration3 ,,fig4 #bff4--;,,european ,,pond ,,turtle 7,emys lutaria74 7,after ,brehms47 ,the body 7of a turtle or tortoise7 is divided distinctly into regions 7,fig4 #bff74 ,is there a head8 ,neck8 ,trunk8 ,tail8 ,the trunk is inclosed by the so-called shell1 which consists of an upper portion1 the carapace1 and a lower portion1 the plastron4 ,how are the other regions covered8 ,what is the shape of the head8 ,is the mouth at the front1 or on the under side8 ,where are the nostrils8 ,are the motions of breathing visible8 ,is there a beak or snout8 ,do the jaws contain teeth8 ,do the eyes project8 ,which is thinner and more movable1 the upper or lower lid8 ,identify the third eyelid 7nictitating membrane74 ,it is translucent and comes from1 and is drawn into1 the inner corner of the eye4 ,it cleanses the eyeball4 ,frogs and birds have a similar membrane4 ,the circular ear drum is in a depression back of the angle of the mouth4 ,what other animal studied has an external ear drum8 ,the tortoise has a longer1 more flexible neck than any other reptile4 ,why does it have the greatest need for such a neck8 ,is the skin over the neck tight or loose8 ,why8 ,do the legs have the three joints or parts found on the limbs of most vertebrates8 ,how is the skin of the legs covered8 ,do the toes have claws8 ,compare the front and hind feet4 ,does the tortoise slide its body or lift it when walking on hard ground8 ,lay the animal on its back on a chair or table at one side of the room in view of the class4 ,watch its attempts to right itself4 ,are the motions suited to accomplish the object8 ,does the tortoise succeed8 ,what are the prevailing colors of turtles8 ,how does their coloration correspond to their surroundings8 ,what parts of the tortoise extend at times beyond the shell8 ,are any of these parts visible when the shell is closed8 ,what movements of the shell take place as it is closed8 ,is the carapace rigid throughout8 ,is the plastron8 ,the ,skeleton 7,fig4 #bfg74--,the carapace is covered with thin epidermal plates which belong to the skin4 ,the bony nature of the carapace is seen when the plates are removed1 or if its inner surface is viewed 7,fig4 #bfg74 ,it is seen to consist largely of wide ribs 7how many87 much flattened and grown together at their edges4 ,the ribs are seen to be rigidly attached to the vertebr4 ,the rear projections of the vertebr are flattened into a series of bony plates which take the place of the sharp ridge found along the backs of most vertebrates4 ,show that the shell of a turtle is not homologous with the shells of mollusks4 ,does the turtle have shoulder blades and collar bones8 ,hip bones8 ,thigh bones8 ,shin bone 7fibia7 and splint bone 7fibula78 7,fig4 #bfg47 ,illustration3 ,,fig4 #bfg4--,,skeleton ,,of ,,european ,,tortoise4 ,c1 rib plates2 ,m1 marginal plates2 ,b1 plastron2 ,h1 humerus bone2 ,r1 radius2 ,u1 ulna2 ,fe1 femur4 ,illustration3 ,,fig4 #bfh4--,,three-,,chambered ,,heart ,,of ,a ,,reptile 7tortoise74 a1 veins2 b1 f1 right and left auricles2 cg1 ventricle2 d1 arteries to lungs2 e1 veins from lungs2 i1 n1 two branches of aorta4 ,compare with ,fig4 #bfi and colored ,fig4 #b4 ,do the plates formed by the ribs extend to the edge of the carapace8 ,see ,fig4 #bfg4 ,about how many bony plates form the carapace8 ,the plastron8 ,do the horny plates outside correspond to the bony plates of the shell8 ,how many axial plates8 ,how many costal 7rib7 plates8 ,how many border plates8 ,which plates are largest8 ,smallest8 ,do the horny plates overlap like shingles1 or meet edge to edge8 ,is there any mark where they meet on the bony shell8 ,basing it upon foregoing facts1 give a connected and complete description of the structure of the carapace4 ,compare the skeleton of the turtle with that of the snake1 and correlate the differences in structure with differences in habits4 ,illustration3 ,,fig4 #bfi4--,,plan ,,of ,,reptilian ,,circulation4 ,see arrows4 ,draw the tortoise seen from the side or above1 with its shell closed1 showing the arrangement of the plates4 ,place soft or tender vegetable food1 lettuce1 mushroom1 roots1 berries1 and water1 also meat1 in reach of the turtle4 ,what does it prefer8 ,how does it eat8 ,it has no lips2 how does it drink8 ,study the movements of its eyeballs and eyelids1 and the respiratory and other movements already mentioned4 ,state a reason for thinking that no species of land animals exists that lacks the simple power of righting itself when turned on its back4 ,illustration3 ,,fig4 #bgj4--,,reptilian ,,viscera 7lizard74 lr1 windpipe2 h1 heart2 lu1 lungs2 le1 liver2 ma1 stomach2 dd1 md1 intestines2 hb1 bladder4 ,tortoise1 ,turtle1 ,terrapin4--,the turtles belong to the order of reptiles called chelonians4 ,no one can have any difficulty in knowing a member of this order4 ,the subdivision of the order into families is not so easy1 however1 and the popular attempts to classify chelonians as turtles1 tortoises1 and terrapins have not been entirely successful4 ,species with a vaulted shell and imperfectly webbed toes and strictly terrestrial habits are called tortoises4 ,species with flattened shells and strictly aquatic habits should be called terrapins 7e4g4 mud terrapin74 ,they have three instead of two joints in the middle toe of each foot4 ,the term turtle may be applied to species which are partly terrestrial and partly aquatic 7e4g4 snapping turtle 7,fig4 #bga774 ,usage1 however1 is by no means uniform4 ,illustration3 ,,fig4 #bga4--,,snapping ,,turtle 7,chelydra serpentina74 ,most reptiles eat animal food2 green terrapins and some land tortoises eat vegetable food4 ,would you judge that carnivorous chelonians catch very active prey8 ,the fierce snapping turtle1 found in ponds and streams1 sometimes has a body three feet long4 ,its head and tail are very large and cannot be withdrawn into the shell4 ,it is carnivorous and has great strength of jaw4 ,it has been known to snap a large stick in two4 ,the box tortoise is yellowish brown with blotches of yellow1 and like its close kinsman1 the pond turtle of ,europe 7,fig4 #bff71 withdraws itself and closes its shell completely4 ,both lids of the plastron are movable1 a peculiarity belonging to these two species4 ,the giant tortoise of the ,galapagos ,islands1 according to ,lyddeker1 can trot cheerfully along with three full-grown men on its back4 8,tortoise shell0 used for combs and other articles is obtained from the overlapping scales of the hawkbill turtle1 common in the ,west ,indies4 ,the diamond-back terrapin1 found along the ,atlantic ,coast from ,massachusetts to ,texas1 is prized for making soup4 ,illustration3 ,,fig4 #bgb4--;,a ,,rattlesnake4 ,illustration3 ,,fig4 #bgc a4--,,head ,,of ,,viper1 showing typical triangular shape of head of venomous snake4 ,illustration3 ,,fig4 #bgc b4--,,side ,,view1 showing poison fangs2 also tongue 7forked1 harmless74 ,illustration3 ,,fig4 #bgd4--,,viper',s ,,head1 showing poison sac at base of fangs4 ,illustration3 ,,fig4 #bge4--,,skull1 showing teeth1 fangs1 and quadrate bone to which lower jaw is joined4 ,see ,fig4 #bhd4 ,poisonous snakes of ,united ,states named in order of virulence3 #a4 ,coral snakes1 ,elaps1 about seventeen red bands bordered with yellow and black 7colored figure #f7 7fatal74 #b4 ,rattlesnakes 7seldom fatal74 #c4 ,copperhead 7may kill a small animal size of dog74 #d4 ,water moccasin 7never fatal74 #e4 ,ground rattler4--,effects3 ,pulse fast1 breathing slow1 blood tubes dilated1 blood becomes stored in abdominal blood tubes1 stupefaction and death from blood being withdrawn from brain4 ,always two punctures1 the closer together the smaller the snake4 ,remedies3 ,ligature between wound and heart1 lance wound and suck2 inject into wound three drops of #a per cent solution of chromic acid or potassium permanganate4 ,give strychnine1 hypodermically1 until strychnine symptoms 7twitchings7 appear4 ,if symptoms of collapse recur1 repeat dose4 ,digitalin or caffein acts like strychnine2 alcohol has opposite effect4 ,illustration3 ,,fig4 #bgf4--8;,,glass ,,snake10 a lizard without legs4 ,illustration3 ,,fig4 #bgg4--,,skull ,,of ,,elaps4 ,see colored ,fig4 #e4 ,illustration3 ,,fig4 #bgh4--,,skull ,,of ,,lampropeltis4 ,protective ,coloration and ,mimicry4--,when an animal imitates the color or form of its inanimate surroundings it is said to be protectively colored or formed4 ,give an instance of protective colorationor form among lizards2 butterflies2 grasshoppers2 amphibians2 echinoderms4 ,when an animal imitates the color or form of another animal it is said to mimic the animal4 ,mimicry usually enables an animal to deceive enemies into mistaking it for an animal which for some reason they avoid4 ,the milkweed butterfly has a taste that is repulsive to birds4 ,the viceroy butterfly is palatable to birds1 but it is left untouched because of its close resemblance to the repulsive milkweed butterfly4 ,the harlequin snake 7,elaps7 of the ,gulf states is the only deadly snake of ,north ,america 7,figs4 #bgg1 #bgh74 ,it is very strikingly colored with rings of scarlet1 yellow1 and black4 ,this is an example of warning coloration4 ,the coral snake 7,lampropeltis7 has bands of scarlet1 yellow1 and black 7colored ,fig4 #f7 of the same tints1 and it is hardly distinguishable from the harlequin4 ,the coral snake is said to mimic the harlequin snake4 ,it also imitates the quiet inoffensive habits of the harlequin snake1 which fortunately does not strike except under the greatest provocation4 ,the rattles of the less poisonous and seldom fatal rattlesnake 7,fig4 #bgb7 may be classed as an example of warning sound which most animals are quick to heed and thus avoid encounters which might be destructive to either the snake or its enemy4 ,illustration3 ,,fig4 #a ,,fig4 #b ,,fig #c4 ,,colored ,,figures #a1 #b1 #c4--;,,circulation ,,in ,,fish1 ,,reptile1 ,,mammal4 ,in which is blood from heart all impure8 ,mixed8 ,both pure and impure8 ,illustration3 ,,fig4 #d4--;,,anatomy ,,of ,,carp4 ,for description see ,fig4 #bbj1 page #aag4 ,illustration3 ,,the ,,harmless ,,coral ,,snake ,,mimics ,,the ,,deadly ,,harlequin ,,snake4 ,,fig4 #e4--;,,harlequin ,,snake 7,elaps74 ,,fig4 #f4--;,,coral ,,snake 7,lampropeltis74 ,illustration3 ,,fig4 #bgi4--;,,gila ,,monster 7,heloderma suspectum71 of ,arizona4 ,if poisonous1 it is the only instance among lizards4 ,it is heavy-built1 orange and black mottled1 and about #af inches long4 ,compare it with the green lizard 7,fig4 #bhj74 ,illustration3 ,,fig4 #bhj4--;,,chameleon 7,anolis71 or green lizard of southern ,u4,s4 ,far excels ,european chameleon 7,fig4 #bha7 and all known animals in power of changing color 7green1 gray1 yellow1 bronze1 and black74 ,survival of the ,fittest4--,the two facts of most far-reaching importance in the history of animals and plants are3 7#a7 ,heredity2 animals inherit the characteristics of their parents4 7#b7 ,variation2 animals are not exactly like their parents4 ,the first fact gives stability1 the second makes progress or evolution possible4 ,the climate of the world is slowly changing1 and animals must change to adapt themselves to it4 ,a more sudden change of environment 7surroundings7 of animals occurs because of migration or isolation2 these in turn are caused by the crowding of other animals or by the formation or disappearance of geographical barriers1 such as deserts1 water1 mountain chains4 ,illustration3 ,,fig4 #bha4--;,,chameleon ,,of ,,southern ,,europe4 ,the young vary in many ways from their parents4 ,some have a more protective color or form1 sharper claws1 swifter movements1 etc4 ,the individuals possessing such beneficial variations live longer and leave more offspring1 and because of heredity transmit the desirable qualities to some of their young4 ,variations which are disadvantageous for getting food1 defense1 etc41 cause shorter life and fewer offspring4 ,thus the fittest survive1 the unfit perish2 an automatic natural selection occurs4 ,darwin taught that variations are infinitesimal and gradual4 ,recent experiments and observations seem to show that many variations are by sudden jumps1 somewhat resembling so-called 8freaks of nature40 ,as to whether these 8sports10 or individuals with new peculiarities1 survive1 depends upon their fitness for their environment4 8,survival of the fittest0 results from this natural selection1 but the selection occurs between animals of marked1 not infinitesimal1 differences1 as ,darwin taught4 ,darwin's theory is probably true for species in the usual state of nature2 the new theory 7of ,de ,vries7 is probably true for animals and plants under domestication and during rapid geographical changes4 ,illustration3 ,,fig4 #bhb4--;,,embryo ,,of ,a ,,turtle1 showing four gill slits4 7,challenger ,report47 ,table for ,review 7for notebooks or blackboards74 ,,fish ,,tadpole ,,frog ,,turtle ,,lizard ---------------------------------------- ------------------------ ,limbs1 kind and number ---------------------------------------- ------------------------ ,are claws present8 ,how many8 ---------------------------------------- ------------------------ ,covering of body ---------------------------------------- ------------------------ ,teeth1 kind of1 if present ---------------------------------------- ------------------------ ,which bones found in man are lacking8 ---------------------------------------- ------------------------ ,chambers of heart ---------------------------------------- ------------------------ ,respiration ---------------------------------------- ------------------------ ,movements ,illustration3 ,,fig4 #bhc4--;,,big-,,headed ,,turtle 7,platysternum megalocephalum74 4 ,china4 ,this and ,fig4 #bhb suggest descent of turtles from a lizardlike form4 ,figure #bhb shows earlier ancestors to have been gill breathers4 ,,chapter ,,xiii ,,birds ,illustration ,,suggestions4--,the domestic pigeon1 the fowl1 and the ,english sparrow are most commonly within the reach of students4 ,the last bird has become a pest and is almost the only bird whose destruction is desirable4 ,the female is somewhat uniformly mottled with gray and brown in fine markings4 ,the male has a black throat with the other markings of black1 brown1 and white1 in stronger contrast than the marking of the female4 ,as the different species of birds are essentially alike in structural features1 the directions and questions may be used with any bird at hand4 ,when studying feathers1 one or more should be provided for each pupil in the class4 ,the feet and bills of birds should be kept for study4 ,does the body of the bird1 like the toad and turtle1 have a head1 trunk1 tail1 and two pairs of limbs8 ,do the fore and hind limbs differ from each other more or less than the limbs of other backboned animals8 ,does any other vertebrate use them for purposes as widely different8 ,eye4--,does the eyeball have parts corresponding to the eyeball of a fish or frog2 viz41 cornea1 iris1 pupil8 ,which is more movable1 the upper or lower eyelid8 ,are there any lashes8 ,the bird 7like what other animal87 has a third eyelid1 or nictitating membrane4 ,compare its thickness with that of the other lids4 ,is it drawn over the eyeball from the inner or outer corner of the eye8 ,can you see in the human eye any wrinkle or growth which might be regarded as remains1 or vestige1 of such a membrane8 ,how many nostrils8 ,in which mandible are they located8 ,are they nearer the tip or the base of the mandible8 7,fig4 #bhd47 ,what is their shape8 ,do the nasal passages go directly down through the mandible or do they go backward8 ,is the inner nasal opening into the mouth or into the throat8 ,the beak or bill consists of the upper and lower mandibles4 ,the outside of the beak seems to be of what kind of material8 ,examine the decapitated head of a fowl or of a dissected bird1 and find if there is a covering on the bill which can be cut or scraped off4 ,is the mass of the bill of bony or horny material8 ,with what part of the human head are the mandibles homologous8 7,fig4 #bhd47 ,illustration3 ,,fig4 #bhd4--,,skull ,,of ,,domestic ,,fowl4 q1 quadrate 78four-sided07 bone by which lower jaw is attached to skull 7wanting in beasts1 present in reptiles2 see ,fig4 #bgg74 ,ears4--,do birds have external ears8 ,is there an external opening leading to the ear8 ,in searching for it1 blow or push forward the feathers4 ,if found1 notice its location1 size1 shape1 and what surrounds the opening4 ,there is an owl spoken of as the long-eared owl4 ,are its ears long8 ,the leg has three divisions3 the uppermost is the thigh 7called the 8second joint0 in a fowl72 the middle division is the shank 7or 8drumstick072 and the lowest1 which is the slender bone covered with scales1 is formed by the union of the ankle and instep4 7,the bones of the three divisions are named the femur1 tibiotarsus1 and tarsometatarsus74 ,the foot consists entirely of toes1 the bones of which are called phalanges4 ,is there a bone in each claw8 7,see ,fig4 #bhe47 ,supply the numerals in this sentence3 ,the pigeon has toes1 the hind toe having joints2 of the three front toes1 the inner has joints 7count the claw as one joint71 the middle has joints1 and the outer toe has joints 7,fig4 #bhe74 ,is the thigh of a bird bare or feathered8 ,the shin8 ,the ankle8 ,where is the ankle joint of a bird8 ,do you see the remains of another bone 7the splint bone1 or fibula7 on the shin bone of the shank8 7,fig4 #bhe or #bhf47 ,why would several joints in the ankle be a disadvantage to a bird8 ,illustration3 ,,fig4 #bhe4--,,leg ,,bones ,,of ,,bird4 ,illustration3 ,,fig4 #bhf4--,,skeleton ,,of ,,bird4 ,rh1 vertebr2 ,cl1 clavicle2 ,co1 coracoid2 ,sc1 scapula2 ,st1 sternum2 ,h1 humerus2 ,r1 radius2 ,u1 ulna2 ,p1 thumb2 ,fe1 femur2 ,t1 tibia4 ,see ,fig4 #cid4 ,questions3 ,which is the stiffest portion of the vertebral column8 ,how are the ribs braced against each other8 ,which is longer1 thigh bone or shin8 ,compare shoulder blade with man's 7,fig4 #cii74 ,which is the extra shoulder bone8 ,compare tail vertebr with those of extinct bird1 ,fig4 #bij4 ,the thigh hardly projects beyond the skin of the trunk1 as may be noticed in a plucked fowl4 ,the thigh extends forward from the hip joint 7,figs4 #bhf1 #bii7 in order to bring the point of support forward under the center of weight4 ,why are long front toes more necessary than long hind toes8 ,as the bird must often bring its head to the ground1 the hip joints are near the dorsal surface and the body swings between the two points of support somewhat like a silver ice pitcher on its two pivots4 ,hence stooping1 which makes a man so unsteady1 does not cause a bird to lose steadiness4 ,the wing has three divisions which correspond to the upper arm1 forearm1 and hand of man 7,fig4 #bhf74 ,when the wing is folded1 the three divisions lie close alongside each other4 ,fold your arm in the same manner4 ,the similarity of the bones of the first and second divisions to the bones of our upper arm and forearm is very obvious 7,fig4 #bhf74 ,explain4 ,the hand of a bird is furnished with only three digits 7,fig4 #bhg74 ,the three palm bones 7metacarpals7 are firmly united 7,fig4 #bhg74 ,this gives firmness to the stroke in flying4 ,illustration3 ,,fig4 #bhg4--;,,hand ,,and ,,wrist ,,of ,,fowl 7after ,parker74 ,,dg4 #a-c1 digits2 ,,mc4 #a-c1 metacarpals2 ,,cc4 #c1 wrist4 ,illustration3 ,,fig4 #bhh4--;,,hand1 ,,wrist 7c71 ,,forearm1 ,,and ,,elbow ,,of ,,young ,,chick 7after ,parker74 ,that the bird is descended from animals which had the fingers and palm bones less firmly united is shown by comparing the hands of a chick and of an adult fowl 7,figs4 #bhg1 #bhh74 ,the wrist also solidifies with age1 the five carpals of the chick being reduced to two in the fowl 7,figs4 #bhg1 #bhh74 ,the thumb or first digit has a separate covering of skin from the other digits1 as may be seen in a plucked bird4 ,the degenerate hand of the fowl is of course useless as a hand 7what serves in its place87 but is well fitted for firm support of the feathers in flying4 ,the two bones of the forearm are also firmly joined4 ,there are eighteen movable joints in our arm and hand2 the bird has only the three joints which enable it to fold its wing4 ,the wrist joint is the joint in the forward angle of the wing4 ,illustration3 ,,fig4 #bhi4--;,,breastbone ,,and ,,shoulder ,,bones ,,of ,,cassowary4 ,illustration3 ,,fig4 #bij4--;,a ,,fossil ,,bird 7archopteryx7 found in the rocks of a former geological epoch4 ,question3 ,find two resemblances to reptiles in this extinct bird absent from skeletons of extant birds4 ,since the fore limbs are taken up with locomotion1 the grasping function has been assumed by the jaws4 ,how does their shape adapt them to this use8 ,for the same reason the neck of a bird surpasses the necks of all other animals in what respect8 ,is the trunk of a bird flexible or inflexible8 ,there is thus a correlation between structure of neck and trunk4 ,explain4 ,the same correlation is found in which of the reptiles8 7,why does rigidity of trunk require flexibility of neck87 ,why does the length of neck in birds correlate with the length of legs8 ,examples8 7,see ,figs4 #cad1 #cae1 #ccb47 ,exceptions8 7,fig4 #cbd47 ,why does a swan or a goose have a long neck1 though its legs are short8 ,to make a firm support for the wings the vertebr of the back are immovably joined1 also there are three bones in each shoulder1 the collar bone1 the shoulder blade1 and the coracoid bone 7,fig4 #bhf74 ,the collar bones are united 7why87 and form the 8wishbone0 or 8pulling bone40 ,to furnish surface for the attachment of the large flying muscles there is a prominent ridge or keel on the breastbone 7,fig4 #bhf74 ,it is lacking in most birds which do not fly 7,fig4 #bhi74 ,illustration3 ,,fig4 #bia4--,,quill ,,feather4 ,d1 downy portion4 ,the feathers are perhaps the most characteristic feature of birds4 ,the large feathers of the wings and tail are called quill feathers4 ,a quill feather 7,fig4 #bia7 is seen to consist of two parts1 the shaft1 or supporting axis1 and the broad vane or web4 ,what part of the shaft is round8 ,hollow8 ,solid8 ,is the shaft straight8 ,are the sides of the vane usually equal in width8 ,can you tell by looking at a quill whether it belongs to the wing or tail1 and which wing or which side of the tail it comes from8 ,do the quills overlap with the wide side of the vane above or beneath the next feather8 ,can you cause two parts of the vane to unite again by pressing together the two sides of a split in the vane8 ,does the web separate at the same place when pulled until it splits again8 ,illustration3 ,,fig4 #bib4--;,i1 ,,contour ,,feather4 ,,ii1 ,,iii1 ,,parts ,,of ,,quill ,,feather1 enlarged4 ,the hollow part of the shaft of a quill feather is called the quill4 ,the part of the shaft bearing the vane is called the rachis 7r-kis74 ,the vane consists of slender barbs which are branches of the shaft 7,,ii1 ,fig4 #bib74 ,as the name indicates 7see dictionary71 a barb resembles a hair4 ,the barbs in turn bear secondary branches called barbules1 and these again have shorter branches called barbicels 7,,iii1 ,fig4 #bib74 ,these are sometimes bent in the form of hooklets 7,fig4 #bib1 ,,iii71 and the hooklets of neighboring barbules interlock1 giving firmness to the vane4 ,when two barbules are split apart1 and then reunited by stroking the vane between the thumb and finger1 the union may be so strong that a pull upon the vane will cause it to split in a new place next time4 ,illustration3 ,,fig4 #bic4--;,a ,,down ,,feather1 enlarged4 ,there are four kinds of feathers1 7#a7 the quill feathers1 just studied2 7#b7 the contour feathers 7,i1 ,fig4 #bib71 which form the general surface of the body and give it its outlines2 7#c7 the downy feathers 7,fig4 #bic71 abundant on nestlings and found among the contour feathers of the adult but not showing on the surface2 7#d7 the pin feathers1 which are hair-like1 and which are removed from a plucked bird by singeing4 ,the contour feathers are similar in structure to the quill feathers4 ,they protect the body from blows1 overlap so as to shed the rain1 and1 with the aid of the downy feathers retain the heat1 thus accounting for the high temperature of the bird4 ,the downy feathers are soft and fluffy1 as they possess few or no barbicels2 sometimes they lack the rachis 7,fig4 #bic74 ,the pin feathers are delicate horny shafts1 greatly resembling hairs1 but they may have a tuft of barbs at the ends4 ,a feather grows from a small projection 7or papilla7 found at the bottom of a depression of the skin4 ,the quill is formed by being molded around the papilla4 ,do you see any opening at the tip of the quill for blood vessels to enter and nourish the feather8 ,what is in the quill8 7,fig4 #bia47 ,the rachis8 ,a young contour or quill feather is inclosed in a delicate sheath which is cast off when the feather has been formed4 ,have you seen the sheath incasing a young feather in a molting bird8 ,there are considerable areas or tracts on a bird's skin without contour feathers4 ,such bare tracts are found along the ridge of the breast and on the sides of the neck4 ,however1 the contour feathers lie so as to overlap and cover the whole body perfectly 7,fig4 #bid74 ,illustration3 ,,fig4 #bid4--;,,dorsal ,,and ,,ventral ,,view ,,of ,,plucked ,,bird1 showing regions where feathers grow4 ,the shedding of the feathers is called molting4 ,feathers1 like the leaves of trees1 are delicate structures and lose perfect condition with age4 ,hence the annual renewal of the feathers is an advantage4 ,most birds shed twice a year1 and with many the summer plumage is brighter colored than the winter plumage4 ,when a feather is shed on one side1 the corresponding feather on the other side is always shed with it4 7,what need for this87 ,a large oil gland is easily found on the dorsal side of the tail4 ,how does the bird apply the oil to the feathers8 ,illustration3 ,,fig4 #bie4--,,wing ,,of ,,bird4 #a1 false quills 7on thumb72 #b1 primaries2 #c1 secondaries2 tertiaries 7dark7 are one above another at right2 a1 b1 coverts4 ,illustration3 ,,fig4 #bif4 ,a1 point dividing primaries from secondaries2 ,b1 coverts4 ,illustration3 ,,fig4 #big4--;,,cedar ,,waxwing1 with regions of body marked4 ,s1 forehead2 ,sc1 crown 7with crest72 ,hh1 nape2 ,k1 throat2 ,br1 breast2 ,ba1 lower parts2 ,r1 back2 ,rt1 tail2 ,b1 tail coverts2 ,p1 shoulder feathers 7scapulars72 ,t1 wing coverts2 ,,hs1 primaries2 ,,as1 secondaries2 ,al1 thumb feathers4 ,in describing and classifying birds1 it is necessary to know the names of the various external regions of the body and plumage4 ,these may be learned by studying ,figs4 #bie1 #bif1 #big1 #bih4 ,the quills on the hand are called primaries1 those on the forearm are the secondaries1 those on the upper arm are the tertiaries4 ,those on the tail are called the tail quills4 ,the feathers at the base of the quills are called the coverts4 ,the thumb bears one or more quills called the spurious quills4 ,is the wing concave on the lower or upper side8 ,what advantage is this when the bird is at rest8 ,when it is flying8 ,illustration3 ,,fig4 #bih4--,,plan ,,of ,,bird4 s1 center of gravity4 ,illustration3 ,,fig4 #bii4--,,position ,,of ,,limbs ,,of ,,pigeon4 ,control of ,flight4--,did you ever see a bird sitting on a swinging limb8 ,what was its chief means of balancing itself8 ,when flying1 what does a bird do to direct its course upward8 ,downward8 ,is the body level when it turns to either side8 ,birds with long1 pointed wings excel in what respect8 ,examples8 ,birds with great wing surface excel in what kind of flight8 ,examples4 ,name a common bird with short wings which has a labored1 whirring flight4 ,is its tail large or small8 ,does it avoid obstacles and direct its flight well8 ,why or why not8 ,when a boat is to be turned to the right1 must the rudder be pulled to the right or the left8 7,the rudder drags in the water and thus pulls the boat around47 ,when the bird wishes to go upward1 must its tail be turned up or down8 ,how when it wishes to go down8 ,when a buzzard soars for an hour without flapping its wings1 does it move at a uniform rate8 ,for what does it use the momentum gained when going with the wind8 ,illustration3 ,,fig4 #cjj4 a1 clambering foot of chimney sweep2 b1 climbing foot of woodpecker2 c1 perching foot of thrush2 d1 seizing foot of hawk2 e1 scratching foot of pheasant2 f1 stalking foot of kingfisher2 g1 running foot of ostrich2 h1 wading foot of heron2 i1 paddling foot of gull2 k1 swimming foot of duck2 l1 steering foot of cormorant2 m1 diving foot of grebe2 n1 skimming foot of coot4 ,question3 ,does any bird use its foot as a hand8 7,fig4 #cbj47 ,flying4--,when studying the quill feathers of the wing1 you saw that the wider side of the vane is beneath the feather next behind it4 ,during the downward stroke of the wing this side of the vane is pressed by the air against the feather above it and the air cannot pass through the wing4 ,as the wing is raised the vanes separate and the air passes through4 ,the convex upper surface of the wing also prevents the wing from catching air as it is raised4 ,spread a wing and blow strongly against its lower surface2 its upper surface4 ,what effects are noticed8 ,study the scales on the leg of a bird 7,fig4 #cjj74 ,why is the leg scaly rather than feathered from the ankle downward8 ,which scales are largest8 7,fig4 #cjj47 ,how do the scales on the front and back differ8 ,what can you say of the scales at the bottom of the foot2 at the joints of the toes8 ,explain4 ,how does the covering of the nails and bill compare in color1 texture1 hardness and firmness of attachment with the scales of the leg8 ,illustration3 ,,fig4 #cja4--;,,an ,,altrical ,,bird1 i4e4 poorly developed at hatching4 ,young pigeon1 naked1 beak too weak for eating4 ,illustration3 ,,fig4 #cjb4--;,a ,,precocial ,,bird 7well developed at hatching74 ,feathered1 able to run and to pick up food4 ,precocity is a sign of instinctive life and low intelligence4 ,a baby is not precocious4 ,question3 ,is pigeon or fowl exposed to more dangers in infancy8 ,draw an outline of the bird seen from the side4 ,make drawings of the head and feet more detailed and on a larger scale4 ,why does a goose have more feathers suitable for making pillows than a fowl8 ,in what country did the domestic fowl originate8 7,encyclopedia47 ,why does a cock crow for day8 7,consider animal life in jungle47 ,activities of a ,bird4--,observe a bird eating4 ,does it seem to chew or break its food before swallowing8 ,does it have to lift its head in order to swallow food8 ,to swallow drink8 ,why is there a difference8 ,after feeding the bird1 can you feel the food in the crop1 or enlargement of the gullet at the base of the neck8 7,fig4 #cjd47 ,feel and look for any movements in breathing4 ,can you find how often it breathes per minute8 ,place hand under the bird's wing4 ,what do you think of its temperature2 or better1 what temperature is shown by a thermometer held under its wing8 ,do you see any connection between the breathing rate and the temperature8 ,test 7as with the crayfish7 whether a bird can see behind its head8 ,notice the movements of the nictitating membrane4 ,does it appear to be transparent8 ,watch a bird fly around a closed room and review the questions on ,control of ,flight4 ,bend a bird's leg and see if it has any effect upon its toes4 ,notice a bird 7especially a large fowl7 walk to see if it bends its toes as the foot is lifted4 ,pull the rear tendon in a foot cut from a fowl for the kitchen4 ,does the bird have to use muscular exertion to grasp a stick upon which it sits8 ,why1 or why not8 ,when is this bending of the toes by bending the legs of special advantage to a hawk8 ,to a duck8 ,a wading bird8 ,why is a fowl safe from a hawk if it stands close to a tree8 ,illustration3 ,,fig4 #cjc4--;,,head ,,of ,,woodpecker4 c1 tongue2 a1 b1 d1 hyoid bone2 e1 q1 windpipe2 f1 salivary gland4 ,do you see any signs of teeth in the bird's jaws8 ,why are duck's 8teeth0 7so called by children7 not teeth8 ,can the tongue of a bird be pulled forward8 7,fig4 #cjc47 ,what is its shape8 ,if there is opportunity1 dissect and study the slender1 bony 7hyoid7 apparatus to which the base of the tongue is attached 7,fig4 #cjc71 the opening of the windpipe1 or trachea1 the slit-like opening of windpipe which is so narrow as to prevent food falling into the windpipe4 ,illustration3 ,,fig4 #cjd4--;,,anatomy ,,of ,,dove 4 bk1 keel of breastbone2 ,g1 g1 brain2 lr1 windpipe2 lu1 lung2 h1 heart2 sr1 gullet2 k1 crop2 dr1 glandular stomach2 mm1 gizzard2 d1 intestine2 n1 kidney2 hl1 ureter2 eil1 openings of ureter and egg duct into cloaca1 kl4 ,illustration3 ,,fig4 #cje4--;,,food ,,tube ,,of ,,bird4 ,p1 pancreas2 ,c1 cca4 ,question3 ,identify each part by means of ,fig4 #cjd4 ,the ,internal ,organs1 or ,viscera 7,figs4 #cjd and #cje74--,the viscera 7visse-ra71 as in most vertebrates1 include the food tube and its glands2 the lungs1 the heart1 and larger blood vessels2 the kidneys and bladder and the reproductive organs4 ,the lower part1 or gullet1 is enlarged into a crop4 ,it is largest in grain-eating birds4 ,it is found in the ,v-shaped depression at the angle of the wishbone1 just before the food tube enters the thorax4 ,the food is stored and softened in the crop4 ,from the crop the food passes at intervals into the glandular stomach4 ,close to this is the muscular stomach1 or gizzard4 ,are the places of entrance and exit on opposite sides of the gizzard1 or near together8 7,fig4 #cjd47 ,is the lining of the gizzard rough or smooth8 ,why8 ,is the gizzard tough or weak8 ,why are small stones in the gizzard8 ,why do not hawks and other birds of prey need a muscular gizzard8 ,the liver and pancreas empty their secretions into the intestines by several ducts a little way beyond the gizzard4 ,beyond the mouths of two cca 7,fig4 #cje7 the many-coiled intestine empties into the straight rectum1 which terminates in a widened part called the cloaca4 ,not only the intestine1 but the two ureters of the urinary system and the two genital ducts of the reproductive system all empty into the cloaca 7,figs4 #cjd1 #cje74 ,illustration3 ,,fig4 #cjf4--,,position ,,of ,,lungs ,,and ,,air ,,sacs 7,pigeon74 ,tr1 windpipe2 ,p1 lungs2 ,lm1 sac under clavicle with prolongation 7,lh7 into humerus2 ,la1 sacs in abdomen4 ,the lungs have their rear surfaces attached to the spinal column and ribs 7lu1 ,fig4 #cjd74 ,they are connected with thin-walled1 transparent air sacs which aid in purifying the blood4 ,when inflated with warm air1 they probably make the body of the bird more buoyant4 ,for the names1 location1 and shape of several pairs of air sacs1 see ,fig4 #cjf4 ,the connection of the air sacs with hollows in the humerus bones is also shown in the figure4 ,many of the bones are hollow2 this adds to the buoyancy of the bird4 ,the pulmonary artery1 as in man1 takes dark blood to the lungs to exchange its carbon dioxide for oxygen4 ,of two animals of the same weight1 which expends more energy1 the one that flies1 or the one that runs the same distance8 ,does a bird require more oxygen or less1 in proportion to its weight1 than an animal that lives on the ground8 ,are the vocal cords of a bird higher or lower in the windpipe than those of a man8 7,fig4 #cjg47 ,the heart of a bird1 like a man's heart1 has four chambers2 hence it keeps the purified blood separate from the impure blood4 ,since pure blood reaches the organs of a bird1 oxidation is more perfect than in the body of any animals yet studied4 ,birds have higher temperature than any other class of animals whatsoever4 ,tell how the jaws1 tail1 and wings of the fossil bird ,archopteryx differed from living birds 7,fig4 #bij74 ,illustration3 ,,fig4 #cjg4--,,position ,,of ,,vocal ,,cords 7str7 ,,of ,,mammal ,,and ,,bird4 ,question3 ,does a fowl ever croak after its head and part of its neck are cut off8 ,explain4 ,,suggestions4--,in the field work1 besides seeking the answers to definite questions1 pupils may be required to hand in a record of the places and times of seeing a certain number of birds 7#bj to #dj71 with the actions and features which made each distinguishable4 ,also1 and more important1 each pupil should hand in a record of a careful and thorough outdoor study of one common species 7see below7 as regards habits1 nesting1 relation to environment1 etc4 ,field ,study of a ,common ,species4--7,for written report47 ,name of species4 ,haunts4 ,method of locomotion when not flying4 ,flying 7rate1 sailing1 accompanying sound if any1 soaring74 ,what is the food8 ,how obtained8 ,association with birds of its own species4 ,relation to birds of other species4 ,where does it build its nest8 ,why is such a situation selected8 ,of what is the nest built8 ,how is the material carried1 and how built into the nest8 ,does the bird's body fill the nest8 ,describe the eggs4 ,does the male bird ever sit or otherwise assist female before hatching8 ,does it assist after hatching8 ,how long is taken to lay a sitting of eggs8 ,how long before the birds are hatched8 ,when hatched are they helpless8 ,blind8 ,feathered8 7,figs4 #cja1 #cjb47 ,do the nestlings require much food8 ,how many times is food brought in an hour8 ,how distributed8 ,even if the old birds sometimes eat fruit do they take fruit to the young8 ,what do they feed to the young8 ,how long before they leave the nest8 ,do the parents try to teach them to fly8 ,do the parents care for them after the nest is left8 ,what songs or calls has the bird8 ,illustration3 ,,fig4 #cjh4--;,,european ,,tomtit',s ,,nest4 ,what are the advantages of its shape8 ,illustration3 ,,fig4 #cji4--,,tailor ,,bird',s ,,nest 7,india74 ,instinct for nest building highly perfected4 ,general ,field ,study4--7,for written report47 ,name the best and poorest flyers you know2 birds that fly most of the time2 birds that seldom fly4 ,observe birds that pair2 live in flocks4 ,does their sociability vary with the season8 ,do you ever see birds quarreling8 ,fighting8 ,what birds do you observe whipping or driving birds larger than themselves8 ,which parent do young birds most resemble8 ,name the purposes for which birds sing4 ,which senses are very acute8 ,why8 ,dull8 ,why8 ,can you test your statements by experiment8 ,a partridge usually sits with #ah to #bd eggs in nest4 ,about how long after laying first egg before sitting begins8 ,do several partridge hens lay in the same nest8 ,illustration3 ,,fig4 #caj4--;,,house ,,wren4 ,haunts4--,name some birds that are found most often in the following localities3 about our homes1 in gardens and orchards1 fields and meadows1 in bushes1 in the woods1 in secluded woods1 around streams of water1 in thickets1 in pine woods4 ,size4--,name birds as large as a robin or larger1 nearly as large1 half as large1 much smaller4 ,colors4--,which sex is more brilliant8 ,what advantage are bright colors to one sex8 ,what advantage are dull colors to the other sex8 ,which have yellow breasts1 red patch on heads1 red or chestnut breasts1 blue backs1 black all over8 ,habits4--,name the birds that walk1 jump1 swim1 live in flocks1 sing while flying1 fly in undulations1 in circles1 have labored flight4 ,such books as ,wright's 8,birdcraft0 7,macmillan1 ,n4 ,y471 ,clark's 8,birds of ,lakeside and ,prairie0 7,mumford1 ,chicago71 and ,pearson's 8,stories of ,bird ,life0 7,b4 ,f4 ,johnson1 ,richmond71 will be of great help4 ,the last book is delightfully written1 and is one of the few treating of bird life in the ,south4 ,economic ,importance of ,birds4--,farmers find their most valuable allies in the class aves1 as birds are the deadliest enemies of insects and gnawing animals4 ,to the innumerable robbers which devastate our fields and gardens1 nature opposes the army of birds4 ,they are less numerous than insects and other robbers1 it is true1 but they are skillful and zealous in pursuit1 keen of eye1 quick1 active1 and remarkably voracious4 ,the purely insectivorous birds are the most useful1 but the omnivorous and graminivorous birds do not disdain insects4 ,the perchers and the woodpeckers should be protected most carefully4 ,the night birds of prey 7and those of the day to a less degree7 are very destructive to field mice1 rabbits1 and other gnawing animals4 ,some ignorant farmers complain continually about the harm done by birds4 ,to destroy them is as unwise as it would be to destroy the skin which protects the human body because it has a spot upon it6 ,it cannot be repeated too plainly that to hunt useful birds is a wrong and mischievous act1 and it is stupid and barbarous to destroy their nests4 ,illustration3 ,,fig4 #caa4--,,screech ,,owl 7,megascops asio74 ,question3 ,compare posture of body1 position of eyes1 and size of eyes1 with other birds4 ,illustration3 ,,fig4 #cab4--;,,goshawk1 or chicken hawk4 ,injurious birds are few4 ,of course birds which are the enemies of other birds are enemies of mankind1 but examples are scarce 7some owls and hawks74 ,many birds of prey are classed thus by mistake4 ,sparrow hawks1 for instance1 do not eat birds except in rare instances2 they feed chiefly upon insects4 ,a sparrow hawk often keeps watch over a field where grasshoppers are plentiful and destroys great numbers of them4 ,when a bird is killed because it is supposed to be injurious1 the crop should always be examined1 and its contents will often surprise those who are sure it is a harmful bird4 ,the writer once found two frogs1 three grasshoppers1 and five beetles that had been swallowed by a 8chicken hawk0 killed by an irate farmer1 but no sign of birds having been used for food4 ,fowls should not be raised in open places1 but among trees and bushes1 where hawks cannot swoop4 ,birds which live exclusively upon fish are1 of course1 opposed to human interests4 ,pigeons are destructive to grain2 eagles feed chiefly upon other birds4 ,illustration3 ,,fig4 #cac4--,,road ,,runner1 or chaparral bird 7,tex4 to ,cal474 ,what order8 7,key1 p4 #agg47 ,if the birds eat the grapes1 do not kill the birds1 but plant more grapes4 ,people with two or three fruit trees or a small garden are the only ones that lose a noticeable amount of food4 ,we cut down the forests from which the birds obtain part of their food4 ,we destroy insect pests at great cost of spraying1 etc4 ,the commission the birds charge for such work is very small indeed4 7,see pages #agg-ahc47 ,illustration3 ,,fig4 #cad4--,,wood ,,duck1 male 7,aix sponsa74 ,nests in hollow trees throughout ,north ,america4 ,also called summer duck in ,south4 ,why8 ,the ,english sparrow is one bird of which no good word may be said4 ,among birds1 it holds the place held by rats among beasts4 ,it is crafty1 quarrelsome1 thieving1 and a nuisance4 ,it was imported in #aheb to eat moths4 ,the results show how ignorant we are of animal life1 and how slow we should be to tamper with the arrangements of nature4 ,in ,southern cities it produces five or six broods each year with four to six young in each brood4 7,notice what it feeds its young47 ,it fights1 competes with and drives away our native useful birds4 ,it also eats grain and preys upon gardens4 ,they have multiplied more in ,australia and the ,united ,states than in ,europe1 because they left behind them their native enemies and their new enemies 7crows1 jays1 shrikes1 etc47 have not yet developed1 to a sufficient extent1 the habit of preying upon them4 ,nature will1 perhaps1 after a long time1 restore the equilibrium destroyed by presumptuous man4 ,protection of ,birds4--#a4 ,leave as many trees and bushes standing as possible4 ,plant trees1 encourage bushes4 #b4 ,do not keep a cat4 ,a mouse trap is more useful than a cat4 ,a tax should be imposed upon owners of cats4 #c4 ,make a bird house and place on a pole2 remove bark from pole that cats may not climb it1 or put a broad band of tin around the pole4 #d4 ,scatter food in winter4 ,in dry regions and in hot weather keep a shallow tin vessel containing water on the roof of an outhouse1 or out-of-the-way place for shy birds4 #e4 ,do not wear feathers obtained by the killing of birds4 ,what feathers are not so obtained8 #f4 ,report all violators of laws for protection of birds4 #g4 ,destroy ,english sparrows4 ,illustration3 ,,fig4 #cae4--;,,great ,,blue ,,heron4 ,in flight1 balancing with legs4 ,migration4--,many birds1 in fact most birds1 migrate to warmer climates to spend the winter4 ,naturalists were once content to speak of the migration of birds as a wonderful instinct1 and made no attempt to explain it4 ,as birds have the warmest covering of all animals1 the winter migration is not for the purpose of escaping the cold2 it is probably to escape starvation1 because in cold countries food is largely hidden by snow in winter4 ,on the other hand1 if the birds remained in the warm countries in summer1 the food found in northern countries in summer would be unused1 while they would have to compete with the numerous tropical birds for food1 and they and their eggs would be in danger from snakes1 wild cats1 and other beasts of prey so numerous in warm climates4 ,these are the best reasons so far given for migration4 ,illustration3 ,,fig4 #caf4--;,,european ,,swallows 7,hirundo urbica71 assembling for autumn flight to ,south4 ,the manner and methods of migration have been studied more carefully in ,europe than in ,america4 ,migration is not a blind1 infallible instinct1 but the route is learned and taught by the old birds to the young ones2 they go in flocks to keep from losing the way 7,fig4 #caf72 the oldest and strongest birds guide the flocks 7,fig4 #cag74 ,the birds which lose their way are young ones of the last brood1 or mothers that turn aside to look for their strayed young4 ,the adult males seldom lose their way unless scattered by a storm4 ,birds are sometimes caught in storms or join flocks of another species and arrive in countries unsuited for them1 and perish4 ,for example1 a sea or marsh bird would die of hunger on arriving in a very dry country4 ,illustration3 ,,fig4 #cag4--;,,cranes ,,migrating1 with leader at point of ,v-shaped line4 ,the landmarks of the route are mountains1 rivers1 valleys1 and coast lines4 ,this knowledge is handed down from one generation to another4 ,it includes the location of certain places on the route where food is plentiful and the birds can rest in security4 ,siebohm and others have studied the routes of migration in the ,old ,world4 ,the route from the nesting places in northern ,europe to ,africa follows the ,rhine1 the ,lake of ,geneva1 the ,rhone1 whence some species follow the ,italian and others the ,spanish coast line to ,africa4 ,birds choose the lowest mountain passes4 ,the ,old ,world martin travels every year from the ,north ,cape to the ,cape of ,good ,hope and back again6 ,another route has been traced from ,egypt along the coast of ,asia ,minor1 the ,black ,sea and ,ural ,mts4 to ,siberia4 ,field ,study of ,migration4--,three columns may be filled on the blackboard in an unused corner1 taking several months in spring or fall for the work4 ,first column1 birds that stay all the year4 ,second column1 birds that come from the south and are seen in the summer only4 ,third column1 birds that come from the north and are seen in winter only4 ,exact dates of arrival and departure and flight overhead should be recorded in notebooks4 ,many such records will enable ,american zoologists to trace the migration routes of our birds4 ,reports may be sent to the chief of the ,biological ,survey1 ,washington1 ,d4,c4 ,illustration3 ,,fig4 #cah4--;,,apteryx1 of ,new ,zealand4 ,size of a hen1 wings and tail rudimentary1 feathers hair-like4 ,molting4--,how do birds arrange their feathers after they have been ruffled8 ,do they ever bathe in water8 ,in dust8 ,dust helps to remove old oil4 ,at what season are birds brightest feathered8 ,why8 ,have you ever seen evidence of the molting of birds8 ,describe the molting process 7page #abj74 ,illustration3 ,,fig4 #cai4--;,,golden1 ,,silver1 ,,and ,,noble ,,pheasants1 males4 ,order8 7,key1 p4 #agg47 ,ornaments of males1 brightest in season of courtship1 are due to sexual selection 7,figs4 #cba-g-i1 #ccc74 ,illustration3 ,,fig4 #cbj4--;,,cockatoo4 ,illustration3 ,,fig4 #cba4--;,,bird ,,of ,,paradise 7,asia74 ,adaptations for ,flying4--,flight is the most difficult and energy-consuming method of moving found among animals1 and careful adjustment is necessary4 ,for balancing1 the heaviest muscles are placed at the lower and central portion of the body4 ,these are the flying muscles1 and in some birds 7humming birds7 they make half of the entire weight4 ,teeth are the densest of animal structures2 teeth and the strong chewing muscles required would make the head heavy and balancing difficult2 hence the chewing apparatus is transferred to the heavy gizzard near the center of gravity of the body4 ,the bird's neck is long and excels all other necks in flexibility1 but it is very slender 7although apparently heavy71 being inclosed in a loose1 feathered skin4 ,a cone is the best shape to enable the body to penetrate the air1 and a small neck would destroy the conical form4 ,the internal organs are compactly arranged and rest in the cavity of the breast bone4 ,the bellows-like air sacs filled with warm air lighten the bird's weight4 ,the bones are hollow and very thin4 ,the large tail quills are used by the bird only in guiding its flight up and down1 or balancing on a limb4 ,the feet also aid a flying bird in balancing4 ,the wing is so constructed as to present to the air a remarkably large surface compared with the small bony support in the wing skeleton4 ,are tubes ever resorted to by human architects when lightness combined with strength is desired8 ,which quills in the wing serve to lengthen it8 7,fig4 #bif47 ,to broaden it8 ,is flight more difficult for a bird or a butterfly8 ,which of them do the flying machines more closely resemble8 ,can any bird fly for a long time without flapping its wings8 ,illustration3 ,,fig4 #cbb4--;,,herring ,,gull4 7,order87 ,exercise in the ,use of the ,key4--,copy this list and write the name of the order to which each of the birds belongs4 7,key1 page #agg47 ,cockatoo 7,fig4 #cbj7 ,sacred ,ibis 7,fig4 #cbh7 ,screech ,owl 7,fig4 #caa7 ,nightingale 7,fig4 #cbe7 ,top-knot ,quail 7,fig4 #cbi7 ,wren 7,fig4 #caj7 ,apteryx 7,fig4 #cah7 ,lyre bird 7,fig4 #cbg7 ,road ,runner 7,fig4 #cac7 ,ostrich 7,fig4 #ccb7 ,penguin 7,fig4 #ccj7 ,pheasant 7,fig4 #cai7 ,wood ,duck 7,fig4 #cad7 ,jacana 7,fig4 #cbd7 ,sea ,gull 7,fig4 #cbb7 ,heron 7,fig4 #cae7 ,hawk 7,fig4 #cab7 ,,key1 ,,or ,,table1 ,,for ,,classifying ,,birds 7,class ,aves7 ,,into ,,orders ,,orders ,a ,wings not suited for flight1 #b or #c toes ,,runners ,a ,wings suited for flight 7except the penguin7 ,b ,toes united by a web for swimming1 legs short ,c ,feet placed far back2 wings short1 tip not ,,divers reaching to base of tail 7,fig4 #cjj7 ,c ,bill flattened1 horny plates under margin of ,,bill-,,strainers upper bill 7,fig4 #cbc7 ,c ,wings long and pointed1 bill slender ,,sea-,,fliers ,c ,all four toes webbed1 bare sac under throat ,,gorgers ,b ,toes not united by web for swimming ,c ,three front toes1 neck and legs long1 tibia ,,waders 7shin1 or 8drumstick07 partly bare ,c ,three front toes1 neck and legs not long ,d ,claws short and blunt 7e1 ,fig4 #cjj7 ,e ,feet and beak stout1 young feathered1 ,,scratchers base of hind toe elevated ,e ,feet and beak weak1 young naked ,,messengers ,d ,claws long1 curved and sharp1 bill hooked ,,robbers and sharp ,d ,claws long1 slightly curved1 bill nearly ,,perchers straight ,c ,two front and two hind toes 7,fig4 #cjj7 ,d ,bill straight1 feet used for climbing ,,foot-,,climbers ,d ,bill hooked1 both bill and feet used for ,,bill-,,climbers climbing ,the ,food of ,birds4--,extracts from ,bulletin ,no4 #ed 7,united ,states ,dept4 of ,agriculture71 by ,f4 ,e4 ,l4 ,beal4 ,the practical value of birds in controlling insect pests should be more generally recognized4 ,it may be an easy matter to exterminate the birds in an orchard or grain field1 but it is an extremely difficult one to control the insect pests4 ,it is certain1 too1 that the value of our native sparrows as weed destroyers is not appreciated4 ,weed seed forms an important item of the winter food of many of these birds1 and it is impossible to estimate the immense numbers of noxious weeds which are thus annually destroyed4 ,if crows or blackbirds are seen in numbers about cornfields1 or if woodpeckers are noticed at work in an orchard1 it is perhaps not surprising that they are accused of doing harm4 ,careful investigation1 however1 often shows that they are actually destroying noxious insects2 and also that even those which do harm at one season may compensate for it by eating insect pests at another4 ,insects are eaten at all times by the majority of land birds4 ,during the breeding season most kinds subsist largely on this food1 and rear their young exclusively upon it4 ,illustration3 ,,fig4 #cbc4--;,,head ,,of ,,duck4 ,illustration3 ,,fig4 #cbd4--;,,jacana4 7,mexico1 ,southwest ,texas1 and ,florida47 ,questions3 ,what appears to be the use of such long toes8 ,what peculiarity of wing8 head8 ,partridges4--,speaking of #ac birds which he shot1 ,dr4 ,judd says3 ,these #ac had taken weed seed to the extent of #fc per cent of their food4 ,thirty-eight per cent was ragweed1 #b per cent tick trefoil1 partridge pea1 and locust seeds1 and #bc per cent seeds of miscellaneous weeds4 ,about #ad per cent of the quail's food for the year consists of animal matter 7insects and their allies74 ,prominent among these are the ,colorado potato beetle1 the striped squash beetle1 the cottonboll-weevil1 grasshoppers4 ,as a weed destroyer the quail has few1 if any1 superiors4 ,moreover1 its habits are such that it is almost constantly on the ground1 where it is brought in close contact with both weed seeds and ground-living insects4 ,it is a good ranger1 and1 if undisturbed1 will patrol every day all the fields in its vicinity as it searches for food4 ,illustration3 ,,fig4 #cbe4--,,nightingale1 4 ,,fig4 #cbf4--,,skylark1 4 ,two celebrated ,european songsters4 ,doves4--,the food of the dove consists of seeds of weeds1 together with some grain4 ,the examination of the contents of #bcg stomachs shows that over #ii per cent of the food consists wholly of vegetable matter4 ,cuckoos4--,an examination of the stomachs of #df black-billed cuckoos1 taken during the summer months1 showed the remains of #ijf caterpillars1 #dd beetles1 #if grasshoppers1 #ajj sawflies1 #cj stink bugs1 and #ae spiders4 ,of the yellow-billed cuckoos1 or 8rain-crow10 #aji stomachs collected from ,may to ,october1 inclusive1 were examined4 ,the contents consisted of #a1hfe caterpillars1 #ic beetles1 #bdb grasshoppers1 #cg sawflies1 #fi bugs1 #f flies1 and #hf spiders4 ,illustration3 ,,fig4 #cbg4--,,lyre ,,bird1 male4 ,woodpeckers4--,careful observers have noticed that1 excepting a single species1 these birds rarely leave any conspicuous mark on a healthy tree1 except when it is affected by wood-boring larv1 which are accurately located1 dislodged1 and devoured by the woodpecker4 ,of the flickers' or yellow-hammers' stomachs examined1 three were completely filled with ants4 ,two of the birds each contained more than #c1jjj ants1 while the third bird contained fully #e1jjj4 ,these ants belong to species which live in the ground4 ,it is these insects for which the flicker is reaching when it runs about in the grass4 ,the yellow-bellied woodpecker or sapsucker 7,sphyrapicus varius7 was shown to be guilty of pecking holes in the bark of various forest trees1 and sometimes in that of apple trees1 and of drinking the sap when the pits became filled4 ,it has been proved1 however1 that besides taking the sap the bird captures large numbers of insects which are attracted by the sweet fluid1 and that these form a very considerable portion of its diet4 ,the woodpeckers seem the only agents which can successfully cope with certain insect enemies of the forests1 and1 to some extent1 with those of fruit trees also4 ,for this reason1 if for no other1 they should be protected in every possible way4 ,illustration3 ,,fig4 #cbh4--,,sacred ,,ibis4 7,order87 ,the night hawk1 or 8bull bat10 may be seen most often soaring high in air in the afternoon or early evening4 ,it nests upon rocks or bare knolls and flat city roofs4 ,its food consists of insects taken on the wing2 and so greedy is the bird that when food is plentiful1 it fills its stomach almost to bursting4 ,ants 7except workers7 have wings and fly as they are preparing to propagate4 ,in destroying ants night hawks rank next to1 or even with1 the woodpeckers1 the acknowledged ant-eaters among birds4 ,illustration3 ,,fig4 #cbi4--,,top-,,knot ,,quail1 or ,california ,partridge4 7,west ,texas to ,california47 ,the kingbird1 or martin1 is largely insectivorous4 ,in an examination of #fb stomachs of this bird1 great care was taken to identify every insect or fragment that had any resemblance to a honeybee2 as a result1 #cj honeybees were identified1 of which #bi were males or drones and #a was a worker4 ,blue ,jay4--,in an investigation of the food of the blue jay #cjj stomachs were examined1 which showed that animal matter comprised #bd per cent and vegetable matter #gf per cent of the bird's diet4 ,the jay's favorite food is mast 7i4e4 acorns1 chestnuts1 chinquapins1 etc471 which was found in #bjj of the #cjj stomachs1 and amounted to more than #db per cent of the whole food4 ,illustration3 ,,fig4 #ccj4--,,penguin ,,of ,,patagonia4 ,wings used as flippers for swimming4 ,crow4--,that he does pull up sprouting corn1 destroy chickens1 and rob the nests of small birds has been repeatedly proved4 ,nor are these all of his sins4 ,he is known to eat frogs1 toads1 salamanders1 and some small snakes1 all harmless creatures that do some good by eating insects4 ,experience has shown that they may be prevented from pulling up young corn by tarring the seed1 which not only saves the corn but forces them to turn their attention to insects4 ,may beetles1 8dorbugs10 or ,june bugs1 and others of the same family constitute the principal food during spring and early summer1 and are fed to the young in immense quantities4 ,ricebird4--,the annual loss to rice growers on account of bobolinks has been estimated at #b1jjj1jjj4 ,meadow ,lark4--,next to grasshoppers1 beetles make up the most important item of the meadow lark's food1 amounting to nearly #ba per cent4 ,may is the month when the dreaded cut-worm begins its deadly career1 and then the lark does some of its best work4 ,most of these caterpillars are ground feeders1 and are overlooked by birds which habitually frequent trees1 but the meadow lark finds and devours them by thousands4 ,illustration3 ,,fig4 #cca4--,umbrella holding the nests of social weaver bird of ,africa2 polygamous4 ,sparrows4--,examination of many stomachs shows that in winter the tree sparrow feeds entirely upon seeds of weeds4 ,probably each bird consumes about one fourth of an ounce a day4 ,farther south the tree sparrow is replaced in winter by the white-throated sparrow1 the white-crowned sparrow1 the fox sparrow1 the song sparrow1 the field sparrow1 and several others2 so that all over the land a vast number of these seed eaters are at work during the colder months reducing next year's crop of worse than useless plants4 ,robin4--,an examination of #ejj stomachs shows that over #db per cent of its food is animal matter1 principally insects1 while the remainder is made up largely of small fruits or berries4 ,vegetable food forms nearly #eh per cent of the stomach contents1 over #dg per cent being wild fruits1 and only a little more than #d per cent being possibly cultivated varieties4 ,cultivated fruit amounting to about #be per cent was found in the stomachs in ,june and ,july1 but only a trifle in ,august4 ,wild fruit1 on the contrary1 is eaten in every month1 and constitutes during half the year a staple food4 ,questions4--,which of these birds are common in your neighborhood8 ,which of them according to the foregoing report are plainly injurious8 ,clearly beneficial8 ,doubtful8 ,which are great destroyers of weed seeds8 ,wood-borers8 ,ants8 ,grain8 ,why is the destruction of an ant by a night hawk of greater benefit than the destruction of an ant by a woodpecker8 ,name the only woodpecker that injures trees4 ,if a bird eats two ounces of grain and one ounce of insects1 has it probably done more good or more evil8 ,illustration3 ,,fig4 #ccb4--;,,african ,,ostrich1 4 7,order87 ,,chapter ,,xiv ,,mammals 7,,beasts ,,and ,,man7 ,,suggestions4--,a tame rabbit1 a house cat1 or a pet squirrel may be taken to the school and observed by the class4 ,domestic animals may be observed at home and on the street4 ,a study of the teeth will give a key to the life of the animal1 and the teacher should collect a few mammalian skulls as opportunities offer4 ,the pupils should be required to identify them by means of the chart of skulls 7p4 #aid74 ,if some enthusiastic students fond of anatomy should dissect small mammals1 the specimens should be killed with chloroform1 and the directions for dissection usual in laboratory works on this subject may be followed4 ,there is a brief guide on page #bbc4 ,the following outline for the study of a live mammal will apply almost as well to the rabbit or squirrel as to the cat4 ,the ,cat4--,the house cat 7,felis domestica7 is probably descended from the ,nubian cat 7,felis maniculata1 ,fig4 #ccc7 found in ,africa4 ,the wild species is about half again as large as the domestic cat1 grayish brown with darker stripes2 the tail has dark rings4 ,the lynx1 or wild cat of ,america 7,lynx rufus71 is quite different4 ,compare the figures 7#ccc1 #cce7 and state three obvious differences4 ,to which ,american species is the house cat closer akin1 the lynx 7,fig4 #cce7 or the ocelot 7,fig4 #ccd78 ,the domestic cat is found among all nations of the world4 ,what is concluded1 as to its nearest relatives1 from the fact that the ,indians had no cats when ,america was discovered8 ,it was considered sacred by the ancient ,egyptians1 and after death its body was embalmed4 ,the body of the cat is very flexible4 ,it may be divided into five regions1 the head1 neck1 trunk1 tail1 and limbs4 ,its eyes have the same parts as the eyes of other mammals4 ,which part of its eye is most peculiar8 7,fig4 #ccc47 ,what part is lacking that is present in birds8 ,how are the eyes especially adapted for seeing at night8 ,does the pupil in the light extend up or down or across the iris8 ,does it ever become round8 ,illustration3 ,,fig4 #ccc4--,,wild ,,cat ,,of ,,africa 7,felis maniculata71 4 ,what is the shape and position of the ears8 ,are they large or small compared with those of most mammals8 ,they are fitted best for catching sound from what direction8 ,what is thus indicated in regard to the cat's habits8 7,compare with ears of rabbit47 ,touch the whiskers of the cat4 ,what result8 ,was it voluntary or involuntary motion8 ,are the nostrils relatively large or small compared with those of a cow8 ,of man8 ,is the neck long or short8 ,animals that have long fore legs usually have what kind of a neck8 ,those with short legs8 ,why8 ,how many toes on a fore foot8 ,hind foot8 ,why is this arrangement better than the reverse8 ,some mammals are sole walkers 7plantigrade71 some are toe walkers 7digitigrade74 ,to which kind does the cat belong8 ,does it walk on the ends of the toes8 ,does it walk with all the joints of the toes on the ground8 ,where is the heel of the cat8 7,fig4 #ccd47 ,the wrist8 ,to make sure of the location of the wrist1 begin above3 find the shoulder blade1 the upper arm 7one or two bones871 the lower arm 7one or two bones871 the wrist1 the palm1 and the fingers 7,fig4 #ccg74 ,is the heel bone prominent or small8 ,illustration3 ,,fig4 #ccd4--,,ocelot 7,felis pardalis71 of ,texas and ,mexico1 4 ,in what direction does the knee of the cat point8 ,the heel8 ,the elbow8 ,the wrist8 ,compare the front and hind leg in length2 straightness2 heaviness2 number and position of toes2 sharpness of the claws4 ,what makes the dog's claws duller than a cat's8 ,what differences in habit go with this8 ,judging from the toe that has become useless on the fore foot of the cat1 which toe is lacking in the hind foot8 ,is it the cat's thumb or little finger that does not touch the ground8 7,fig4 #ccg47 ,locate on your own hand the parts corresponding to the pads on the forefoot of a cat4 ,of what use are soft pads on a cat's foot8 ,some animals have short1 soft fur and long1 coarse over hair4 ,does the cat have both8 ,is the cat's fur soft or coarse8 ,does the fur have a color near the skin different from that at the tip8 ,why is hair better suited as a covering for the cat than feathers would be8 ,scales8 ,where are long1 stiff bristles found on the cat8 ,their length suggests that they would be of what use to a cat in going through narrow places8 ,why is it necessary for a cat to be noiseless in its movements8 ,illustration3 ,,fig4 #cce4--,,lynx 7,lynx rufus74 ,the 8,bob-tailed cat0 7,north ,america74 ,observe the movements of the cat4--,why cannot a cat come down a tall tree head foremost8 ,did you ever see a cat catch a bird8 ,how does a cat approach its prey8 ,name a jumping insect that has long hind legs2 an amphibian2 several mammals 7,figs4 #cfb1 #cgd74 ,does a cat ever trot8 ,gallop8 ,does a cat chase its prey8 ,when does the cat move with its heel on the ground8 ,the claws of a cat are withdrawn by means of a tendon 7see ,fig4 #cch74 ,does a cat seize its prey with its mouth or its feet8 ,how does a cat make the purring sound8 7,do the lips move8 ,the sides87 ,how does a cat drink8 ,do a cat and dog drink exactly the same way8 ,is the cat's tongue rough or smooth8 ,how is the tongue used in getting the flesh off close to the bone8 ,can a cat clean a bone entirely of meat8 ,illustration3 ,,fig4 #ccf4--;,,jaguar1 of tropical ,america4 ,in what state of development is a newly born kitten8 ,with what does the cat nourish its young8 ,name ten animals of various kinds whose young are similarly nourished4 ,what is this class of animals called8 ,why does a cat bend its back when it is frightened or angry8 ,does a cat or a dog eat a greater variety of food8 ,which refuses to eat an animal found dead8 ,will either bury food for future use8 ,which is sometimes troublesome by digging holes in the garden8 ,explain this instinct4 ,which lived a solitary life when wild8 ,which had a definite haunt1 or home8 ,why are dogs more sociable than cats8 ,a dog is more devoted to his master4 ,why8 ,a cat is more devoted to its home1 and will return if carried away4 ,why8 ,why does a dog turn around before lying down8 7,consider its original environment47 ,illustration3 ,,fig4 #ccg4--,,skeleton ,,of ,,cat4 ,the ,skeleton 7,fig4 #ccg74--;,compare the spinal column of a cat in form and flexibility with the spinal column of a fish1 a snake1 and a bird4 ,the skull is joined to the spinal column by two knobs 7or condyls71 which fit into sockets in the first vertebra4 ,compare the jaws with those of a bird and a reptile4 ,there is a prominent ridge in the temple to which the powerful chewing muscles are attached4 ,there is also a ridge at the back of the head where the muscles which support the head are attached 7,fig4 #cdh74 ,illustration3 ,,fig4 #cch4--;,,claw ,,of ,,cat 7#a7 retracted by ligament1 and 7#b7 drawn down by muscle attached to lower tendon4 ,count the ribs4 ,are there more or fewer than in man8 ,the breastbone is in a number of parts1 joined1 like the vertebr1 by cartilages4 ,compare it with a bird's sternum2 why the difference8 ,the shoulder girdle1 by which the front legs are attached to the trunk1 is hardly to be called a girdle1 as the collar bones 7clavicles7 are rudimentary4 7,they often escape notice during dissection1 being hidden by muscles47 ,the shoulder blades1 the other bones of this girdle1 are large1 but relatively not so broad toward the dorsal edge as human shoulder blades4 ,the clavicles are tiny because they are useless4 ,why does the cat not need as movable a shoulder as a man8 ,the pelvic1 or hip girdle1 to which the hind legs are attached1 is a rigid girdle1 completed above by the spinal column1 to which it is immovably joined4 ,thus the powerful hind legs are joined to the most rigid portion of the trunk4 ,mammals4--,the cat belongs to the class ,mammalia or mammals4 ,the characteristics of the class are that the young are not hatched from eggs1 but are born alive1 and nourished with milk 7hence have lips71 and the skin is covered with hair4 ,the milk glands are situated ventrally4 ,the position of the class in the animal kingdom was shown when the cow was classified 7p4 #i74 ,their care for the young1 their intelligence1 and their ability to survive when in competition with other animals1 causes the mammals to be considered the highest class in the animal kingdom4 ,according to these tests1 what class of vertebrates should rank next to mammals8 ,compare the heart1 lungs1 blood1 and parental devotion of these two highest classes of animals4 ,illustration3 ,,fig4 #cci4--,,skeleton ,,of ,,lion 7cat family74 ,the first mammals1 which were somewhat like small opossums1 appeared millions of years ago1 when the world was inhabited by giant reptiles4 ,these reptiles occupied the water1 the land1 and the air1 and their great strength and ferocity would have prevented the mammals from multiplying 7for at first they were small and weak71 but the mammals carried their young in a pouch until able to care for themselves1 while the reptiles laid eggs and left them uncared for4 ,the first mammals used reptilian eggs for food1 though they could not contend with the great reptiles4 ,because birds and mammals are better parents than reptiles1 they have conquered the earth1 and the reptiles have been forced into subordination1 and have become smaller and timid4 ,illustration3 ,,fig4 #cdj4--,,walrus 7,trichechus rosmarus74 ,classification of ,mammals4--,which two have the closest resemblances in the following lists3 ,horse1 cow1 deer4 ,why8 ,cat1 cow1 bear4 ,why8 ,monkey1 man1 sheep4 ,why8 ,rat1 monkey1 squirrel4 ,why8 ,giraffe1 leopard1 camel4 ,why8 ,walrus1 cat1 cow4 ,why8 ,check the five mammals in the following lists that form a group resembling each other most closely3 ,lion1 bear1 pig1 dog1 squirrel1 cat1 camel1 tiger1 man4 ,state your reasons4 ,giraffe1 leopard1 deer1 cow1 rat1 camel1 hyena1 horse1 monkey4 ,state reasons4 ,illustration3 ,,fig4 #cda4--,,weasel1 in summer2 in ,canada in winter it is all white but tip of tail4 ,teeth and toes are the basis for subdividing the class mammalia into orders4 ,although the breathing1 circulation1 and internal organs and processes are similar in all mammals1 the external organs vary greatly because of the varying environments of different species4 ,the internal structure enables us to place animals together which are essentially alike2 e4g4 the whale and man are both mammals1 since they resemble in breathing1 circulation1 and multiplication of young4 ,the external organs guide us in separating the class into orders4 ,the teeth vary according to the food eaten4 ,the feet vary according to use in obtaining food or escaping from enemies4 ,this will explain the difference in the length of legs of lion and horse1 and of the forms of the teeth in cat and cow4 ,make a careful study of the teeth and limbs as shown in the figures and in all specimens accessible4 ,write out the dental formulas as indicated at the top of page #aid4 ,the numerals above the line show the number of upper teeth2 those below the line show the number of lower teeth in one half of the jaw4 ,they are designated as follows3 ,i1 incisors2 ,c1 canine2 ,m1 molars4 ,multiplying by two gives the total number4 ,which skulls in the chart have the largest canines8 ,why8 ,the smallest1 or none at all8 ,why8 ,compare the molars of the cow1 the hog1 and the dog4 ,explain their differences4 ,in which skulls are some of the molars lacking8 ,rudimentary8 ,why are the teeth that do not touch usually much smaller than those that do8 ,illustration3 ,,fig4 #cdb4--;,,foot ,,of ,,bear 7,plantigrade74 ,illustration3 ,,fig4 #cdc4--,,polar ,,bear 7,ursus maritimus74 ,,key1 ,,or ,,table1 ,,for ,,classifying ,,mammals 7class ,mammalia7 ,,into ,,orders ,orders ,a ,imperfect ,mammals1 young hatched or prematurely born ,b ,jaws a birdlike beak1 egg-laying ,monotremes ,b ,jaws not beaklike1 young carried in pouch ,marsupials ,a ,perfect ,mammals1 young not hatched1 nor prematurely born ,c ,front part of both jaws lack teeth ,edentates ,b ,c ,teeth with sharp points for ,digits piercing shells of insects ,insectivors with claws ,c ,canines very long1 molars suited for tearing ,carnivors ,c ,canines lacking1 incisors very large ,rodents ,b ,c ,head large2 carnivorous ,cetaceans ,digits not ,c ,head small2 herbivorous ,sireneans distinct ,c ,five toes1 nose prolonged into a snout ,proboscideans ,c ,toes odd number1 less than five ,equines ,b ,digits ,c ,toes even number1 upper front ,un- with teeth lacking1 chew the cud ,ruminants gu- nails or lates hoofs ,c ,toes even number1 upper front teeth present1 not cud-chewers ,swine ,c ,all limbs having hands ,quadrumans ,c ,two limbs having hands ,bimans ,exercise in ,classification4--,copy the following list1 and by reference to figures write the name of its order after each mammal3-- ,ape 7,figs4 #dje1 #djf7 ,rabbit 7,fig4 #cde7 ,dog 7,figs4 #cef1 #djh7 ,hog 7,figs4 #ceg1 #cic7 ,bat 7,figs4 #cdg1 #cgj7 ,cat 7,figs4 #ccg1 #cdh7 ,armadillo 7,figs4 #cdi1 #cfe7 ,cow 7,figs4 #cdd1 #chf7 ,walrus 7,fig4 #cdj7 ,monkey 7,figs4 #ceb1 #dja7 ,horse 7,figs4 #cee1 #cie7 ,ant-eater 7,figs4 #ced1 #cfd7 ,antelope 7,fig4 #cia7 ,mole 7,figs4 #cfg1 #cfh7 ,beaver 7,figs4 #cgb1 #cgc7 ,duckbill 7,fig4 #cei7 ,tapir 7,fig4 #chd7 ,dolphin 7,figs4 #cgi1 #cig7 ,use chart of skulls and ,figs4 #cha1 #chb1 #cie-djj in working out this exercise4 ,chart of ,mammalian ,skulls 7,illustrated ,study7 #e #a #b ,man's dental formula is 7,m -1 ,c -1 ,i -7 #cb4 #e #a #b ,in like manner fill out formulas below3-- ,cow 7,m - ,c - ,i -7 #cb ,rabbit 7,m - ,c - ,i -7 #bh ,walrus 7,m - ,c - ,i -7 #cd ,bat 7,m - ,c - ,i -7 #cd ,cat 7,m - ,c - ,i -7 #cj ,armadillo 7,m - ,c - ,i -7 #bh ,horse 7,m - ,c - ,i -7 #dj ,whale 7,m - ,c - ,i -7 #j ,am4 ,monkey 7,m - ,c - ,i -7 #cf ,sloth 7,m - ,c - ,i -7 #ah ,ant-eater 7,m - ,c - ,i -7 #j ,dog 7,m - ,c - ,i -7 #db ,hog 7,m - ,c - ,i -7 #dd ,sheep 7,m - ,c - ,i -7 #cb ,illustration3 ,,fig4 #cdd4--,skull and front of lower jaw of ,,cow4 ,illustration3 ,,fig4 #cde4--,,rabbit4 ,a1 ,b1 incisors2 ,c1 molars4 ,illustration3 ,,fig4 #cdf4--,,walrus 7see ,fig4 #cda74 ,illustration3 ,,fig4 #cdg4--;,,bat4 ,illustration3 ,,fig4 #cdh4--;,,cat4 ,chart of ,mammalian ,skulls ,illustration3 ,,fig4 #cdi4--;,,armadillo4 ,illustration3 ,,fig4 #cej4--;,,horse 7front of jaw74 ,illustration3 ,,fig4 #cea4--;,,greenland ,,whale4 ,illustration3 ,,fig4 #ceb4--;,,american ,,monkey4 ,illustration3 ,,fig4 #cec4--,,sloth 7,fig4 #cfc74 ,illustration3 ,,fig4 #ced4--;,,ant-,,eater 7,fig4 #cfd74 ,illustration3 ,,fig4 #cee4--;,,horse4 ,illustration3 ,,fig4 #cef4--;,,dog4 ,upper 7,a7 and lower 7,b7 jaw4 ,illustration3 ,,fig4 #ceg4--;,,hog4 ,illustration3 ,,fig4 #ceh4--,,sheep4 ,the lowest order of mammals contains only two species1 the duckbill and the porcupine ant-eater1 both living in the ,australian region4 ,do you judge that the duckbill of ,tasmania 7,fig4 #cei7 lives chiefly in water or on land8 ,why8 ,is it probably active or slow in movement8 ,it dabbles in mud and slime for worms and mussels1 etc4 ,how is it fitted for doing this8 ,which feet are markedly webbed8 ,how far does the web extend8 ,the web can be folded back when not in use4 ,it lays two eggs in a nest of grass at the end of a burrow4 ,trace resemblances and differences between this animal and birds4 ,illustration3 ,,fig4 #cei4--;,,duckbill 7,ornithorhynchus paradoxus74 ,illustration3 ,,fig4 #cfj4--,,spiny ,,ant-,,eater 7,echidna aculeata74 ,view of under surface to show pouch4 7,after ,haacke47 ,the porcupine ant-eater has numerous quill-like spines 7,fig4 #cfj7 interspersed with its hairs4 7,use87 ,describe its claws4 ,it has a long prehensile tongue4 ,it rolls into a ball when attacked4 ,compare its jaws with a bird's bill4 ,it lays one egg1 which is carried in a fold of the skin until hatched4 ,since it is pouched it could be classed with the pouched mammals 7next order71 but it is egg-laying4 ,suppose the two animals in this order did not nourish their young with milk after hatching1 would they most resemble mammals1 birds1 or reptiles8 ,write the name of this order4 7,see ,table1 p4 #aic47 ,why do you place them in this order 778 7,see p4 #aic47 ,the name of the order comes from two ,greek words meaning 8one opening10 because the ducts from the bladder and egg glands unite with the large intestine and form a cloaca4 ,what other classes of vertebrates are similar in this8 ,illustration3 ,,fig4 #cfa4--,,opossum 7,didelphys ,virginianus74 ,pouched ,mammals4--,these animals1 like the last1 are numerous in the ,australian region1 but are also found in ,south ,america1 thus indicating that a bridge of land once connected the two regions4 ,the opossum is the only species which has penetrated to ,north ,america 7,fig4 #cfa74 ,are its jaws slender or short8 ,what kinship is thus suggested8 ,as shown by its grinning1 its lips are not well developed4 ,does this mean a low or a well-developed mammal8 ,where does it have a thumb8 7,fig4 #cfa47 ,does the thumb have a nail8 ,is the tail hairy or bare8 ,why8 ,do you think it prefers the ground or the trees8 ,state two reasons for your answer4 ,it hides in a cave or bank or hollow tree all day1 and seeks food at night4 ,can it run fast on the ground8 ,it feigns death when captured1 and watches for a chance for stealthy escape4 ,the kangaroo 7,fig4 #cfb71 like the opossum1 gives birth to imperfectly developed young4 7,kinship with what classes is thus indicated87 ,after birth1 the young 7about three fourths of an inch long7 are carried in a ventral pouch and suckled for seven or eight months4 ,they begin to reach down and nibble grass before leaving the pouch4 ,compare fore legs with hind legs1 front half of body with last half4 ,describe tail4 ,what is it used for when kangaroo is at rest8 ,in jumping1 would it be useful for propelling and also for balancing the body8 ,describe hind and fore feet4 ,order 4 ,why8 4 ,see key1 page #aic4 ,illustration3 ,,fig4 #cfb4--;,,giant ,,kangaroo4 ,imperfectly ,toothed ,mammals4--,these animals live chiefly in ,south ,america 7sloth1 armadillo1 giant ant-eater7 and ,africa 7pangolin74 ,the sloth 7,fig4 #cfc7 eats leaves4 ,its movements are remarkably slow1 and a vegetable growth resembling moss often gives its hair a green color4 7,what advantage87 ,how many toes has it8 ,how are its nails suited to its manner of living8 ,does it save exertion by hanging from the branches of trees instead of walking upon them8 ,illustration3 ,,fig4 #cfc4--,,sloth of ,south ,america4 ,illustration3 ,,fig4 #cfd4--;,,giant ,,ant-,,eater of ,south ,america4 7,see ,fig4 #ced47 ,find evidences that the edentates are a degenerate order4 ,describe another ant-eater 7,fig4 #cfj74 ,judging from the figures 7#cfc1 #cfd1 #cfe71 are the members of this order better suited for attack1 active resistance1 passive resistance1 or concealment when contending with other animals8 ,the ant-eater's claws 7,fig4 #cfd7 on the fore feet seem to be a hindrance in walking2 for what are they useful8 ,why are its jaws so slender8 ,what is probably the use of the enormous bushy tail8 ,the nine-banded armadillo 7,fig4 #cfe7 lives in ,mexico and ,texas4 ,it is omnivorous4 ,to escape its enemies1 it burrows into the ground with surprising rapidity4 ,if unable to escape when pursued1 its hard1 stout tail and head are turned under to protect the lower side of the body where there are no scales4 ,the three-banded species 7,fig4 #cff7 lives in ,argentina4 ,compare the ears and tail of the two species2 give reasons for differences4 ,why are the eyes so small8 ,the claws so large8 ,order 4 ,why8 4 ,illustration3 ,,fig4 #cfe4--,,nine-,,banded ,,armadillo of ,texas and ,mexico4 7,dasypus novemcinctus47 ,it is increasing in numbers2 it is very useful1 as it digs up and destroys insects4 7,see ,fig4 #cdi47 ,illustration3 ,,fig4 #cff4--,,three-,,banded ,,armadillo 7,tolypeutes tricinctus74 ,insect ,eaters4--,the soft interior and crusty covering of insects makes it unnecessary for animals that prey upon them to have flat-topped teeth for grinding them to powder1 or long cusps for tearing them to pieces4 ,the teeth of insect eaters1 even the molars 7,fig4 #cfh71 have many sharp tubercles1 or points1 for holding insects and piercing the crusty outer skeleton and reducing it to bits4 ,as most insects dig in the ground or fly in the air1 we are not surprised to learn that some insect-eating mammals 7the bats7 fly and others 7the moles7 burrow4 ,are the members of this order friends or competitors of man8 ,illustration3 ,,fig4 #cfg4--,,the ,,mole4 ,illustration3 ,,fig4 #cfh4--,,skeleton ,,of ,,mole4 7,shoulder blade is turned upward47 ,why does the mole have very small eyes8 ,small ears8 ,compare the shape of the body of a mole and a rat4 ,what difference8 ,why8 ,compare the front and the hind legs of a mole4 ,why are the hind legs so small and weak8 ,bearing in mind that the body must be arranged for digging and using narrow tunnels1 study the skeleton 7,fig4 #cfh7 in respect to the following3 ,bones of arm 7length and shape71 fingers1 claws1 shoulder bones1 breastbone 7why with ridge like a bird871 vertebr 7why are the first two so large871 skull 7shape74 ,there are no eye sockets1 but there is a snout gristle2 for the long1 sensitive snout must serve in place of the small and almost useless eyes hidden deep in the fur4 ,is the fur sleek or rough8 ,why8 ,close or thin8 ,it serves to keep the mole clean4 ,the muscles of neck1 breast1 and shoulders are very strong4 ,why8 ,the mole eats earthworms as well as insects4 ,it injures plants by breaking and drying out their roots4 ,experiments show that the ,western mole will eat moist grain1 though it prefers insects4 ,if a mole is caught1 repeat the experiment1 making a careful record of the food placed within its reach4 ,illustration3 ,,fig4 #cfi4--,,skeleton ,,of ,,bat4 ,as with the mole1 the skeletal adaptations of the bat are most remarkable in the hand4 ,how many fingers8 7,fig4 #cfi47 ,how many nails on the hand8 ,use of nail when at rest8 ,when creeping8 7,fig4 #cfi47 ,instead of feathers1 the flying organs are made of a pair of extended folds of the skin supported by elongated bones1 which form a framework like the ribs of an umbrella or a fan4 ,how many digits are prolonged8 ,does the fold of the skin extend to the hind legs8 ,the tail8 ,are the finger bones or the palm bones more prolonged to form the wing skeleton8 ,illustration3 ,,fig4 #cgj4--,,vampire 7,phyllostoma spectrum7 of ,south ,america4 4 ,the skin of the wing is rich in blood vessels and nerves1 and serves1 by its sensitiveness to the slightest current of air1 to guide the bat in the thickest darkness4 ,would you judge that the bat has sharp sight8 ,acute hearing8 ,the moles do not hibernate2 the bats do4 ,give the reason for the difference4 ,if bats are aroused out of a trance-like condition in winter1 they may die of starvation4 ,why8 ,the mother bat carries the young about with her1 since1 unlike birds1 she has no nest4 ,how are the young nourished8 ,order 4 ,why8 4 7,key1 p4 #aic47 ,illustration3 ,,fig4 #cga4--,,pouched ,,gopher 7,geomys bursarius7 1 a large1 burrowing field rat1 with cheek pouches for carrying grain4 ,illustration3 ,,fig4 #cgb4--;,hind foot a1 fore foot b1 tail c1 of ,,beaver4 ,illustration3 ,,fig4 #cgc4--;,,beaver4 ,illustration3 ,,fig4 #cgd4--,,position ,,of ,,limbs ,,in ,,rabbit4 ,the ,gnawing ,mammals4--,these animals form the most numerous order of mammals4 ,they lack canine teeth4 ,inference8 ,the incisors are four in number in all species except the rabbits1 which have six 7see ,fig4 #cde74 ,they are readily recognized by their large incisors4 ,these teeth grow throughout life1 and if they are not constantly worn away by gnawing upon hard food1 they become inconveniently long1 and may prevent closing of the mouth and cause starvation4 ,the hard enamel is all on the front surface1 the dentine in the rear being softer2 hence the incisors sharpen themselves by use to a chisel-like edge4 ,the molars are set close together and have their upper surfaces level with each other4 ,the ridges on them run crosswise so as to form a continuous filelike surface for reducing the food still finer after it has been gnawed off 7,fig4 #cde74 ,the lower jaw fits into grooves in place of sockets4 ,this allows the jaw to work back and forth instead of sidewise4 ,the rabbits and some squirrels have a hare lip2 i4e4 the upper lip is split4 ,what advantage is this in eating8 ,in ,england the species that burrow are called rabbits2 those that do not are called hares4 ,name six enemies of rabbits4 ,why does a rabbit usually sit motionless unless approached very close8 ,do you usually see one before it dashes off8 ,a rabbit has from three to five litters of from three to six young each year4 ,squirrels have fewer and smaller litters4 ,why must the rabbit multiply more rapidly than the squirrel in order to survive8 ,english rabbits have increased in ,australia until they are a plague4 ,sheep raising is interfered with by the loss of grass4 ,the ,australians now ship them to ,england in cold storage for food4 ,rabbits and most rodents lead a watchful1 timid1 and alert life4 ,an exception is the porcupine1 which1 because of the defense of its barbed quills1 is dull and sluggish4 ,the common rodents are3-- squirrels rabbits rats mice beavers muskrats porcupines guinea pig pouched gopher prairie dog prairie squirrel chipmunk ground hog field mouse ,which of the above rodents are commercially important8 ,which are injurious to an important degree8 ,which have long tails8 ,why8 ,short tails8 ,why8 ,long ears8 ,why8 ,short ears8 ,why8 ,which are aquatic8 ,which dig or burrow8 ,which are largely nocturnal in habits8 ,which are arboreal8 ,which are protected by coloration8 ,which escape by running8 ,by seeking holes8 ,economic ,importance4--,rabbits and squirrels destroy the eggs and young of birds4 ,are rabbits useful8 ,do they destroy useful food8 ,the use of beaver and muskrat skins as furs will probably soon lead to their extinction4 ,millions of rabbits' skins are used annually1 the hair being made into felt hats4 ,there are also millions of squirrel skins used in the fur trade4 ,the hairs of the tail are made into fine paint brushes4 ,the skins of common rats are used for the thumbs of kid gloves4 ,order 4 ,why8 4 ,illustration3 ,,fig4 #cge4--;,,flying ,,squirrel 7,pteromys volucella74 4 ,elephants4--,elephants1 strange to say1 have several noteworthy resemblances to rodents4 ,like them1 elephants have no canine teeth2 their molar teeth are few1 and marked by transverse ridges and the incisors present are prominently developed 7,figs4 #cgf1 #cgg74 ,instead of four incisors1 however1 they have only two1 the enormous tusks1 for there are no incisors in the lower jaw4 ,elephants and rodents both subsist upon plant food4 ,both have peaceful dispositions1 but one order has found safety and ability to survive by attaining enormous size and strength2 the other 7e4g4 rats1 squirrels7 has found safety in small size4 ,explain4 ,suppose you were to observe an elephant for the first time1 without knowing any of its habits4 ,how would you know that it does not eat meat8 ,that it does eat plant food8 ,that it can defend itself8 ,why would you make the mistake of thinking that it is very clumsy and stupid8 ,why is its skin naked8 ,thick8 ,why must its legs be so straight8 ,why must it have either a very long neck or a substitute for one8 7,fig4 #cgf47 ,are the eyes large or small8 ,the ears8 ,the brain cavity8 ,what anatomical feature correlates with the long proboscis8 ,is the proboscis a new organ not found in other animals1 or is it a specialization of one or more old ones8 ,reasons8 ,what senses are especially active in the proboscis8 ,how is it used in drinking8 ,in grasping8 ,what evidence that it is a development of the nose8 ,the upper lip8 ,illustration3 ,,fig4 #cgf4--;,,head ,,of ,,african ,,elephant4 ,illustration3 ,,fig4 #cgg4--,,molar ,,tooth ,,of ,,african ,,elephant4 ,the tusks are of use in uprooting trees for their foliage and in digging soft roots for food4 ,can the elephant graze8 ,why1 or why not8 ,there is a finger-like projection on the end of the snout which is useful in delicate manipulations4 ,the feet have pads to prevent jarring2 the nails are short and hardly touch the ground4 ,order 4 ,why8 4 ,key1 page #aic4 ,whales1 ,porpoises1 ,dolphins4--,as the absurd mistake is sometimes made of confusing whales with fish1 the pupil may compare them in the following respects3 eggs1 nourishment of young1 fins1 skin1 eyes1 size1 breathing1 temperature1 skeleton 7,figs4 #bji1 #cgi1 and #cig74 ,illustration3 ,,fig4 #cgh4--;,,harpooning ,,greenland ,,whale 7see ,fig4 #cea74 ,porpoises and dolphins1 which are smaller species of whales1 live near the shore and eat fish4 ,explain the expression 8blow like a porpoise40 ,they do not exceed five or eight feet in length1 while the deep-sea whales are from thirty to seventy-five feet in length1 being by far the largest animals in the world4 ,the size of the elephant is limited by the weight that the bones and muscles support and move4 ,the whale's size is not so limited4 ,the whale bears one young 7rarely twins7 at a time4 ,the mother carefully attends the young for a long time4 ,the blubber1 or thick layer of fat beneath the skin1 serves to retain heat and keep the body up to the usual temperature of mammals in spite of the cold water4 ,it also serves1 along with the immense lungs1 to give lightness to the body4 ,why does a whale need large lungs8 ,the tail of a whale is horizontal instead of vertical1 that it may steer upward rapidly from the depths when needing to breathe4 ,the teeth of some whales do not cut the gum1 but are reabsorbed and are replaced by horny plates of 8whalebone10 which act as strainers4 ,give evidence1 from the flippers1 lungs1 and other organs1 that the whale is descended from a land mammal 7,fig4 #cig74 ,compare the whale with a typical land mammal1 as the dog1 and enumerate the specializations of the whale for living in water4 ,what change took place in the general form of the body8 ,it is believed that on account of scarcity of food the land ancestors of the whale1 hundreds of thousands of years ago1 took to living upon fish1 etc41 and1 gradually becoming swimmers and divers1 lost the power of locomotion on land4 ,order 4 ,why8 4 ,illustration3 ,,fig4 #cgi4--;,,dolphin4 ,elephants are rapidly becoming extinct because of the value of their ivory tusks4 ,whales also furnish valuable products1 but they will probably exist much longer4 ,why8 ,the manatees and dugongs 7sea cows7 are a closely related order living upon water plants1 and hence living close to shore and in the mouths of rivers4 ,order 4 ,why8 4 ,illustration3 ,,fig4 #chj4--,,manatee1 or sea cow2 it lives near the shore and eats seaweed4 7,florida to ,brazil47 ,hoofed ,mammals4--,all the animals in this order walk on the tips of their toes1 which have been adapted to this use by the claws having developed into hoofs4 ,the order is subdivided into the odd-toed 7such as the horse with one toe and the rhinoceros with three7 and the even-toed 7as the ox with two toes and the pig with four74 ,all the even-toed forms except the pig and hippopotamus chew the cud and are given the name of ruminants4 ,horse and ,man ,compared 7,figs4 #cha1 #cii74--,to which finger and toe on man's hand and foot does the toe of a horse's foot correspond8 ,has the horse kneecaps8 ,is its heel bone large or small8 ,is the fetlock on toe1 instep1 or ankle8 ,does the part of a horse's hind leg that is most elongated correspond to the thigh1 calf1 or foot in man8 ,on the fore leg1 is the elongated part the upper arm1 forearm1 or hand8 ,does the most elongated part of the fore foot correspond to the finger1 palm1 or wrist8 ,on the hind foot is it toe1 instep1 or ankle8 ,is the fetlock at the toe1 instep1 or heel8 7,fig4 #che47 ,is the hock at the toe1 instep1 heel1 or knee8 ,order 4 ,why8 4 ,illustration3 ,,fig4 #cha4--,left leg of man1 left hind leg of dog and horse2 homologous parts lettered alike4 ,specializations of the ,mammals4--,the early mammals1 of which the present marsupials are believed to be typical1 had five toes provided with claws4 ,they were not very rapid in motion nor dangerous in fight1 and probably ate both animal and vegetable food4 ,illustration3 ,,fig4 #chb4--,,skeletons ,,of ,,feet ,,of ,,mammals4 ,p1 horse2 ,d1 dolphin2 ,e1 elephant2 ,a1 monkey2 ,t1 tiger2 ,o1 aurochs2 ,f1 sloth2 ,m1 mole4 ,question3 ,explain how each is adapted to its specialized function4 ,according to the usual rule1 they tended to increase faster than the food supply1 and there were continual contests for food4 ,those whose claws and teeth were sharper drove the others from the food1 or preyed upon them4 ,thus the specialization into the bold flesh eating beasts of prey and the timid vegetable feeders began4 ,which of the flesh eaters has already been studied at length8 ,the insectivora escaped their enemies and found food by learning to burrow or fly4 ,the rodents accomplished the same result either by acquiring great agility in climbing1 or by living in holes1 or by running4 ,the proboscidians acquired enormous size and strength4 ,the hoofed animals found safety in flight4 ,illustration3 ,equus ,protohippus ,pliohippus ,miohippus ,mesohippus ,orohippus ,,fig4 #chc4--;,feet of the ancestors of the horse4 ,illustration3 ,,fig4 #chd4--,,tapir ,,of ,,south ,,america 7,tapirus americanus74 4 ,questions3 ,how does it resemble an elephant8 7,fig4 #cgf47 ,a horse8 7p4 #baj47 ,illustration3 ,,fig4 #che4--;,,horse1 descended from a small wild species still found in ,western ,asia4 ,ungulates1 as the horse1 need no other protection than their great speed1 which is due to lengthening the bones of the legs and rising upon the very tip of the largest toe1 which1 to support the weight1 developed an enormous toe-nail called a hoof4 ,the cattle1 not having developed such speed as the horse1 usually have horns for defense4 ,if a calf or cow bellows with distress1 all the cattle in the neighborhood rush to the rescue4 ,this unselfish instinct to help others was an aid to the survival of wild cattle living in regions infested with beasts of prey4 ,which of sop's fables is based upon this instinct8 ,the habit of rapid grazing and the correlated habit of chewing the cud were also of great value1 as it enabled cattle to obtain grass hurriedly and retire to a safe place to chew it4 ,rudiments of the upper incisors are present in the jaw of the calf1 showing the descent from animals which had a complete set of teeth4 ,the rudiments are absorbed and the upper jaw of the cow lacks incisors entirely1 as they would be useless because of the cow's habit of seizing the grass with her rough tongue and cutting it with the lower incisors as the head is jerked forward4 ,this is a more rapid way of eating than by biting4 ,which leaves the grass shorter after grazing1 a cow or a horse8 ,why8 ,grass is very slow of digestion1 and the ungulates have an alimentary canal twenty to thirty times the length of the body4 ,thorough chewing is necessary for such coarse food1 and the ungulates which chew the cud 7ruminants7 are able1 by leisurely and thorough chewing1 to make the best use of the woody fiber 7cellulose7 which is the chief substance in their food4 ,illustration3 ,,fig4 #chf4--,,skeleton ,,of ,,cow4 ,compare with horse 7,fig4 #cie7 as to legs1 toes1 tail1 mane1 dewlap1 ears1 body4 ,ruminants have four divisions to the stomach4 ,their food is first swallowed into the roomy paunch in which1 as in the crop of a bird1 the bulky food is temporarily stored4 ,it is not digested at all in the paunch1 but after being moistened1 portions of it pass successively into the honeycomb1 which forms it into balls to be belched up and ground by the large molars as the animal lies with eyes half closed under the shade of a tree4 ,it is then swallowed a second time and is acted upon in the third division 7or manyplies7 and the fourth division 7or reed74 ,next it passes into the intestine4 ,why is the paunch the largest compartment8 ,in the figure do you recognize the paunch by its size8 ,the honeycomb by its lining8 ,why is it round8 ,the last two of the four divisions may be known by their direct connection with the intestine4 ,illustration3 ,,fig4 #chg4--;,food traced through stomachs of cow4 7,follow arrows47 ,illustration3 ,,fig4 #chh4--,section of cow's stomachs4 ,identify each4 7,see text47 ,illustration3 ,,fig4 #chi4--,,okapi4 ,this will probably prove to be the last large mammal to be discovered by civilized man4 ,it was found in the forests of the ,kongo in #aijj4 ,questions3 ,it shows affinities 7find them7 with giraffe1 deer1 and zebra4 ,it is a ruminant ungulate 7explain meaning--see text74 ,the true gastric juice is secreted only in the fourth stomach4 ,since the cud or unchewed food is belched up in balls from the round 8honeycomb10 and since a ball of hair is sometimes found in the stomach of ruminants1 some ignorant people make the absurd mistake of calling the ball of hair the cud4 ,this ball accumulates in the paunch because of the friendly custom cows have of combing each other's hair with their rough tongues1 the hair sometimes being swallowed4 ,explain the saying that if a cow stops chewing the cud she will die4 ,illustration3 ,,fig4 #cij4--;,,african ,,camel 7,camelus dromedarius74 ,does a cow's lower jaw move sidewise or back and forth8 ,do the ridges on the molars run sidewise or lengthwise8 ,is a cow's horn hollow8 ,does it have a bony core8 7,fig4 #cdd47 ,illustration3 ,,fig4 #cia4--,,prong-,,horned ,,antelope 7,antelocarpa ,americana74 ,western states4 ,the permanent hollow horns of the cow and the solid deciduous horns of the deer are typical of the two kinds of horns possessed by ruminants4 ,the prong-horned antelope 7,fig4 #cia7 of the ,united ,states1 however1 is an intermediate form1 as its horns are hollow1 but are shed each year4 ,the hollow horns are a modification of hair4 ,do solid or hollow bones branch8 ,which are possessed by both sexes8 ,which are pointed8 ,which are better suited for fighting8 ,why would the deer have less need to fight than the cattle8 ,deer are polygamous1 and the males use their horns mostly for fighting each other4 ,the sharp hoofs of deer are also dangerous weapons4 ,the white-tail deer 7probably the same species as the ,virginian red deer7 is the most widely distributed of the ,american deer4 ,it keeps to the lowlands1 while the black-tailed deer prefers a hilly country4 ,the moose1 like the deer1 browses on twigs and leaves4 ,the elk1 like cattle1 eats grass4 ,illustration3 ,,fig4 #cib4--,,rocky ,,mountain ,,sheep 7,ovis montana74 4 ,the native sheep of ,america is the big horn1 or ,rocky ,mountain sheep 7,fig4 #cib74 ,the belief is false that they alight upon their horns when jumping down precipices4 ,they post sentinels and are very wary4 ,there is also a native goat1 a white species1 living high on the ,rocky ,mountains near the snow4 ,they are rather stupid animals4 ,the bison once roamed in herds of countless thousands1 but1 with the exception of a few protected in parks1 it is now extinct4 ,its shaggy hide was useful to man in winter1 so it has been well-nigh destroyed4 ,for gain man is led to exterminate elephants1 seals1 rodents1 armadillos1 whales1 birds1 deer1 mussels1 lobsters1 forests1 etc4 ,illustration3 ,,fig4 #cic4--,,peccary 7,dicotyles torquatus7 of ,texas and ,mexico4 4 ,our only native hog is the peccary1 found in ,texas 7,fig4 #cic74 ,in contrast with the heavy domestic hog1 it is slender and active4 ,it is fearless1 and its great tusks are dangerous weapons4 ,the swine are the only ungulates that are not strictly vegetable feeders4 ,the habit of fattening in summer was useful to wild hogs1 since snow hid most of their food in winter4 ,the habit has been preserved under domestication4 ,are the small toes of the hog useless8 ,are the 8dew claws0 of cattle useless8 ,will they probably become larger or smaller8 ,order8 ,illustration3 ,illustrated ,study ,,fig4 #cid4--;,,bird4 ,,fig4 #cie4--;,,horse4 ,,fig4 #cif4--,,ox4 ,,fig4 #cig4--;,,dolphin4 ,,fig4 #cih4--;,,fish4 ,illustration3 ,illustrated ,study ,,fig4 #cii4--,,man4 ,,fig4 #djj4--;,,chimpanzee4 7,see ,fig4 #djf47 ,illustrated ,study of ,vertebrate ,skeletons3 ,taking man's skeleton as complete1 which of these seven skeletons is most incomplete8 ,regarding the fish skeleton as the original vertebrate skeleton1 how has it been modified for 7#a7 walking1 7#b7 walking on two legs1 7#c7 flying8 ,which skeleton is probably a degenerate reversion to original type8 7p4 #bji47 ,how is the horse specialized for speed8 ,do all have tail vertebr1 or vertebr beyond the hip bones8 ,does each have shoulder blades8 ,compare 7#a7 fore limbs1 7#b7 hind limbs1 7#c7 jaws of the seven skeletons4 ,which has relatively the shortest jaws8 ,why8 ,what seems to be the typical number of ribs8 limbs8 digits8 ,does flipper of a dolphin have same bones as arm of a man8 ,how many thumbs has chimpanzee8 ,which is more specialized1 the foot of a man or a chimpanzee8 ,is the foot of a man or a chimpanzee better suited for supporting weight8 ,how does its construction fit it for this8 ,which has a better hand1 a man or a chimpanzee8 ,what is the difference in their arms8 ,does difference in structure correspond to difference in use8 ,which of the seven skeletons bears the most complex breastbone8 ,which skeleton bears no neck 7or cervical7 vertebr8 ,which bears only one8 ,are all the classes of vertebrates represented in this chart8 7p4 #abe47 ,illustration3 ,,fig4 #dja4--,,sacred ,,monkey ,,of ,,india 7,semnopithecus entellus74 4 ,monkeys1 ,apes1 and ,man4--,study the figures 7#cii1 #djj72 compare apes and man and explain each of the differences in the following list3 7#a7 feet1 three differences2 7#b7 arms2 7#c7 brain case2 7#d7 jaws2 7#e7 canine teeth2 7#f7 backbone2 7#g7 distance between the eyes4 ,illustration3 ,,fig4 #djb4--,,lemur 7,lemur ,mongoz74 4 ,which digit bears a claw8 ,a hand1 unlike a foot1 has one of the digits1 called a thumb1 placed opposite the other four digits that it may be used in grasping4 ,two-handed man and four-handed apes and monkeys are usually placed in one order1 the ,primates1 or in two orders 7see table1 page #aic74 ,the lowest members of this order are the lemurs of the old world4 ,because of their hands and feet being true grasping organs1 they are placed among the primates1 notwithstanding the long muzzle and expressionless1 foxlike face4 7,fig4 #djb47 ,next in order are the tailed monkeys1 while the tailless apes are the highest next to man4 ,illustration3 ,,fig4 #djc4--;,,broad-,,nosed ,,monkey4 4 ,america4 ,illustration3 ,,fig4 #djd4--,,narrow-,,nosed ,,monkey4 4 ,old ,world4 ,illustration3 ,,fig4 #dje4--;,,gorilla4 7,size of a man47 ,the primates of the ,new ,world are all monkeys with long tails and broad noses4 ,they are found from ,paraguay to ,mexico4 ,the monkeys and apes of the ,old ,world have a thin partition between the nostrils1 and are thus distinguished from the monkeys of the ,new ,world1 which have a thicker partition and have a broader nose4 7,figs4 #djc1 #djd47 ,the monkeys of ,america all have six molar teeth in each half jaw 7,fig4 #ceb72 the monkeys and apes of the ,old ,world have thirty-two teeth which agree both in number and arrangement with those of man4 ,which of the primates figured in this book appear to have the arm longer than the leg8 ,which have the eyes directed forward instead of sideways1 as with cats or dogs8 ,nearly all the primates are forest dwellers1 and inhabit warm countries1 where the boughs of trees are never covered with ice or snow4 ,their ability in climbing serves greatly to protect them from beasts of prey4 ,many apes and monkeys are able to assume the upright position in walking1 but they touch the ground with their knuckles every few steps to aid in preserving the balance4 ,illustration3 ,,fig4 #djf4--;,,chimpanzee4 ,the ,simians are the highest family of primates below man1 and include the gorilla1 chimpanzee1 orang1 and gibbon4 ,some of the simians weave together branches in the treetops to form a rude nest1 and all are very affectionate and devoted to their young4 ,how are apes most readily distinguished from monkeys8 7,figs4 #dja1 #djf47 ,the study of man as related to his environment will be taken up in detail in the part called ,human ,biology4 ,we will there examine the effect upon man's body of the rapid changes since emerging from savagery that he has made in food eaten1 air breathed1 clothing1 and habits of life4 ,illustration3 ,,fig4 #djg4--;,,anatomy ,,of ,,rabbit4 a1 incisor teeth2 b1 b1 b1 salivary glands2 k1 larynx2 l1 windpipe2 c1 gullet2 d1 diaphragm 7possessed only by mammals72 e1 stomach2 g1 small intestine2 h1 h1 large intestine2 f1 junction of small and large intestine2 g1 g1 ccum1 or blind sac from f 7corresponds to the shrunken rudimentary vermiform appendix in man72 m1 carotid arteries2 n1 heart2 o1 aorta2 p1 lungs2 q1 end of sternum2 r1 spleen2 s1 kidney2 t1 ureters 7from kidney to bladder v74 #b brain of rabbit3 a1 olfactory nerves2 b1 cerebrum2 c1 midbrain2 d1 cerebellum4 ,table for ,review ,,fish ,,frog ,,turtle ,,bird ,,cat ,,horse ,,man ---------------------------------------- ----------------------- ,names of limbs ---------------------------------------- ----------------------- ,acutest sense ---------------------------------------- ----------------------- ,digits on fore and hind limb ---------------------------------------- ----------------------- ,locomotion ---------------------------------------- ----------------------- ,kind of food ---------------------------------------- ----------------------- ,care of young ,illustration3 ,st4 ,bernard ,eskimo ,poodle ,dachshund ,german mastiff ,english bloodhound ,pointer ,bulldog ,greyhound ,newfoundland ,shepherd ,spitz ,,fig4 #djh4--;,,artificial ,,selection4 ,its effects in causing varieties in one species4 ,which of the dogs is specialized for speed8 ,driving cattle8 ,stopping cattle8 ,trailing by scent8 ,finding game8 ,drawing vehicles8 ,going into holes8 ,house pet8 ,cold weather8 ,in ,mexico there is a hairless dog specialized for hot climates4 ,the widely differing environments under various forms of domestication cause 8sports0 which breeders are quick to take advantage of when wishing to develop new varieties4 ,professor ,de ,vries by cultivating ,american evening primroses in ,europe has shown that a sudden change of environment may cause not only varieties but new species to arise4 ,,human ,,biology ,,chapter ,i ,,introduction ,to which branch of animals does man belong8 ,to which class and order in that branch8 7,animal ,biology1 pages #abe1 #aic47 ,there is no other animal species in the same genus or order with man4 ,this shows a wide physical difference between man and other animals1 but man's mind isolates him among the other animals still more4 ,illustration3 ,,fig4 #a4--;,,facial ,,angles of ,caucasian 7nearly #ij7 and ,ethiopian 7about #gj74 ,the angle between lines crossing at front of upper jaw near base of nose1 one line drawn from most prominent part of forehead1 the other through hole of ear4 ,the human species is divided into five varieties or races3 #a4 ,caucasian 7,fig4 #a74 ,skin fair1 hair wavy1 eyes oval4 7,europe except ,finns and ,lapps1 ,western ,asia1 ,america47 #b4 ,mongolian4 ,skin yellow1 hair straight and black1 face flat1 nose blunt1 almond eyes4 7,central ,asia1 ,china1 ,japan1 ,lapps and ,finns of ,europe1 ,eskimos of ,north ,america47 #c4 ,americans4 ,skin copper red1 hair straight1 nose straight or arched4 7,north and ,south ,america47 #d4 ,malay4 ,skin brown1 face flat1 hair black4 7,australia and ,islands of ,pacific47 #e4 ,ethiopian 7,fig4 #a74 ,skin dark1 hair woolly1 nose broad1 lips thick1 jaws and teeth prominent1 forehead retreating1 great toe shorter than next toe and separate4 7,africa1 ,america47 ,there is a struggle between the races for the possession of different lands4 ,the ,caucasian is gaining in ,australia1 ,africa1 and ,america4 ,with difficulty the ,mongolians are kept from the western shores of ,america4 ,the ,ethiopian in ,america shows a lessened rate of increase every decade2 this may be due to the tendency of the race to crowd into cities and the strain of suddenly changing from jungle life in less than two centuries4 ,civilization is a strain upon any race4 ,it is destroying the ,american ,indian4 ,the ,mongolian and ,caucasian survive civilization best1 but insanity is increasing rapidly among the latter4 ,illustration3 ,,fig4 #b4--;,,indian ,,weapons3 ,,lance ,,and ,,arrow ,,heads4 ,from a bank of mussel shells 7remains of savage feast7 at ,keyport1 ,n4,j4 ,man's ,original ,environment4--,primitive man lived without the use of fire or weapons other than sticks or stones4 ,his first home was in the tropics1 where his needs were readily supplied1 and probably in ,asia4 ,many nations have a tradition of a home in a garden 7,greek1 paradisos74 ,his food was chiefly tree fruits and nuts4 ,when because of crowding he left nature's garden1 he acquired skill in hunting and fishing and the use of fire that flesh might supplement the meager fruits of colder climates4 ,his weapons were of rough 7chipped7 stone at first--in the old stone age4 ,in this age the mammoth lived4 ,he learned to polish implements in the new stone age4 ,the ,indians were in that stage when ,columbus came to ,america 7,figs4 #b1 #c74 ,the cultivation of grain and the domestication of animals probably began in this age4 ,the bronze and iron ages followed the stone age4 ,illustration3 ,,fig4 #c4--;,,indian ,,tomahawk4 ,polished ,stone4 ,keyport1 ,n4,j4 ,the ,reaction between ,man and his ,environment4--,the estimates by various geologists of the time man has existed as a species vary from #bj1jjj to #bjj1jjj years4 ,the active life out of doors which man led for ages 7,fig4 #d7 has thoroughly adapted his body only for such a life4 ,now steam and other forces work for him1 and his muscles dwindle2 his lungs are seldom fully expanded1 and the unused portions become unsound2 he lives in tight houses1 and the impure air makes his blood impure and his skin delicate2 he eats soft concentrated food1 and his teeth decay and his too roomy food tube becomes sluggish4 ,his nerves and brain are fully active and they become unsound from overwork and impure blood4#c #c ,it has been prophesied that the future man will be a brownie-like creature with near-sighted eyes1 shrunken body1 slim little legs and arms1 large hairless head1 toothless gums1 a stomach using only predigested food1 muscles suited only to push an electric button or pull a lever1 and mind very active4 ,but this disregards the indispensable need of a sound mind for a sound body4 ,there cannot even be a play of emotion without a change in the circulation4 ,illustration3 ,,fig4 #d4--,,primitive ,,man1 showing clothing and weapons of chase and war4 ,degeneration of ,unused ,parts4--,several facts just stated illustrate the biological law that disuse causes degeneration4 ,man's ,modification of his ,environment4--,the energy of the world1 whether of coal1 waterfall1 oil1 forest1 or rich soil1 has the sun as its source4 ,all of these are being destroyed by man1 often with recklessness and wantonness4 ,the promised land which 8flowed with milk and honey0 is now almost a desert4 ,other examples are ,italy1 ,carthage1 ,spain4 ,the destruction of forests causes floods which wash away the soil4 ,it is estimated that there are only one fourth as many song birds in the ,united ,states as there were fifteen years ago4 ,insects and weeds or deserts replace rich soil1 noble quadrupeds1 singing birds1 and stately trees4 ,many farmers1 however1 preserve the fertility of the soil4 ,to the erect posture is due man's free use of his hands and the coperation of hands and senses4 ,this has given man his intellectual development4 ,the erect position has given greater freedom to the chest4 ,man uses fewer organs of locomotion than any other animal4 ,the opossum has two hands1 but they are on the hind limbs4 ,the ape has four hands1 but must use them all in locomotion4 7,what is a hand87 ,the erect position1 however1 makes spinal deformity easier to acquire1 and the whole weight being upon one hip at each step man is liable to hip-joint diseases4 ,in the horizontal trunk the organs lie one behind another2 in man they lie one upon another1 and are more liable to crowding and displacement4 ,the prone position in sickness helps to restore them4 ,large blood vessels at neck1 armpits1 and groins1 which occupy protected positions in quadrupeds1 are held to the front and exposed to danger4 ,the open end of the vermiform appendix and of the windpipe are upward in the erect trunk of man4 ,valves are lacking in some vertical veins and present where little needed in horizontal veins4 ,but the freedom of the hands more than makes up for all the disadvantages of erectness4 ,the ,survival of the ,fittest4--,those who do not work degenerate4 ,those who overwork1 or work with only a few organs1 as the brain and nerves1 degenerate4 ,the workers survive and increase in numbers1 the idle perish and leave few descendants4 ,what rate of adjustment to new environment is possible for man8 ,this has not been ascertained2 it is probably much slower than has been generally imagined4 ,the natives of ,tasmania1 ,new ,zealand1 and many of the ,pacific ,islands became extinct in less than a century after adopting clothing and copying other habits from ,europeans4 ,life in the country in civilized lands differs less from the environment of primitive man than does life in cities4 ,cities have been likened to the lion's cave in the fable1 to which many tracks led1 but from which none led4 ,the care of health in cities is now making rapid strides along the biological basis of purer air1 more open space1 less noise1 simple food1 and pure water4 ,biology1 by supplying as a standard the conditions which molded man's body for ages1 furnishes a simple and sure basis for hygiene4 ,to mention one instance among many1 man blundered for centuries in attempting the cure of consumption1 and well-nigh gave up in despair4 ,yet it has recently been shown that if the sufferer returns only in a measure to the open-air habits of his remote ancestors1 tuberculosis is one of the most curable of diseases4 ,the biological guide to health is surer and simpler than tinkering with drugs1 fussing with dietetics1 and avoiding exposure4 ,man is of all animals least thoroughly adjusted to his environment1 because of his continual and rapid progress4 ,disease may be defined as the process by which the body adapts1 or attempts to adapt1 itself to so sudden a change of environment that some organ has failed to work in harmony with the others4 ,by disease the body comes into adjustment with the new condition1 or attempts to do so4 ,protoplasm4--,the life and growth of man's body1 as the life and growth of all animals and plants1 depend upon the activity of the living substance called protoplasm1 as manifested in minute bodies called cells4 ,in fact1 protoplasm cannot exist outside of cells4 ,the cells of the human body and their relation to the body as a whole will next be considered4 ,illustration3 ,,fig4 #e4--;,,an ,,ameba1 highly magnified4 nu1 nucleus2 psd1 false foot4 ,the ,ameba4--,of all the animal kingdom1 the minute creatures that can be seen only with a microscope are most different from man4 ,one of the most interesting of these is the a-meba 7,fig4 #e2 spelled also amba1 see ,animal ,biology1 ,chap4 ,,ii74 ,a thousand of them placed in a row would hardly reach an inch4 ,some may doubt whether the ameba is a complete animal4 ,study the figures of it1 and no head1 or arms1 or legs1 or mouth can be found4 ,it appears1 when still1 to be merely a lump of jelly4 ,but the ameba can push out any part of its body as a foot1 and move slowly by rolling its body into the foot4 ,it can put out any part of its body as an arm1 and take in a speck of food2 or1 if the food happens to be near1 the ameba can make a mouth in any part of its body1 and swallow the food by closing around it 7,animal ,biology1 ,fig4 #ab74 ,the ameba has no lungs1 but breathes with all the surface of its body4 ,any part of its body can do anything that another part can do4 ,when the ameba grows to a certain size1 it multiplies by squeezing together near the middle 7,animal ,biology1 ,fig4 #ac7 and dividing into two parts4 ,amebas have not been observed to die of old age2 starvation and accident aside1 they are immortal4 ,illustration3 ,,fig4 #f4--;,a ,,white ,,blood ,,cell1 magnified2 forms noticed at intervals of one minute4 ,the ,ameba and ,man ,compared4--,the microscope shows us that the skin1 the muscles1 the blood1--in fact1 all parts of the body1--contain numberless small parts called cells4 ,these cells are continually changing with the activities of the body4 ,one of the most interesting kinds of cells we shall find to be the white blood cells1 or corpuscles4 ,one is shown in ,fig4 #f1 with the changes that it had undergone at intervals of one minute4 ,the thought readily occurs that these cells1 although part of man's body1 resemble the ameba that lives an independent life4 ,a man or a horse or a fish--in fact any animal not a protozoan--has something of the nature of a colony1 or collection1 of one-celled animals4 ,we are now prepared to understand a little as to how the body grows1 and how a cut in the skin is repaired4 ,the cells take the nourishment brought by the blood1 use it1 and grow and multiply like the ameba4 ,thus new tissue is formed4 ,all animals and vegetables--that is to say1 all living things--are made of cells4 ,illustration3 ,,fig4 #g4--;,,diagram ,,of ,a ,,cell4 p1 protoplasm2 n1 nucleus2 n1 nucleolus4 ,a living cell always contains a still smaller body called a nucleus 7,fig4 #g74 ,there is sometimes a small dot in the nucleus1 called the nucleolus4 ,the main body of the cell consists of the living substance called protoplasm1 containing nitrogen4 ,usually1 but not always1 there is a wall surrounding the cell1 called the cell wall4 ,workers with the microscope found long ago that animals and plants are constructed of little chambers which they called cells4 ,it was found later that the soft contents in the little chambers is of more importance than the walls which the protoplasm builds around itself4 ,a living cell is not like a cell in a honeycomb or a prison4 ,in biology we define a cell as a bit of protoplasm containing a nucleus4 ,no smaller part of living matter can live alone4 ,the protoplasm of the nucleus is called nucleoplasm2 the rest of the protoplasm is called cytoplasm4 ,illustration3 ,,fig4 #h4--;,a ,,cell 7from involuntary muscle71 so slender that it is called a fiber4 ,a fiber is threadlike1 and is either a slender cell 7,fig4 #h71 a slender row of cells 7,fig4 #aj71 or a branch of a cell4 ,a tissue is defined as a network of fibers or a mass of similar cells serving the same purpose1 or doing the same work4 ,a membrane is a thin sheetlike tissue4 ,the ,nature of the ,human ,body4--,the human body is a community of cells1 and may be compared to a community of people4 ,it is a crowded community1 for all the citizens live side by side as they work4 ,they are so small that it takes several hundred of them to make a line an inch long4 ,we should never have suspected the existence of cells had it not been for the microscope2 but now we know that they eat and breathe and work and divide into young cells which take the place of the old ones4 ,a child that is born in a community of people may become a railroad man and carry food and other freight from place to place2 so1 in the great community of cells 7see ,fig4 #i7 making up the human body1 the red blood cells1 like the railroad man1 are employed in carrying material from place to place4 ,but the community is old-fashioned1 for the citizens build canals instead of railroads for their commerce 7see ,fig4 #hd74 ,just as a child may grow up to be a farmer and aid in the conversion of crude soil into things suitable for the use of man1 so the digestive cells take the food we eat and change it into material with which the cells can build tissue4 ,some of the citizens of a community must1 at times1 take the part of soldiers and policemen1 and protect the community against the attacks of enemies4 ,the white blood cells1 already referred to1 may be called the soldiers2 for they go to any part attacked by injurious germs1 a particle of poison1 or other enemy1 and try to destroy the enemies by devouring or digesting them4 ,at other times they help to repair a break in the skin4 ,if a splinter gets into the skin1 the white blood cells form a white pus around the splinter and remove it4 ,in fact1 the white blood cell has been referred to as a kind of ,jack-at-all-trades4 ,in the human community there are certain persons who reach the positions of teachers1 lawmakers1 and governors2 they instruct and direct the other members of the community4 ,just so1 in the community of cells1 there are certain cells called nerve cells 7see ,fig4 #aa7 that have the duty of governing and directing the other cells4 ,the nerve cells are most abundant in the brain4 ,large cities must have scavengers4 ,likewise in the human body1 a community composed of millions of cells1 there are certain cells in the skin and the kidneys which have this duty4 ,they are continually removing impurities from the body4#d #d ,from ,coleman's 8,hygienic ,physiology10 ,the ,macmillan ,co41 ,n4,y4 ,illustration3 ,,fig4 #i4--,,various ,,cells of the body4 7,jegi47 ,tiny citizens of the bodily community4 ,division of ,labor4--,there is a great advantage in each cell of the human body having its special work1 instead of having to do everything for itself1 as each ameba cell must do4 ,under this system each cell can do its own work better than a cell of any other kind can do it4 ,among wild tribes there is very little division of labor4 ,each man makes his own weapons1 each knows how to weave coarse cloth1 how to cook1 how to farm1 etc4 ,savages do not have as good weapons as do people who leave the making of weapons to certain men whose special business it is4 ,what kind of pocketknives or pencils do you think the boys of this country would have if each boy had to make his own pocketknife or pencil8 ,what kind of scissors and thread would the girls have if each girl had to make them herself8 ,our muscle cells can contract better than the ameba2 the cells in the lungs can absorb oxygen better than the ameba4 ,we have just as great an advantage in digestion1 feeling1 and other processes2 for the ameba eats without a mouth1 digests without a stomach1 feels without nerves1 breathes without lungs1 and moves without muscles4 ,division of labor between the sexes also occurs among the higher animals4 ,those who desire that man and woman should have the same education and work would violate the biological law of 8progress by specialization10 which could only cause race degeneration4 ,a part of the body which is somewhat distinct from surrounding parts1 and has special work to do1 is called an organ2 the special work which the organ does is called its function4 ,the eye is the organ of sight4 ,the skin is an organ2 its function is to protect the body4 ,this book will treat of 7#a7 the structure1 appearance1 and position of each organ1 or anatomy2 7#b7 the function of each organ1 or physiology2 7#c7 the conditions of health for each organ1 or hygiene2 7#d7 the conditions under which each organ worked in the primitive life of the race2 7#e7 the effects of change of environment2 7#f7 the anatomy of man compared with the lower animals4 7#e7 belongs to the science of ,ecology4 ,these sciences are parts of the science of ,biology4 ,illustration3 ,,fig4 #aj4--,,three ,,muscle ,,fibers from the heart 7showing the nuclei of six cells74 ,illustration3 ,,fig4 #aa4--,,nerve ,,cells1 showing their branches interlacing4 ,the ,tissues4--,as the organs have different functions1 they must have different structures that they may be adapted to their work4 ,just as a house must have brick for the chimney1 shingles for the roof1 and nails to hold the timbers and other parts together1 so the body has various tissues to serve different purposes4 ,the bones must not be constructed like the muscles1 and the muscles cannot be like the skin4 ,the chief work of the cells is to construct the tissues and repair them4 ,during life changes are constantly going on4 ,careful little workmen are keeping watch over every part of the body2 thrifty little builders are busy in repairing and restoring4 ,no sooner is one particle removed than another takes its place4 ,in one direction the cells1 acting as undertakers1 are hurrying away matter which is dead2 in the other direction the unseen builders are filling the vacant places with matter that is living4 ,the ,seven ,tissues4--,there are seven kinds of tissues4 ,two of them1 the muscular and nervous tissues1 are called the master tissues1 since they control and expend the energies of the body4 ,the other five tissues are called the supporting tissues1 since they supply the energy to the master tissues1 support them in place1 nourish and protect them4 ,the ,master ,tissues4--,the muscular tissue consists chiefly of rows of cells placed end to end 7,fig4 #aj74 ,these cells have the remarkable property of becoming broader and shorter when stimulated by impulses from nerve cells4 ,illustration3 ,,fig4 #ab4--;,,connective ,,tissue ,,cells1 removed from among the fibers of ,fig4 #ac4 n1 c1 nucleus2 p1 branches4 ,the nerve tissue consists of cells with long1 spiderlike branches 7,fig4 #aa74 ,some nerve cells have branches several feet long1 so long that they go from the backbone to the foot4 ,the branches are called nerve fibers 7,fig4 #adb74 ,nerve fibers which carry impulses to the nerve cells are called sensory fibers4 ,the nerve fibers which carry impulses from the nerve cells are called motor fibers4 ,the organs are set to work by impulses through the motor fibers4 ,besides these two master tissues there are five supporting tissues4 ,illustration3 ,,fig4 #ac4--;,,connective ,,tissue ,,fibers4 a1 b1 bundles of white fibers2 c1 a yellow fiber4 ,connective tissue1 like all other tissues1 contains cells 7see ,fig4 #ab71 but it consists chiefly of fine fibers4 ,these fibers are of two kinds1--very fine white fibers which are inelastic1 and larger yellow fibers which are very elastic 7see ,fig4 #ac74 ,connective tissue is found in every organ1 binding together the other tissues and cells4 ,it is interwoven among the muscle cells1 and the tendons at the ends of the muscles are composed almost wholly of it4 ,if every other tissue were removed1 the connective tissue would still give a perfect model of all the organs4 ,how abundant this tissue is in the skin may be known from the fact that leather consists entirely of it4 ,fatty 7,adipose7 ,tissue4--,fatty tissue is formed by the deposit of oil in connective tissue cells 7see ,fig4 #ad74 ,fat is held in meshes of connective tissue fibers4 ,that fatty tissue consists not alone of fat1 but of fibers also1 is shown when hog fat is rendered into lard1 certain tough parts called 8cracklings0 being left4 ,what is the difference between beef fat and tallow8 ,illustration3 ,,fig4 #ad4--;,,fatty ,,tissue4 ,five fat cells1 held in bundles of connective tissue fibers4 a is a large oil drop2 m1 cell wall2 nucleus 7n7 and protoplasm 7p7 have been pushed aside by oil drop 7a74 ,epithelial tissue consists of one or more layers of distinct cells packed close together 7see ,fig4 #ae74 ,it contains no connective tissue or other fibers1 and is the simplest of the tissues4 ,epithelial tissue forms the outer layer of the skin1 called the epidermis1 and the mucous membrane lining the interior of the body4 ,it contains no blood vessels1 the epithelial cells obtaining their nourishment from the watery portion of the blood which soaks through the underlying tissues4 ,epithelial cells are usually transparent2 for instance1 the blood is visible beneath the mucous membrane of the lips4 ,the finger nails are made of epithelial cells1 and they are nearly transparent4 ,illustration3 ,,fig4 #ae4--;,,epithelial ,,tissue 7epidermis of skin1 magnified74 ,illustration3 ,,fig4 #af4--;,,epithelial ,,tissue2 cells forming two glands in wall of stomach4 ,illustration3 ,,fig4 #ag4--,,six ,,gland ,,cells3 at left1 shrunken after activity2 at right1 rested1 full of granules4 ,there are two classes of epithelial cells2 one class forms protective coverings 7,fig4 #ae72 the other class forms the lining of glands 7,fig4 #af74 ,glands are cavities whose lining of epithelial cells 7,fig4 #ag7 form either useful fluids called secretions to aid the body in its work1 or harmful fluids called excretions to be cast out1 or excreted4 ,most glands empty their fluids through tubes called ducts4 ,cartilaginous tissue is tough1 yet elastic4 ,cartilage or gristle may be readily felt in the ears1 the windpipe1 and the lower half of the nose4 ,this tissue consists of cartilage cells embedded in an intercellular substance through which run connective tissue fibers 7see ,fig4 #ah74 ,if yellow fibers predominate1 the cartilage is yellow and very elastic1 as in the ear2 if white fibers predominate1 it is white and less elastic1 as in the pads of gristle between the bones of the spinal column4 ,cartilage is to prevent jars1 and1 in movable joints1 to lessen friction4 ,bony 7,osseous7 ,tissue4--,solid bone is seen under the microscope to contain many minute cavities 7,fig4 #ai74 ,in these cavities the bone cells lie self-imprisoned in walls of stone2 for these cells have formed the bone by depositing limestone and phosphate of lime around themselves4 ,there are minute canals 7#c1 ,fig4 #ai71 however1 through which nourishment comes to the cells4 ,the watery portion of the blood passes through these small canals from the blood vessels that flow through the larger canals 7#a1 ,fig4 #ai74 ,bone cells may live for years1 although some of the other cells of the body live only a few hours4 ,illustration3 ,,fig4 #ah4--;,,cartilaginous ,,tissue4 ,a thin slice highly magnified4 a1 b1 c1 groups of cells2 m1 intercellular substance4 ,new cells to repair the tissues are formed by subdivision of the cells1 as with the ameba4 ,unlike protozoans1 many-celled animals are mortal because the outer cells prevent the deeper cells from purifying themselves perfectly and obtaining pure food and oxygen4 ,even the arteries of an old man become hardened by the deposit of mineral matter which the body has been unable to excrete4 ,illustration3 ,,fig4 #ai4--;,,bony ,,tissue4 ,thin slice across bone1 as viewed through microscope4 ,larger blood tubes pass through the large holes 7#a72 the cavities containing bone cells lie in circles1 and are connected by fine tubes 7#c7 with the larger tubes4 ,the body is kept alive and warm by burning1 or oxidation4 ,one fifth of the air is oxygen gas4 ,we breathe it during every minute of our existence4 ,it is carried by the blood to all the tissues4 ,not one of the cells could work without oxygen4 ,without it the body would soon be cold and dead1 for oxygen keeps the body alive and warm by uniting in the cells with sugar1 fat1 and all other substances in the body except water and salt4 ,oxygen burns or consumes the substances with which it unites1 and the process is called oxidation4 ,hence the cells have to be continually growing and multiplying to repair the tissue and replace the material used up by oxidation4 ,sugar and flour and fat oxidize1 or burn1 outside of the body1 as well as in it1 as can be proved by throwing them into a fire4 ,water and salt are two foods that do not burn4 ,hence they can furnish no heat or energy to the body4 ,water puts out a fire instead of helping it1 and so does salt4 ,throw salt into a fire or on a stove2 it will pop like sand1 but will not burn4 ,the cells need the oxygen of fresh air2 they need food for the oxygen to unite with1 but they are injured by many substances called poisons4 ,arsenic destroys the red blood cells4 ,strychnine attacks the nerve cells in the spinal cord4 ,alcohol attacks the epithelial cells lining the stomach and1 when it is absorbed1 attacks the nerve cells and other cells4 ,morphine attacks the nerve cells4 ,,written ,,exercises4--,draw a series of seven pictures to show the seven tissues 7,figs4 #aj1 #ad1 #ae1 #ah1 #ai74 ,write the 8,autobiography0 of a ,white ,blood ,cell 7see also pages #ei and #fh74 ,the ,rewards of ,caring for the ,health4 ,health and the ,disposition4 ,which is more important1 a ,thorough ,knowledge of ,geography or of ,physiology8 ,five ,things which people ,value above ,health 7and lose health to obtain74 ,the ,blessings that follow ,good ,health4 ,the ,tissues ,compared 7function1 proportion of cells1 intercellular material and fibers1 activity1 rate of change74 ,see also pages #ej1 #aaf4 ,pupils should choose their own subjects4 ,,chapter ,,ii ,,the ,,skin ,,note ,,to ,,teacher4--,the experiments should be assigned in turn to the pupils as each chapter is reached3 e4g4 this set of #ac will leave #c pupils in a class of #ci to stand responsible for each experiment4 ,each pupil should do the work separately and credit may be given for the best results4 ,encourage 7or require7 each pupil to try every experiment and record them in a note book4 ,experiment #a4 7,at home or in class47 ,albinism4--,study a white rabbit as an example of albinism4 ,does albinism affect only the skin8 ,what evidence that its blood is of normal color8 ,experiment #b4 ,use of ,hairs on the ,skin4--,let one pupil rest his hand upon the desk behind him while another touches a hair on his hand with a pencil4 ,he should speak at the moment1 if it is felt4 ,do the hairs increase the sensitiveness of the skin8 ,what was their use with primitive man8 ,are the hands of all your acquaintances equally hairy8 ,are the hairs to be classed as rudimentary8 ,will they disappear8 ,will the race become baldheaded8 ,experiment #c4 7,home or school47 ,invisible ,perspiration4--,hold a piece of cold glass near the hand or place the cheek near a cold window pane and notice for evidence of moisture4 ,its source8 ,experiment #d4--;,effect of ,evaporation on ,temperature4--,read a thermometer and cover its bulb with a moist cloth4 ,read again after twenty minutes4 ,repeat experiment in breeze4 ,experiment #e4 ,moisten one hand and allow it to dry4 ,touch the other hand with it4 ,explain result4 ,experiment #f4 ,absorbing ,power of ,fabrics4--,wet the hands and dry them upon a piece of cotton cloth4 ,repeat with woolen1 linen1 and silk4 ,arrange in list according to readiness in absorbing water4 ,experiment #g4 ,rates of ,drying4--,immerse the cloths in water and hang them up to dry4 ,test their rates of drying with dry powder or by touch4 ,experiment #h4 ,test ,looseness of ,weave of above cloths by measuring the distance pieces of equal length will stretch4 ,illustration3 ,,colored ,,figure #a4--,,section ,,of ,,skin 7diagram1 enlarged #be times74 ,on the left the connective tissue fibers of the true skin are shown4 ,in cutis 7c71 or dermis1 find capillaries1 nerve fibers1 fat cells1 two sweat glands and ducts1 four oil glands 7two in section71 two hairs1 three nerve papill1 five papillae containing capillaries1 two muscles for erecting hairs4 ,in epidermis find flat cells1 round cells1 and pigment cells4 ,,fig4 #b4--,,where ,,the ,,food ,,is ,,absorbed 7villus of intestine74 ,,fig4 #c4--,,where ,,the ,,food ,,is ,,used 7cells with lymph spaces74 ,,fig4 #d4--;,,ideal ,,section ,,of ,,mammal4 ,compare with organs of man 7colored ,fig4 #f74 j1 j1 jaws2 ol1 nerve of smell2 op1 nerve of sight2 b1 brain2 t1 tongue2 ep1 epiglottis2 oe1 gullet2 th1 thymus gland2 lg1 lung2 h1 heart2 l1 liver2 g1 stomach2 s1 spleen2 p1 pancreas2 k1 kidney2 d1 diaphragm2 m1 muscle2 u1 bladder2 ch1 spinal cord2 v1 vertebr4 ,experiment #i4 ,does ,cotton or ,wool protect better from ,radiant ,heat8--,lay a thermometer in the sun for ten minutes1 first covering it with a woolen cloth4 ,note change in reading4 ,after it regains first reading1 repeat1 covering it with a cotton cloth of same weight and texture4 ,conclusion8 ,expose wrists or arms to sun for five minutes1 one protected by the cotton1 the other by the wool4 ,result8 ,conclusion8 ,experiment #aj4 ,rates of ,heat ,absorption and ,radiation by ,different ,colors4--,expose thermometer to sunlight1 covered successively by pieces of cloth of same thickness1 material1 and texture4 ,use black1 blue1 red1 yellow1 and white cloth4 ,note rise of temperature for equal times in each case2 also the fall of temperature for equal times after removal to shade4 ,experiment #aa4 ,effects of ,dry ,powders4--,prepare two squares from the same piece of leather 7e4g4 an old shoe74 ,moisten them both1 and apply face powder to one4 ,which dries more quickly8 ,repeat after oiling them4 ,powder a portion of the face or arm daily for a week and compare with the clean portion4 ,experiment #ab4 ,dissect the kidney of an ox or sheep1 making out the parts mentioned in the text1 p4 #bf4 ,experiment #ac4 7,in class47 ,emergency ,drill4--,have one pupil wet an imaginary burn on the arm of another1 treat it with flour or soda1 and bandage4 7,see text47 ,the ,skin has ,two ,layers4--,the outer layer is called the epidermis2 it is thinner1 more transparent1 and less elastic than the inner layer1 or dermis4 ,the epidermis is composed of epithelial cells packed close together 7see colored ,fig4 #a74 ,the dermis1 or inner layer1 is a closely woven sheet of connective tissue 7colored ,fig4 #a7 containing a great number of sweat and oil glands1 roots of hairs1 blood vessels1 absorbent vessels 7lymphatics71 and nerves 7colored ,fig4 #a74 ,the dermis is sometimes called the true skin because it is of greater importance than the epidermis4 ,it is united loosely to the underlying organs by a layer of connective tissue4 ,it is in this layer that fat is stored4 ,the upper surface of the dermis rises into a multitude of projections 7see colored ,fig4 #a7 called papill 7singular1 papilla74 ,the epidermis fits closely over them and completely levels up the spaces between them except on the palms and the soles4 ,here the papill are in rows1 and there is a fine ridge in the skin above each row of papill 7,fig4 #bd74 ,in the papill are small loops of blood vessels and sometimes a nerve fiber 7colored ,fig4 #a74 ,illustration3 ,,fig4 #bj4--;,,epidermis ,,of ,,ethiopian4 ,illustration3 ,,fig4 #ba4--;,,epidermis ,,of ,,caucasian4 ,the epidermis is composed of a mass of cells held together by a cement resembling the white of an egg4 ,the cells near the surface are hard and flattened2 those deeper down near the dermis are round and soft 7see ,fig4 #ba74 ,these cells are living cells4 ,they are kept alive by the nourishment in the watery portion of the blood which soaks through from the blood tubes in the neighboring papill4 ,hence these cells are growing cells2 they subdivide when they reach a certain size1 and replace those wearing away at the surface1 thus constantly repairing the epidermis4 ,the dry outer cells wear away rapidly4 ,they have no nuclei and are dead cells4 ,the new cells forming beneath push them so far away from the dermis that nourishment no longer reaches them1 and they die4 ,pigment4--,the cells in the lower layers of the epidermis contain grains of coloring matter1 or pigment4 ,all other cells of the epidermis are transparent2 the pigment has the function of absorbing and arresting light4 ,albinos or animals entirely without pigment have pallid skins and pink eyes 7,exp4 #a74 ,immigrants from a ,cloudy to a ,sunny ,climate4 ,adaptation4--,the cells of the deeper tissues can readily be exhausted by the stimulation of too much light4 ,the sunnier the climate1 the greater the need of pigment2 hence the dark skin of the negro and the blonde skin and hair of the ,norwegian4 ,european immigrants to sunny ,america will grow darker4 ,the ,indian's skin is better suited to our climate than is a fair skin4 ,brunettes have a better chance for adaptation than blondes4 ,the ,american type when developed will doubtless be brunette4 ,the hair grows from a pit or follicle 7,fig4 #bb74 ,blood vessels and a nerve fiber go to the root or bulb from which a hair grows4 ,the hair will grow until this papilla1 or bulb1 is destroyed 7,exp4 #b74 ,illustration3 ,,fig4 #bb4--;,,development ,,of ,a ,,hair ,,and ,,two ,,oil ,,glands4 ,adaptation of the scalp to a tight warm covering is accomplished through the shedding of the hair rendered useless by the covering4 ,it is impossible to stop the growth of superfluous hair unless the hair papill are destroyed with an electric needle1 such is the vitality of hair2 yet many men1 by overheating the head and cutting off the circulation with tight hats1 destroy much of the hair before reaching middle age4 ,the health of the hair can be restored and its loss be stopped by going bareheaded except in the hot sun or in extremely cold weather4 ,this frees the circulation2 cold air and light stimulate the cells of the scalp4 ,some men wear hats1 even at night in summer4 ,the brain needs the protection of the hair4 ,beard protects the larynx or voice box1 which is large and exposed in man4 ,it was also a protection in hunting wild beasts and in war4 ,compare mane of lion1 not possessed by lioness4 8,goose-flesh0 after a cold bath is caused by the contraction of small muscles 7colored ,fig4 #a71 raising the now tiny hairs in an absurdly useless effort to keep the body warm4 ,the nails are dense1 thick plates of epidermis growing from a number of papill situated in a groove1 or fold1 of the skin2 there are many fine papill along the bed from which the nail grows4 ,since it grows from its under side as well as from the little fold of skin at its root1 the nail is thicker at the end than near the root4 ,illustration3 ,,fig4 #bc4--;,a1 ,,development ,,of ,,sweat ,,gland2 ,b1 ,,sweat ,,tube ,,developed4 ,the oil glands empty into the hair follicles 7colored ,fig4 #a74 ,they form an oil from the blood that keeps the hair glossy and the surface of the skin soft and flexible by preventing excessive drying4 ,hair oil should never be used upon the hair1 as the oil soon becomes rancid1 and besides causes dust and dirt to stick to the hair4 ,the sweat glands 7,fig4 #bc71 like the hair bulbs1 are deep in the lowest part of the dermis4 ,a sweat gland has the form1 of a tube coiled into a ball 7colored ,fig4 #a74 ,this tube continues as a duct through the two layers of skin1 and its opening at the surface is called a pore 7,fig4 #bd74 ,the perspiration evaporates as fast as it flows out through the pores1 if the secretion is slow2 but if poured out rapidly1 it gathers into drops 7,exp4 #c74 ,the perspiration is chiefly water1 containing in solution several salts1 including common salt and a trace of a white1 crystalline substance called urea4 ,the material for the perspiration is furnished by the blood flowing around the gland in a network of fine tubes4 ,the amount of the perspiration is controlled in two ways3 by nerves that regulate the activity of the epithelial cells lining the gland1 and by nerves that regulate the size of the blood vessels supplying the gland 7,fig4 #be74 ,illustration3 ,,fig4 #bd4--,,pores on ridges in palm of hand4 ,,thought ,,questions4--,freckles1 ,warts1 ,moles1 ,scars1 ,proud ,flesh1 ,pimples1 ,blackheads4 ,use these names in the proper places below3-- ,a rough prominence formed by several papill growing through the epidermis at a weak spot and enlarging is called a 4 ,small patches of pigment developing on the hands and face from much exposure to the sun are called 4 ,the growth of exposed dermis sprouting through an opening in the epidermis due to accident is called 4 7,this should be scraped off and cauterized to aid the epidermis to grow over it again47 ,sometimes a cut heals in such a way that no epidermis and therefore no pigment cells cover the place of injury1 which is occupied only by white fibrous tissue 7cicatricial tissue7 of the true skin4 ,in this case the mark left is called a cicatrice or 4 ,if pores or the openings of oil glands become clogged1 but not enlarged1 little swellings called may result4 ,an enlarged pore filled with oil and dirt is called a 4 ,a spot present since birth1 dark with pigment1 and often containing hairs and blood vessels1 is called a 4 ,regulation of ,temperature4--,as is well known1 rapid running or violent exercise of any kind causes profuse perspiration4 ,the sweat glands are connected with the brain by means of nerves1 and when the body has too much heat1 a nerve impulse from the lowest part of the brain causes the sweat glands to form sweat more rapidly4 ,heat and exercise may cause the activity of the sweat glands to increase to forty times the usual rate4 ,the evaporation of the sweat cools the body1 for a large amount of heat is required to evaporate a small amount of water 7,exp4 #d and #e74 ,this is shown by the cooling effect of sprinkling water on the floor on a warm day4 ,by fanning we hasten the cooling of the body 7,exp4 #d74 ,exercise tends to heat the body1 but it also causes us to breathe faster and causes much blood to flow through the skin4 ,both of these effects aid in cooling the body1 for the cool air is drawn into the lungs1 becomes warm1 and takes away heat when it leaves2 and the warm blood flowing in the skin loses some of its heat to the cool air in contact with the skin4 ,effects of ,alcohol upon the ,skin4--,the more blood goes to the skin1 the more blood is cooled4 ,the body as a whole may be cooler1 but we feel warmer when there is more blood in the skin because of the effect of the warm blood upon the nerves of temperature4 ,there are no nerves for perceiving temperature except in the skin and mucous membrane1 and the body has practically no sensation of heat or cold except from the skin or mucous membrane4 ,that alcoholic drinks make the skin red is commonly noticed4 ,often the skin is flushed by one drink2 the bloodshot eyes and purple nose of the toper are the results of habitual use4 ,can you explain why alcohol brings a deceptive feeling of warmth8 ,why does alcohol increase the danger of freezing during exposure in very cold weather8 ,during the chill which precedes a fever1 the body 7except the skin7 is really warmer than usual4 ,exercise will relieve internal congestion and send the blood to the skin better than alcohol4 ,this is the effect sought by sedentary people who use it to replace exercise4 ,the long and sad experience of the race with alcohol proves that the attempt to adapt the body to its use should be given up4 ,,thought ,,questions4 ,the ,functions of the ,skin4--#a4 ,state a fact which shows that the skin is a protection2 gives off offensive substances2 regulates the temperature4 #b4 ,what is lacking in the skin when it cracks or chaps8 ,why does this occur more often in cold weather8 ,when the hands are bathed with great frequency8 ,effects of ,indoor and ,outdoor ,life4--,those who live much out of doors1 exposed to sunlight and pure1 cold air1 are robust and hardy2 while those whose occupations keep them constantly indoors1 especially if no physical labor is necessary1 show by their pale skins1 their fat and flabby1 or their thin and emaciated bodies1 the weakening effect of such a life4 ,we are descended from ancestors who lived in the open air1 and it is impossible for a human being to live much indoors without degeneration of the body and shortening of life4 ,a ,well-trained ,skin4--,we hear a great deal about training the muscles1 the brain1 the eye1 the hand2 yet we may fail to realize that the skin also can be trained and its powers developed1 or it can be allowed to become weak and powerless4 ,soundness of the skin is as essential to health as soundness of any other organ4 ,a rosy color indicates good health because of a well-balanced circulation4 ,paleness often means internal congestion and great liability to indigestion1 colds1 etc4 ,hence we think a rosy skin beautiful and a pale skin ugly4 ,with the skin in a healthy condition1 the danger of taking most diseases is removed4 ,characteristics of a ,vigorous ,skin4--,a person who readily takes cold1 who is fearful of drafts of air at all times1 has a weak skin4 ,to one who has a healthy skin drafts are dangerous only when the skin is moist with perspiration1 and the body is inactive2 cold drafts may then do harm4 ,cold air and cold water are the best means of toughening a tender skin4 ,a bath is to the skin what gymnastic exercises are to the muscles4 ,the muscle fibers in the walls of the blood vessels and the nerves controlling them need exercise as well as the rest of the body 7,fig4 #be74 ,illustration3 ,,fig4 #be4--;,,blood ,,vessels1 with the ,,vaso-,,motor ,,nerves which accompany and control them4 ,importance of ,bathing4--,if we followed the outdoor life and wore the scanty clothing of savage races1 the rains1 the cool air1 and the sunlight would keep our skins vigorous and sound4 ,but want of exercise to induce perspiration allows the sweat glands to become stopped up4 ,the wearing of clothes is a very uncleanly custom4 ,clothes make the skin inactive1 yet confine the impurities which the weakened skin may still be able to excrete4 ,thick and heavy clothing and overheated rooms prevent the nerves from being stimulated by cold air and sunlight4 ,the best way to counteract these weakening conditions is by frequent cool or cold baths4 ,an air bath1 which consists of exposing the bare skin to the air for half an hour or more before dressing in the morning1 may take the place of a cold bath4 ,even the lower animals bathe3 birds1 dogs1 and many lower animals bathe in the rivers4 ,an elephant sometimes takes a bath by showering water over his back with his trunk4 ,treatment of ,burns4--,wet the burn with a little water and sprinkle common baking soda or flour thickly on it4 ,bind with a narrow bandage4 ,for deeper burns soak a small square of cloth in a strong solution of baking soda1 bandage it on wound1 and keep it wet with the solution4 ,olive1 cotton seed1 and linseed oils are excellent for burns 7,exp4 #ac74 ,hygiene of ,bathing4--,a bath should not be taken within an hour after a meal4 ,cold baths 7#a7 should never be taken in a cold room nor when the skin is cold2 7#b7 are more beneficial in summer and in warm climates1 but are necessary in winter for those who live in overheated houses or dress very warmly2 7#c7 should be followed in winter by vigorous rubbing and a glowing reaction2 7#d7 should usually not last longer than one minute in winter4 ,warm baths 7#a7 are more cleansing than cold baths2 7#b7 should not be used alone but should always be followed by a dash of cold water2 7#c7 are better than cold baths if the body is greatly fatigued2 7#d7 are more beneficial when going to bed than upon rising4 ,cold baths and very hot baths are both stimulants to the nervous system and cause an expenditure of nervous energy4 ,for one whose nervous energy is at a very low ebb cold baths may be weakening if prolonged beyond a few seconds4 ,for one with skin relaxed and body sluggish from indoor life1 cool baths arouse activity1 tone up the body1 and may be as beneficial as outdoor exercise in restoring vigorous health4 ,as with every hygienic measure1 each person must find out by experience what suits him best4 ,clothing was first employed for ornament4 ,in cold climates it aids in maintaining the uniform temperature of the body2 to it man owes his distinction of being the most widely distributed of animal species4 ,clothing prevents rapid escape of bodily heat by confining air1 a non-conductor of heat1 in its meshes4 ,hence1 the effect of clothing varies with the weave2 likewise with the tendency of its fibers to keep dry1 for if water replaces air in the meshes1 the body loses heat rapidly4 ,for cool clothing the weave should be hard and tight1 for warm clothing it should be soft and loose4 ,the warmth of clothing is affected more by its weave than by its weight4 ,the weave may be tested by stretching2 the fabric with softest weave will stretch the most 7,exp4 #h74 ,linen makes the coolest of all clothing because it weaves hard with small meshes2 silk ranks next in coolness4 ,when warmth is desired1 linen or cotton garments should be made of fabrics woven like stockings4 ,linen and cotton both absorb water rapidly and dry rapidly 7,exp4 #f72 if woolen did also1 it would make the warmest of all clothing1 but it dries so slowly 7,exp4 #g7 that it cools the body after the activity is over instead of drying rapidly and1 as with linen and cotton1 keeping the body cool during the exertion 7,exp4 #e74 ,woolen weaves with the largest air meshes of all materials2 hence its warmth increases perspiration1 but woolen removes perspiration most slowly and tends to relax the skin if the wearer has an active skin or makes active exertion4 ,woolen is best for underclothing during extreme cold only or for persons who never make such vigorous muscular exertion as to perspire4 ,in general1 cotton or linen is best for underwear4 ,they possess the added advantages of less cost and of not shrinking out of size and shape when washed4 ,a mixture of cotton and silk or of cotton and wool is more durable than either alone4 ,cotton and linen1 unlike woolen1 are not attacked by insect pests4 ,it is better to depend more upon outer clothing than underclothing for warmth4 ,in the ,gulf states the wearing of woolen outer clothing indoors during warm weather 7which lasts eight months7 is unhealthful and uncleanly because of the perspiration absorbed2 this is as absurd as to wear cotton outer clothing in ,northern states during the eight cold months4 ,black clothing absorbs twice1 blue almost twice1 red and yellow almost one and a half times1 as much heat as white clothing 7,exp4 #aj74 ,which material protects best from radiant heat8 7,exp4 #i47 ,because large blood vessels are near the surface at the neck1 wrists1 and ankles very thin or no covering at those points aids greatly in keeping the body cool4 ,high collars1 long sleeves1 and high shoes are unhealthful in warm climates and in summer4 ,what objection to black shoes in summer8 ,patent leather8 ,show how women dress more sensibly in hot weather than men4 ,the kidneys are located on each side of the spinal column in the 8small of the back0 and extend slightly above the level of the waist4 ,they are bean-shaped organs about four inches long 7,fig4 #bf74 ,the kidneys of a sheep or ox closely resemble those of man4 ,they are outside of the peritoneum 7,fig4 #ii7 and attached to the rear wall of the abdomen4 ,a large artery 7#ab1 colored ,fig4 #e7 goes to each kidney and divides into many capillaries which surround tubules in the kidneys 7,fig4 #bg74 ,the secretion1 containing nitrogenous impurities of the blood1 is continually being deposited in the tubules1 which take it to a funnel-shaped cavity at the inner edge of the kidney 7,fig4 #bf74 ,from this cavity a white tube called the ureter leads down to a storage organ in the pelvis called the bladder4 ,illustration3 ,,fig4 #bf4--,,section ,,of ,,kidney4 ,,ra1 renal artery2 ,py1 pyramids surrounding hollow space from which the ureter 7,u7 leads the secretion to the bladder4 ,changes in ,blood in the ,kidneys4--,the water holding the nitrogenous waste varies in amount with the amount of water drunk and with the activity of the skin1 being less in summer when the perspiration is great4 ,the lungs aid the skin and kidneys in disposing of superfluous moisture4 ,the kidneys have almost the entire responsibility of relieving the body of certain mineral salts and a white crystalline solid called urea4 ,this is very injurious if retained1 causing headaches1 rheumatism1 and other troubles4 ,illustration3 ,,fig4 #bg4--,,plan ,,of ,a ,,urinary ,,tubule1 ,tb1 with artery ,a1 and ,v in p,v4 ,,thought ,,questions4 ,hygiene of the ,skin4--#a4 ,what kind of a scar is not affected by freckles or tan8 #b4 ,can a scar on a negro be white8 #c4 ,does a scar on a child grow in size8 #d4 ,why is heat most oppressive in moist weather8 #e4 ,how do you account for the shape and location of the usual bald spot8 #f4 ,how does the wearing away of the outer cells of the epidermis contribute to the cleanliness of the body8 #g4 ,why does the palm of the hand absorb water more rapidly than the back of the hand8 #h4 ,is it more necessary for mental workers to bathe often or change their clothes often8 ,for physical workers8 #i4 ,is cotton or woolen clothing more liable to stretch or shrink out of shape or size8 ,to catch fire8 ,to make the skin clammy with moisture8 ,to cost more8 ,to be eaten by moths8 ,illustration3 ,,fig4 #bh4--,,the ,,skeleton4 ,,chapter ,,iii ,,the ,,skeleton ,experiment #a4 7,at home47 ,is the ,arch of the ,foot ,elastic8--,wet the foot in a basin of water and1 while sitting1 place the foot flat upon a piece of paper4 ,draw the outline of the track4 ,repeat1 but stand with your whole weight upon the foot4 ,draw track4 ,conclusion8 7,take sketches to school4 ,which sketch shows the flattest foot87 ,devise a method for measuring the length of the foot with and without the weight of the body upon it4 ,what difference8 ,conclusion8 ,experiment #b4 ,composition of ,bone4--,place a bone in a hot fire and let it remain for three or four hours4 ,it will keep its shape however long you burn it2 but unless you handle it carefully when you take it out1 it will crumble to pieces4 ,if not thoroughly burned1 the bone will be black from the carbon of the animal matter still left in it4 ,experiment #c4 ,obtain a slender bone like the rib of a hog or the leg bone of a fowl1 and put the raw bone into a vessel containing strong vinegar or two ounces of muriatic acid and a pint of water4 ,leave it there for four days4 ,when the bone is taken out1 it can be tied into a knot4 ,the acid may be washed off1 and the bone preserved in a bottle of alcohol or glycerine4 ,experiment #d4 ,the ,forms of ,joints4--,obtain the disjointed bones of a fowl or small mammal and place them one at a time in their sockets and study the fit and motion of the joints4 ,experiment #e4 ,pivot ,joints4--,through what fraction of a circle do the pivot joints in the forearm and neck allow the hand and head to rotate8 ,review ,questions4--,where are the bone cells8 ,how does nourishment reach them8 ,how has the mineral part of the bones been deposited8 ,how long may bone cells live8 ,name animals with outside skeletons4 ,inside skeletons4 ,no skeleton4 ,forms and ,uses of ,bones4--,the three chief uses of bones are protection1 motion1 and support4 ,in order to fulfill these purposes1 the bones must have different sizes1 shapes1 and positions4 ,the bones are classed by shape1 as long1 flat1 and irregular4 ,those whose chief use is to protect are broad and flat4 ,the bones which furnish support are thick and solid2 those designed to aid in motion are long and straight4 ,including six small bones in the ear1 there are two hundred and six bones in the adult skeleton4 ,gross ,structure of ,bones4--,the structure of a long bone is shown in ,fig4 #bi4 ,it has a long1 hollow shaft of hard1 compact bone1 and enlarged ends composed of spongy bone4 ,the hollow in the shaft is filled with yellow marrow1 which is composed of blood vessels and fat1 and aids in nourishing the bone4 ,the long bones are found in the limbs 7,fig4 #bh74 ,the ribs and other flat bones and the irregular bones contain no yellow marrow2 they are spongy inside1 and hard and compact near the surface4 ,there is a red marrow in the cavities in the spongy parts of bones 7,fig4 #bi74 ,new red blood cells are formed in this marrow4 ,the bones have a close-clinging1 fibrous covering composed of connective tissue and blood vessels4 ,it is called periosteum4 ,illustration3 ,,fig4 #bi4--;,,femur1 sawed lengthwise4 ,the red blood cells are formed in the red marrow of the spongy part4 ,illustration3 ,,fig4 #cj4--;,,front ,,view ,,of ,,right ,,femur4 ,chemical ,composition of ,bone4--,experiments 7#b and #c7 show that the bones contain a mineral or earthy substance1 which makes them hard and stiff1 and a certain amount of animal matter1 called gelatine1 which binds the mineral matter together and makes the bones tough and somewhat elastic4 ,the fire burned out the animal matter of the first bone1 and the acid dissolved out the mineral matter of the second bone4 ,the mineral matter is chiefly lime1 and makes up about two thirds of the weight of the bone4 7,why is more mineral than animal matter needed87 ,the animal gelatine is a gristly substance4 ,as the body grows old1 the animal matter of the bones decreases1 and they become lighter4 ,they are more easily broken and do not heal so readily as the bones of young persons4 ,the skeleton is subdivided into the bones of the head1 trunk1 and limbs4 ,the bones of the trunk are those of the spine1 the chest1 the shoulder blades1 collar bone1 and hip bones4 ,illustration3 ,,fig4 #ca4--,,vertebral ,,column4 ,side view4 ,the spinal or vertebral column is made up of twenty-six bones 7,fig4 #ca74 ,it is the axis of the human skeleton1 to which all other bones are directly or indirectly attached4 ,animals with inside skeletons have this column1 and are called vertebrates4 ,fish1 reptiles1 birds1 beasts1 apes1 and man are vertebrates4 ,the spine1 as this column is sometimes called1 is not only the main connecting structure and support of the body1 but it forms a channel through which passes the spinal cord4 ,fig4 #cb shows a vertebra1 or one of the bones that compose the column4 ,the three projecting points or processes are for the attachment of ligaments and muscles4 ,the main body of each vertebra is for supporting the weight transmitted by the column above4 ,just behind this thick body is a half ring 7,fig4 #cb71 which with the half rings on the other vertebrae form the channel for the spinal cord4 ,between the vertebrae are thick pads of gristle1 or cartilage1 which act as cushions to prevent jars1 and by compression allow bending of the spinal column in all directions4 ,illustration3 ,,fig4 #cb4--,,side ,,and ,,under ,,view ,,of ,a ,,vertebra4 ,the ,chest 7see ,fig4 #ge74--,the twelve pairs of ribs are attached to the spinal column behind1 and extend around toward the front of the body1 somewhat like hoops4 ,the first seven pairs1 called true ribs1 are attached directly to the flat breastbone1 or sternum4 ,each of the next three pairs1 called false ribs1 is attached to the pair above it4 ,the last two pairs1 called floating ribs1 are free in front4 ,the ,shoulder ,girdle4--,the collar bones 7,fig4 #bh7 can be traced from the shoulders until they nearly meet on the breastbone at the top of the chest4 ,the collar bone is shaped like the italic letter f2 it helps to form the shoulder joint and holds the shoulder blade out from the chest that the motions of the arm may be free4 ,the flat1 triangular shoulder blade 7,fig4 #ge7 can be felt by reaching with the right hand over the left shoulder4 ,it spreads over the ribs like a fan4 ,its edges can be made out1 especially if the shoulder is moved while it is being felt4 ,the high ridge which runs across the bone can be felt extending to the top of the shoulder4 ,the ,pelvic ,girdle4--,the edges of the hip bones can be felt at the sides of the hips 7,fig4 #bh74 ,the hip bones1 with the base of the spine1 form a kind of basin called the pelvis4 ,the skull 7,fig4 #cc7 rocks1 or nods1 on the top vertebra4 ,it consists of the cranium1 or brain case1 and the bones of the face4 ,the shapes and names of the bones of the skull are shown in ,fig4 #cc4 ,illustration3 ,,fig4 #cc4--;,,human ,,skull1 disjointed4 ,adaptations of the ,skull for ,protection4--,its arched form is best for resisting pressure and turning aside blows4 ,like all flat bones1 the skull has a spongy layer of bone between the layers of compact bone forming the outer and inner surfaces2 hence it is elastic and not easily cracked4 ,the nose1 brow1 and cheek bones project around the eye for its protection4 ,the delicate portions of the ear are embedded in the strongest portion of the skull4 ,the branches of the nerves of smell end in the lining of the bony nasal chambers4 ,the spinal cord rests securely in the spinal canal4 ,the arms and legs have bones that closely correspond to each other4 ,the ,latin names of these bones1 as well as of all the other bones1 are given in ,fig4 #bh4 ,there are #cj bones in each arm and #cj in each leg 7,fig4 #cd74 ,here is a list of the bones of the arm1 followed by the names in brackets of the corresponding leg bones3 upper arm bone thigh bone1 #b forearm bones shin bone and splint bone1 #h wrist bones #g ankle bones1 #e palm bones #e bones of instep1 #ad finger bones #ad toe bones4 ,the shin bone is the larger bone between knee and ankle4 ,the long1 slender splint bone and the shin bone are bound side by side4 ,illustration3 ,,fig4 #cd4--;,,bones ,,of ,,arm ,,and ,,leg4 ,illustration3 ,,fig4 #ce4--,,sutures ,,of ,,skull4 ,differences between ,arm and ,leg4--,there is a saucer-like bone1 called the kneecap1 embedded in the large ligament which passes over each knee4 ,there is no such bone in the elbow4 ,there is one less bone in the ankle than in the wrist1 hence there are the same number of bones in the arm and leg4 ,the shoulder joint is more freely movable than the hip joint4 ,the fingers are longer and more movable than the toes2 the thumb moves far more freely than the big toe4 ,the instep is much stronger than the palm2 for each instep must support1 unaided1 the weight of the whole body at each step1 with any other weight that the person may be carrying4 ,the palm is nearly flat1 but the instep is arched to prevent jars4 ,when the weight of the body is thrown on the foot at each step1 the top of the arch is pressed downward1 making the foot longer than before4 ,the arch springs up when the weight is removed 7,exp4 #a74 ,,illustrated ,,study4 ,the ,shapes of ,bones4--,write ,l1 ,f1 or ,i after these names 7see ,fig4 #bh1 etc471 according as the bones are long1 flat1 or irregular3 face1 cranium1 vertebra1 hip1 rib1 breastbone1 collar bone1 shoulder blade1 upper arm bone1 lower arm bones1 wrist1 palm1 fingers1 thigh bone1 shin bone1 splint bone1 ankle1 instep1 toes1 kneecap4 ,structure of ,joints4--,the meeting of two bones forms a joint 7,exp4 #d74 ,some of the joints are immovable4 ,the skull bones join in zigzag lines called sutures1 formed by the interlocking of sawlike projections 7,fig4 #ce74 ,these immovable joints are necessary for the protection of the brain1 which is the most delicate of the organs4 ,the brain attains almost its full size by the seventh year of life2 its bony case needs to grow very little after that4 ,the joints of the pelvis are also immovable4 ,all movable joints have two cartilages1 and as the bones turn1 one cartilage slips over the other4 ,there is an intermediate class of joints found between the vertebr and where the ribs join the breastbone4 ,these joints depend for their motion upon the flexibility and compressibility of their cartilages4 ,they are called mixed1 or elastic1 joints1 and allow slight motion4 ,such a joint has only one cartilage4 ,kinds of ,movable ,joints4--,the movable joints are found chiefly in the limbs4 ,when one end of the bone is rounded and fits into a cuplike hollow1 the joint allows motion in all directions1 and is known as a ball-and-socket joint4 ,the hip joints and shoulder joints are examples4 ,a hinge joint allows motion in only two 7opposite7 directions2 for example1 the to-and-fro motion of the elbow4 ,a pivot joint allows a rotary motion2 examples1 the first vertebra on the second1 one bone of forearm upon the other4 ,a gliding joint consists of several bones that slide upon one another1 as at the wrists and ankles4 ,the ,four ,features presented by a ,movable ,joint 7,fig4 #cf74--;,if not held in place1 the bones would slip out of their sockets1 hence there are ligaments1 or tough bands1 to bind the bones together4 ,sudden jolts would jar the bones and injure them2 shocks are prevented by a layer of elastic cartilage over the end of each bone4 ,the moving of one bone over another in bending a joint would wear the bone with friction unless the cartilages were very smooth and lubricated with a fluid called the synovial fluid4 ,the synovial fluid would be constantly escaping into the surrounding tissues except for the collarlike ligament called the capsule1 which surrounds the joint and is attached to each bone entirely around the joint 7,fig4 #cf74 ,illustration3 ,,fig4 #cf4--;,,diagram ,,of ,a ,,joint4 ,,thought ,,questions4 ,the ,kinds of ,joints4--,write ,b1 ,h1 ,g1 ,e1 ,p1 or ,i after these names according to the kind of joint 7ball-and-socket1 hinge1 gliding1 elastic1 pivot1 immovable73 between bones of skull1 head nodding1 head turning1 vertebr1 lower jaw1 ribs to breastbone 7,fig4 #ge71 shoulder1 elbow1 wrist1 fingers1 hip1 knee1 ankle1 toes4 ,growth of ,bones4--,the blood vessels pass into the bones from the periosteum4 ,if the periosteum is removed1 the larger blood vessels are taken away and the bone beneath it perishes4 ,if the underlying bone is removed and the periosteum left1 the bone will be replaced4 ,a curious proof of the active circulation in the bone is furnished when madder is mixed with the food of pigs4 ,in a few hours the bones become a darker pink than usual2 and if the madder is fed to the pigs for a few days1 their bones become red4 ,a child grows in height chiefly during three or four months in spring and summer2 but its body broadens and becomes heavier during autumn4 ,health of the ,bones4--,it is plain that a strong and free circulation of pure blood contributes to the health and strength of the bones2 good food and pure air make pure blood4 ,cases of 8delayed union10 or slow mending of broken bones1 occur more often with intemperate than with sober people4 ,this is because the vitality of the bone cells has been weakened by the use of alcohol4 ,many surgeons dislike to operate on an old drunkard4 ,posterior ,curvature of the ,spine4--,the spine 7see ,figs4 #bh1 #ca7 has two backward curves 7opposite chest and hips7 and two forward curves 7at loins and neck74 ,the deformity called posterior curvature is chiefly an exaggeration of the upper posterior curve4 ,round shoulders is the slightest1 and hunchback the most marked1 degree of this deformity4 ,causes3 #a1 bending over the work while either standing or sitting2 #b1 slipping down in the seat1 as in ,figure #ea2 #c1 working habitually with the work low in front1 as reading and writing at too low a desk 7,fig4 #di71 or bending over while hoeing1 sitting on the floor 7,japanese and ,chinese72 #d1 weak muscles in the back2 #e1 wearing shoes with high heels2 #f1 binding the ribs down with tight clothing2 #g1 walking with the head drooped forward or the chest flat2 #h1 wearing suspenders without a pulley1 or lever1 at the back2 #i1 carrying the hands in the pockets4 7,swing the arms to keep the hands out of the pockets and break the habit72 #aj1 wearing a coat or vest that is tight at the back of the neck4 ,this deformity is brought about by stretching the ligaments at the back side of the spine1 and by compressing the cartilages until they become wedge-shaped1 with the thin part of the wedge in front4 ,the flexibility of the spine is a great advantage1 but it increases the risk of deformity4 ,one of the most serious evils of posterior curvature is a flat chest and restricted breathing4 ,illustration3 ,,fig4 #cg4--;,,incorrect ,,posture4 ,illustration3 ,,fig4 #ch4--;,,correct ,,posture1 but strained and stiff4 ,lateral ,curvature of the ,spine4--,a perfect spine curves to neither side 7,fig4 #dg71 but is perfectly erect4 ,the least habitual lateral curvature is deformity4 ,causes3 #a1 writing at a desk that is too high2 #b1 habitually carrying a book1 satchel1 or other weight in the same hand2 #c1 carrying the head on one side 7,fig4 #df72 #d1 habitually standing with the weight on the same foot2 #e1 a certain defect of vision 7astigmatism1 ,chap4 ,,ix74 ,to overcome ,spinal ,deformities4--,the work1 or the manner of doing the work1 should be so changed as to give extra labor to the neglected muscles4 ,avoid the habits mentioned above as causing deformity4 ,sit and stand in the manner described in the next paragraph4 ,sleeping on the back upon a hard mattress without a pillow tends to cure posterior curvature and flat chest4 ,the correct position in standing is3 chest forward1 chin in1 hips back 7,figs4 #ch1 #ci74 ,to sit correctly1 sit far back in the chair 7,figs4 #di1 #ej1 #ea7 with the body erect and balanced4 ,in youth the bones are soft and growing2 they will readily grow into perfect shape1 and will almost as readily grow deformed4 ,sprains4--,immerse the part in hot water for half an hour1 then bandage to keep the part at rest4 ,use the limb as little as possible4 ,it may be necessary for a physician to apply a plaster dressing to a very bad sprain where the ligament is torn from the bone4 ,broken ,bones4--,to prevent bone from cutting flesh and skin1 do not move the person until a temporary splint has been provided by tying sticks or umbrellas around the limb with handkerchiefs4 ,,practical ,,questions4 ,the ,skeleton4--#a4 ,what kind of a chair back causes one to slide forward in the seat8 #b4 ,what fault in sitting is made necessary by using a chair with so large a seat that the front edge strikes the occupant behind the knee8 #c4 ,why is the shoulder more often dislocated than the hip8 #d4 ,high pillows may cause what deformity8 #e4 ,find three bones in the body not attached to other bones4 ,find twenty-five bones attached to other bones by one end only 7,figs4 #bh and #ci74 #f4 ,what deformities may result from urging a young child to stand or walk8 #g4 ,which bone is most often broken by falling upon the shoulder8 #h4 ,where in bones is fat stored for future use8 #i4 ,ligaments grow very slowly4 ,why is recovery from a sprain often tedious8 ,illustration3 ,,fig4 #ci4--,,the ,,human ,,skeleton ,,in ,,action4 ,,chapter ,,iv ,,the ,,muscles ,it has already been stated that there are at least two muscles attached to a bone to move it in opposite directions4 ,since there are two hundred and six bones1 you are not surprised to learn that to move the bones and accomplish the various purposes just stated1 there are five hundred and twenty-six 7#ebf7 skeletal muscles4 ,two ,kinds of ,muscles4--,all muscles are controlled by means of the nervous system4 ,some of them are directed by parts of the brain that work consciously2 others are controlled by the spinal cord and the parts of the brain that work unconsciously4 ,those of the first kind are usually controlled by the will1 but they sometimes act involuntarily4 ,they are called voluntary muscles4 ,they move the bones and are located in the limbs and near the surface of the trunk 7,fig4 #dd74 ,the other kind of muscles are never controlled by the will1 and are called involuntary muscles4 ,we cannot cause them to act1 nor can we prevent them from acting4 ,they contract more slowly than the voluntary muscles4 ,most of them are tubular and found in the cavity of the trunk4 ,the involuntary muscles belong to the internal organs1 and relieve the will of the responsibility and trouble of the activity of these organs2 otherwise1 the mind would have no time for voluntary actions4 ,gross ,structure of ,voluntary ,muscles4--,a beefsteak is seen to be chiefly red1 although parts of it are white or yellowish4 ,the white or yellowish flesh is fat2 the red1 lean flesh is voluntary muscle4 ,if a piece of beef is thoroughly boiled1 it may be easily separated into bundles the size of large cords4 ,these bundles may1 by the use of needles1 be picked apart and separated into threadlike fibers 7,fig4 #dj74 ,illustration3 ,,fig4 #dj4--,,muscle ,,bundles bound together by connective tissue sheaths4 ,microscopic ,structure of ,muscles4--,these threadlike fibers may1 under a magnifying glass1 be separated into fine strands called fibrils4 ,these last are the true muscle cells2 they are shown by the microscope to be crossed by many dark lines 7,fig4 #dh74 ,hence voluntary muscles are called striated or striped muscles4 ,prolonged boiling and patient picking with a needle are needed to dissect muscle1 because the bundles are held together by thin1 glistening sheets of connective tissue by which they are surrounded4 ,this connective tissue surrounds and holds in place the separate fibers of each bundle 7,fig4 #dj74 ,illustration3 ,,fig4 #da4--,,two ,,muscle ,,fibers ,,of ,,heart4 ,illustration3 ,,fig4 #db4--;,,involuntary ,,muscle ,,cells 7or fibers74 ,the fibrils of involuntary muscles are spindle-shaped 7see ,fig4 #db74 ,there are no cross lines on the fibrils2 hence involuntary muscles are called smooth or unstriped muscles4 ,the heart fibers are exceptional2 they are the only involuntary muscle fibers that are striped 7,fig4 #da74 ,,thought ,,questions4 ,classification of ,some of the ,muscles4--,copy the following list and mark ,i for involuntary and ,v for voluntary after the appropriate muscles4 ,muscles for chewing4 ,muscles of gullet4 ,muscles of the heart4 ,muscles that move arms4 ,muscles for breathing4 ,muscles in the skin that cause the hair to stand on end4 ,muscles that move eyelids4 ,muscles that contract pupil of eye4 ,muscles for talking4 ,muscles that contract and expand the arteries 7in blushing and turning pale74 ,muscles that move eyeball4 ,muscles that give expression to the face4 ,tendons4--,the connective tissue which binds the fibers of muscles into bundles1 and forms sheaths for the bundles1 extends beyond the ends of the muscles and unites to form tough1 inelastic white cords called tendons4 ,some muscles are without tendons1 and are attached directly to bones4 ,study the figures and find examples of this 7see ,figs4 #dd1 #ge74 ,to realize the toughness of tendons1 feel the tendons under the bent knee or elbow1 where they feel almost as hard as wires4 ,the tendons save space in places where there is not room enough for the muscles1 and permit the bulky muscles to be located where they are out of the way4 ,wherever the tendons would rise out of position when a joint is bent1 as at the wrist and ankle1 they are bound down by a ligament4 ,illustration3 ,,fig4 #dc4--7;,for blackboard47 ,,biceps relaxed and contracted4 ,arrangement of ,voluntary ,muscles4--,circular muscles1 called sphincter muscles1 are found around the mouth and eyes4 ,muscles that extend straight along the limb either bend it and are called flexors1 or straighten it and are called extensors4 ,most of the voluntary muscles are arranged in pairs and cause motion in opposite directions2 they are said to be antagonists4 ,the biceps 7,fig4 #dc7 bends the arm4 ,its antagonist is the triceps on the back of the arm4 ,by feeling them swell and harden as they shorten1 locate on your own body the muscles mentioned in ,fig4 #dd4 ,how a ,muscle grows ,stronger2 its ,blood ,supply4--,nature has provided that any part of the body shall receive more blood when it is working than when it is resting4 ,when it works the hardest1 the blood tubes expand the most and its blood supply is greatest4 ,so whenever a muscle is used a great deal1 an unusual amount of material is carried to it by the blood1 the cells enlarge and multiply1 and the muscle grows4 ,the walls of the capillaries are so thin that the food which is in the blood readily passes from them to the muscle4 ,because of the oxidation taking place1 a working muscle is warmer than one at rest4 ,by use a muscle grows large1 firm1 and of a darker red2 by disuse1 it becomes small1 flabby1 and pale4 ,but if muscles are worked too constantly1 especially in youth1 their cells do not have time to assimilate food and oxygen1 and their growth is stunted4 ,unless the meal has been a very light one1 vigorous exercise should not be taken after eating1 as the blood will be drawn from the food tube to the muscles and the secretion of the digestive fluids will be hindered4 ,persons whose entire circulation is weak may find that light exercise after a meal1 such as walking slowly1 may help circulation and digestion4 ,why the ,muscles work in ,harmony4--,when a boy throws a stone1 almost every part of the body is concerned in the action4 ,his arms1 his legs1 his eyes1 the breathing1 the beating of the heart1 are all modified to assist in the effort4 ,as the boy wills to throw the stone1 nerve impulses are sent to all the organs that can assist1 and they are excited to just the amount of action needed4 ,illustration3 ,illustrated ,study of ,muscular ,function ,draw a dotted line from each function mentioned on margin to the muscle or muscles having that function4 ,bows the head8 ,straightens the elbow8 ,straightens the fingers8 ,swings leg outward8 ,bends the knee8 ,straightens the knee8 ,crosses the leg8 ,straightens toes8 ,draws shoulder back8 ,lifts the whole arm outward and upward8 ,draws whole arm downward and forward8 ,bends the elbow8 ,bends the fingers8 ,raises the body on the toes8 ,raises toes8 ,,fig4 #dd4--,,superficial ,,muscles ,,after ,,the ,,statue ,,of 8,,the ,,digger0 7,lami74 ,the ,nerve ,impulse and the ,contraction4--,each nerve that goes to a muscle is composed of many fibers2 the fibers soon separate and go to all parts of the muscle1 and each muscle fiber receives its nerve fiber 7see ,fig4 #de74 ,in the brain each fiber is stimulated at once1 and all the fibers shorten and thicken together4 ,this change is spoken of as contraction2 but since the muscle does not become smaller1 the word may be misleading4 ,when the muscle shortens1 it thickens in proportion and occupies as much space as it did when relaxed4 ,where does ,muscular ,energy come from8--,the nerve does not furnish the energy which the muscle uses when contracting4 ,the muscle cells have already stored up energy from the food and oxygen brought to them by the blood1 and the process called oxidation sets free the energy4 ,activity of muscle may increase the carbon dioxid output fivefold4 ,mental work has practically no effect upon it4 ,illustration3 ,,fig4 #de4--,,motor ,,nerve ,,fibers1 ending among fibrils of voluntary muscle4 ,compare with ,fig4 #dh4 ,how a ,muscle stays ,contracted4--,the muscle relaxes at once after contraction2 and in order to keep it contracted1 nerve impulses must be sent in quick succession1 causing in fact many contractions2 the effect of this is sometimes visible1 as the trembling of the muscle4 ,figure #dg shows an easy standing posture4 ,what causes ,fatigue4--,fatigue or exhaustion is due to the using up of the living material in the nerve cells and muscle cells by oxidation4 ,rest is necessary to give cells opportunity to repair themselves4 ,why is it less fatiguing to walk for an hour than to stand perfectly still for ten minutes8 ,illustration3 ,,fig4 #df4--;,,improper ,,position2 causes spine to curve to side2 raises one hip and shoulder above the other4 ,illustration3 ,,fig4 #dg4--;,,best ,,position2 chest is free to expand1 and weight is easily shifted from one foot to other4 ,degeneration of ,muscles begins with habitual disuse4 ,we dare not furnish a substitute for the work of a muscle1 if we wish the muscle to remain sound4 ,a belt or a stay at the waist will cause the muscles of the trunk to become flabby and the abdomen to relax and protrude4 ,how ,muscular ,activity helps the ,health4--,life is change1 stagnation is death4 ,muscular activity uses up the food1 gives a good appetite1 and sets the digestive organs to work2 it uses up the oxygen and sets the lungs to work2 but most of all1 every contraction of a muscle helps the blood to flow4 ,as a muscle contracts1 it presses upon the veins and lymphatics1 and1 by this pressure1 forces the blood and lymph along 7,fig4 #dh74 ,in any ordinary activity1 dozens of muscles are being used4 ,that the effect upon the circulation is very powerful1 is shown by the rosy skin1 deep breathing1 and rapid heart beat4 ,the many benefits of an active circulation of the blood and lymph will be discussed in the next chapter4 ,see page #fg4 ,illustration3 ,,fig4 #dh4--;,,capillaries among fibers of voluntary 7cross striped7 muscle4 7,peabody47 ,a grave danger from athletics is that of developing the muscles1 including the heart1 to an enormous extent by training2 then when training ceases the muscles undergo fatty degeneration from disuse4 ,heart disease and other diseases may follow4 ,many athletes die young1 killed by trying to turn their bodies into mere machines for running1 boxing1 or rowing1 instead of living complete lives4 ,the athletic ideal is not the highest ideal of health2 general activity1 resembling the occupations of hunting and farming by which the early race supported itself1 is best for health4 ,many kinds of factory work use only one set of muscles4 ,the savage did not lead a monotonous life1 and monotony is bad for both muscles and nerves4 ,advantages of ,work and ,play over ,gymnastic ,exercises4--,the interest that comes from doing something useful1 makes muscular exertion doubly beneficial to the health4 ,the lifting of dumbbells1 ,indian clubs1 and pulley weights1 and letting them down again1 tends to become very irksome1 even though done with the knowledge that the exercise will benefit the health4 ,useful labor and games place definite objects in view and do not require so great an effort of the will nor exhaust the nerves so much as mere exercise4 ,the interest in the work or the game serves to arouse all the nerves and muscles to work in harmony4 ,illustration3 ,,fig4 #di4--;,,desk ,,too ,,low4 7,jegi47 ,illustration3 ,,fig4 #ej4--;,,correct ,,position4 ,illustration3 ,,fig4 #ea4--,,slipping ,,down ,,in ,,seat4 ,an ,advantage of ,gymnastics over ,work and ,play4--,gymnastics can furnish any required variety of exercises and can develop exactly the muscles that need development and leave those idle that have become overdeveloped by doing constantly one kind of work or playing continually the same game4 ,the deformity of a flat chest 7and round shoulders which always accompany it7 does not so often indicate a weak chest or small lungs as it indicates weak or relaxed muscles of the back and the habit of sitting in a relaxed position at work 7,figs4 #di1 #ej1 #ea74 ,gymnastic exercise is not wholly an artificial custom4 ,cats stretch themselves1 stretching each leg in succession2 many animals gambol and play4 ,a gymnastic drill1 taken to music and with large numbers of pupils in the drill1 is interesting as work or play1 and should not be neglected for any study1 however important4 ,environment of ,early ,man and ,modern ,man4--,a well-developed man of one hundred and fifty pounds weight should have sixty pounds of muscles4 ,the proportion is often different in the puny bodies of the average civilized men1 such as clerks1 merchants1 lawyers1 and other men with sedentary occupations2 their bodies are as likely to be lean and scrawny or fat and flabby as to be correctly proportioned4 ,why does a normal man have sixty pounds of muscles instead of twenty pounds of puny strings such as would have sufficed for a clerk1 student1 or a writer8 ,this is because1 in his native condition1 he had to seek his food by roaming through the forest1 contending with wild beasts or with other savage men1 often traveling many miles a day1 climbing trees1 etc4 ,too ,rapid ,change of ,environment2 ,destructive ,tendencies of ,civilization4--,it is impossible for the human body to change greatly in a few hundred years4 ,the body of man served him for many ages for the manner of life outlined above4 ,it was suited for these conditions1 and the muscles and the organs that support them cannot accommodate themselves to changed conditions in a few generations4 ,it has only been a few hundred years since the ancestors of the ,britons and ,germans1 for instance1 were running wild in the ,german forests1 clad in the skins of wild beasts4 ,yet civilized man lets his muscles fall into disuse1 he takes a trolley car or horse vehicle to go half a mile1 an elevator to climb to the height of thirty feet4 ,he neglects all his muscles except those that move the tongue and the fingers of the right hand4 ,he never makes enough exertion to cause him to draw a deep breath1 and his lungs contract and shrivel4 ,he seldom looks at anything farther than a few inches from his nose1 and his eyes become weak4 ,at the same time that he neglects his muscles and his lungs1 he overworks his brain and his stomach2 yet he expects his body to undergo the rapid changes to suit the demands of his life4 ,such rapid changes in the human race are impossible4 ,a man that does not see that sound health is the most valuable thing in the world1 except a clear conscience1 is in danger both of wrecking his own happiness and of failing in his duty to others4 ,,thought ,,questions4 ,shoes4--#a4 ,what the faults of shoes may be in size2 shape2 sole2 heel2 toe2 instep4 #b4 ,name deformities resulting to skin of foot2 nails2 joints2 arch2 ankle2 spine4 #c4 ,state effects of uncomfortable shoes on muscular activity2 mind and disposition4 #d4 ,state effect of aversion to walking on muscles2 circulation4 #e4 ,if a shoe is too loose1 it slips up and down at the heel and chafes the skin there2 if too tight1 there is pressure on the toes1 which causes a corn or ingrowing nail4 ,have your shoes been correct1 or have they been too loose or too tight8 ,according to this test1 what proportion of people wear shoes that are too tight8 #f4 ,how many sprained ankles have you known among boys2 girls8 #g4 ,why is it that people who grow up in warm climates have high1 arched insteps1 and short1 broad1 elastic feet1 but people of the same race who pass their childhood in cold climates often have long narrow feet with low arches and sometimes have the deformity called 8flat foot08 ,illustration3 ,,fig4 #eb4--;,,arch ,,of ,,foot4 ,it forms an elastic spring4 ,instinct as a ,guide for using the ,muscles4--,the instinctive feeling called fatigue tells us when to rest4 ,there is also a restless1 uneasy feeling that comes over a normal human being when confinement and restraint of the muscles have reached an unhealthy limit4 ,this feeling should not be repressed for long at a time4 ,many1 ruled by avarice1 ambition1 interest in sedentary work1 a silly notion of respectability1 or a false conception of duty1 have repressed this feeling and have lost it4 ,there is then a feeling of languor1 and a disinclination to the very activity which health demands4 ,an unheeded instinct is as useless as an alarm clock that has been habitually disregarded4 ,exercise and ,climate4--,in our warmest states and in the tropics1 one hour's vigorous physical labor a day1 combined with the ordinary activities of life1 will keep a person in good condition4 ,in the colder states1 muscular exertion for several hours is needed daily4 ,complete ,living4--,numberless people have devoted themselves to an intellectual occupation1 and planned to keep their bodies sound by gymnastics and special exercises4 ,because of the monotony of exercises1 they are soon given up in nearly every instance4 ,the safest way is never to allow all the energies to be devoted to a one-sided occupation1 but so to plan one's life and work that a part of the time is devoted to some physical work1 whether it be in a garden1 workshop1 or orchard2 in walking a long distance to the office2 at bookbinding1 cooking1 wood carving1 or any one of various other useful occupations4 ,the result of manual training shows that not only strength of body1 but strength of mind1 is promoted by physical labor4 ,problems of war and of the chase kept active both the body and mind of the savage4 ,hence he led a more nearly complete life than his civilized descendants1 and his body was strong accordingly4 ,we should admit the hopelessness of having permanent good health without muscular activity and should determine that muscular exertion shall be as much a habit and pleasure as eating and sleeping4 ,alcohol and ,muscular ,strength4--,benjamin ,franklin1 one of the wisest and greatest of ,americans1 was a printer when he was a young man4 ,in his autobiography he gives an account of his experience as a printer in ,london4 ,he says3 8,i drank only water2 the other workmen1 fifteen in number1 were great drinkers of beer4 ,on occasion ,i carried up and down stairs a large form of types in each hand1 when others carried but one in both hands4 ,they wondered to see1 from this and several instances1 that the ,water-,american1 as they called me1 was stronger than themselves1 who drank strong beer4 ,my companion at the press drank every day a pint before breakfast1 a pint at breakfast with his bread and cheese1 a pint between breakfast and dinner1 a pint at dinner1 a pint in the afternoon about #f o'clock1 and another when he had done his day's work4 ,i thought it a detestable custom1 but it was necessary1 he supposed1 to drink strong beer that he might be strong to labor40 ,,exercises ,,in ,,writing4--,the ,right and the ,wrong ,way to ride a ,bicycle4 ,pay ,day at a ,factory4 ,a ,graceful ,form3 how ,acquired2 how ,lost4 ,a ,drinking ,engineer and a ,railway ,wreck4 ,,practical ,,questions4--#a4 ,can we always control the voluntary muscles8 ,do we shiver with the voluntary or involuntary muscles8 #b4 ,if a man had absolute control over his muscles of respiration1 what might he do that he cannot now do8 #c4 ,why is one who uses alcoholic drinks not likely to be a good marksman8 #d4 ,why should a youth who wishes to excel in athletic contests abstain from the use of tobacco8 #e4 ,is there any relation between the amount of bodily exertion necessary for a person's health and the amount of wealth or the amount of intelligence he possesses8 #f4 ,can you relax the chewing muscles so that the lower jaw will swing loosely when the head is shaken8 ,can you relax your arm so that it falls like a rope if another person raises it and lets it fall8 #g4 ,the average man has sixty pounds of muscle and two pounds of brain2 one half of the blood goes through the muscles and less than one fifth goes through the brain4 ,what inference may you draw as to the kind of life we should lead8 #h4 ,why is a slow walk of little value as exercise8 #i4 ,how can we best prove that we have admiration and respect for our wonderful bodies8 #aj4 ,why is the ability to relax the muscles thoroughly of great benefit to the health8 ,how is this ability tested8 7,question #f47 #aa4 ,why is it as correct to say that the muscles support the skeleton as the reverse8 ,illustration3 ,,colored ,,figure #e4 ,,diagram ,,of ,,circulation4 #a4 ,head arteries 7carotid74 #b4 ,nameless arteries 7innominate74 #c4 ,collar bone 7subclavian7 artery4 #d4 ,great bend of the aorta4 #e4 ,pulmonary arteries4 #f4 ,thoracic aorta4 #g1 #aj4 ,abdominal aorta4 #h4 ,artery to liver 7hepatic74 #i4 ,artery to spleen 7splenic74 #aa4 ,artery to intestine 7mesenteric74 #ab4 ,artery to kidney 7renal74 #ac4 ,descending vena cava4 #ad4 ,nameless vein 7innominate1 #ae and #af before branching74 #ae4 ,collar bone vein 7subclavian74 #af4 ,jugular vein4 #ag4 ,pulmonary vein4 #ah4 ,ascending vena cava4 #ai4 ,vein from liver 7hepatic74 #bj4 ,vein from stomach 7gastric74 #ba4 ,vein from spleen4 #bb4 ,vein from intestine4 #bc4 ,vein to liver 7portal74 #bd4 ,vein from kidney4 #be4 ,right auricle4 #bf4 ,left auricle4 #bg4 ,right ventricle4 #bh4 ,left ventricle4 #bi4 ,thoracic duct4 #cj4 ,stomach4 #ca4 ,spleen4 #cb4 ,liver4 #cc4 ,kidneys4 #cd4 ,duodenum4 #ce4 ,ascending colon4 #cf4 ,descending colon4 #cg4 ,lymphatic glands of mesentery4 ,,chapter ,v ,,the ,,circulation ,experiment #a4 ,anatomy of ,mammalian ,heart4--,get a sheep's or beef's heart from the butcher4 ,get the whole heart1 not simply the ventricles 7as usually sold74 ,note the blood vessels1 four chambers1 thickness of different walls1 valves1 cords1 openings4 ,experiment #b4 ,does ,gravity affect the ,blood ,flow8--,hold the right hand above the head for a few minutes4 ,at the same time let the left hand hang straight down4 ,then bring the hands together and see which is of a darker red because of containing more blood4 ,now reverse the position of the hands for a few minutes1 and find whether the effect is reversed4 7,entire class47 ,experiment #c4 ,study of ,human ,blood4--,examine a drop of blood under the microscope1 first diluting it with a little saliva4 ,see ,fig4 #fj4 ,experiment #d4 ,the ,circulation in a ,frog4--,wrap a small frog in a moist cloth1 lay on a slip of glass1 place under the microscope1 and study the circulation in the web of its foot4 ,experiment #e4 7,entire class47 ,effect of ,exercise upon the ,pulse4--,tap a bell as the second hand of a watch begins a minute and let the pupils count the pulse at the radial artery on the wrist above base of thumb4 ,repeat standing1 or after gymnastics or recess4 ,result8 ,experiment #f4 ,the ,action of the ,valves in the ,veins4--,place the tip of the middle finger on one of the large veins of the wrist2 with the forefinger then stroke the vein toward the elbow so as to push the blood from a portion of it1 keeping both fingers in place4 ,the vein remains empty between the fingers4 ,lift the finger nearer the heart and no blood enters the vein2 there is a valve above which holds it back4 ,lift the other finger and the vein fills instantly4 ,stroke a vein toward the hand1 and notice that the veins swell up into little knots where the valves are4 ,stroke in the reverse direction4 ,result8 ,experiment #g4 ,finding the ,capillary ,pressure4 ,this is found by pressing a glass plate or tumbler upon a red part of the skin4 ,when the skin becomes pale the capillary pressure is counterbalanced4 ,experiment #h4 ,emergency ,drill4--,let one pupil come forward1 mark with blue chalk or pencil the position on his arm of a supposedly cut vein4 ,let another pupil use means to stop the imagined blood flow4 ,experiment #i4 ,let another pupil stop the flow from an imaginary cut artery marked red4 ,see text4 ,experiment #aj4 ,in a case of nose bleed do not let pupil lean over a bowl4 7,why87 ,cause him to stand rather than lie4 7,why8 ,see ,exp4 #b47 ,apply cold water to contract arteries to nose1 also have pupil hold a small roll of paper or a coin under upper lip 7to make muscular pressure on arteries to nose74 ,experiment #aa4 ,let one pupil treat another for a bruise 7see p4 #fb74 ,experiment #ab4 ,emergency drill1 restoration from fainting 7see p4 #eg74 ,the ,cells have a ,liquid ,home4--,the cells in the body of man1 like the ameba1 live in a watery liquid4 ,this liquid is called lymph4 ,the cells cannot move about as the ameba does to obtain food1 so the blood brings the food near them and it soaks through the blood tubes into the lymph spaces next to the cells 7see colored ,fig4 #c74 ,the ameba gives off waste material into the water2 the cells of the body give it off into the lymph to be carried off by the circulation4 ,the blood1 then1 has two functions3 7#a7 to take nourishment to the tissues2 7#b7 to take away waste material from them4 ,the ,organs of ,circulation4--,these are the heart1 which propels the blood2 the arteries1 which take blood away from the heart2 the veins1 which take the blood back to the heart2 and the capillaries 7,fig4 #ec71 which take the blood from the arteries to the veins4 ,illustration3 ,,fig4 #ec4--;,,capillaries1 connecting artery 7b7 with vein 7a74 ,the heart is a cone-shaped organ about the size of its owner's fist4 ,it lies in a diagonal position behind the breastbone1 with the small end of the cone extending toward the left4 ,the smaller end 7,exp4 #a7 taps or beats against the chest wall at a point between the fifth and sixth ribs on the left side4 ,the breastbone and ribs protect it from blows4 ,an inclosing membrane called the pericardium secretes a serous fluid and lessens the friction from its beating4 ,why the ,heart is ,double4--,there must be a pump to move the impure blood from the body to the lungs to get oxygen from the air1 and there must be another pump to send the pure blood from the lungs back to the body4 ,hence there are two pumps bound together into one heart1 beating at the same time like two men keeping step1 or like two carpenters keeping time with their hammers4 ,there are valves in the heart1 as in other pumps4 ,these valves are so arranged that when any part of the heart contracts and forces the blood onward1 the blood cannot return after that part of the heart relaxes4 ,are the pumps placed one behind the other8 ,or is one above the other8 ,neither2 they are side by side1 with a fleshy partition between them 7,fig4 #ed74 ,the pump on the right moves the impure blood from the body to the lungs1 and the one on the left moves the pure blood from the lungs to the body4 ,there is no direct connection between the right and left sides of the heart4 ,illustration3 ,,fig4 #ed4--;,,diagram ,,of ,,heart4 ,notice the two dark spots in the right auricle1 and four dark spots in left auricle1 where the veins enter4 ,does the aorta pass in front of1 or behind1 the pulmonary artery8 ,to trace one complete circuit of the blood 7,fig4 #ed71 let us begin with the blood in the capillaries of the outer tissues1 such as the skin or muscles4 ,the blood goes through small veins which unite into two large veins1 through which it enters the receiving chamber1 or right auricle1 goes through the tricuspid valve into the expelling chamber1 or right ventricle1 then through a semilunar valve into the pulmonary artery leading to the lungs4 ,becoming purified while passing through the capillaries of the lungs1 the blood goes through the pulmonary veins to the left auricle 7,fig4 #ed71 then through the bicuspid or mitral valve1 to the left ventricle1 whence it is forced through a semilunar valve into the largest artery of the body1 called the great aorta 7,fig4 #ed74 ,thence it goes to the smaller arteries1 and then to the capillaries of the tissues in general1 thus completing the circuit4 ,illustration3 ,,fig4 #ee4--,,the ,,left ,,side ,,of ,,heart 7plan71 showing the left ventricle at the moment when relaxing and receiving the blood from the auricle2 and the same at the beginning of contraction to send blood into aorta4 ,notice action of the valve4 ,structure of ,veins and ,arteries4--,seen under the microscope the arteries and veins show that they are made of three kinds of tissues arranged in three coats 7,fig4 #ef73 a tissue resembling epithelial tissue 7,chap4 #a71 as a lining to lessen friction2 an outer connective tissue 7,chap4 #a71 to give elasticity2 and a middle coat of muscular tissue to enable the vessels to change in size4 ,let us see why blood vessels must have these three properties4 ,why the ,blood ,vessels must be ,elastic4--,the aorta and its branches are always full of blood4 ,when the left ventricle with its strong1 muscular walls contracts1 the blood in the aorta and small blood tubes cannot move forward fast enough to make room for the new supply so suddenly sent out of the ventricle4 ,where can this blood go8 ,if a cup is full1 it cannot become more full2 not so with an artery4 ,the elastic connective tissue allows it to expand as a rubber hose does under pressure4 ,the first part of the aorta having expanded to receive the incoming blood1 the stretched walls contract because of the elasticity of the outer connective tissue coat and force blood into the portion of the aorta just ahead1 forcing it to expand in turn4 ,thus a wave of expansion travels along the arteries4 ,this wave is called the pulse4 ,the ,pulse may be most easily felt in the wrists and neck4 ,as the artery stretches and springs back1 one beat of the pulse is felt4 ,in men there are about seventy heart beats or pulse beats a minute4 ,in women the rate is about eighty a minute4 ,it is slowest when one is lying down1 faster while sitting1 still faster when standing1 and fastest of all during running or violent exercise4 7,exp4 #e47 ,it should not be thought that the muscular or middle layer of the artery actively contracts and helps to send along the pulse wave2 for this wave is simply the passive stretching and contracting of the outer connective coat1 and travels like a wave crossing a pond when a stone is dropped into the water4 ,the force of the pulse is furnished1 not by the muscle fibers in the artery1 but by the beat of the heart2 the outer1 or connective tissue1 coat enables the pulse to travel4 ,why must there be a middle1 or muscular1 coat for variation in size8 ,illustration3 ,,fig4 #ef4--,,section ,,of ,,artery1 ,a1 ,,and ,,vein1 ,v1 showing inner coat1 e 7endothelial72 middle coat1 m 7muscular72 and third coat1 a 7connective tissue74 ,use of the ,middle ,coat2 ,quantity of ,blood and its ,distribution4--,the body of an adult contains about five quarts of blood4 ,the blood furnishes the nourishment needed for the activity of each organ4 ,the more vigorous the work of any organ1 the greater is the amount of blood needed4 ,the whole amount of blood in the body cannot be suddenly increased1 but the muscular coat of the arteries going to the working organ relaxes1 and allows the arteries to become enlarged by the pressure from the heart4 ,consequently1 more blood goes to the active organ1 and the other organs get along with less blood for the time4 ,when we are studying1 our brains get more blood2 when running1 the leg muscles get more2 after a hearty dinner1 the stomach and intestines get more than any other part of the body4 ,why is it difficult to do the best studying and digest a meal at the same time8 ,we see that the muscular coat of the arteries is a very useful coat1 for it enables the supply of blood to be increased in any organ which is in temporary need of it4 ,why the ,blood ,vessels must be ,smooth4--,the inner coat of the heart and other blood vessels is made of tissue like the epithelial tissue which forms the epidermis and the smooth lining of the mouth and other organs4 ,the purpose of this lining is to lessen friction1 and thus save the work of the heart4 ,the friction is greatest in the capillaries because of their small size4 ,the inner coat of smooth cells is the only coat that is prolonged to form the capillaries 7see ,fig4 #eg74 ,illustration3 ,,fig4 #eg4--;,,capillaries ,,magnified1 ,,showing ,,cells forming their walls4 ,notice that each cell has a nucleus and three branches4 ,the capillaries are small1 thin1 short1 and very numerous4 ,they are very small so that they may go in between the cells of the tissues4 ,the capillaries are very thin so that the nourishment from the blood may pass readily into the tissues1 and the waste material pass readily into the blood4 ,they are very short so that the friction may be less2 and they are very numerous so that all parts of the tissues may be supplied with blood1 and that the blood may flow very slowly through them4 ,because of the number of the capillaries1 their total volume is several hundred times larger than the volume of the arteries that empty into them1 or of the veins that flow from them4 ,hence the blood flows slowly through the capillaries1 as water flows slowly through a lake along the course of a river4 ,all the changes between the blood and the lungs1 and between the blood and the tissues1 take place in the capillaries1 and the object of the other parts of the circulation is merely to move the blood continually through the capillaries4 ,the effect of gravity is to retard the flow in certain parts of the body and aid the flow in other parts1 according to the position of the body 7,exp4 #b74 ,fainting is usually due to lack of blood in the brain1 which in turn results from a weakening of the heart beat4 ,since the brain cannot work without fresh blood1 fainting is accompanied by unconsciousness4 ,recovery from fainting is aided by loosening the clothing at the neck and by placing the head of the patient a little lower than the body so that the weight of the blood may aid the flow to the brain4 ,dashing a little cold water in the face shocks the nerves and arouses the heart to stronger beats4 ,the veins have valves placed frequently along their course 7,fig4 #eh74 ,these valves are pockets made by a fold in the inner coat of the wall of the vein4 ,when a boy places his hand in his pocket1 the pocket swells out2 but if he rubs his hand on the outside of the pocket from the bottom toward the top1 it flattens down4 ,so with the action of the blood upon the valves in the veins4 7,repeat ,exp4 #f in class47 ,illustration3 ,,fig4 #eh4--,,valves ,,in ,,veins4 7,jegi47 ,how ,muscular ,exercise aids the ,heart4--,when a muscle contracts1 it hardens and presses upon a vein which goes through the muscle1 and the blood is pressed out of the vein 7see ,fig4 #eh74 ,the blood cannot go toward the capillaries1 for the valves fill and close when it starts that way2 so it must all go out toward the heart4 ,when the muscle relaxes1 the blood that has been pressed forward cannot go back because of the valves1 but the valves nearer the capillaries open1 and the veins are filled from the capillaries 7,fig4 #ec74 ,when the muscle contracts again1 the same effect on the blood movement is repeated4 ,we see1 therefore1 that every contracting muscle converts into a pump the vein running through it1 and when a person works or exercises1 many little pumps are working all over the body1 aiding the heart in its function4 ,this aid makes the blood flow faster and relieves the heart of part of its work1 so that it beats faster1 just as a horse might trot faster if another horse helped to draw the load 7,exp4 #c74 ,the pressure of a contracting muscle upon an artery does not aid the blood flow in the artery because the latter is destitute of valves4 ,how ,breathing aids the ,heart4--,breathing is a blood-pumping process as well as an air-renewing process4 ,when the chest expands1 blood is drawn into it4 ,when the chest contracts1 the flow of blood away from it is aided4 ,as the chest expands1 the downward pressure of a great1 broad muscle1 the diaphragm 7,fig4 #gd7 compresses the liver1 stomach1 and other abdominal organs1 and forces the venous blood upward into the expanding chest1 thus helping it on its way to the heart4 ,but if the abdominal wall is weakened by tight lacing or by the pressure of belts and bands which support the clothing1 the weak abdominal wall yields to the downward pressure of the diaphragm1 and no compression of the liver or aid to the circulation will result4 ,illustration3 ,,fig4 #ei4--,,the ,,ventricles ,,of ,a ,,dog',s ,,heart relaxed 7above71 and contracted 7below74 ,how the ,blood ,vessels are ,controlled4--,evidently the blood vessels are not regulated by the will4 ,we cannot voluntarily increase the beating of the heart1 or cause it to slacken its action4 ,even an actor cannot cause his face to turn pale or to blush at will4 ,this is because the tiny muscles in the walls of the blood vessels are involuntary muscles4 ,they are controlled by nerves of the sympathetic system called vaso-motors4 ,they are not subject to the will 7see ,fig4 #be74 ,the nerve center which controls the blood vessels is located in the top of the spinal cord at the base of the brain4 ,when cold air strikes the skin the nerves near the arteries are stimulated1 the arteries in the skin contract1 and the skin turns white4 ,when the heat from a hot fire strikes the skin1 the nerves are soothed1 the arteries relax1 and the face becomes red4 ,when the stomach is filled with food1 the heart beats faster and sends more blood to aid in digestion4 ,when we run fast1 the heart beats fast to supply more blood to the muscles1 but it slows down as sleep comes on1 that the body and brain may rest4 ,parts of the ,blood4--,the blood which flows from a cut finger seems to be a bright red throughout4 ,when a drop of it is looked at through a microscope1 however1 the liquid itself is seen to be almost as clear as water4 ,this liquid is called the plasma4 ,floating in it are millions of biconcave disks containing a pigment 7hemoglobin7 which gives the red color to the blood4 ,the disks are called red corpuscles 7,fig4 #fj74 ,a few irregularly shaped bodies1 nucleated and almost transparent1 and called white corpuscles1 are also found in the blood4 ,the red corpuscles go only where the plasma carries them 7,exps4 #c1 #d74 ,the white corpuscles sometimes leave the blood vessels entirely4 ,at times one may be seen shaped like a dumb-bell1 half of it through the wall of the blood vessel and half still in the blood vessel4 ,after the corpuscle is out1 no hole can be found to account for its mysterious passage4 ,the white corpuscles consist of protoplasm4 ,the red corpuscles contain no protoplasm4 ,hence the latter are not really alive4 ,illustration3 ,,fig4 #fj4--;,,human ,,blood ,,cells 7magnified #dj1jjj areas71 showing many red cells and a single white blood cell on left1 larger than red cells4 7,peabody47 ,illustration3 ,,fig4 #fa4--,,side ,,and ,,front ,,views ,,of ,,frog',s ,,and ,,man',s ,,red ,,corpuscles1 drawn to same scale4 ,compare outline1 concavity1 diameters4 ,the ,use of ,each ,part of the ,blood4--,the plasma keeps the blood in a liquid state1 so that it may flow readily2 the plasma also transports the food that has been eaten and digested1 and carries carbon dioxid to the lungs and other waste material to the kidneys4 ,the red corpuscles transport the oxygen from the lungs to the tissues4 ,the white corpuscles devour and destroy irritating particles1 such as drugs1 poisons1 and germs4 ,they are of great importance in purifying the blood and as a protection against disease4 ,one is shown in ,fig4 #fj4 ,the sounds of the heart beat may be heard by applying the ear to the chest4 ,they are two1 a long1 dull sound and a short1 clear one4 ,the first comes from the vibration of the bicuspid valve together with an unexplained tone arising from large contracting muscles1 in this case the walls of the ventricles4 ,the second1 or short1 clear sound1 is produced by the sudden closing and vibration of the semilunar valves4 ,changes in the ,composition of the ,blood as it passes through the ,various ,organs4--,when the blood is forced out by the heart1 part of it goes to the stomach and intestines through arteries which divide into capillaries4 ,these capillaries absorb all kinds of food from the alimentary canal except the fats 7see p4 #fd71 and unite to form the portal vein1 which takes the absorbed food to the liver4 ,in the liver some of the impurities of the blood are burned up and changed into bile4 ,the blood1 purified and laden with food1 is carried from the liver to the heart1 where it renters the general blood stream4 ,the blood flow from the food tube through portal vein and liver to the heart1 as just described1 is called the ,portal circulation4 ,renal circulation4 ,two branches from the aorta carry blood to the kidneys4 ,there the urea and a large amount of water are taken out1 and the purified blood is emptied into the large vein that leads up to the heart4 ,pulmonary circulation 7,fig4 #fg74 ,this is the circulation through the lungs4 ,during this circulation carbon dioxid gas is removed from the blood and oxygen is added to it4 ,illustration3 ,,fig4 #fb4--;,,blood ,,clot separated from serum4 ,some impurities and a large amount of water escape from the blood as it passes through the skin4 ,coagulation4--,so long as blood is in an uninjured blood vessel it remains a liquid4 ,in a few minutes after it flows from a blood vessel1 it forms into a stiff1 jellylike mass called a clot 7,fig4 #fb74 ,the process of forming the clot is called coagulation1 and it is brought about by the albuminous substance called fibrin1 which is always in the plasma of healthy blood4 ,on exposure to air the fibrin forms into a network of fine threads throughout the mass 7,fig4 #fc7 and the corpuscles become entangled in the meshes4 ,the clot consists of the fibrin of the plasma and corpuscles2 the watery portion of the plasma1 called the serum1 separates from the clot 7,fig4 #fb74 ,the property of coagulating is a great safeguard1 as a clot often plugs up a cut blood vessel4 ,what is the difference between serum and plasma8 ,illustration3 ,,fig4 #fc4--,,network ,,of ,,fibrin ,,in ,,human ,,blood 7enlarged74 ,veins and ,arteries compared4--,the veins have thin1 soft walls and the arteries have thick1 tough1 elastic walls4 ,when a vein is cut1 it may usually be closed by pinching the walls of the end together4 ,if an artery is cut1 the walls will not readily stick together1 but often stand open until the end of the artery is tied4 ,for this reason1 and because an artery is subject to the direct pressure of the heart1 a cut artery is more dangerous to life than a cut vein4 ,because of the toughness of the arteries1 and because they are located close to the bones1 they are less likely to be cut than the veins1 which are softer and nearer the surface4 ,the veins begin in capillaries and empty into the auricles2 the arteries begin at the ventricles and empty into capillaries2 and there is a semi-lunar valve at the origin of each artery4 ,cuts and ,bruises4--#a4 ,wash a cut under running water4 #b4 ,stop the bleeding4 ,the washing in cold water may do this4 ,elevating an injured arm or leg will aid the blood greatly in forming a clot at the opening4 #c4 ,bandage firmly with a strip of cloth and sew the end4 ,keep wet the part of the bandage where the cut is2 this lowers the temperature of the wound4 ,it may be necessary to hold a gaping wound closed with strips of surgeon's plaster placed across the cut4 ,a handkerchief folded first into a triangle and then into a narrow bandage is often useful4 ,a cut artery may be known from a cut vein by the brighter color of the blood1 and by the flow being stronger at each heart beat1 while the flow from a vein is uniform4 ,pressure to stop the flow of blood from an artery should be applied between the cut and the heart2 but when the blood comes from a vein1 the pressure should be applied to the side of the cut farthest from the heart4 ,apply hot water immediately for several minutes to a bruise4 ,either a bruise or a cut may be washed with a weak solution of some antiseptic such as carbolic acid4 ,after washing a bruise it may be bound with a cloth soaked in witch hazel or arnica4 ,,the ,,lymphatic ,,system ,this system contains and conveys a liquid called the lymph4 ,it consists of lymph spaces1 lymph tubes1 7lymphatics71 and lymphatic glands4 ,lymph corresponds nearly to the blood without the red corpuscles4 ,it is the familiar liquid seen in a blister1 or oozing out where the skin has been grazed without breaking a blood vessel4 ,necessity for ,lymph and ,lymph ,spaces4--,the body cannot be nourished with the albumin1 sugar1 oxygen1 and other digested food in the blood1 until this food passes out of the blood vessels4 ,the food leaves the blood through the thin walls of the capillaries4 ,many of the cells do not touch the capillaries1 and the lymph penetrates the spaces between the cells to reach them 7see colored ,fig4 #c74 ,if there were no lymph spaces1 these cells could not get any food4 ,the lymph bathes the cells1 and the cells absorb what they want from the nourishing fluid4 ,the red corpuscles bearing the oxygen cannot pass through the capillary walls4 ,oxygen1 being a gas1 readily passes through the walls and reaches the cells through the lymph in the lymph spaces4 ,the waste materials must go back into the blood2 carbon dioxid passes back through the capillary walls and is taken to the lungs2 how the other waste materials formed in the cells pass back will soon be explained4 ,need of ,lymphatics4--,the plasma continually passes into the tissues1 but it cannot return directly into the blood4 ,the lymph contains waste material which must be removed1 and also much unused food which nature1 like an economical housekeeper1 will offer to the tissues again4 ,there are vessels called lymphatics that take the lymph back into the blood 7see ,fig4 #fd74 ,the ,lymphatic ,circulation 7,fig4 #fd74--,the blood flow does not begin nor end1 but makes a never ending circle4 ,the countless lymphatics begin1 with open ends1 in the lymph spaces between the cells 7colored ,fig4 #c74 ,the smaller lymphatics unite into larger ones until finally they all unite into two large ones that empty into the large veins under the collar bones1 near the neck4 ,the one that empties under the left collar bone 7#c1 ,fig4 #ff7 is called the thoracic duct because it goes up through the thorax just in front of the spinal column 7#a1 ,fig4 #ff74 ,the other at the right side of the neck is called the right lymphatic duct 7see ,figs4 #fd1 #fe74 ,illustration3 ,,fig4 #fd4--,,surface ,,lymphatics ,,of ,,hand4 ,in persons with the dropsy1 the lymph accumulates in the lymph spaces and is not drained away by the lymph flow4 ,dropsy usually shows itself first by swelling of the feet and the leg below the knee4 7,why8 ,see ,exp4 #b47 ,there is a set of lymphatics called lacteals1 situated in the abdomen1 which have the function of absorbing digested fats from the intestine 7,figs4 #ff1 #ajj1 and colored figure #b74 ,illustration3 ,,fig4 #fe4--;,,diagram ,,to ,,show ,,the ,,two ,,parts ,,of ,,the ,,body ,,drained ,,by ,,the ,,two ,,lymph ,,ducts4 ,what makes the ,lymph ,flow8--,the heart does not1 for its pressure is not transmitted beyond the blood tubes4 ,the successive pressures of a working muscle move the lymph forward in the lymphatics in the same way that the blood is moved forward in the veins1 and the valves keep it from moving back4 ,when riding a trotting horse1 or in a jolting vehicle1 the lymph is moved beyond the valves at every jolt 7,fig4 #fd74 ,without exercise the lymph stagnates1 and the body becomes poisoned by its own wastes4 ,at every expansion of the lungs lymph is drawn into the chest2 and it is forced out of the chest at every contraction4 ,deep breathing is as great a benefit to the body in moving stagnant lymph as it is in purifying the blood4 ,illustration3 ,,fig4 #ff4--;,,chief ,,lymphatic ,,vessels ,,and ,,glands of trunk4 #a1 #c1 ,thoracic duct 7emptying at #c72 #b1 receptacle for chyle 7lacteals below it74 ,the lymphatic glands are kernel-like enlargements along the lymphatics1 and they contain a great many lymph cells which purify the lymph as it passes through them4 ,the lymphatic glands are numerous in the armpits and the groins4 ,the cells in the lymph glands multiply1 and some of them are carried by the lymph into the blood to become those remarkable little bodies1 the white corpuscles4 ,,hygiene ,,of ,,the ,,circulation ,effects of ,work1 ,fresh ,air1 and ,rest on ,corpuscles and ,plasma4--,work uses up the nutritious elements in the blood4 ,a few hours after food is eaten the nutritious materials in the blood are found to be increased4 ,by the breathing of fresh air the carbon dioxid in the plasma is diminished and the oxygen in the colored corpuscles is increased1 changing the blood to a brighter red4 ,sleep gives time for the exhausted cells and depleted blood to be replenished4 ,loss of sleep means longer hours of activity and greater consumption of nutriment with shorter hours for replacing the nutriment4 ,the pale skin of one who has lost sleep tells of the exhausted condition of the blood4 ,how the ,muscles help the ,circulation4--,the imperative need of muscular exercise to keep the body sound exists because of the lack of other means to cause movement in the veins and lymphatics4 ,good food1 pure air1 and plenty of exercise are necessary for healthy blood4 ,many so-called 8blood purifiers0 are advertised to entrap the ignorant4 ,it is impossible to imagine how 8blood purifiers0 can aid the blood4 ,the blood is purified1 not by putting anything into the blood1 but by something going out of it as it passes through the skin1 kidneys1 liver1 and lungs4 ,these organs all send out impurities brought to them by the blood4 ,the one great hygienic effect of muscular exercise is an active circulation1 and from an active circulation nine chief effects may be traced4 ,the effects upon the body will be given in order1 beginning with the surface--skin1 fat1 muscles1 bones2 and the effects upon the internal organs are given in order of position1 beginning with the highest--brain1 lungs1 heart1 digestive organs4 ,effects of ,exercise and ,improved ,circulation4--#a4 ,the skin is made fresh1 pink1 and smooth from the flushing of the capillaries2 it is purified by the perspiration and the renewal of cells4 #b4 ,if the fat is too great in amount1 it is burned up2 if it is too small in amount1 the better nourishment brought by the blood increases it4 #c4 ,the muscles are better fed 7see ,fig4 #dh7 and grow firm1 strong1 and large4 #d4 ,the skeleton is held in proper position by the stronger muscles1 and deformity is prevented4 #e4 ,the brain4 ,the pure1 fresh blood1 loaded with oxygen from expanded lungs1 flushes every capillary of the brain1 clears the mind1 and doubles or trebles its power to work4 #f4 ,the lungs are expanded by deep breathing if the exercise be rapid and vigorous4 ,a slow stroll or saunter is not of value4 #g4 ,the circulation4 ,every contracting muscle aids the heart in its work4 ,the deep breathing moves stagnant lymph4 #h4 ,the stomach4 ,exercise burns up the food and increases the appetite4 #i4 ,general effects4 ,exercise promotes good humor1 decreases loafing1 cigarette smoking1 gossiping1 and other vices4 ,the effect of tobacco on the heart1 if cigarettes or cigars are used1 is sometimes to cause attacks of irregular beating2 the heart flutters faintly for a while1 then palpitates strongly1 then flutters again4 ,this condition is called tobacco heart1 or trotting heart4 ,effect of ,alcohol upon the ,circulation4--,after a person has taken an alcoholic drink his face and skin are likely to become flushed1 and perhaps his heart beats faster4 ,most investigators have found that the alcohol itself does not directly increase or strengthen the action of the heart4 ,hence it is probably wrong to call alcohol a heart stimulant4 ,the flushing of the skin is believed to be due to the relaxing effect of alcohol4 ,it relaxes1 it paralyzes1 the vasomotor nerves which control the little muscle fibers in the walls of the blood vessels4 ,the relaxing and enlarging of the blood vessels decreases the resistance to the blood flow1 and the heart beats faster under its lighter load4 ,the narcotic effect of alcohol is much more powerful than its irritating or stimulating effect4 ,the effect of alcohol in causing fatty degeneration of the muscles often weakens the heart and other blood vessels4 ,climate and ,brain ,work4--,in going to sleep the vessels in the skin dilate and blood is drawn from the brain to the skin4 ,it is difficult to go to sleep when cold1 for cold sends the blood to the brain and keeps the mind active4 ,on the same principle1 mental work is difficult in very warm weather because of the enlarged capillaries in the skin and the withdrawal of blood from the brain to the skin4 ,this increases the perspiration and keeps the temperature of the body down to normal1 but it deprives the brain of blood needed for good mental work4 ,mental workers in warm weather and in warm climates should seek every condition favoring coolness4 ,benjamin ,franklin was accustomed to strip himself almost entirely of clothing when he was writing and wanted his brain to work at its best4 ,the wearing of barefoot sandals and the thinnest cotton clothing1 light in color1 helps to prevent mental inertia in hot weather4 ,in the ,gulf states in summer and in our tropical islands the best mental work can be done by rising at dawn and working before the hot part of the day begins4 ,some of the greatest thinkers in the world have lived in warm climates 7,greece and ,india71 but they wore very few clothes and ate moderately of the simplest food 7see p4 #dd74 ,congestion is a swelling of the blood vessels of some part1 with the accumulation of blood therein4 ,congestion is active when a rapid flow of blood distends the capillaries4 ,example1 flushing of face when running4 ,congestion is passive when there is a narrowing of the outlet of the capillaries1 the blood moves slowly and partly stagnates in the swollen vessels4 ,example1 when the nose feels stopped up during a cold4 ,if a syringe is worked so fast that the rubber tube swells1 this is like active congestion2 if the end of the tube is pinched together so that moderate pumping causes it to swell1 this is like passive congestion4 ,inflammation is congestion where the vessels of any part are strained and injured4 ,white corpuscles collect there to repair the vessels and devour the blood that escapes and stagnates there4 ,they also destroy germs that have usually found lodgment and begun to multiply4 ,the serum of the blood also destroys the germs by the antitoxins in it4 ,inflammatory troubles are3 colds1 rheumatism1 diarrha1 and all diseases with name ending 8itis40 ,an inflamed part is red1 swollen1 hot1 and painful4 ,prevention and ,care of ,colds4--,a cold is an inflammation of a mucous membrane4 ,colds are prevented by so living as to encourage a free1 vigorous circulation1 and especially by not coddling the body so tenderly that the circulation becomes deranged by the least exposure4 ,the circulation may be deranged by overheating as well as by chilling the body2 usually it would be more appropriate to say that the person caught 8a hot0 than 8a cold40 ,at the first sign of a cold vigorous exercise1 a cold bath1 or going outdoors into cold air may aid in sending fresh blood to remove the stagnation and stop the inflammation4 ,a warm foot bath and hot drinks may relieve by drawing blood from the congested mucous membrane4 ,after the cold has become fixed such measures will not help1 but the cure is aided by helping the skin to keep its full share of blood4 ,the cold must run its course4 ,the cells will be given every chance to repair the injury and destroy the germs 7if any7 by avoiding hard work1 eating moderately of digestible food1 avoiding drugs1 especially infallible drugs advertised in newspapers1 even if recommended by otherwise intelligent people4 ,repeated colds tend to become a disgusting disease called chronic catarrh4 ,constricting the blood vessels of the skin causes congestion of the 7internal7 mucous membranes4 ,a skin tenderly protected constricts more readily than one accustomed to cold4 ,cold is the best preventive of cold4 ,cold baths1 pure air1 light clothing1 free breathing1 moderate eating1 ward off colds4 ,fussing with sprays1 gargles1 and drugs will not2 for the main factor in bringing on a cold is not germs1 nor temperature1 but the state of the system itself4 ,persons who have suffered much with colds have found that after substituting cotton underwear for woolen1 colds became very rare4 ,linen will have a similar effect1 but it is not as durable1 soft1 or heat-retaining as cotton 7see p4 #af74 ,,practical ,,questions4--#a4 ,through what kind of skin do the blue veins in the wrist show most plainly8 #b4 ,which is more compressible1 a vein or an artery8 #c4 ,why are those who take little exercise likely to have cold feet8 7p4 #eg47 #d4 ,where does the so-called venous blood flow through an artery8 #e4 ,what vein begins and ends in capillaries8 7,the portal vein1 colored ,fig4 #e47 #f4 ,to what purifying organ1 after leaving the lungs1 does the heart send part of the blood for further purification8 7,colored ,fig4 #e47 #g4 ,what keeps the blood moving between the beats of the heart8 ,,chapter ,,vi ,,the ,,respiration ,experiment #a4 7,home47 ,study of the ,throat4--,sit with the back to the light4 ,study the open mouth and throat with a mirror and make out the uvula1 tonsils1 and other parts shown in ,fig4 #fh4 ,experiment #b4 ,anatomy of ,lungs4--,study fresh lungs of sheep1 hog1 fowl1 or frog4 ,will they float8 ,will they contract when expanded by air blown in through a quill or other tube8 ,what is the structure of the windpipe8 ,can you distinguish the arteries from the veins by the stiffness of their walls8 ,which contain pure blood8 ,study branching of air tubes4 ,make a sketch4 ,experiment #c4 ,tests of ,expired ,air4--,breathe upon a mirror1 bright knife blade1 or cold window pane4 ,result8 ,state your conclusion4 ,experiment #d4--;,carbon dioxid added to limewater will cause a white cloud consisting of particles of limestone4 ,breathe through a tube or straw or the hollow stem of a reed into clear limewater4 ,result8 ,conclusion8 7,limewater may be had at druggist's or made by pouring water upon a lump of unslackened lime and draining it off when lime has settled47 ,experiment #e4 ,breathe for several minutes upon the bulb of a thermometer4 ,result8 ,conclusion8 ,experiment #f4 ,breathe a few times into a large1 carefully cleaned pickle jar1 or a bottle4 ,cork it tightly1 and set it in a warm place for several days4 ,then uncork and smell the air in it4 ,result8 ,conclusion8 ,experiment #g4 ,pierce a small hole in a card1 place card over a wide-mouthed bottle1 and breathe into bottle through a tube1 lemonade straw1 or hollow reed4 ,pull out straw4 ,place bottle1 mouth downward1 on table1 and slip out card4 ,slide bottle to edge of table and lift lighted candle into bottle4 ,result8 ,experiment #h4 ,place bottle of fresh air over lighted candle4 ,result8 ,conclusion8 7,see ,animal ,biology1 p4 #d47 ,experiment #i4 7,school47 ,testing the ,air of a ,room4--,fill a fruit jar or large bottle with water1 and take it into a room containing many people4 ,pour out the water4 7,this insures that all the air now in the jar is air obtained in the room to be tested47 ,seal the jar if test is not to be made at once4 ,test by pouring in two tablespoonfuls of clear limewater and shake4 ,if the limewater turns milky1 the ventilation is bad4 ,experiment #aj4 7,home and school47 ,homemade ,current ,detector4--,dangle a bit of paper by means of a spider web or thread from the end of a walking stick or ruler4 7,or test with the flame of a candle47 ,hold it near cracks of window1 above and below doors1 and especially before openings intended for entry and exit of air1 and test if air moves as desired4 ,experiment #aa4 ,ventilation of the ,schoolroom4--,let the whole class rise1 and with the fingers test cracks around doors and windows4 ,wherever the air feels cold to the hand the air is entering4 ,experiment #ab4 ,dust4--,with a mirror cause a sunbeam to play like a search light into a closed room several hours after it has been swept4 ,result8 ,do the same in a room where every window and door were open during sweeping and left open afterwards4 ,result8 ,conclusion8 ,note also the amount of dust on the furniture of each room4 ,experiment #ac4 ,study of ,habitual ,quiet ,breathing4--,without any more disturbance of the breathing than can be helped1 direct your attention to your breathing while sitting quietly4 ,record motions of any parts of chest and abdominal walls that may be noticeable4 ,if necessary1 lay the hands successively against different parts of the wall to test for motion4 ,think of another subject1 and later repeat observations4 ,experiment #ad4 ,study of ,deep ,breathing4--,place your hands successively upon the front and sides of your chest1 waist1 and abdomen1 while drawing in and sending out deep breaths4 ,what motions of the several parts are observed at each stage8 ,experiment #ae4 ,study of ,elasticity as a ,factor in ,breathing4--7#a7 ,notice whether in quiet breathing there is an elastic rebound as the breath goes either in or out4 ,if so1 it is due to the elasticity of the cartilages or air cells of lungs1 or both4 7#b7 ,breathe by inflating the lungs strongly at each breath4 ,is the air then forced out without effort8 7#c7 ,breathe by flattening the chest and abdomen as much as possible at each breath4 ,does the air then rush in without effort8 ,experiment #af4 ,chest ,breathing4--,try to breathe wholly by deep expansions and contractions of chest wall4 ,what motions1 if any1 are noticed in abdominal wall as breath goes in8 ,as it goes out8 7,test motions with hand47 ,experiment #ag4 ,abdominal ,breathing4--,try to hold the chest walls still and breathe by strong contraction and expansion of abdomen4 ,do the chest walls move at all8 ,neither 8chest breathing0 nor 8abdominal breathing0 is the normal way4 ,see text4 ,experiment #ah4 ,full ,breathing4--,try breathing by outward and inward movement of walls of chest1 waist1 and abdomen4 ,do you succeed8 ,this is normal breathing4 ,is the motion greater at the front or the sides of the waist8 ,put a belt around the waist tight enough to stay in place and repeat4 ,is the waist motion interfered with8 ,experiment #ai4 ,how the ,ribs are ,lifted4--,make a model-like sketch to represent backbone1 breastbone1 and two ribs1 using pins to make joints loose at corners4 ,use cords for diagonals4 ,what happens when cord ac is pulled8 ,when cord bd is pulled8 ,the cords correspond to the two sets of muscles between the ribs4 ,illustration ,experiment #bj4 ,study of ,laughing4--,place the hands upon the waist and abdomen when laughing4 ,what motion occurs at each sound of laugh8 ,draw in the abdominal wall with a jerk4 ,what is the effect upon the breath8 ,experiment #ba4 ,modifications of the ,breath4--,write ,i1 ,e1 or ,,ie after each word in this list1 according as inspiration1 expiration1 or both1 are involved in the action4 7,test with sham acts if possible47 ,sighing1 sobbing1 crying 7of a child71 coughing1 laughing1 yawning1 sneezing1 hiccoughing1 snoring4 ,experiment #bb4 ,effects of ,exercise4--,count and record the rates of breathing before and after vigorous exercise4 ,experiment #bc4 ,comparative ,study4--,observe and record the rate and manner of breathing of cow1 horse1 dog1 cat1 etc4 ,is the air drawn in or sent out more quickly8 ,is there a pause8 ,if so1 after which stage of breathing8 ,experiment #bd4 ,emergency ,drill4--,resuscitation from drowning1 etc4 ,see ,coleman's 8,elements of ,physiology10 page #cef4 ,necessity for ,breathing and for ,specialized ,organs of ,breathing4--,the body is a self-regulating machine which possesses energy4 ,this energy1 like that of steam engines1 arises from oxidation which takes place continually1 but at a varying rate4 ,food for fuel is taken at intervals1 but oxygen must be taken in continually4 ,man breathes about eighteen times per minute4 ,the blood in the tissues soon becomes dark because of loss of oxygen and absorption of carbon dioxid4 ,it is then pumped through the heart to the organ which has the function of absorbing oxygen and giving off carbon dioxid 7,fig4 #fg74 ,in some animals1 as the ameba and the earthworm1 the surface of the body suffices for breathing4 ,this cell breathing is the true essential respiration2 it is universal among living things1 both plants and animals4 ,to supply the deeper cells large animals require a breathing surface greater than the area of the skin4 ,this is supplied by having the oxygen-absorbing surface folded inward to form folds1 tubes1 and cavities of great complexity4 ,if the lungs of a man were unfolded and all their tubes and cavities spread upon one surface1 an area of more than one hundred square feet 7or ten feet square7 would be covered4 ,each respiration1 or breath1 consists of the passing in of the air1 or inspiration1 sending it out1 or expiration1 and a pause after one but not after both of the other stages4 ,illustration3 ,,fig4 #fg4--;,,circulation ,,through ,,lungs 7schematic73 8venous0 blood 7in pulmonary artery7 black2 8arterial0 blood 7in pulmonary veins7 white4 ,illustration3 ,,fig4 #fh4--,,open ,,mouth1 showing palate and tonsils4 ,illustration3 ,,fig4 #fi4--,,lungs1 ,p2 with trachea1 ,,ta2 thyroid gland1 th2 larynx1 ,l2 and hyoid bone1 ,h4 ,the ,air ,passages4--,the air usually passes in at the nose and returns by the same way1 except during talking or singing4 ,observe your mouth with a mirror 7,fig4 #fh72 at the back part1 an arch is seen which is the rear boundary line of the mouth 7,exp4 #a74 ,just above the arch is likewise the rear boundary line of the nasal passages4 ,the funnel-shaped cavity beyond1 into which both the mouth and nasal passages open1 is called the pharynx 7farinks71 or throat 7see ,fig4 #fh1 also ,fig4 #hc74 ,below1 two tubes open from the pharynx4 ,one is the trachea 7trkea7 or windpipe1 the other is the esophagus or gullet4 ,at the top of the trachea is the cartilaginous larynx1 or voice box4 ,if the finger is placed upon the larynx or ,adam's apple1 it is plainly felt to move up and down when swallowing4 ,the opening into the larynx is provided with a lid of cartilage1 the epiglottis4 ,inside the larynx1 the vocal cords are stretched from front to back4 ,just below the larynx comes the trachea proper1 which is a tube about three fourths of an inch in diameter and about four inches long 7,fig4 #fi74 ,it consists of hoops of cartilage 7,fig4 #fi7 which are not complete circles1 but are shaped somewhat like the letter ,c1 being completed at the rear by involuntary muscular tissue1 whose function is to draw the ends together at times 7for instance1 during coughing7 and reduce the size of the tube4 ,the function of the hoops of cartilage is to keep the windpipe open at all times4 ,if it should be closed by pressure1 life might be lost4 ,these rings of cartilage may be felt in the neck4 ,illustration3 ,,fig4 #gj4--,,lobule ,,of ,,lung4 ,the lower end of the trachea is just behind the upper end of the breastbone2 there it divides into two large tubes4 ,these subdivide into a great number of smaller branches called bronchial tubes4 ,cartilage is found in the walls of all but the smallest of the tubes4 ,the subdivision continues1 somewhat like the branching of a tree1 until the whole lung is penetrated by bronchial tubes4 ,each tiny tube finally ends in a wider funnel-shaped chamber called a lobule 7,fig4 #gj71 into which so many dilated sacs1 called air cells1 open1 that the walls of the terminal chamber or lobule may be said to consist of tiny cups1 or air cells1 placed side by side4 ,the lobules1 or clusters of air cells1 are chiefly near the surface of the lung4 7,the word 8cell0 is here used in its original sense to denote a cavity or chamber1 and not in the sense of a protoplasmic cell47 ,illustration3 ,,fig4 #ga4--;,,capillaries ,,around ,,air ,,sacs ,,of ,,lungs 7enlarged #cj diameters74 ,air sacs in white spaces4 ,dark lines are capillaries4 7,peabody47 ,the air cells are elastic and enlarge by stretching as the chest expands2 hence1 the cells must have many of the yellow elastic fibers of connective tissue in their walls4 ,they are lined with an exceedingly thin membrane of epithelial cells through which oxygen and carbon dioxid are exchanged4 ,in the walls of the air cells there is a network of capillaries 7,fig4 #ga74 ,the dark red blood comes into these capillaries from the pulmonary arteries1 and is changed to a bright red by the time it leaves them to enter the pulmonary veins4 ,the air leaves the lungs warmer1 moister1 and containing more carbon dioxid than when it entered4 ,most of the mucous membrane lining the air passages has a surface layer of ciliated cells4 ,cilia are tiny thread-like projections 7,fig4 #gb7 which continually wave to and fro1 the quicker stroke always being outward2 for their function is to remove particles of dust and germs that may find entrance to the air passages4 ,when the mucus containing the dust is raised nearly to the larynx1 it may be thrown out by coughing4 ,near the opening of the nostrils are placed many hairs1 hundreds of times larger than cilia1 through which the air is strained as it enters the nose4 ,hairs are multicellular2 cilia are parts of cells4 ,see ,animal ,biology1 ,fig4 #ad4 ,illustration3 ,,fig4 #gb4--;,,ciliated ,,cells1 lining the air passages4 ,the ,lungs4--,the entire chest cavity is occupied by the lungs except the space occupied by the heart1 the larger blood vessels1 and the gullet4 ,the right lung has three lobes1 or divisions1 and the left lung has two lobes4 ,the lungs are light pink in early life1 but become grayish and darker as age advances4 ,this change is more marked in those who dwell in cities1 or wherever the atmosphere is smoky and dusty4 ,the lungs are covered and inclosed by a smooth membrane called the pleura4 ,this membrane turns back and lines the chest wall1 so that when the chest expands1 the two sleek membranes glide over each other with far less friction than would be the case if the lungs and chest wall were touching 7,exp4 #b74 ,illustration3 ,,fig4 #gc4--,,vertical ,,section ,,of ,,trunk1 showing diaphragm1 cavities of thorax and abdomen4 ,the ,respiratory ,muscles4--7,repeat ,exps4 #ac1 #ad1 #ae47 ,the chief breathing muscles are the diaphragm 7see ,figs4 #gc and #gd71 the muscles forming the abdominal walls 7see ,fig4 #dd71 and two sets of short muscles 7an internal and an external set71 between the ribs4 ,they are called intercostals4 7,they are the flesh eaten when eating pork ribs47 ,the diaphragm1 which is shaped like a bowl turned upside down1 rounds up under the base of the lungs somewhat like a dome and separates the chest from the abdomen4 ,its hollow side is toward the abdomen and its edges are attached to the lowest ribs and the vertebra of the loins4 ,inspiration is brought about by the rising of the ribs and the descent of the diaphragm4 ,expiration takes place when the ribs descend1 the abdominal walls draw in1 and the transmitted pressure lifts the relaxed diaphragm4 ,illustration3 ,,fig4 #gd4--;,,diaphragm 7or midriff71 seen from below4 7,cunningham47 ,the central portion 7light7 is tendinous4 ,as the diaphragm descends1 it acts like the piston of a great pump and the blood is forced up through the vena cava1 and the lymph through the thoracic duct 7,fig4 #ff74 ,inspiration4--,to cause inspiration the diaphragm contracts1 it flattens and descends1 since its edges are attached lower than its middle 7,fig4 #gc72 the lungs descend with it1 thus lengthening the chest from top to bottom2 at the same time the ribs are raised upward and outward 7,fig4 #gf7 by the contraction of the outer set of muscles between the ribs4 ,thus the chest is made longer1 broader1 and deeper from front to back4 ,the lungs expand when the chest expands1 and the air rushes in4 ,why is this8 ,the lungs contain no muscles and cannot expand themselves2 the air cannot be pulled in1 for its parts do not stick together4 ,the true reason is that the air has weight4 ,the atmosphere has a height of many miles1 and the air above is pressing on that below4 ,when the chest walls are raised there would be an empty space or vacuum between these walls and the lungs1 did not the pressure of the outside air push air through the windpipe into the lungs and expand them 7,exp4 #ai74 ,illustration3 ,,fig4 #ge4--;,,framework ,,of ,,chest4 ,expiration4--,in very active breathing the abdominal walls actively contract so that they press strongly upon the digestive organs1 which in turn press the diaphragm up4 ,the ribs are also drawn down and in4 ,thus the chest becomes smaller and forces the air to flow out through the windpipe 7,exps4 #bj and #ba74 ,illustration3 ,,fig4 #gf4--;,,blackboard ,,sketch1 to show how the chest is expanded when the ribs move upward and outward4 ,,thought ,,questions4--,why breathing with the waist is easier than breathing with the upper chest4 ,effects of confining the waist4 #a4 ,there are two pairs of ribs below1 while there are none above4 #b4 ,there are three pairs of ribs below1 while there are none above1 but all ribs of the upper chest are ribs4 #c4 ,the lower of the joints between the seven pairs of true ribs and the sternum are more flexible than the upper joints because 4 7,observe the joints in ,fig4 #ge47 #d4 ,the walls of the waist swing and 1 while the walls of the upper chest must move and 4 #e4 ,the bones of the rest upon the upper chest4 ,in upper chest breathing their weight1 and the weight of both of the must1 therefore1 be lifted4 7,fig4 #bh47 ,test by trying it4 ,illustration3 ,,fig4 #gg4 ,,fig4 #gh4 ,,fig4 #gi4 ,,fig4 #gg4--;,,female ,,figure ,,encased ,,in ,,corset4 ,expansion at the waist is here impossible and the breathing is called 8collar-bone breathing40 ,,fig4 #gh4--,,male ,,figure4 ,here1 owing to pressure of clothing and faulty position1 expansion of chest is hindered and breath is taken by the 8abdominal method40 ,,fig4 #gi4--;,,figure ,,properly ,,poised ,,and ,,free4 ,here the entire thorax can move freely1 and natural breathing is the result4 7,for blackboard47 ,from ,latson4 ,hygienic ,habits of ,breathing4--,chest breathing uses chest chiefly1 abdominal breathing uses abdomen chiefly1 full breathing uses both4 ,these three forms depend upon whether the breathing is carried on by using the muscles of 7#a7 the chest1 7#b7 the abdomen1 or 7#c7 both 7see ,figs4 #gg1 #gh1 #gi74 ,there has been much debate among physicians1 surgeons1 and singers as to which of these methods is best4 ,probably this question would not have been raised but for the confining and deforming effect of clothing upon the waist4 ,full breathing is used by children of all races1 by both men and women of wild tribes1 and by men of civilized countries4 ,it is undoubtedly the natural way1 as well as the easiest and most effective way 7,exps4 #af1 #ag1 #ah74 ,breathing with the upper chest is exhausting because of the stiffness of the upper part of the bony cage 7see ,fig4 #ge72 for it is inclosed by true ribs fixed to the breastbone by short cartilages4 ,the ribs in the waist 7,fig4 #ge7 are either floating in front or fixed by long cartilages to the ribs above4 ,in pure abdominal breathing the diaphragm must contract more than in full breathing in order to descend1 because its edges have been drawn together and fixed by binding the ribs at the waist4 ,in full breathing the floating and false ribs at the waist 7five pairs in all7 float in and out as nature provided4 ,as they move out1 this broadens and deepens the chest1 and aids the flattening of the diaphragm by moving its edges farther apart4 ,those persons1 perhaps one in a thousand1 who voluntarily deform the body with tight clothing are beneath contempt4 ,but so uniform is the pressure of tight clothes and shoes that the wearer soon becomes unconscious of them1 and so powerful are the effects that not one person in a thousand escapes deformity and injury4 ,children's clothing should be supported by the shoulders1 and adults' clothing by both shoulders and hips1 but by the waist1 never4 ,cellular ,respiration4--,the chemical activities within the cells and their need of oxygen1 not the amount of oxygen in the lungs or blood1 determine how much oxygen the cells absorb from the blood4 ,oxygen cannot be forced even into the blood beyond the required amount4 ,deep breathing movements1 however1 help the flow of the blood and lymph4 ,carried to excess1 they tire the will and exhaust the nerves4 ,changes in ,blood while in the ,lungs4--,the coloring matter 7or hemoglobin7 of the corpuscles absorbs oxygen 7and becomes oxy-hemoglobin74 ,carbon dioxid is given off from the plasma4 ,the blood becomes a brighter red4 ,changes in ,air in the ,lungs4--,the air entering the lungs consists of about one fifth oxygen and four fifths nitrogen4 ,this nitrogen is of no use to the body1 and is exhaled unchanged4 ,a part of the oxygen inspired is taken up by the blood1 and carbon dioxid is sent out in its place4 ,about half a pint of water is given off through the lungs in a day4 ,minute quantities of injurious animal matter are also given off in the breath from even the soundest person4 ,the air leaves the lungs warmer1 damper1 and with more carbon dioxid than when it entered 7,exps4 #c to #i74 ,illustration3 ,,fig4 #hj4--,,ventilation ,,of ,,stove-,,heated ,,room4#e ,how are the inlet and outlet situated with reference to the stove8 #e ,from ,coleman's ,elements of ,physiology 7#djj pp474 ,the ,macmillan ,co41 ,n4,y4 ,persons with decayed teeth1 catarrh1 indigestion1 diseased lungs1 or other unsoundness give off still more of this material4 ,when many people are assembled in a badly ventilated room1 the amount of injurious animal matter in the air is much increased1 and is called 8crowd poison40 ,its odor is strong and repulsive to one who just enters the room1 but the sense of smell becomes dull to it in a few minutes4 ,it would seem that nature gives a fair warning against harm2 but if we disregard the warning it soon ceases4 ,people who are really ,unclean4--,nature's plan seems to be for us to live out of doors4 ,air once breathed is impure4 ,it is just as unfit to enter our bodies as muddy water or decayed food4 ,yet many who call themselves cleanly and refined1 and will not allow a speck of dirt to remain on their clothes1 nor use a spoon just used by another1 do not object to breathing into their lungs1 over and over again1 the cast-off air from the lungs of others4 ,if a window is opened for ventilation1 they are horror-stricken for fear of drafts4 ,drafts are injurious only to persons perspiring1 or to those who have coddled the skin by continually overheating it4 ,there are thousands of schools1 churches1 and theaters all over the land which reek daily with the malodorous particles from the lungs of their occupants4 ,although the air in them is odorless to those who occupy them1 it is disgusting to any one who enters from the fresh air4 ,figure #hj shows the correct ventilation of a stove-heated schoolroom4 ,dust causes catarrh of the bronchial tubes and chronic inflammation of the lungs2 it prepares for consumption1 by gradually weakening the lungs of those who breathe it4 ,intelligence and common sense are necessary to prevent it from accumulating in the house4 ,the chief purpose of the house cleaning should be not only to remove bits of paper from the floor1 which do no harm even to the shoes1 but to remove impurities from the air4 ,it does no good to stir up the dust and allow it to settle down again 7,exp4 #ab74 ,in many houses dust is thus allowed to accumulate for months4 ,experiments show that dust and germs floating in the air are not diminished to a great extent by a gentle draft through the room4 ,the windows must be open and sweeping done in the direction of the air currents2 the windows should be left open for a long while after the sweeping4 ,a windy day is best for sweeping4 ,the habit some housekeepers have of buying furnishings and bric--brac for the home until it looks like a retail store or junk shop1 makes it almost impossible to clean their houses4 ,a few articles1 carefully selected1 adorn a home more than many bought at random1 and they do not litter the house and serve as traps for dust4 ,with all precautions some dust may settle down4 ,this should not simply be stirred up again with a feather duster1 but the dusting should be done with a damp cloth4 ,ashes should be sprinkled before they are moved4 ,carpet sweepers1 but never brooms1 should be used upon carpets4 ,carpets and lace curtains are truly dust traps1 in which dust will accumulate without limit4 ,those who value the health will not use such uncleanly abominations1 at least in bedrooms4 ,though linoleum1 bare floors with movable rugs1 oiled and painted floors1 may not look so comfortable as a fixed carpet1 they bring far more comfort in the end4 ,the weakening effect of ordinary dust is one of the chief causes of lung diseases1 and prepares a fertile soil for the consumptive germ4 ,the sputum coughed up by consumptives falls upon the floor or street1 soon dries1 and the germs are driven about by the wind4 ,in many cities there is a law against spitting in public places1 and the streets are flushed with water before they are swept4 ,illustration3 ,,fig4 #ha4--,the air enters through a special inlet and is warmed as it passes through hood surrounding the stove4 ,illustration3 ,,fig4 #hb4--;,chimney with a passage behind fireplace1 or grate1 in which the air is warmed as it enters4 ,ventilation presents no difficulties in the summer time or in warm climates4 ,the reason that it is a difficult question in cold weather is because the air furnished must be not only pure1 but warm4 ,to keep cold air out often means to keep foul air in4 ,heating with hot air1 by which system pure air is passed over a furnace1 and fresh air constantly admitted1 may be a good method 7,figs4 #hj1 #ha71 but is often a dismal failure because it dries out the air1 which in turn dries out the skin4 ,to prevent this1 wide vessels of water should be set at the inlets4 ,dry air is cooling4 ,why8 ,dr4 ,barnes proved that moist air at #fe is as comfortable as dry air at #ga4 ,air saturated with vapor at #fj will only be #ej per cent saturated at #hj4 ,such air dries out the mucous membrane of eyes1 nose1 and throat4 ,heating by hot water circulating in pipes1 or by steam1 gives no means of introducing fresh air1 and is likely to cause worse ventilation than any other method4 ,the radiators should stand close to windows or other fresh-air inlet1 that the air may be heated as it enters1 and the outlet for air should be farthest from the radiators4 ,the same rules apply to heating by stoves4 ,an oil stove for heating is an inconceivable iniquity to any but a person densely ignorant of hygiene4 ,heating by fireplaces 7,fig4 #hb7 is the most healthful of all methods1 for there is a constant removal of air through the chimney1 and this air will be replaced2 even if all doors and windows are closed1 it will come in through tiny cracks4 ,radiant heat travels in straight lines from a fireplace and warms solid objects1 but not the air passed through4 ,hence an open fire will keep the body warm with the room at a low temperature4 ,fireplaces1 however1 do not afford sufficient heat in severe climates4 ,stoves are not as healthful as fireplaces1 for there is not so much air removed through the pipe as through the chimney4 ,carbon monoxid1 unlike carbon dioxid1 is an active poison causing the blood corpuscles to shrivel4 ,it passes through red-hot iron or a cracked stove or furnace4 ,illustration3 ,,fig4 #hc4--;,,blackboard ,,sketch4 ,illustration3 ,,fig4 #hd4--;,facial expression in mouth breathing1 and breathing through the nose4 ,reasons for ,breathing through the ,nose 7,fig4 #hc74--7a7 ,the many blood vessels in the mucous membrane lining the nasal passages so heat the air that it does not irritate the bronchial tubes4 7#b7 ,the hairs in the nostrils strain the air and catch dust2 the cilia of the nasal passages also do this4 7#c7 ,a mouth-breather often swallows food before chewing it sufficiently1 because he cannot hold his breath longer4 7#d7 ,the nasal mucous membrane of an habitual mouth-breather dries and shrinks and obstructs the circulation1 bringing on catarrh of the nose4 7#e7 ,mouth breathing causes an unpleasant expression of countenance 7see ,fig4 #hd74 7#f7 ,the breath does not come through the nose as quickly as through the mouth2 the lungs are kept more expanded1 and one does not get 8out of breath0 so quickly4 7#g7 ,the voice of the mouth breather has a hard twang1 not a full1 resonant tone as when the nostrils are open4 7#h7 ,flavors and odors are better appreciated4 ,sometimes the sense of smell is almost lost by mouth breathers4 ,if one cannot breathe through the nose1 even for a short time1 there is probably an adenoid1 or tonsil-like1 growth in nose or pharynx1 and a physician should be consulted4 8,adenoids0 are glandular or grapelike in form4 ,diseases of the ,respiratory ,organs4--,a cold or catarrh is an inflammation of a mucous membrane4 ,if the inflammation is in the nasal passages1 it is called a cold in the head2 if it is in the pharynx1 it is called a sore throat2 if it is in the larynx or voice box1 there is hoarseness2 if it is in the bronchial tubes1 it is bronchitis2 finally1 if it is in the air cells1 it is pneumonia4 ,if the air is cut off from access to the air cells1 there is an attack of the painful disease called asthma1 which is accompanied by a feeling of suffocation4 ,some believe that asthma is caused by the mucous membrane lining the finest bronchial tubes becoming inflamed and swollen1 and closing the tubes2 others think that the muscles in the large bronchial tubes contract and close the tubes4 ,pleurisy is inflammation of the pleura and makes breathing painful4 ,if much fluid forms between the pleuras1 the inner pleura may press upon the lungs and interfere with breathing4 ,alcohol not only weakens the blood vessels near the surface1 but the blood vessels in general4 ,weakened and congested blood vessels in the lungs make them more liable to pneumonia and other congestive diseases4 ,continual congestion causes an abnormal growth of connective tissue fiber in the walls of the cells4 ,this diminishes the capacity of the lungs and interferes with the exchange of carbon dioxid and oxygen4 ,tobacco4--,it is often asked why cigarettes are so much more injurious to the health than pipes and cigars4 ,the nature of the paper of cigarettes and various other absurd reasons have been assigned4 ,the true reason is that the cigarette smoker usually inhales the tobacco smoke4 ,cigar smoke1 if drawn into the lungs1 would usually be coughed up at once4 ,cigarette smoke is weaker--it is so weak that the smoker is not content simply to absorb the nicotine through the mucous membrane of the mouth2 he draws it into the lungs4 ,the very mildness of the smoke leads to inhalation4 ,hence1 as the surface of the lungs is a hundred times greater than the surface of the mouth1 and its lining much thinner1 cigarette smoking is far more injurious than cigar smoking4 ,the poison accumulates in the bowl of a pipe2 hence an old pipe is very injurious4 ,the irritation of tobacco smoke often sets up a chronic dry catarrh of the air passages2 rarely it causes cancer of lips or tongue4 ,sir ,henry ,thompson says3 8,the only persons who enjoy smoking and find it tranquillizing at times are those who smoke in great moderation4 ,men who are rarely seen without a cigar between the lips1 have long ceased to enjoy smoking4 ,they are confirmed in a habit1 and are merely miserable when the cigar is absent40 ,they do not smoke for pleasure1 but to escape misery which wiser men escape by avoiding tobacco altogether4 ,illustration3 ,,fig4 #he4 ,,fig4 #hf4 ,,fig4 #he4--;,,flattened ,,chest and waist organs sunken from wearing tight clothing since the age of fourteen4 ,such women often walk with bodies bent forward to hide the prominent abdomen4 ,,fig4 #hf4--;,a ,,natural ,,woman4 ,,practical ,,questions4--#a4 ,state how in the case of a person with round shoulders a gradual remolding of cartilages 7which ones871 the strengthening of the muscles 7which ones871 and the practice of deep breathing may each contribute toward acquiring an erect and perfect figure4 #b4 ,should a hat be well ventilated8 7,a punch for making the holes costs a dime47 ,should a hat be stiff or soft8 #c4 ,name habits that impair the power of the lungs4 #d4 ,how could you convince a person that a bedroom should be open while and after it is swept8 ,that it should be ventilated at night8 #e4 ,which is the more injurious to others1 tobacco chewing which causes the ground to be unclean1 or smoking which renders the air impure8 #f4 ,why do those who stand straight up to hoe not get tired half so quickly as those who bend or 8hump0 over8 7,chap4 ,,vi47 #g4 ,why do students who sit in rocking chairs1 or from other causes lean the head forward when they study1 often find that they recover from drowsiness if they sit erect1 or sit in a straight chair8 #h4 ,how are high collars a fruitful source of bad colds8 #i4 ,if the draft up the chimney of the fireplace1 when the fire is burning1 takes up a volume of air sufficient for many people1 why is it unnecessary to open a window8 #aj4 ,why does cold impure air make a person colder than cold pure air8 7p4 #ad47 #aa4 ,do the modern customs of uniformity in dress for all classes and climates1 shipping foods from great distances1 one section or nation imitating the ways of another section or nation1 lead toward health or disease8 ,do such customs violate or conform to the great biological law that life is a process of adaptation to environment8 ,illustration3 ,,fig4 #hg4--,,suspenders should have a pulley or lever at the back1 that the strap on one side may loosen when one shoulder is raised4 ,illustration3 ,,colored ,,figure #f4--,,organs ,,of ,,the ,,trunk4 cb1 collar bone2 r1 ribs2 z1 tongue bone 7hyoid72 k1 k1 cartilages of larynx2 l1 windpipe2 s1 thyroid gland2 rv1 right ventricle2 lv1 left ventricle2 ru1 right auricle2 lu1 left auricle2 a1 aorta2 ka1 artery to head 7carotid72 sa1 subclavian artery2 la1 pulmonary artery2 oh1 superior vena cava2 hv1 jugular vein2 lu1 lungs2 f1 diaphragm2 lb1 liver2 g1 gall bladder2 s1 stomach2 x1 spleen2 n1 mesentery with vessels2 d1 small intestine2 gd1 large intestine2 b1 ccum2 w1 vermiform appendix2 h1 bladder4 ,,chapter ,,vii ,,food ,,and ,,digestion ,experiment #a4 ,tests for ,acid1 ,alkaline1 and ,neutral ,substances4--,repeat tests described in ,general ,introduction4#f #f ,see also ,peabody's 8,laboratory ,exercises in ,physiology10 ,holt1 ,n4,y4 ,experiment #b4 ,test for ,starch4--,see ,general ,introduction4 ,experiment #c4 ,test for ,grape ,sugar4--,see ,general ,introduction4 ,experiment #d4 ,test for ,proteid4--,see ,general ,introduction4 ,experiment #e4 ,test for ,fats4--,see ,general ,introduction4 ,experiment #f4 ,human ,teeth4--,study the form of teeth from every part of the mouth4 ,get a handful from a dentist4 ,break some of the teeth to make out their structure4 ,classify them4 ,draw section1 enlarged4 ,experiment #g4 ,study of the ,teeth4 7,at home47--,sit with the back to the light and look into a mirror1 with the mouth wide open4 ,do you see the four kinds of teeth named in text8 ,which are fitted for cutting8 ,which for grinding8 ,are any suited for tearing8 ,are any of the teeth pointed8 ,what is the difference in the bicuspids and molars8 ,are there any decayed places8 ,are the teeth clean8 ,are the so-called canine teeth so long that they project beyond the line of the other teeth1 as they do in a dog8 ,do the edges of the upper and lower incisors meet when the mouth is closed1 or do they miss each other like the blades of scissors8 ,how many roots has each lower tooth8 7,see ,fig4 #ib474 ,which tooth has the longest root8 ,experiment #h4 ,structure of ,mammalian ,stomach4--,get a piece of tripe from the market4 ,study its several coats4 ,the velvety inner coat is covered with mucous membrane4 7,photomicrograph1 ,fig4 #ie47 ,experiment #i4 ,model of ,human ,food ,tube4--,make a model of the food tube out of yellow cambric1 giving to each organ its correct size4 ,follow the dimensions given in text4 ,necessity for ,foods4--,growing plants and growing animals need new material to enable them to increase in size or grow4 ,plants never cease to grow while they live2 most mammals attain their full size in one fifth of the time occupied by their whole lives4 7,by this rule how long ought man to live87 ,animals1 moreover1 move from place to place1 and work with their muscles4 ,the energy for this comes from the food they eat4 ,plants do not use food for this purpose4 ,another need for food comes from the necessity for heat in all living things4 ,the activities of animals cause the tissues to wear out1 or break down1 and food furnishes material with which new living matter is built up by the cells and the tissues repaired4 ,we have already stated the rle of oxygen in setting free energy in the living substance of the cell by oxidizing it4 ,there is no furnace in the body as in an engine1 but the oxidation occurs in the cells themselves and the fuel is built up into living matter by the cells before it is oxidized4 ,plants must lift mineral from the inorganic to the organic world before it can be food for animals4 ,plants can assimilate minerals2 animals cannot4 ,the body cannot make bone out of limewater4 ,the iron in iron tonics cannot be used4 ,iron makes the grain brown1 and the peach red4 ,there is ten times as much iron in our food as the body needs4 ,state four reasons why animals need food4 ,which of these reasons is very powerful with plants8 ,least powerful8 ,absent altogether8 ,why is constant breathing necessary for life8 ,when is breathing more rapid8 ,why8 ,people who lead what kind of lives usually have poor appetites8 ,good appetites8 ,why8 ,what was the first distinct organ evolved by animals8 7,animal ,biology1 ,chap4 ,,iv47 ,the ,body is a ,machine for transferring ,energy4--,energy cannot be destroyed1 but it can be transferred and changed in form4 ,when a coin is rubbed on the table1 muscular energy1 supplied by oxidation in the muscle1 produces the motion4 ,friction may change motion into heat1 and the coin will become very hot4 ,the uniting of food and oxygen in the cells of the body gives the heat and motion 7energy7 of the body4 ,only substances which will oxidize1 or burn1 are true foods4 ,water1 salt1 and carbon dioxid will not burn2 hence1 they cannot give rise to energy in the body4 ,but the sun energy1 acting in the green leaf1 tears apart the carbon from the oxygen 7,plant ,biology1 ,chap4 ,,xiii71 sets free the oxygen1 and the carbon is stored in starch for future burning4 ,sunshine is energy 7light and heat74 ,the sun sustains the life of plants and through them the life of animals4 ,the oxidation in the body is so slow that it can hardly be called a burning1 but it is faster than the oxidation of iron in rusting or of wood in rotting1 and is about equal to the continual burning of two candles4 ,the ,four ,kinds of ,nutrients1 or ,food ,stuffs4--,the kinds of food which we eat seem to be numberless1 but they contain only four kinds of food stuffs1--starches1 fats1 proteids1 and minerals4 ,many foods contain all four classes of food stuffs4 ,milk contains sugar 7a changed form of starch71 cream 7a fat71 curd 7a proteid71 and water 7a mineral74 ,oatmeal contains starch1 oil1 gluten1 and water4 ,,uses ,,of ,,the ,,nutrients1 ,,or ,,food ,,stuffs #a4 ,proteids4 ,the tissue-building foods 7also of value as fuel74 #b4 ,starches 7and sugars7 ,energy and heat 7fuel7 and fat producing foods4 #c4 ,fats 7and oils7 #d4 ,minerals 7water1 salt74 ,important aids in using other foods4 ,relative ,fuel ,value4--,a pound of fat produces as much heat in the body as #b4c lb4 of proteid or #b4c lb4 of starch1 the last two having equal fuel value in the body4 ,starch and the sugars are closely related2 starch readily changes into sugar4 ,they contain much carbon and are called carbohydrates4 ,starch is especially abundant in grains1 seeds1 and fleshy roots 7,fig4 #hh74 ,the sugar in ripe fruit and in honey is called fruit sugar4 ,milk sugar is found in sweet milk4 ,grape sugar is found in grapes and honey2 the small grains seen in raisins consist of grape sugar2 it can also be prepared artificially from starch4 ,cane sugar is found in cane1 in sap of the maple1 and in the sugar beet 7,exps4 #b1 #c74 ,illustration3 ,,fig4 #hh4--;,a ,,tiny ,,bit ,,of ,,potato1 highly magnified1 showing cells filled with grains of starch4 ,cooking bursts these cells4 ,fats include the fats and oils found in milk1 flesh1 and plants4 ,a fat1 such as tallow1 is solid at the ordinary temperature2 while an oil1 such as olive oil1 is liquid at the same temperature4 ,tallow was oil while it was in the warm body of the ox4 ,sugar is transformed into fatty tissue as readily as is fatty food itself4 ,proteids are the only foods that contain the tissue-building nitrogen4 ,protoplasm cannot be formed without nitrogen4 ,we do not often see a pure proteid food1 for this food stuff is not so readily separated from foods containing it as are starch1 sugar1 and fat4 ,albumen1 or white-of-egg1 is proteid united with four times its weight of water4 ,pure proteid is also called albumin4 ,coagulation by heat is one test for proteid 7,exp4 #d74 ,these are the names of proteids1 or albumins1 found in several common foods3 casein1 the curd or cheesy part of milk2 myosin of lean meat2 fibrin in blood2 legumin in beans and peas2 gluten1 or the sticky part of wet flour2 gelatin in bones4 ,proteid is valuable to the body as fuel as well as a tissue builder4 ,we could burn beans and peas as well as the strictly fuel foods1 starch and fat1 in an engine1 and get heat to move the engine4 ,if one takes up athletics or hard physical labor1 he should increase the amount of fats and carbohydrates eaten1 but not of proteid4 ,muscular activity increases the carbon waste but not the nitrogen waste of the body4 ,minerals4--,the iron of the blood and the mineral salts in bone 7carbonate and phosphate of lime7 must enter the body in organic form in order to be used4 ,water and salt are mineral foods4 ,the body is about two thirds water4 ,the cells must do their work under water4 ,they cannot live when dried4 ,water enables the blood to flow2 and the blood is not only the feeder1 but also the washer and cleanser of the tissues4 ,some persons get out of the habit of drinking plenty of water1 and their health suffers thereby4 ,in such a case drinking plenty of water will be safer and more effective than taking poisonous drugs to restore health4 ,adulteration of ,food4--,sometimes cheaper materials1 of little or no value as food but of no great injury to health1 are added to foods4 ,examples3 water added to milk1 sawdust to ground spices1 chicory to coffee1 glucose to maple syrup4 ,other forms of adulteration not only cheat the purse but tend to destroy health1 or actually do so4 ,examples3 ,boracic acid or formalin added to milk to prevent souring1 copper to canned peas1 etc41 to give a bright green color2 salicylic acid or borax used in minute quantities as a preservative with canned corn1 tomatoes1 etc42 acids added to 8apple0 vinegar2 dried fruit treated with sulphur to prevent a dull color4 ,pure food laws tend to repress these evils4 ,it is best to buy foods in their original form4 ,for instance1 lemons are more reliable than vinegar4 ,a bit of lemon at each plate1 in households that can afford it1 is far preferable to vinegar4 ,we should always buy from neighbors when possible4 ,farmers and gardeners should do their own drying and canning4 ,for purity of water1 see ,chap4 ,x4 ,the ,daily ,ration4--,a quarter of a pound 7#d oz47 of proteid foods and one pound 7#af oz47 of fuel foods 7total #bj oz4 of water-free foods7 are needed to replace the daily waste of the body4 ,hence a balanced ration has proteid and fuel food in the ratio of #d to #af1 or #a to #d4 ,but recent experiments at ,yale ,university indicate that #b oz4 of proteid daily are more strengthening than four4 ,appetite is a perfect guide for those who lead an active life and eat slowly of simple food4 ,highly seasoned food and complex mixtures deprave the appetite2 it then leads astray1 instead of guiding safely4 ,of course the appetite cannot guide one to eat the right kind and quantity of food at a table where the food lacks any of the four necessary food stuffs1 or where innutritious or indigestible food is provided4 ,it is well to select one food for a meal because it is rich in proteids1 another because it is rich in fat1 and the third because it is rich in starch or sugar4 7,see table1 p4 #ie47 ,intelligence in regard to diet enables a housekeeper to provide nourishing food for less money than an ignorant housekeeper often pays for food deficient in nourishing qualities4 ,a ,balanced ,ration4--,a deficiency of starch may be supplied by an excess of fat or sugar4 ,it is most essential to provide proteid as it cannot be replaced by any other food stuff4 ,an excess of proteid is most harmful4 ,an excess of starch or fat is oxidized into water and carbon dioxid1 which are harmless waste products2 an excess of proteid is changed into urea which may become harmful by overworking the liver and kidneys which excrete it4 ,,composition ,,of ,,one ,,ounce ,,of ,,various ,,foods ,,in ,,fractions ,,of ,,an ,,ounce ,,carbo- ,,min- ,,pro- ,,hy- ,,eral,,woody ,,teids ,,fats ,,drates ,,water ,,salts,,fiber ---------------------------------------- ----------------------- ,daily ,ration #d oz4#b oz4#ad oz4#b qt4 #j ,i4 ,,nuts4 ,pecan 4#ajc 4#gjh 4#adc 4#jc 4#jag ,walnut 4#aeh 4#egd 4#af 4#jc 4#jad ,almonds 4#bce 4#ec 4#ab 4#jgh ,cocoanut 4#jef 4#ea 4#ce 4#jd ,chestnut 4#jcg 4#jb 4#ch 4#ed 4#jji 4#jb ,,ii4 ,,fruits4 ,sugar ,peach 4#jjg 4#jde 4#he 4#jjg 4#jd ,apple 4#jjd 4#jgb 4#hd 4#jje 4#je ,blackberry 4#jje 4#jdj 4#hf 4#jjd 4#ja ,cherry 4#jje 4#aj 4#hd 4#jjg 4#jb ,grape 4#abe 4#ae 4#gj 4#jje ,fig 7dried7 4#jdj 4#jad 4#ej ,banana 4#jej 4#bj 4#ge ,,iii4 ,,animal ,,food4 ,lean beef 4#bj 4#jce 4#jji 4#ge 4#jaf ,fat pork 4#jih 4#dhi 4#cij 4#jbc ,smoked ham 4#be 4#cfe 4#bgh 4#aja ,whitefish 4#aha 4#jbi 4#ghj 4#jaj ,poultry 4#baj 4#jch 4#gdj 4#jab ,oysters 4#age 4#jje 4#hjj 4#jae ,cow's milk 4#jce 4#jdj 4#jdj 4#hgj 4#jjg ,eggs 4#abe 4#abj 4#gce 4#jaj ,cheese 4#cce 4#bdc 4#cfh 4#jed ,butter 4#jjc 4#iaj 4#jfj 4#jba ,,iv4 ,,pods ,,or ,,legumes4 ,starch ,beans 4#be 4#jbj 4#eb 4#abe 4#jce 4#jfj ,peas 4#bag 4#jai 4#egg 4#ab 4#jbh 4#jcb ,peanuts 4#bidg 4#dfe 4#afb 4#jb 4#jbh 4#jdc ,v4 ,,grains4 ,wheat flour 7white7 4#aaj 4#jbj 4#gjc 4#aej 4#jag 4#jjc ,wheat bread 4#jhj 4#jae 4#dij 4#djj 4#jab 4#jjc ,oatmeal 4#abf 4#jef 4#fcj 4#aej 4#jcj 4#jaf ,maize 7corn7 4#ajj 4#jfg 4#gjf 4#ace 4#jad 4#jae ,rice 4#jej 4#jjh 4#hcb 4#ajj 4#jje 4#jdj ,,vi4 ,,vegetables4 ,potatoes 4#jab 4#jja 4#bje 4#gfg 4#jji 4#jjf ,cabbage 4#jb 4#jcj 4#jeh 4#iaj 4#jjg 4#jae ,studies based on ,table4--,what nuts are rich in proteids8 ,what fruits8 ,what animal foods8 ,what legumes8 ,what grains8 ,what foods are rich in fats8 ,what are rich in carbohydrates8 ,which grains have much starch8 ,which nut8 ,which fruits have much sugar8 ,a family was living chiefly on corn bread1 potatoes1 syrup1 cakes1 and sweetmeats3 what two of the four food stuffs were deficient in their diet8 ,another family lived chiefly on fat pork1 bread1 rice1 vegetables1 and fruit3 which food stuff was deficient8 ,a dozen eggs weigh #a lb4 ,which give cheaper nourishment1 eggs at #ae cents a dozen or beef at #ae cents a pound8 ,which is cheapest among the foods abounding in proteid8 ,fat8 ,carbohydrates8 ,which is cheaper food1 a pound of beef at #bj cents or a pound of pecans at the same price8 7,fig4 #aja47 ,what food contains most water8 ,least water8 ,which of the foods abounding in proteid is costliest8 ,cheapest8 ,notice that nearly all foods containing much proteid are costly4 ,water and woody fiber are not counted as nutriment4 ,what weight of nutriment in #a oz4 of cow's milk8 ,if a quart of whole milk costs #ab cts41 what is a quart of skimmed milk worth8 ,how the ,right ,proportions of ,fuel ,foods and ,proteid are reached by ,different ,nations4--,milk has an excess of nitrogen1 and oatmeal an excess of carbon2 oatmeal and milk form a popular food with the ,scotch4 ,potatoes are mostly starch and water1 and an ,irishman who tried to live on potatoes alone would have to eat seven pounds a day to get enough proteid4 ,the ,irish peasant keeps a cow and chickens2 by eating milk and eggs he gets along on half the amount of potatoes named above4 ,the ,mexicans eat bread made of corn meal1 and supply the proteid by using beans as a constant article of diet4 ,hundreds of millions of people in ,asia 7the ,hindus1 ,chinese1 and others7 subsist mainly on rice1 which contains only five per cent of proteid and no fat2 the chief addition they make is butter1 or other fat1 and beans1 which contain vegetable proteid4 ,outline of ,digestion4--,the food is made soluble in the alimentary canal and is absorbed by the blood vessels and lymphatics in its walls4 ,this canal is about thirty feet long 7,figs4 #hi1 #ij7 and consists of-- 7#a7 ,the mouth1 where the food remains about a minute1 while it is chewed and mixed with the saliva2 the saliva changes a portion of the starch to malt sugar4 7#b7 ,the gullet1 a tube nine inches long1 running from mouth to stomach and lying in front of the spinal column4 ,illustration3 ,illustrated ,study of ,food ,tract4 ,,fig4 #hi4--,,organs ,,of ,,trunk from the side4 ,l1 larynx2 th1 thyroid gland2 ,t1 trachea2 ,st1 breastbone2 ,c1 heart2 ,d1 diaphragm2 ,f1 liver2 ,e1 stomach2 ,i1 intestine2 ,co1 colon2 ,r1 rectum2 ,v1 bladder4 ,question3 ,parts of which organs are farther back than spinal column8 ,compare this figure with colored ,fig4 #f4 ,,fig4 #ij4--;,,digestive ,,organs1 from the front 7liver turned up74 #a1 gullet2 #b1 stomach2 #c1 spleen2 #d1 pancreas2 #e1 liver 7turned upward72 #f1 gall bladder2 #g1 #h1 #i1 small intestine2 #i1 junction of small with large intestine2 #aj1 caecum 7blind sac72 #aa1 vermiform appendix2 #ab1 #ab1 #ab1 ascending1 transverse1 and descending colon2 #ac1 rectum 7straight7 just below ,s-shaped flexure of colon4 ,question3 ,compare with ,fig4 #hi1 and colored ,fig4 #f4 7#c7 ,the stomach1 a large pouch where the food is stored1 and from which it passes in the course of several hours1 having become semi-liquid1 and the proteids having been partly digested by the gastric juice1 an acid secretion from the small glands in the stomach walls4 7#d7 ,the small intestine1 a narrow tube more than twenty feet long1 where the fats are acted upon for the first time1 and where the starches and proteids are also acted upon1 and where1 after about ten hours1 the digestion of the three classes of foods is completed by pancreatic juice from the pancreas1 and bile from the liver4 7#e7 ,the large intestine1 about five feet long1 where the last remnant of nutriment is absorbed1 and the indigestible materials in the food are gathered together 7,exp4 #i74 ,the ,teeth4--,the main body of the tooth consists of bone-like dentine1 or ivory4 ,hard1 shining enamel protects the crown1 or visible portion4 ,the part of the tooth beneath the gum is called the neck1 and the part in the bony socket1 is called the root4 ,the enamel ends just beneath the gum1 where it is overlapped by cement of the root4 ,there is a pulp cavity in every tooth 7,fig4 #ia72 it contains pulp made up of connective tissue1 with nerves and blood vessels which enter at the tip of the root 7,exp4 #f74 ,illustration3 ,,fig4 #ia4--;,,canine ,,tooth ,,cut ,,lengthwise4 ,the temporary set of teeth is completed at about two years of age and consists of twenty teeth4 ,the teeth cannot grow as the jaw grows1 and soon a larger and permanent set starts to growing deeper in the jaw4 ,at the age of twelve or thirteen years all the permanent set have appeared except the four wisdom teeth1 which appear between the ages of seventeen and twenty-five4 ,the second set not only replaces the twenty of the first set1 but to fill the larger jaws twelve molars are added1 three at the back in each half jaw1 making thirty-two teeth in the second set 7,exp4 #g74 ,the teeth in each quarter of the mouth1 named in order from the front1 are3 two incisors1 one canine1 two premolars1 three molars4 ,illustration3 ,,fig4 #ib4--,,the ,,permanent ,,teeth in right half of lower jaw4 ,illustration3 ,,fig4 #ic4--,,upper ,,jaw ,,with ,,teeth4 ,care of the ,teeth4--,the best way to care for the teeth is to keep the digestion perfect4 ,perfect digestion tends to preserve the teeth1 and sound teeth tend to keep the digestion perfect4 ,the teeth should be washed regularly4 ,prepared chalk is the best dentifrice4 ,do not rub across1 but from gums to teeth1 to prevent rubbing the gums loose from the teeth4 ,an unclean brush may harbor germs4 ,toothpicks and dental floss are useful4 ,if one eats only soft food1 in which the mill and the cooking stove have left no work for the teeth1 the teeth will decay2 for it seems to be a law of nature that useless organs are removed4 ,the pressure from chewing hard food is an aid to the teeth by helping the circulation and nerves in the pulp4 ,to take a very hot or very cold drink into the mouth may cause the enamel to crack4 ,if a tooth aches1 or a small decayed place is found in it1 a dentist should be consulted at once4 ,a tooth is so valuable to the health that no tooth should be extracted when it can be saved4 ,the process of digestion consists in liquefying the food that it may pass through the walls of the food tube into the blood1 and through the walls of the blood vessels into the tissues4 ,it is accomplished3 7#a7 by mechanical means1 including the chewing muscles1 the teeth1 and three layers of muscles in the walls of the food tube2 7#b7 by chemical means1 or the action of alkalies and acids upon the food2 7#c7 by organic agency1 or the action of ferments4 ,a ferment 7or enzyme7 is a vegetable substance which has the power of producing a chemical change in large quantities of substance brought in contact with it1 without being itself changed4 ,there is one ferment secreted in the mouth1 two in the stomach1 and three in the small intestine4 ,digestion in the ,mouth4--,saliva is formed by six glands3 one in the cheek in front of each ear1 one at the angle of each lower jaw1 and one pair is beneath the tongue4 ,each gland opens into the mouth by a duct4 ,saliva is ropy because it is mixed with mucus formed by the mucous membrane lining the mouth2 it usually contains air bubbles4 ,there is a ferment in the saliva called ptyalin1 which has the power of changing starch to malt sugar4 ,if a bit of bread is chewed for a long time1 it becomes sweet1 because some of the starch is changed to sugar4 ,the flow of saliva is caused by chewing1 or by the sight1 or even the thought1 of agreeable food4 ,dryness of food is by far more powerful than anything else in causing the saliva to flow4 ,saliva is secreted only one fourth as fast when eating oatmeal and milk as when eating dry toast 7,fig4 #id74 ,illustration3 ,,fig4 #id4--;,,cells ,,of ,a ,,salivary ,,gland ,a1 after rest1 full of granules2 ,b1 after short activity2 ,c1 after prolonged activity1 cells shriveled and granules lost4 ,starchy grains and fruits were eaten by early man without cooking1 and required more chewing than sweet1 ripe fruits or oils or proteids4 ,hence the saliva was given the power of acting upon the starch1 for it must remain in the mouth longer4 ,the saliva is alkaline2 and if the food is not thoroughly mixed with it1 the stomach digestion will also be imperfect1 for the alkaline saliva is necessary to excite an abundant flow of gastric juice in the stomach 7,exp4 #a74 ,eating slowly is difficult because of the grinding and cooking of food2 hence the common practice of overeating4 ,to eat slowly 7#a7 do not take large mouthfuls2 7#b7 do not take a second morsel until the first has been swallowed2 7#c7 sit erect or lean back after putting food into the mouth2 7#d7 the hands should lie idle most of the time4 ,to lean forward and keep food traveling to the mouth like coal into a chute means overeating with all its bad effects4 ,chewing gum is a coarse and impolite habit1 and wastes the saliva1 besides weakening the glands and irritating the stomach by the saliva that is continually swallowed4 ,chewing tobacco has several of these disadvantages1 besides allowing the poison in the tobacco to be absorbed by the mucous lining of the mouth4 ,the pharynx 7farinks71 or throat1 is a muscular bag suspended behind the nose and mouth4 7,see ,fig4 #hi1 also ,fig4 #hc47 ,there are seven openings into the pharynx3 two from the nostrils1 two from the ears1 one each from the mouth1 larynx1 and gullet4 ,which of these openings are downward8 ,forward8 ,lateral8 ,the gullet 7or esophagus7 is a muscular tube about nine inches long4 7,see ,fig4 #hi47 ,like the rest of the food tube1 it is lined with mucous membrane4 ,it has two layers of muscles in its walls1 the fibers of one layer running lengthwise1 and the fibers of the other layer being circular4 ,in swallowing1 the food does not fall down the gullet of its own weight1 but the circular bands of muscle in front of the food relax1 and those behind it contract and push it on into the stomach4 ,this wavelike motion is called peristalsis4 ,the stomach1 the greatest enlargement of the food tube1 is like a large bag lying sideways4 ,it lies to the left side of the abdomen4 ,the walls of the stomach consist chiefly of muscular fibers which run lengthwise1 crosswise1 and slantwise1 making three coats 7,exp4 #g1 also ,fig4 #ie74 ,as soon as the food reaches the stomach1 the layers of muscles begin to contract1 changing the size of the stomach1 first in length1 then in breadth1 thus churning the food to and fro1 and mixing it with the gastric juice1 a fluid more active than the saliva4 ,for as the food enters the stomach1 the mucous membrane lining it turns a bright red1 and many little gastric glands in the lining begin to secrete gastric juice4 ,illustration3 ,,fig4 #ie4--,,muscular ,,and ,,other ,,layers ,,in ,,wall ,,of ,,stomach4 #a1 mucous lining2 #b1 layer of blood vessels and connective tissue2 #c1 muscular layers 7involuntary muscles72 #d1 connective-tissue fibers4 7,peabody47 ,digestion in the ,stomach4--,the stomach churns the food from two to four hours after the meal1 according to the kind of food eaten1 the way it has been cooked1 and the thoroughness with which it has been chewed4 ,the gastric juice is chiefly water1 and contains two ferments called pepsin and rennin1 and a small quantity of hydrochloric acid4 ,rennin acts upon the curd of milk1 and is abundant only during infancy4 ,hydrochloric acid kills germs that may enter the stomach1 and changes the food which has been made alkaline by the saliva into an acid condition 7,exp4 #a74 ,this enables the pepsin to act upon the proteid part of the food1 for pepsin will not act while the food is alkaline4 ,gastric juice digests lean meat1 which is a proteid food1 by first dissolving the connective tissue that holds the fibers in place1 and they fall apart2 it then acts upon the fibers separately and makes them soluble4 ,like human fatty tissue 7,fig4 #ad71 fat meat consists of cells filled with fat and held together by threads of connective tissue4 ,the cell walls and the threads1 both being proteid1 are soon dissolved by the gastric juice1 and the free fat is melted into oil1 but still undigested4 ,the food is reduced in the stomach to a creamy1 half-fluid mass called chyme4 ,where the stomach opens into the small intestine1 there is a folding in or narrowing of the tube so as to form a kind of valve called the pylorus4 ,after the food has been changed to chyme1 this fold relaxes every minute or two1 and allows some of the chyme to escape into the intestine4 ,illustration3 ,,fig4 #if4--;,a ,,portion ,,of ,,small ,,intestine cut open to show the folds in its lining4 ,the small intestine is about one inch in diameter and twenty feet long1 with many coils and turns in its course 7,fig4 #ij74 ,its mucous lining is wrinkled into numerous folds in order to increase the secreting and absorbing surface 7,fig4 #if74 ,on and between the folds are thousands of little threadlike projections called villi 7,fig4 #ig74 ,in each villus are found fine capillaries and a small lymphatic called a lacteal 7colored ,fig4 #b74 ,the villi are so thick that they make the lining of the intestine like velvet1 and enormously increase the absorbing surface4 ,illustration3 ,,fig4 #ig4--,,lining ,,of ,,small ,,intestine1 magnified1 showing villi and mouths of intestinal glands4 ,digestion in the ,small ,intestine4--,this is by far the most active and important of the digestive organs4 ,the mouth digests a small part of the starch1 and the stomach digests a small part of the proteid2 the small intestine digests most of the starch1 most of the proteid1 and all of the fats4 ,the food is in the mouth a few minutes1 and in the stomach two or three hours2 it is in the small intestine ten or twelve hours4 ,there are thousands of small glands called intestinal glands that open between the villi 7,fig4 #ig7 and secrete the intestinal juice1 which digests cane sugar4 ,besides these1 there are two very large and active glands1 the pancreas and liver1 which empty into the intestine by ducts4 ,the ,pancreas4--,the small intestine is the most important of the digestive organs1 chiefly because it receives the secretion from the pancreas1 the most important of digestive glands4 ,the pancreas is a long1 flat1 pinkish gland situated behind the stomach 7see ,fig4 #ij74 ,the pancreatic juice contains three powerful ferments1 one of which 7amylopsin7 digests the starches1 another 7trypsin7 digests proteids1 and the third 7steapsin71 with the aid of the bile1 breaks up the fats into tiny globules4 ,fat in small globules floating in a liquid is called an emulsion2 fresh milk is an emulsion of cream 7,fig4 #ih74 ,fat is not changed to another substance by digestion1 but it is emulsified1 and in this condition it readily passes through the walls of the intestines and is absorbed by the lymphatics called lacteals 7colored ,fig4 #e7 found in the villi4 ,it then ascends through the thoracic duct to a large vein at the left side of the neck 7,fig4 #ajj74 ,the digested proteid1 starch1 and sugar pass into the capillaries of the portal vein1 and go to the liver on their way to the general circulation 7,fig4 #ajj74 ,the portal circulation empties into the large ascending vein leading to the right auricle 7,fig4 #ajj74 ,illustration3 ,,fig4 #ih4--;,,junction ,,of ,,large ,,and ,,small ,,intestine4 ,the ,liver4--,this large1 chocolate-colored gland is located just beneath the diaphragm on the right side 7,fig4 #ij1 colored ,fig4 #f74 ,it is on a level with the stomach1 which it partly overlaps in front4 ,the liver has three important functions3 7#a7 ,it is a storeroom2 digested sugar and starch are stored in it as a substance called liver starch 7or glcogen74 7#b7 ,it is a guardian1 and destroys poisonous substances which may be swallowed1 and which would otherwise enter the blood4 ,twice as much morphine or other poison is necessary to kill a man when it is taken by the mouth and passes through the liver as when it is injected through the skin4 ,alcohol1 morphine1 coffee1 and drugs are partly burned up in the liver4 7#c7 ,it is a gland1 and secretes bile4 ,the bile is made chiefly from waste products and impurities in the blood2 it is an excretion4 ,although an excretion1 it is of use on its way out of the body4 ,it is alkaline and helps to neutralize the acid in the chyme2 it excites the peristalsis1 or wavelike motion1 of the intestines1 and it aids the pancreatic juice to emulsify the fats4 ,illustration3 ,,fig4 #ii4--;,,diagram ,,of ,,trunk to show the many folds of the ,,peritoneum supporting the liver1 stomach1 and intestines4 ,the large intestine1 or colon1 is about two and one half inches in diameter and five feet long4 ,the small intestine joins it in the lower right side of the abdomen 7,fig4 #ij74 ,there is a fold1 or valve1 at the juncture1 and just below the juncture there is a tube attached to the large intestine1 called the appendix1 which sometimes becomes inflamed1 causing a disease called appendicitis 7,figs4 #ij1 #ih74 ,the appendix is a vestigial 7vestigium1 trace7 or rudimentary organ1 long since useless4 ,absorption of the watery part of the food continues in the colon1 but the colon secretes no digestive fluid4 ,the undigested and innutritious parts of the food are regularly cast out of the colon4#g ,the peritoneum is a membrane with many folds that supports the food tube 7,fig4 #ii74 #g ,no truly refined person will allow business1 pleasure1 haste1 or neglect to interfere with regular attention to emptying the colon4 ,this is more necessary for real cleanliness than regular baths4 ,absorption4--,the way in which the various digested foods are absorbed has been stated in several preceding topics4 ,what is the name of the organs of absorption in the small intestine8 ,which of the following pass into the lacteals1 and which into the capillaries of the portal vein3 sugar1 digested proteid1 emulsified fats8 ,water and salt need no digestion1 and are absorbed all along the food tube1 the absorption beginning even in the mouth4 ,what reasons can you give for the absorption of food being many times greater in the small intestine than in the stomach8 ,through what large tube is the fat carried in passing from the lacteals to the veins8 ,into what large vein do all the capillaries that take part in absorption empty8 7,colored ,fig4 #e47 ,what is the provision for storing the sugar so that it will not pass suddenly into the blood after a meal1 but may be given to the blood gradually8 ,food is assimilated1 or changed into living matter 7protoplasm71 in the cells4 ,blood and lymph 7except the white corpuscles7 are not living matter4 7,fig4 #ajj47 ,illustration3 ,,fig4 #ajj4--,,the ,,two ,,paths ,,of ,,food ,,absorption4 ,thoracic duct 7for fats72 through the portal vein and liver 7for all other foods74 ,,thought ,,questions4 ,the ,digestive ,organs4--#a4 ,in which of the digestive organs is only one kind of secretion furnished by glands8 #b4 ,in which organ are three kinds of secretions furnished by glands8 #c4 ,which class of food goes through the lymphatics8 #d4 ,which classes of foods go through the liver8 #e4 ,which classes of foods are digested in only one organ8 #f4 ,which classes of foods are digested in two organs8 #g4 ,which division of the food tube is longest8 ,broadest8 ,least active8 ,most active8 #h4 ,soup is absorbed quickly2 why does eating it at the beginning of a meal tend to prevent overeating8 ,hygienic ,habits of ,eating4--,in hot weather much blood goes to the skin and little to the food tube1 and digestion is less vigorous4 ,hearty eaters suffer from heat in summer because of much fuel1 and because the blood is kept away from the skin where it would become cool and then cool the whole body4 ,some persons believe that the stomach should be humored and given nothing that it digests with difficulty2 others believe that it should be gradually trained to digest any nutritious food4 ,some believe that no animal food should be eaten2 others believe that animal food is as valuable as any4 ,some believe that all food should be eaten raw1 but this would irritate a delicate stomach4 ,it is doubtless best to use no stimulant1 either tea or coffee1 pepper or alcohol4 ,some eat fast and drink freely at meals2 it is better to eat slowly and drink very little or none at all while eating1 nor soon afterwards4 ,some eat five meals a day1 and between meals if anything that tastes good is offered them2 others eat only two or three meals a day1 and never between meals1 thus allowing the digestive organs time to rest4 ,some omit breakfast and some omit supper4 ,some prepare most of the food with grease2 this is a tax upon digestion4 ,physical workers often believe in eating the peelings and seeds of fruits1 and partaking freely of weedy vegetables1 such as cabbage1 turnip tops1 string beans4 ,mental workers usually try to reject all woody fiber and indigestible pulp from the food before swallowing it4 ,some eat large quantities of food and digest a small portion2 others eat little but digest nearly all4 ,the ,power of ,adaptation of the ,digestive ,organs4--,of course some habits of eating are better for the health than others1 yet the undesirable ways often bring so little injury that they are not discontinued4 ,this shows that the food tube has great powers of adaptation to different conditions4 ,but there are limits to this adaptation2 there is an old saying that what is one man's meat is another man's poison4 ,a brain worker cannot follow the same diet as a field hand without working at a disadvantage4 ,an irritable stomach may be injured by coarse food that would furnish only a healthful stimulus to a less sensitive one4 ,a business man who has little leisure at noon should take the heaviest meal after business hours4 ,in general1 it may be said that it does not make so much difference what is eaten as how it is eaten1 and how much is eaten4 ,there is a common tendency to exaggerate the importance of dietetics4 ,,thought ,,questions4 ,indigestion4--,i4 ,a ,fetid ,breath4 #a4 ,name three causes of bad breath4 #b4 ,let us investigate whether indigestion could cause a bad breath4 ,in what kind 7two qualities7 of weather does meat spoil the quickest8 #c4 ,suppose that meat or other food is put into a stomach with its gastric glands exhausted and its muscular walls tired out1 what will be the rate of digestion1 and what might happen to the food8 #d4 ,odorous contents of the stomach 7e4g4 onion7 can be taken by the blood to the lungs where it will taint the breath4 ,after answering the above questions1 write in a few words how indigestion may cause a bad breath4 ,,ii4 ,a ,coated or ,foul ,tongue4 #a4 ,when the doctor visits you1 at what does he first look8 #b4 ,what sometimes forms on old bread8 7p4 #aeh47 #c4 ,do you think such a growth possible on undigested bread in the stomach8 #d4 ,the microscope shows the coating on the bread to be a growth of mold4 ,if it forms on the walls of the stomach1 it may extend to what8 ,,iii4 ,stomach ,ache4 #a4 ,how can you tell whether fruit preserved in a sealed glass jar is fermenting8 #b4 ,what connection is there between belching after eating too freely of sweet or starchy food1 and the observation above8 #c4 ,a muscle gives pain when it is stretched4 ,why does belching sometimes give relief to an uneasy stomach8 #d4 ,can you1 by using these facts1 explain a cause of stomach ache8 ,for what ,kind of ,man were the ,human ,digestive ,organs created8--,that food is best to which the food tube has been longest accustomed4 ,it would be of the greatest value as a guide to diet if we knew the food eaten by early man during the many ages when he led a wild life in the open air4 ,the organs of early man were doubtless perfectly adapted to the life he led4 ,the food tube is adapted to the needs of those long ages1 for a few centuries of civilization cannot change the nature of the digestive organs2 yet some people disregard natural appetites and try to force the digestive organs to undergo greater changes in a few months than centuries could bring about4 ,to test whether an ,article of ,food belonged to ,man's ,original ,diet4--,scientists agree that the human race began in a warm country2 that early man was without gristmills1 stoves1 or fire1 and ate his food raw4 ,if an article of food is pleasant to the taste in its raw1 pure state1 there is little doubt that it1 or a similar food1 was eaten by primitive man before he knew the use of fire in preparing his food4 ,apply this test to the following foods1 underlining those foods that pass the test3 apples1 bananas1 lettuce1 turnip greens1 turnips1 fruits1 nuts1 beef1 fowls1 eggs1 oysters1 green corn1 cabbage1 pork1 watermelons1 grains1 crabs1 fish1 white or ,irish potatoes1 yams1 tomatoes4 ,illustration3 ,,fig4 #aja4--;,,blackboard ,,diagram4 ,amount of nourishment 7black7 and waste 7white7 in several foods4 7,after ,latson47 ,the ,order in which ,man increased his ,bill of ,fare4--,flesh-eating animals have a short food tube1 as their food is digested quickly2 they have long1 pointed teeth for tearing1 sharp claws for holding1 and a rough tongue for rasping meat from the bones4 ,man's even teeth1 long food tube1 soft and smooth tongue1 and flattened nails1 indicate that he is suited for a diet largely vegetable 7see ,table1 p4 #aaa74 ,the race at first probably ate tree fruits1#h both nuts and fleshy fruits 7,fig4 #aja74 ,because of famine1 or after migration to colder climates1 and after learning the use of fire1 the race probably began to use flesh for food4 ,afterward the hunters became farmers and learned to cultivate grain1 which formed a most important addition to the food supply1 and made possible a dense population4 ,coarse1 woody foods1 like the leaves and stems of herbs1 were probably added last of all4 ,woody fiber 7cellulose7 can be digested by cattle1 but it cannot be digested by man4 #h ,see ,genesis i4 #bi4 ,some raw food should be eaten daily4 ,pecans are the most digestible of all nuts4 ,a half dozen or more eaten regularly for breakfast will prevent constipation or cure it in ten days or less4 ,the ,natural ,guide in ,eating is ,taste4 ,man should preserve his taste uncorrupted as1 next to his conscience1 his wisest counselor and friend4 ,it has been developed and transmitted through countless ages as a precious heritage4 ,simple food is more delicious to people with natural tastes than the most artificial concoctions are to those with perverted taste4 ,animal ,food4--,the flesh of animals furnishes proteid and fat 7,fig4 #ajb74 ,as cooking coagulates and hardens albumin1 raw or half-cooked meat is said to be more digestible than cooked meat2 but meat that is not thoroughly cooked is dangerous because it may contain trichin 78,animal ,biology10 p4 #ej7 and other parasites4 ,lean meats contain much proteid4 ,some persons who cannot easily digest starch and sugar because of fermentation eat fat for a fuel food4 ,beef tea and beef extracts contain but a small part of the proteid in meat and all of the waste matter1 including urea4 ,illustration3 ,,fig4 #ajb4--;,,diagram ,,showing ,,cuts ,,of ,,beef4 #a4 sirloin #b4 loin #c4 rump #d4 round #e4 top sirloin #f4 prime ribs #g4 blade #h4 chuck #i4 neck #aj4 brisket #aa4 cross-rib #ab4 plate #ac4 navel #ad4 flank #ae4 shoulder #af4 leg ,,mammals ,,carnivora1 ,,or,,herbivora1 ,,or,,omnivora1 ,,or ,,frugivora1 ,,or ,,compared ,,flesh-,,eaters ,,herb-,,eaters ,,all-,,eaters ,,fruit-,,eaters ---------------------------------------- -------------------------- ,examples4 ,cat1 dog1 ,cow1 horse4 ,hog1 peccary4,man1 monkey4 lion4 ---------------------------------------- -------------------------- ,length of #c times #cj times #aj times #ab times food tube4 length of length of length of length of body4 body4 body4 head-trunk4 ---------------------------------------- -------------------------- ,teeth4 ,pointed for ,layers of ,cutting teeth,teeth even1 tearing enamel and project4 close flesh4 ,caninedentine ,canines form together4 teeth long4 forming tusks4 ,canines not ridges4 projecting4 ---------------------------------------- -------------------------- ,digits4 ,sharp claws4 ,hoofs4 ,hoofs4 ,flattened nails4 ---------------------------------------- -------------------------- ,colon4 ,smooth4 ,sacculated4 ,smooth4 ,sacculated4 ,milk of cows is improperly called a perfect food by some writers4 ,although it contains the four classes of food stuffs1 the proteid is in excess1 the fuel food being deficient4 ,buttermilk is more digestible than sweet milk4 ,buttermilk and sugar form a valuable food for infants4 ,skimmed milk still contains the proteid1 the most nutritious part of the milk4 ,sour milk1 or 8clabber10 and curds pressed into 8cottage cheese0 are more digestible than sweet milk4 ,cream is more easily digested than butter1 which is a solid fat4 ,cheese is a very concentrated proteid food1 and should be eaten sparingly4 ,eggs are a valuable food4 ,is there more proteid or fat in eggs8 7,see ,table47 ,pork and veal are the most indigestible of meats4 ,fish is nearly as nutritious as meat4 ,there used to be a supposition that fish nourished the brain because it contains phosphates2 but there are more phosphates in meat than in fish1 and more in grains than in meat4 ,grains contain considerable proteid 7gluten71 but they especially abound in starch4 ,wheat flour contains more gluten than corn meal1 hence it is more sticky1 and retains the bubbles of gas so that the dough rises well in bread making4 ,eggs are sometimes added to corn meal to make it sticky and cause it to rise well4 ,which grain has the largest percentage of oil8 7,see ,table47 ,of starch8 ,of gluten8 ,which is poorest in gluten8 ,grains may be made to resemble fruit by long cooking at a high temperature 7#cjj ,fahr471 for their starch is thus changed to dextrin1 a substance resembling sugar4 ,you learned that the starch of fruit is turned into sugar as the sun ripens it4 ,dextrin is yellow and gives the dark color to toasted bread4 ,it is changed to sugar almost instantly when brought in contact with saliva4 ,it is used as a paste on postage stamps4 ,vegetables contain much water and woody fiber4 ,white potatoes are underground stems and are one fifth starch4 ,yams1 or sweet potatoes1 resemble roots1 and contain both starch and sugar4 ,beans and peas are very nutritious4 ,they have been called 8the lean meat of the vegetable kingdom40 ,they require boiling for several hours4 ,if the skins are removed by pressing them through a colander1 they are very easy of digestion4 ,this pure of beans makes delicious soup4 8,hull-less beans0 and 8split peas0 are also sold by grocers4 ,,practical ,,questions4--#a4 ,clothing and shelter for man or beast economize what kind of food8 #b4 ,why should bread remain longer in the mouth than meat8 #c4 ,in snowballing1 what is the appearance of the hands when they itch from cold8 ,extreme cold irritates and congests the stomach more quickly than it does the hands4 ,why is it that ice water does not satisfy the thirst1 but often produces a craving to drink more water8 #d4 ,should biscuits having a yellow tint or dark spots due to soda be eaten or thrown away8 #e4 ,why1 during an epidemic1 are those who have used alcohol as a beverage usually the first to be attacked8 #f4 ,do you buy more wood 7cellulose7 when you buy beans or when you buy nuts8 7p4 #ie47 #g4 ,do you buy more water when you buy bread or when you buy meat8 #h4 ,why do people who live in overheated rooms often have poor appetites8 7p4 #ij47 #i4 ,explain how the stomach may be weakened by the eating of predigested foods4 #aj4 ,why are deep breathing and exercises that strengthen weak abdominal walls better for the liver than are drugs8 7,see p4 #eh47 #aa4 ,sixty students at the ,university of ,missouri found by doing without supper that their power to work was greater1 their health better1 and many of them gained in weight4 ,so they ate only two meals thereafter4 ,if sixty plowboys tried the experiment1 would the result probably have been the same8 #ab4 ,if a person began to eat less at each meal1 or only ate one meal a day1 yet gained in weight1 should he agree with a friend who told him he was starving himself8 ,should he agree if1 instead of gaining1 he lost weight8 #ac4 ,why is half-raw or soggy bread harder to digest than the raw grain itself8 ,which would be thoroughly chewed and cause a great flow of saliva8 #ad4 ,ask a fat person whether he drinks much water4 ,a lean person4 #ae4 ,why is one whose waist measures more than his chest a bad life insurance risk8 #af4 ,what changes in habits tend to make a rheumatic middle-aged person more youthful8 #ag4 ,how is the ingenious 8fireless cooker0 constructed8 ,atwater's ,experiments with ,alcohol4--,a few years ago ,professor ,atwater proved that if alcohol is taken in small quantities1 it is so completely burned in the body that not over two per cent is excreted4 ,he inferred that it is a food1 since it gives heat to the body and possibly gives energy also4 ,his experiments did not show whether any organ was weakened or injured by its use4 ,as alcohol is chiefly burned in the liver1 it probably cannot supply energy as is the case with food burned in nerve cell and muscle cell4 ,the heat supplied by its burning is largely lost by the rush of blood to the skin usually caused by drinking the alcohol4 ,dr4 ,beebe1 unlike ,professor ,atwater1 experimented upon persons who had never taken alcohol1 and whose bodies had not had time to become trained to resist its evil effects4 ,he found that it caused an increased excretion of nitrogen4 ,when the body became used to it1 this decreased1 but the proteid excreted by the kidneys contained an abnormal amount of a harmful material called uric acid4 ,uric acid1 a substance which is present in rheumatism and other diseases1 is usually destroyed by the liver4 ,as the burden of destroying the alcohol falls chiefly upon the liver1 it is not surprising to find that it is so weakened and injured by alcoholic drink that it cannot fully perform its important functions4 ,bright's disease and other diseases accompanied by uric acid are more frequent among persons who use alcoholic drinks4 ,definition of ,food4--,a food is anything which1 after being absorbed by the body1 nourishes the body without injuring it4 ,does alcohol or tobacco come within this definition8 ,advantages of ,good ,cooking4--,taste and flavor may be developed2 parasites are killed2 taste may be improved by combining foods2 starch grains are burst and the food softened4 ,thus digestion is aided4 ,disadvantages of ,bad ,cooking4--,proteid foods are hardened2 flavors may be driven off2 too many kinds of food may be mixed2 cooked vegetables are more likely to ferment than raw vegetables2 palatable food may be made tasteless or soggy or greasy2 soda and other indigestible ingredients may be added2 food may be so highly seasoned as to cause catarrh of the stomach2 it may so stimulate the appetite that so much is eaten as to overload the stomach4 ,food may be made so soft that it cannot be chewed and is eaten too rapidly2 for instance1 bread shortened with much grease4 ,the ,five ,modes of ,cooking4--,food may be cooked 7#a7 by heat radiating from glowing coals or a flame1 as in broiling2 7#b7 by hot air1 as baking in a hot oven2 7#c7 by boiling in hot water or grease1 as frying2 7#d7 by hot water1 not boiling1 as in stewing2 7#e7 by steaming4 ,radiant ,heat4--,toasting bread and broiling meat are examples4 ,the meat should be turned over every ten seconds to send its juices back and forth1 thus preventing their escape1 and broiling the meat in the heat of its own juices4 ,roasting is an example of this method combined with the second method4 ,the fire should be hot at first in order to sear the outside of the meat and prevent the escape of its juices4 ,if the piece roasted is small1 the hot fire may be kept up2 but if it is large1 a longer time is required1 and the fire should be decreased1 otherwise the outside will be scorched before the central part becomes heated4 ,white1 or ,irish1 potatoes roasted with their skins on best retain their flavor as well as valuable mineral salts 7potash1 etc474 ,cooking by hot air can only be used with moist foods4 ,baking is an example4 ,foods only slightly moist are made hard1 dry1 and unpalatable if cooked by this method4 ,cooking by ,boiling4--,to boil potatoes so as to make them mealy instead of soggy1 the water should be boiling when they are put in1 and after they are cooked the water should be poured off and the pot set on the back of the stove for the potatoes to dry4 ,boiling onions drives off the acrid1 irritating oil4 ,rapid boiling of vegetables gives less time for the water to dissolve out the nutrients4 7,see ,steaming47 ,raw cabbage is treated by the stomach as a foreign substance1 and sent promptly to the intestine2 cabbage boiled with fat may remain in the stomach for five hours4 ,instead1 it should be boiled in clear water for twenty minutes4 ,beans and peas require several hours' boiling4 ,cooking in hot liquid below the boiling point is better than boiling4 ,in frying meat1 it should be put in hot grease that a crust may be formed to prevent the grease from soaking in4 ,grease much above boiling point becomes decomposed into fatty acids and other indigestible products4 ,hence butter is more digestible than cooked fats4 ,in whatever way meat is cooked1 it should never be salted until the cooking is finished or the salt will draw out the juices which flavor it4 ,eggs may be cooked by placing them in boiling water and setting the kettle off the stove at once to cool4 ,a finely minced hard-boiled egg is as digestible as a soft-boiled egg4 ,since boiling for more than a very few minutes coagulates and hardens albumin1 there is no such thing as boiling meat without making it tough and leathery throughout4 ,it may be stewed1 a process which belongs to the next method4 ,in stewing meat1 it may be plunged into boiling water for a few minutes2 this coagulates the albumin on the surface4 ,the fire should then be reduced1 or the vessel set on the cooler part of the stove1 or a metal plate should be placed beneath it1 that the water may barely simmer4 ,the water should show a temperature of #ahe or #aij if tested with a thermometer4 ,a piece of meat cooked in this way is tender and juicy4 ,cooking by steam requires a double vessel or a vessel with a perforated second bottom above the water1 through which the steam may rise to the food that is to be steamed4 ,steamed vegetables have a better flavor and are more nutritious than those cooked in any other way4 ,a steamer is different from a double boiler4 ,oatmeal should be cooked for at least forty minutes1 and it is more digestible if steamed for several hours until it is a jelly4 ,to do this1 it may be cooked during the preparation of two meals4 ,cooking that leaves it lumpy and sticky is a disadvantage1 and makes it more likely to ferment than if eaten raw4 ,,thought ,,questions4 ,cooking4--,meat4 #a4 ,in making soup1 why should the meat be put in while the water is cold8 #b4 ,in roasting meat1 why should the oven be hot at first1 and more moderate afterward8 ,how should you regulate the temperature in boiling or stewing meat8 #c4 ,what happens to salt or anything salty on a cloudy1 damp day8 ,this is because the salt attracts 4 ,this shows that meat should not be salted until after it has been cooked1 because if salted before 4 #d4 ,very tough meat should be bed or sted4 #e4 ,meat may be prevented from becoming grease-soaked when frying by having the grease very 1 use very 1 simply greasing the 4 #f4 ,bread4 ,bread crust causes the to be used more and cleans them4 ,it will not together in the stomach like the crumb4 ,it increases the quantity of the 1 and is more digestible than the crumb1 since the has been changed by slow heat to 7p4 #aab74 ,therefore loaves or biscuit should be 7large or small87 and they should 7touch or be separated87 in a pan4 #g4 ,how can you tell whether the oven has been too hot while the bread was baking8 #h4 ,why can you tell best about the digestibility of bread when you are slicing it8 #i4 ,regulating the heat is the greatest art of the cook4 ,how may the temperature of the oven be lowered by means of the damper8 ,the draft8 ,the fuel8 ,,exercises ,,in ,,writing4--,story of a ,savage who went to dwell in a ,city 7his trouble with artificial ways74 ,is it easier to learn ,physiology or to practice it8 ,how to make ,bread4 ,describe ,people seen in an ,audience 7tell what their appearance suggests74 ,a ,scene at a ,dinner ,table4 ,thoughts of a ,physician on his ,round of ,visits4 ,a ,good ,cook4 ,a ,bad ,cook4 ,is ,cooking a ,greater ,accomplishment than ,piano ,playing8 ,common ,causes of ,illness4 ,the ,influence of ,imperfect ,digestion upon the ,other ,organs4 ,effect of ,lack of ,muscular ,activity4 ,the ,way of the ,transgressor is ,hard4 ,what ,fools we ,mortals be6 ,health ,fads4 ,temperance in all ,things4 ,the ,right ,way the ,easiest4 ,looking ,back4 ,looking ,forward4 ,hygiene of the ,schoolroom4 ,patent ,medicines4 ,microbes4 ,mind ,cure4 ,nervous ,women4 ,dissipated ,men4 ,how a ,friend of mine lost his ,health4 ,why a ,friend of mine is ,sound and ,strong4 ,tobacco4 ,it never pays to neglect the ,health4 ,which does more ,harm1 an ,ignorant ,cook or an ,ignorant ,janitor8 ,a ,visit to a ,sick ,room4 ,alcohol and ,crime4 ,natural ,instincts and ,appetites2 how preserved1 how lost4 ,a ,lesson about ,alcohol based upon the ,morning ,news4 ,effects of ,alcohol upon the ,greatness of our ,country 7workmen1 voters1 soldiers1 children74 ,adam's ,apothecary ,shop4 ,adam's ,ale 7water74 ,,chapter ,,viii ,,the ,,nervous ,,system ,review ,questions introducing this ,subject4--,what is a cell8 ,what are the five supporting tissues8 ,what are the two master tissues8 ,why are they so called8 ,what kind of cells have many branches8 ,does the food ever come in contact with the salivary glands8 ,when you look at a basket of apples1 the sight 8makes your mouth water40 ,is there a connection between the eye and the mouth8 ,what two tissues enable the skin to blanch and to blush8 ,do the different organs share the blood in the same proportions at all times8 ,how can this proportion be changed8 ,how is the brain protected from injury8 ,how is the spinal cord protected8 ,is the hole for the spinal cord through the main body of the vertebra1 or behind the main body8 ,harmonious ,activity4--,strike suddenly at the eye of another1 and the lids fall to protect it1 and the hands rise to ward off the blow4 ,if a grain of dust gets into the eye1 the tear glands form tears to wash it out4 ,if you touch the hand unexpectedly to a hot iron1 the muscles of the arm jerk the hand away4 ,if the foot of a sleeping person is tickled1 the muscles of the leg pull it away4 ,many muscles coperate in the act of running4 ,if the human being were merely an assemblage of working organs1 the organs might act independently1 and there would be such confusion that the body would be powerless1 and life could not be maintained4 ,the nervous system enables the organs to work together for the common good4 ,why does an ameba not need a nervous system8 ,the ,need of ,nerve ,centers as well as ,nerves4--,if there were no central office in a telephone system of one thousand subscribers1 then every subscriber1 in order to communicate with every other subscriber1 would need one thousand wires running into his house2 all together1 there would have to be several hundred thousand 7to be exact1 #dii1ejj7 wires4 ,with a central office only one thousand are needed4 ,as a telephone system has central offices1 so the nervous system has nerve centers4 ,nerve centers contain nerve cells4 ,although there are some subordinate nerve centers in the spinal cord1 the greatest collection of nerve centers in our bodies is in the skull1 and is called the brain4 ,fishes were the lowest animals studied in animal biology found to possess a true brain4 ,the nervous system1 unlike a telephone system1 has other duties besides allowing communication4 ,it enables us to think1 and1 after reflection1 to will and to act by controlling the various organs4 ,illustration3 ,,fig4 #ajc4--,showing a ,,neuron1 ,a1 or nerve cell with all its parts--dendrites1 cell body1 and axon2 ,b1 a portion of a white fiber highly magnified4 7,jegi47 ,the ,units of which the ,nervous ,system is ,constructed4--,a nerve cell with all its branches1 or fibers1 is called a neuron 7see ,fig4 #ajc72 some neuron branches are several feet long4 ,neurons are the units that compose the nervous system4 ,the living substance in cells is called protoplasm4 ,the protoplasm in nerve cells possesses the most marvelous and varied powers of any known substance1 for the nerve cells are the seat of the mind4 ,illustration3 ,,fig4 #ajd4--,,large ,,nerve ,,trunk1 such as supplies the muscles4 ,cross-section 7magnified #f diameters71 showing bundles of nerve fibers4 7,peabody47 ,nerve ,cells and ,fibers4--,the many branches of nerve cells make them the most remarkable of all cells for irregularity in shape4 ,since the protoplasm of the cell continues into the fibers1 it is plainly wrong to consider the nerve cell as something apart from its fibers4 ,it is not a complete cell without them4 ,a cell usually has many short branches called dendrons or dendrites 7see ,fig4 #ajc7 for communicating with near-by cells1 and one long branch called an axn 7,fig4 #ajc7 for communicating with distant parts4 ,the axons form the fibers that go to the skin1 muscles1 and other organs4 ,a ,nerve4--,these long branches1 or axons1 of nerve cells go all over the body and are often bound together into visible cords called nerves1 or nerve trunks 7,fig4 #ajd74 ,illustration3 ,,fig4 #aje4--;c1 a white fiber with its fatty sheath 7dark72 d1 two gray fibers 7without sheath74 ,white and ,gray ,fibers 7,fig4 #aje74--,some fibers have a fatty covering surrounding the thread of protoplasm2 they are white and glistening1 and are called white fibers4 ,others are without this fatty covering1 and are called gray fibers4 ,both kinds of fibers have connective tissue on the outside to strengthen them4 ,if we let a lead pencil represent a white fiber1 the lead corresponds to the axis of protoplasm2 the wood corresponds to the white1 shiny fat that surrounds it2 and the varnish corresponds to connective tissue on the surface of the fiber4 ,a number of white fibers together makes a white mass that is called white matter4 ,the axis of a white fiber1 of course1 is not white4 ,a mass of cells or of gray fibers is called gray matter4 ,the oxidation of the gray matter1 or protoplasm1 in neurons gives rise to nerve energy4 ,feeling ,cells and ,working ,cells4--,nerve cells are divided into two classes3 sensory cells1 which feel or receive impressions2 and motor cells1 which send out impressions to the working organs4 ,those fibers which carry impressions to the receiving cells are called sensory fibers2 those which carry impulses from the cells to the working organs are called motor fibers4 ,ganglia and ,nerve ,centers4--,nerve cells are not scattered uniformly in nervous tissue1 but are gathered into groups4 ,a group of nerve cells is called a ganglion 7,fig4 #ajf74 ,one or more ganglia having a single function1 such as to control the muscles of breathing1 form what is called a nerve center4 ,the brain consists of a number of nerve centers with their connecting fibers4 ,illustration3 ,,fig4 #ajf4--;,a ,,ganglion4 ,illustration3 ,,fig4 #ajg4--;,,cross-,,section ,,of ,,spinal ,,cord1 showing area of gray matter 7dark74 ,gross ,structure of the ,spinal ,cord4--,the nerve fibers from nearly all over the body lead to cells situated in a large cord in the spinal column called the spinal cord4 ,the spinal cord is separated by a deep fissure almost into halves 7,fig4 #ajg74 ,the cells are situated in the central portion of each half1 and the two masses of gray matter thus formed are connected by a narrow isthmus of gray matter4 ,the outer part of the cord consists chiefly of white fibers4 ,the white matter is thus on the outside of the cord 7,fig4 #ajg74 ,the brain1 unlike the cord1 has the gray matter on the outside and the white matter on the inside4 ,for microscopic study of the spinal cord1 see ,fig4 #ajh4 ,the ,work of the ,spinal ,cord4--,there are two functions of the cord3 reflex action and transmission of impulses from the body to the brain4 ,reflex action is action that takes place without the aid of the will4 ,illustration3 ,,fig4 #ajh4--,,section ,,of ,,spinal ,,cord1 showing nerve cells 7large black spots7 with their branches 7black dots and lines74 ,five bundles of nerve fibers are shown near upper margin4 7,peabody47 ,reflex action never begins in the cord1 but at the outer end of a sensory fiber1 usually located in the skin4 ,the impression goes to the cord along a sensory fiber4 ,it is received in a sensory cell and transferred by dendrons to a motor cell which sends back an impulse along a motor fiber to a muscle2 the muscle contracts and the action is complete4 ,at least two nerve cells are necessary for reflex action4 ,the actions of the lowest animals are almost entirely reflex4 ,reflex ,action1 ,consciousness1 and ,will4--,usually not all of the force of the impulse is transferred to the motor cell4 ,the sensory cell by means of another of its many branches may transfer part of the impulse to a cell which sends it to the brain4 ,hence a reflex act is not necessarily an unconscious one4 ,if you unintentionally touch the hand to a hot stove pipe1 you may be conscious of the pain and the involuntary jerking away of the hand at the same time4 ,reflex ,action and the ,will4--,the will may inhibit1 or prevent1 an expected reflex act4 ,yet many reflex acts occur in spite of the effort of the will to prevent them4 ,one cannot always keep from closing the eyes before a threatened blow even if from the other side of a plate glass window1 and it is known there is no danger4 ,sneezing is a reflex act and cannot always be prevented4 ,the forming of saliva and other secretions are reflex acts4 ,reflex acts are quicker than voluntary acts4 ,an eighth of a second is about the time required for a person to press an electric button after seeing a signal2 a reflex act may occur in a shorter time4 ,illustration3 ,,fig4 #aji4--;,,brain ,,and ,,spinal ,,cord4 ,the ,brain consists of ,three ,chief ,parts4--7#a7 ,there is an enlargement at the top of the spinal cord called the medulla1 or the medulla oblongata4 ,it may be regarded as the part of the spinal cord within the skull 7see ,figs4 #aji1 #aaj1 #aad74 7#b7 ,above the medulla is the cerebellum1 or little brain4 7#c7 ,the cerebrum1 or large brain1 fills all the skull except the small part occupied by the medulla and cerebellum4 ,the cerebrum covers the cerebellum4 7,fig4 #aaj47 ,is this true of the monkey's brain8 7,see ,fig4 #aac47 ,the work of the medulla is chiefly to control the vital functions 7see ,figs4 #aaj1 #aad74 ,here are located the centers for regulating the breathing1 the heart beat1 the size of the blood vessels 7thus regulating nutrition71 and also the less important centers that control swallowing1 secretion of saliva1 and vomiting4 ,the center for breathing is sometimes called the vital knot1 because although the cerebrum and cerebellum may be removed from an animal without causing immediate death1 the slightest injury to the vital knot kills the animal at once4 ,in cases of hanging1 death is caused by injury to this center4 ,illustration3 ,,fig4 #aaj4--,,the ,,brain 7cerebrum1 cerebellum1 medulla74 ,illustration3 ,,fig4 #aaa4--;,,association ,,fibers1 connecting cells within the cerebrum4 7,jegi47 ,automatic ,action4--,the center called the vital knot is said to regulate the breathing automatically1 not reflexly4 ,reflex acts start in the skin2 automatic acts start in the interior of the body4 ,the condition of the blood regulates the breathing automatically during sleep1 and partly regulates it during waking4 ,if too much carbon dioxid accumulates in the blood this excites the vital knot1 which sends out stronger impulses to the respiratory muscles4 ,deeper breathing follows1 which purifies the blood1 and the breathing is then shallow or slow until carbon dioxid accumulates again4 ,the ,four ,kinds of ,nerve ,action and the ,centers that control them4--,the cord controls chiefly reflex action2 the medulla controls chiefly automatic action2 the cerebellum controls chiefly cordinate1 or harmonizing1 action2 the cerebrum controls the purely voluntary acts1 for it is the seat of consciousness and thought4 ,the medulla1 like the cord1 has the gray matter on the inside 7,fig4 #aji74 ,illustration3 ,,fig4 #aab4--,,sensory ,,and ,,motor ,,fibers4 7,jegi47 ,structure of the ,cerebellum4--,the cerebellum1 like the cerebrum1 has the gray matter or cells on the outside4 ,the gray matter is folded into furrows that are not nearly so winding as the folds in the cerebrum 7see ,fig4 #aae74 ,the fibers going to the surface cells have a branched arrangement called the arbor vit1 or tree of life1 which is shown where the cerebellum is cut4 ,the cerebellum1 like the cerebrum1 is deeply cleft and thus divided into halves1 called hemispheres1 connected by a band of white matter4 ,illustration3 ,,fig4 #aac4--;,,brain ,,of ,a ,,monkey4 ,numerals show location of motor centers4 7,see ,fig4 #aae47 ,illustration3 ,,fig4 #aad4--,,the ,,lobes ,,of ,,the ,,right ,,side ,,of ,,brain and their functions4 7,jegi47 ,the speech center is true only for left-handed persons4 ,medulla is marked 8,bulb40 ,the work of the cerebellum is to aid the cerebrum in controlling the muscles4 ,it cordinates the muscular movements2 that is1 it makes the muscles act at the right time and with due force in complex acts1 such as standing1 walking1 talking4 ,a man could strike just as hard without the action of the cerebellum1 but he would not be likely to hit what he aimed at4 ,a drunken man staggers and fails to control the muscles in walking because the alcohol has caused the blood to collect and congest around the cerebellum and press upon it4 ,one whose cerebellum has been injured by accident staggers like a drunken man4 ,illustration3 ,,fig4 #aae4--,,motor ,,and ,,sensory ,,areas ,,of ,,left ,,hemisphere4 ,speech center marked 8,lips40 ,in what region are the motor centers8 ,the sensory centers8 ,coverings of the ,brain4--,lining the skull and covering the cerebrum are found two membranes which inclose a lymph-like fluid4 ,thus a kind of water bed is made which surrounds the soft and delicate cerebrum and protects it from jars4 ,a membraneous net1 or meshwork1 of blood vessels covers the cerebrum and plentifully supplies it with blood4 ,structure of the ,cerebrum4--,the gray matter1 or cell mass of the cerebrum1 forms a surface layer1 called the cortex 78bark071 about one eighth of an inch thick4 ,this gray layer is deeply folded1 the folds1 or convolutions1 being separated by deep furrows1 some of them an inch deep 7see ,fig4 #aaj74 ,thus the area of the surface layer is increased to several times what it would be if smooth4 ,intelligence increases with increase in the number and depth of the convolutions4 ,the greater part of the cerebrum is white matter4 ,this consists largely of associational fibers 7,fig4 #aaa7 which connect the cells in the gray matter with each other and with important interior ganglia at the base of the cerebrum 7,fig4 #aab74 ,these basal ganglia are the largest parts of the brains of the lower vertebrates 7,animal ,biology1 ,figs4 #bbb1 #bei74 ,why do these animals not need large cerebrums8 ,the human cerebrum comprises nearly seven eighths of the weight of the brain4 ,a deep fissure divides it into the right and left cerebral hemispheres4 ,a band of white matter connects the hemispheres4 ,functions of the ,cerebrum4--,the cerebrum is the seat of consciousness and thought1 and of all activity controlled by the will4 ,it also directs the work of the lower nerve centers in the spinal cord1 medulla1 and cerebellum4 ,it receives sensory messages from all parts of the skin and through the special senses4 ,it sends out motor messages to all the voluntary muscles1 and more indirectly to the involuntary muscles4 ,the cerebral fibers are of three kinds3 sensory1 associational 7connecting cells in cerebrum71 and motor 7,figs4 #aaa1 #aab74 ,it is estimated that the cerebrum alone contains #i1bjj1jjj1jjj cells4 ,spinal and ,cranial ,nerves4--,the nerves from the spinal cord go out through notches between the vertebr4 ,since there are thirty-one pairs of spinal nerves 7,fig4 #aji7 and only twenty-four vertebr1 some of the nerves go out through holes in the sacrum4 ,the cranial nerves 7to eyes1 ears1 tongue1 nose1 face1 etc47 leave the brain through holes in the cranium1 or skull4 ,there are twelve pairs of them4 ,relation of the ,cerebrum to the ,lower ,centers4--,as already stated1 nerve activities are of four kinds1--reflex1 automatic1 cordinate1 and voluntary4 ,a manufactory has more complex work than a shop4 ,a man with a shop may enlarge it into a factory and leave trained assistants in charge of the different shops1 keeping only the general management for himself4 ,if he should cease to control his assistants entirely1 the work of the factory would soon be in disorder4 ,if the manager should try to direct everything1 he would become exhausted4 ,so the cerebrum1 the seat of the will and the reason1 leaves the reflex centers in the spinal cord1 medulla1 and cerebellum to do most of the work4 ,if the mind wishes the hand to move and grasp the hand of a friend1 the motor center in the cerebrum sends a message to the cerebellum2 and if the cerebellum has been well trained1 the act is accurately performed4 ,a less imperfect wisdom than that of the mind is in the lower nerve centers4 ,the reason and will control the lower centers through the cerebrum1 but the control is very limited4 ,it is well that this is so1 not only for the relief of the cerebrum1 but for the safety of the body4 ,can you change the rate of the heart beat by the exercise of the will8 ,can you blush at will1 or prevent the flushing of the capillaries when you are embarrassed1 or when you go close to a hot fire8 ,it is impossible for a person to commit suicide by holding the breath4 ,what change in the blood would soon force a breath to be taken8 ,repeat the two examples of reflex action triumphing over the will which have already been given4 ,we shall next take up a system of nerves almost independent of the will4 ,the ganglionic or sympathetic portion of the nervous system controls the viscera 7viss-ra71 or internal organs1 e4g4 peristalsis of food tube1 tone of arteries4 ,the nerves that go to the viscera branch off from the spinal nerves not far from the spinal column1 and enter a row of ganglia on each side of the spine 7see ,fig4 #aae74 ,each ganglion is connected by nerves with the one above and below it1 so that they appear like two knotted cords suspended one on each side of the spinal column and tied together below2 for both chains of ganglia end in the same ganglion in the pelvis4 ,some of the fibers from the spinal cord pass through these ganglia on their way to the viscera1 losing their white sheaths in the ganglia and emerging as gray fibers4 ,the spinal cord and brain with the fibers which do not pass through the double chain of ganglia are called the cerebro-spinal system4 ,the double chain of ganglia and the fibers which go through them are called the ganglionic or sympathetic system4 ,illustration3 ,,fig4 #aaf4--;,,diagram ,,of ,,sympathetic ,,system showing double chain of ganglia2 also plexus at heart and solar plexus4 ,why these ,nerves are called the ,sympathetic ,system4--,these nerves1 after leaving the double chain of ganglia1 form many intricate networks of ganglia and fibers4 ,each network is called a plexus 7,fig4 #aaf74 ,the largest of the plexuses is just back of the stomach1 and is called the solar plexus4 ,a blow upon the stomach may paralyze this plexus and cause sudden death4 ,the plexuses and fibers connect the viscera so perfectly that one organ cannot suffer without the others changing their activity1 or sympathizing with it4 ,an overloaded stomach causes the heart to beat faster and send it more blood2 a loss of appetite usually accompanies illness and allows the stomach to rest4 ,this sympathy is necessary1 for if one organ is diseased1 the others do not continue to work and tax the strength of the ailing organ4 ,how the ,sympathetic and ,cerebro-spinal ,nerves ,differ4--,the ganglionic nerves 7#a7 contain mostly gray fibers2 7#b7 pass through ganglia after leaving the spinal cord2 7#c7 control the unconscious activities of the body2 7#d7 pass to organs which contain slow-acting involuntary muscles1 not to sense organs and quick-acting voluntary muscles2 7#e7 transmit impulses slowly 7about #bj ft4 instead of #ajj ft4 per second74 ,crawfish and insects have hardly more than the ganglionic system of nerves 7,animal ,biology1 ,figs4 #ib1 #acb1 #aig74 ,examples of the ,supervisory ,functions of the ,sympathetic ,system4--,regulation of the heart beat and of the size of the blood vessels2 secretion of sweat glands2 contraction of pupils of eyes in a bright light2 peristalsis4 ,examples of ,sympathetic ,nerve ,impulses reaching ,consciousness4--,pain in colic and cramps2 8heartburn0 7pain in stomach from indigestion72 backache 7from nerves in organs prolapsed by tight clothing pulling upon their attachments at spine72 hunger2 thirst4 ,the ,mind and ,health4--,a contented or peaceful mind is indispensable to soundest health4 ,worry causes difficult breathing with bated breath4 ,happiness brings full1 easy breathing4 ,biological study of physiology shows the futility of making health a care or anxiety1 and teaches 8no meddling0 with the body1 whether by stimulating it1 drugging it1 deforming it1 overheating it1 half smothering it in close rooms1 cultivating artificial instincts1 etc4 ,if the body degenerates through wrong living1 and disease ensues1 a new way of living is needed1 not some quick and wonderful remedy4 ,the new life will renew the body and nothing else can4 ,,hygiene ,,of ,,the ,,nervous ,,system ,necessity of ,food1 ,fresh ,air1 and ,rest for ,sound ,nerves4--,the health of the nerves depends upon a free supply of pure1 nutritious blood4 ,nearly one fifth of the blood goes to the brain4 ,it is clear that the brain cannot give out energy until it has first received it2 the blood supplies energy to the brain4 ,the blood in turn receives the nourishment from food and pure air4 ,a rested cell is full of nourishment2 a tired cell is shriveled 7see ,fig4 #aag74 ,illustration3 ,,fig4 #aag4--;,,effects ,,of ,,fatigue ,,on ,,nerve ,,cells4 ,a1 resting cell1 ,b1 fatigued cell1 with its body and nucleus shrunken4 ,sleep4--,during waking hours energy is used up faster than it is stored in the cells1 and protoplasm is oxidized faster than the cells can replace it4 ,during sleep the opposite is true2 repair is more rapid than waste4 ,during sleep the muscles are strengthened1 the breathing is less1 the heart beats more slowly1 less heat is produced1 digestion is slower1 less blood goes to the brain4 ,why is it necessary to be more warmly protected by clothing or bed covering when asleep than when awake8 ,above all1 the nervous system has an opportunity to recuperate from the constant activity of waking hours4 ,the eye and the ear are rested by darkness and silence4 ,sleep caused by morphine or other drug is not normal sleep and brings little refreshment4 ,practical ,suggestions4--,sleep is deepest during the second hour after going to sleep1 and a greater shock is given to the nervous system by waking a sleeper during that hour than at another time4 ,an alarm clock is a very unhealthful device4 ,one who cannot trust to nature even to awaken has great presumption4 ,if one does not rise promptly upon waking naturally1 the instinct to awake when enough sleep has been taken will be lost1 and the habit of sleeping too much will be formed1 and the brain1 like the muscles1 will become weak from inactivity4 ,infants sleep most of the time1 and it is injurious to them to be waked4 ,adults usually require about eight hours of sleep4 ,there is a risk in going to sleep in a warm room1 for the bed covering which is comfortable then may not be enough to prevent taking cold when the fire goes out4 ,sleep usually comes more promptly to one who goes to bed at the same hour each night4 ,the muscles are relaxed in sleep1 and relaxing them perfectly upon lying down and breathing slowly1 tends to bring sleep4 ,one who is sleepless usually finds that he is breathing fast and is holding the head stiff on the shoulders1 the teeth clenched1 and the muscles contracted1 even though he is lying down4 ,excitement and worry during the day1 but especially just before retiring1 tend to produce sleeplessness4 ,one who overworks his mind by too great attention to business is inviting ruin4 ,a student who loses sleep while preparing for an examination will probably fail4 ,rested brain cells and pure blood are needed for good work4 ,rules for ,preventing ,sleepiness4--7#a7 ,do not sit close to stove or especially a fireplace or in very warm room1 and do not wear very warm clothing in the house4 7#b7 ,let in fresh air freely4 7#c7 ,do not sit in rocking chair nor with chest flattened4 7#d7 ,make the last meal a very light one4 ,habits4--,our habits of doing and thinking and feeling really constitute our characters4 ,this shows the importance of right habits4 ,by gradually changing our habits we can strengthen our characters and form them somewhat as we wish4 ,when a muscle contracts in a certain way1 this act makes it easier for the muscle to contract in that way the next time2 thus great muscular strength may be developed4 ,when a nerve cell acts1 the circulation around the cell is increased1 the fibers develop by use1 and the act is easier the next time4 ,we cannot entirely get rid of our habits1 because we cannot get rid of our brains4 ,healthy fatigue is caused by the accumulation of waste products resulting from the oxidation of substances in nerve1 muscle1 and gland cells4 ,the presence of waste in the tissues affects the nerves4 ,we are rested and strong when these wastes are removed and the tissues are supplied with fresh food and oxygen4 ,work causes the accumulation of carbon dioxid1 which is nature's narcotic4#i ,the drowsy feeling that ensues is more pleasant than the drowsy feeling from alcohol or opium4 ,those who do not employ nature's narcotic but free themselves of it by hurried1 anxious breathing become restless and crave artificial narcotics4 #i ,it has been found that it is injurious to rebreathe expired air containing one per cent of carbon dioxid1 but a far greater percentage is harmless if introduced into fresh air1 thus indicating that the injury from poor ventilation comes chiefly from the 8crowd poison10 or organic particles thrown off4 ,fatigue without work occurs with people who are idle4 ,the oxidation in their cells is not complete1 and poisonous products of the incomplete burning result4 ,this is known as self-poisoning 7auto-toxemia74 ,the poisons are taken by the blood to the nerves and brain1 and give a tired feeling as effectually as does hard work2 or the food may ferment in the food tube and form poisons which increase the tired feeling4 ,such persons are usually irritable1 while persons who are fatigued by useful labor are likely to be dull and drowsy4 ,illustration3 ,,fig4 #aah4--,,the ,,situation ,,of ,,headaches with reference to their causes4 ,headaches are caused by poisons in the blood or by pressure of blood congested in the head4 ,like all other pains they should be a source of benefit in that they show us ways of living to be shunned in the future4 ,many persons1 however1 not only derive no profit from a headache1 but by unwise efforts to cure the pain1 bring permanent injury to themselves in addition to the suffering of the headache4 ,bromides1 opium1 and other poisons deaden and weaken the nervous system while preventing the headache from being felt4 ,headache powders1 phenacetin1 acetanelid1 antikamnia1 and other vile poisons made from coal tar1 shock and weaken the heart and reduce the vital activities so that the headache is no longer felt4 ,in consequence of shocks from repeated doses of such drugs1 the heart will not work so well1 and may give way some time in the future when an effort or strain makes unusual demands upon it4 ,their use has made heart disease more prevalent4 ,the liver and kidney cells and the white corpuscles have to destroy and remove the drugs4 ,many people are foolish enough to injure their bodies and risk death rather than suffer pain or avoid pain by prudent living4 ,sick headaches are foretold by a dull feeling1 sleepiness after eating1 a coated tongue1 and constipation4 ,it would be better to remove the undigested1 spoiled food from the stomach 7four glasses of water will cause vomiting7 than to take a drug4 ,at the first indication of trouble1 abstain from eating1 or use a fruit diet for twenty-four hours1 and drink water freely4 ,this will enable the body to dispose of the excess of waste matter4 ,the ,highest ,living ,medical ,authority on ,drugs4--,dr4 ,osler1 formerly of ,johns ,hopkins ,university and now of ,oxford ,university1 says3 8,but the new school does not feel itself under obligation to give any medicines whatever1 while a generation ago not only could few physicians have held their practice unless they did1 but few would have thought it safe or scientific4 ,of course there are still many cases where the patient or the patient's friends must be humored by administering medicine1 or alleged medicine1 where it is not really needed1 and indeed often where the buoyancy of mind1 which is the real curative agent1 can only be created by making him wait hopefully for the expected action of medicine2 and some physicians still cannot unlearn their old training4 ,but the change is great4 ,the modern treatment of disease relies very greatly on the old so-called natural methods1 diet and exercise1 bathing and massage1 in other words giving the natural forces the fullest scope by easy and thorough nutrition1 increased flow of blood1 and removal of obstructions to the excretory systems or the circulation in the tissues4 ,one notable example is typhoid fever4 ,at the outset of the nineteenth century it was treated with 8remedies0 of the extremest violence1--bleeding and blistering1 vomiting and purging1 antimony and calomel1 and other heroic remedies4 ,now the patient is bathed and nursed and carefully tended1 but rarely given medicine4 ,this is the result partly of the remarkable experiments of the ,paris and ,vienna schools into the action of drugs which have shaken the stoutest faiths2 and partly of the constant and reproachful object lesson of homeopathy4 ,no regular physician would ever admit that the homeopathic 8infinitesimals0 could do any good as direct curative agents2 and yet it was perfectly certain that homeopaths lost no more of their patients than others4 ,there was but one conclusion to draw1 that most drugs had no effect whatever on the diseases for which they were administered40--8,encyclopdia ,americana10 ,vol4 ,x4 7,munn ,co41 ,new ,york47 ,applying ,hygienic ,tests ,systematically4--,the cause of ill health 7e4g4 a headache7 should be sought with system and thoroughness1 applying the tests in rotation to every function of the body3 ,lungs4 ,is the air habitually breathed fresh and free from dust8 ,is the body held up1 and is the chest or waist cramped by clothing8 ,muscles4 ,is enough physical exertion made to cause deep breaths to be drawn8 ,food4 ,is it simple1 digestible1 and eaten properly8 ,drink4 ,is the water pure8 ,cleanliness1 ,work and ,rest1 ,clothing1 ,ventilation1 and ,mental ,state may be inquired into until the source of trouble is found and the cause of ill health removed4 ,to give drugs and leave the cause of ill health untouched1 is to fail4 ,there are signs of coming weakness or illness which1 if heeded and the ways of living improved1 will usually prevent illness4 ,among these signs are headaches1 paleness1 sensitiveness to cold1 heavy feeling or pain after meals1 constipation4 ,huxley says that young people should so learn physiology and so understand their bodies that they will heed the first sign of nature's displeasure1 and not wait for a box on the ear4 ,nervous ,children4--,a report on the health of the school children in one of our large cities shows that one third of the children in those schools have some disorder of the nerves4 ,nervousness 7weakened control of the nerves7 may show itself by sluggishness of mind1 great irritability of temper1 frequent spells of the 8blues10 or by involuntary movements of a jerky or fidgety kind4 ,sound development of city children's nerves is hindered because of the constant noise in cities both day and night2 by shortening of the hours of sleep2 by excessive use of sugar for food2 by living much among people with no chance to be alone and let the nerves rest1 and among boys by the use of cigarettes4 ,how to ,prevent the ,school from injuring ,children4--7#a7 ,ventilation is of first importance4 ,breathing the breath of fifty other children does far more harm than overstudy4 7#b7 ,the time devoted to work should not be long1 especially in the lower grades 7no study out of school74 7#c7 ,the work should be diversified2 not only printed words1 but pictures1 natural objects1 and the outdoor world should be studied4 7#d7 ,the teacher and parent should see that the habitual poise of the child is favorable to health4 7#e7 ,the children should be encouraged to play4 ,running games at recess are of the greatest value1 and are as indispensable to the health of a boy or girl as of a colt4 7#f7 ,physical exercise should be provided at short intervals between lessons1 especially stretching exercises and movements that straighten the spine and hips and elevate the chest4 ,the ,effect of ,alcohol upon ,nerve ,function4--,in attacking the nerve centers1 alcohol begins with the cerebrum1 the highest1 and proceeds toward the lowest4 ,hence as a man becomes drunk he first talks foolishly 7cerebrum affected71 then he staggers 7cerebellum affected71 and he finally goes to sleep and breathes very hard 7medulla affected7 in a drunken stupor4 ,it rarely happens that the breathing center is completely disabled and the man dies from the strong poison4 ,the greatest evil of alcohol is seen in the case of steady drinking4 ,this gradually destroys the soundness of the nervous system and weakens self-control4 ,the tendency with nearly all drinkers is to increase the amount taken4 ,not ,total ,abstainers1 but the ,advocates of ,universal ,moderation are the ,visionaries4--,the evil results from alcohol are so great as to be almost incredible4 ,the plainest statements of its effects are sometimes denounced as unscientific by persons prejudiced in its favor4 ,a part of the two billion dollars annually paid for liquors is used in influencing public opinion through the press4 ,,practical ,,questions4--#a4 ,why does travel often cure a sick person when all else fails8 #b4 ,why is working more healthful than 8taking exercise08 7p4 #dg47 #c4 ,is it better for children to play or to take exercise8 #d4 ,why can one walk and carry on a conversation at the same time8 7p4 #abg47 #e4 ,how does indigestion cause a headache8 7p4 #acc47 #f4 ,does perfectly comfortable clothing from head to foot help to make one at ease in company8 ,does uncomfortable clothing tend to make one awkward8 #g4 ,why is it as important to have the shoes and clothes perfectly comfortable when going out as when staying at home8 #h4 ,when one's finger is cut1 where is the pain8 #i4 ,in what two ways may opening a window when a student is becoming dull and drowsy at his books enable him to wake up and study with ease8 #aj4 ,what kinds of cells shrivel like a baked apple when they become fatigued8 7,fig4 #aag47 #aa4 ,a nerve or nerve fiber can hardly become tired or fatigued1 for the nerve cell supplies the energy4 ,what do we mean when we say the nerves are worn out8 7,fig4 #aag47 #ab4 ,why do you throw cold water upon a fainting person8 #ac4 ,why does constant1 moderate drinking undermine the health more than occasional intoxication8 #ad4 ,why does stoppage of the circulation cause one to faint8 7,see ,chap4 ,,vi47 #ae4 ,why is grazing the skin often more painful than cutting it8 7,colored ,fig4 #a47 #af4 ,why do the lower animals always act upon sudden impulse8 ,what part of the brain enables man to retain sensations and not act upon them until later8 #ag4 ,does 8nervousness0 more probably indicate a bright mind or a high temper8 #ah4 ,what is the effect of a cold bath upon the nerves8 7,chap4 ,,ii47 #ai4 ,did you ever know a cigarette smoker whose hand trembled8 #bj4 ,need there be any fear of a sobbing child holding its breath until it dies8 #ba4 ,why is muscle tone greater in cold weather8 ,the ,true ,function of ,stimulants4--,one whose heart has nearly given out because of exposure to severe weather may be temporarily revived by alcohol4 ,it will not be wise to do so unless it is certain that a warm fire and protection will be reached before the reaction comes4 ,much less would be necessary to revive an abstainer than a drunkard4 ,habitually disturbing the body with stimulants makes them ineffective in a time of emergency4 ,a cup of coffee will not keep a watcher awake if he is used to coffee4 ,definitions3 ,stimulant1 ,narcotic1 ,poison4--,a stimulant is anything that excites the body to activity1 but is of no help or of insignificant help1 in replacing the strength used up4 ,a narcotic is anything that deadens or dulls the nervous system4 ,it comes from a word meaning 8to benumb40 ,poisons are active substances1 which1 taken in quantities1 as man takes food1 destroy life2 in smaller quantities they injure the body and may destroy life4 ,alcohol is a poison4 ,wine1 beer1 whisky1 contain varying quantities of it4 ,the ,narcotic and ,stimulant ,effects of ,poisons4--,examples of poisons are alcohol1 nicotin1 opium1 arsenic1 strychnin4 ,poisons excite the body when taken in small doses1 while in large doses they produce paralysis and death4 ,the irritating or stimulating effect is due to derangement of the functions or to the efforts of the cells to free the body of the destructive substance4 ,the narcotic effect is due to the poison having so benumbed the nerves and injured the cells that their activities cease1 or become less for a time4 ,you readily see how the same poison can be both a stimulant and a narcotic3 the stimulating effect always comes first1 followed by the stupefying effect4 ,if the dose is very small1 the stimulating effect will last longer2 if it is large1 the narcotic effect is greater and felt more quickly4 ,a habit of using stimulants is an invariable sign of weakness4 ,the first dose of morphine or cocaine may be the first step in a lifelong blight of strength and happiness4 ,if physicians whose treatment of a case results in leaving a patient with a drug or alcohol habit were sued for malpractice1 they would be less reckless4 ,the annual consumption of morphine is estimated at twenty-seven grains per capita in ,china1 and fifty grains in the ,united ,states4 ,reaction4--,this is the depressed and exhausted condition that comes on after a period of unnatural activity4 ,it follows the exciting effects of a stimulant4 ,natural ,stimulants4--,if there were nothing to arouse activity1 life would be impossible4 ,a cold wind is a natural stimulant4 ,the activity aroused by a cold wind is just enough to help the body withstand the cold2 artificial stimulants cause an expenditure having no relation to the needs of the body4 ,hence there is a great waste of energy4 ,feelings may stimulate1 as love for his family may stimulate a man to labor4 ,the desire for knowledge may stimulate a boy to study4 ,hunger may stimulate a man to eat4 ,hunger is a natural stimulant1 and is not likely to make him eat to excess2 tea1 coffee1 pepper1 etc41 arouse a false appetite4 ,these things are used chiefly for their stimulant effect1 for they contain little or no nourishment4 ,we will now study about artificial stimulants4 ,such stimulants always cause an unregulated and unhealthy action1 and are always followed by reaction4 ,how much ,strength is stored in the ,body8--,dr4 ,tanner of ,minnesota believed that most people eat too much4 ,another physician said that no human being could go forty days without food4 ,dr4 ,tanner made the experiment4 ,he lost thirty-six pounds in weight1 but he weighed #aba pounds and had considerable strength at the end of the forty days4 ,the first thing he ate at the close of his fast was the juice of a ripe watermelon4 ,once some miners were shut in by the caving of a part of a mine4 ,but1 unlike the case just described1 they were without water as well as food4 ,when1 by digging1 the rescuers reached them seven days after1 several were still found alive1 although most of them had died4 ,the miners1 no doubt1 had nourishment in their bodies for some weeks more of life1 but the body lacked water to dissolve it and bring it within the reach of the cells most needing it4 ,a ,stupendous ,fact4--,these incidents show how wisely the body is made1 and prove that the cells store up nourishment for weeks ahead4 ,the large amount of nourishment stored in the human body is one of the most striking and important facts with which the science of physiology has to deal1 and it should be borne in mind1 or we may make great mistakes about some very simple matters and especially in regard to the effects of stimulants4 ,foolish ,rashness4--,did you ever get so tired that you had to give up and stop1 however much you would have liked to continue at work or play8 ,to rest was the wise thing to do4 ,because you know there is much energy stored in the body1 this need not tempt you to go on until you almost break down4 ,probably you know people who are conceited about their bodies and say they are 8made of cast iron02 that nothing can hurt them4 ,such conceit will be almost sure to get its possessor into trouble4 ,how a ,safeguard may be broken down4--,it is a very wise arrangement that1 under ordinary conditions1 we cannot get at the surplus energy we have4 ,carbon dioxid and other wastes accumulate in the tissues and paralyze the nerves4 ,fatigue and other feelings compel us to be provident1 as it were2 yet stimulants and narcotics1 by irritating the nerve cells1 arouse them and cause us to expend some of this reserve energy4 ,thus man is enabled to get at this precious store which he should save for emergencies1 when he is sick and cannot digest food1 or when he is making some mighty effort4 ,a weak1 ill man who has eaten very little for weeks1 when delirious is sometimes so powerful that it takes several strong men to hold him in bed4 ,but the delirious mania often uses up the little energy left1 and costs the man his life4 ,the only source of energy for man's body is the union of food and oxygen2 he must get his energy from the same source that the engine does2 and this is from his food1 which serves as fuel1 and the oxygen which burns it4 ,if one has been working hard preparing for examinations1 or gathering hay1 or in attending to some important business1 or has been under the excitement of some pleasure trip1 and feels 8blue0 and worn out1 then let him bear the result like a man1 or like a true boy or girl1 as the case may be4 ,giving up for a while1 or 8toughing it out0 with the blues1 or losing a little time from business1 will not hurt1 but will restore strength1 while a stimulant will leave him less of a man than before4 ,nervousness4--,the attempt to divide the race into brain workers1 muscle workers1 and loafers1 whether men or women1 is a powerful factor in race degeneration4 ,leonard ,hill says3 8,hysteria and nervous exhaustion are the fruits not of overwork1 but of lack of varied and interesting employment4 ,the absurd opinion that hard work is menial and low1 leads to most pernicious consequences4 ,the girl who1 turning from brain work to manual labor1 can cook1 scrub1 wash1 and garden1 invites the bloom of health to her cheeks2 while the fine do-nothing lady loses her good looks1 suffers from the blues1 and is a nuisance to her friends and a misery to herself40 ,a ,japanese lady holds views similar to those of ,dr4 ,hill4 ,read footnote4#aj #aj ,statement by ,madame ,toyi ,niku of ,yeddo1 ,japan1 after a six months' visit to the ,united ,states4--8,worry and inactivity1 it seems to me1 sharply mark the women of your middle classes4 ,i did not attempt to study your leaders of society1 for they are much alike the world over--the same fuss1 the same display of jewels and finery1 the same scandals1 the same uselessness4 ,your women do not diversify enough4 ,if they are good cooks1 they stop there2 perhaps another is a good housekeeper1 another can sew finely2 but doing one thing makes narrow-mindedness4 ,in ,japan we strive to do many things4 ,the worry troubles of your women1 it seems to me1 come largely from improper eating and overeating4 ,i have sat at many of your tables and there is too much food on them and too much variety4 ,first1 women overeat1 then they doctor1 then they starve1 and then they become nervous4 ,a woman's diet1 especially a mother's1 should always be simple4 ,cut down eating and increase variety of labor and exercise4 ,my own people live that way with a result that we have better feminine bodies1 better skins1 and better tempers than your women4 ,i like the brightness of your young women4 ,perhaps you will take the hideous hats off them some day1 find a substitute for the bad corset1 and let them wear clothes that are loose1 yet are soft and clinging4 ,they are bound up in their clothes too much now and their judgment of colors and combinations is not good4 ,their clothing is either garish or very dull in hue4 ,the simplest girl in ,japan knows how to harmonize color with herself40--,mother's ,magazine1 ,november1 #aijg4 ,,subjects ,,for ,,debate4--7#a7 ,does the ,chinese woman deform her body less than the ,caucasian woman and suffer less from it8 7#b7 ,does as much disease originate in the dining room as the barroom8 7#c7 ,are drugs a necessary evil8 7#d7 ,does pride cause as much illness as ignorance8 7#e7 ,is it ever right to neglect the health8 7#f7 ,does the mind or the way of living have more effect upon the health8 ,disuse and ,degeneration4--,many persons in civilized countries cherish a vain hope of having sound muscles without habitual use of them1 pure blood without deep breathing1 a strong circulation in an inactive body1 a fresh skin without keeping the body sound1 a hearty appetite without enough physical labor to use the food already eaten1 steady nerves with a part of the body overworked and a part stagnating from disuse4 ,their flabby muscles1 pale skins1 highly seasoned food to arouse appetite1 narcotics to deaden irritable nerves1 and the wide use of drugs as a fancied substitute for right living all show the attempt to be a miserable failure4 ,if the parents leading such a life escape with fairly good health and average length of life1 they leave a few unhealthy children in whom physical degeneration is plain4 ,complete1 balanced living only prevents degeneration4 ,although there are cases of illness which are not necessarily a disgrace1 disease usually originates in weakness of character or lack of common sense4 ,the snob who thinks himself above physical labor1 the dupes who at the bidding of avaricious fashion mongers think more of clothes than of a free body1 the narrow1 unbalanced man1 who concentrates all his energies on one ambition1 the short-sighted one who worries1 all grow into a diseased state4 ,,chapter ,,ix ,,the ,,senses ,experiment #a4 ,where are the ,nerves of ,touch most ,abundant8--,open a pair of scissors so that the points are one eighth of an inch apart1 and touch both points to the tip of the finger4 ,are they felt as one or as two points8 ,find how far they must be separated to be felt as two points when applied to the back of the neck4 ,record results4 ,caution3 ,the person should be blindfolded1 or should look away while the tests are being made4 ,two pins stuck in a cork will be more convenient to use than scissors4 ,experiment #b4 ,nerves of ,temperature1 or ,thermic ,nerves4--,draw the end of a cold wire along the skin4 ,does the wire feel cold all the time8 ,repeat with a hot wire4 ,do you conclude that temperature is felt only in spots8 ,illustration3 ,,fig4 #aai4--8;,,cold0 ,,spots 7light shading74 8,,hot0 ,,spots 7dark71 skin of thigh4 ,muscular ,sense4--,experiment #c4 ,make tests of the ability to distinguish the weight of objects weighing nearly the same1 when laid by another in outstretched hand2 also by laying them in the hand while it rests upon a table4 ,which test showed more delicate distinctions8 ,in which were muscles brought into use8 ,experiment #d4 ,close the eyes and let some one move your left arm to a new position2 then see if you can with the forefinger of the right hand touch the forefinger of the left hand in its new position at the first attempt4 ,experiment #e4 ,functions of the ,several ,parts of the ,tongue4--,test the tip1 edges1 and back of the tongue with sugar1 vinegar1 quinine1 and salt4 ,where is the taste of each most acute8 ,record results4 ,flavors4--,experiment #f4 ,blindfold a member of the class1 and while he holds his nostrils firmly closed by pinching them1 have him place successively upon his tongue a bit of potato and of onion4 ,can he distinguish them8 ,experiment #g4 ,mark ,f after each of the following foods that have a flavor 7see text73 vanilla1 apple1 lemon1 beef1 peaches1 grapes1 coffee1 onion1 potato1 cinnamon4 ,experiment #h4 ,a ,smelling ,contest4--,place the following and other things having taste in vials around which paper has been pasted to conceal their contents3 pepper sauce1 vinegar1 kerosene1 flavoring extracts 7diluted71 several perfumes1 iodine1 bits of banana1 lemon1 apple1 etc4 ,number the vials and have pupils test and write results in a list4 ,correct the lists and announce pupil having keenest sense of smell4 ,experiment #i4 ,a tasting contest may be arranged in a similar way4 ,smelling and tasting tests should be made quickly as these senses are soon dulled by repeating a sensation4 ,experiment #aj4 ,advantage of ,two ,eyes over ,one4--,try to touch forefinger to something held by another at arm's length from you1 bringing the finger in from the side3 7#a7 with one eye closed2 7#b7 with both eyes open4 ,result8 ,conclusion8 ,we tell the distance of an object by the amount of convergence of the eyeballs needed to look at it4 ,experiment #aa4 ,duration of ,impression4--,whirl a stick with a glowing coal on one end 7see ,fig4 #abc74 ,experiment #ab4 ,color ,blindness4--,provide a number of yarns of different tints1 and the same tints4 ,test color blindness by having each pupil match tints and assort the yarns4 ,experiment #ac4 ,fatigue of ,optic ,nerve4--,gaze long and steadily at a moderately bright object1 then close the eyes4 ,result8 ,conclusion8 ,experiment #ad4 ,dissection of ,eye4--,the eye of an ox is an interesting subject for dissection4 ,the lens is like a clear crystal4 ,make out all parts named in the text 7see ,fig4 #abb74 ,experiment #ae4 ,image formed by a ,convex ,lens4--,for a few cents obtain from a jeweler a convex lens1 or use a strong pair of spectacles worn by an old person4 ,hold the lens a few feet from a window 7darken any other windows near74 ,a little beyond the lens hold a white card or book open at a blank page to catch the image4 ,have some one walk before the window4 ,experiment #af4 ,work of ,iris4--,notice the size of the pupils4 ,cover one eye with the hand for a few minutes4 ,uncover and look in a mirror4 ,gaze at bright window and look again in the mirror4 ,conclusion8 ,do the two pupils still keep the same size when one eye is shaded8 ,experiment #ag4 ,accommodation4--,by holding your finger or a pencil in line with writing on the blackboard1 you find that you cannot see both finger and blackboard distinctly at the same time--first one and then the other is distinct4 ,explain 7see text74 ,experiment #ah4 ,astigmatism 7effect of unequal curvature of cornea or lens along certain lines74 ,with end of crayon draw about twelve straight1 even lines crossing at one point on the blackboard4 ,have the lines of equal distinctness4 ,how many pupils report that the lines in certain directions are blurred8 ,inquire whether these pupils have frequent headaches from eye strain4 ,experiment #ai4 ,can ,sound reach the ,ear through the ,bones8--,hold a watch between the lips and notice its ticking4 ,close the teeth down upon it and notice any change in the sound4 ,cover one1 then both ears1 and note the result4 ,experiment #bj4 ,test keenness of hearing by having pupils walk away from a ticking watch until it becomes inaudible4 ,test each ear4 ,a 8stop0 watch is preferable4 ,experiment #ba4 ,advantage of ,two ,ears over ,one4--,have the class stand in a circle4 ,blindfold some one and place him in the middle of the circle4 ,let various pupils clap the hands as the teacher points to each4 ,can the blindfolded one point in the direction whence the sound comes8 ,stop one ear with a handkerchief and repeat4 ,result8 ,conclusion8 ,from what two points in the circle does the sound fall upon both ears alike8 ,experiment #bb4 ,the ,cause of ,nasal ,tones4--,let a pupil go to the back of the room and read a paragraph1 and hold his nose until partly through the reading4 ,or the teacher may read with his face and hand hidden by a large book4 ,let the other pupils raise their hands when they notice a change in the quality of the reader's voice4 ,does the experiment show that a 8nasal0 tone comes partly through the nose or through the mouth only8 ,does stoppage of the nostrils by catarrh cause a nasal tone8 ,five ,differences between ,special and ,general ,sensation4--,first1 the nerves of special sense all end in special organs at the surface2 for instance1 the touch corpuscles are for touch1 the eye is for sight1 etc4 ,there are many nerves in the body that do not end in special organs2 these nerves give what is called general sensation4 ,a second difference is that general sensation tells of the condition of the interior of the body1 while special sensations tell us of the condition of the surface of the body and of the outside world4 ,third1 general sensations are not so exact as the reports of the special senses4 ,one can locate a point on the skin that has been touched much more accurately than he can locate an internal pain4 ,a fourth difference is that the meaning of each special sensation must be learned 7usually in infancy72 but the meaning of general sensations is inherited4 ,this inherited knowledge of what general sensations mean is also called instinct4 ,fifth1 the sympathetic nerves usually bring general sensations2 the spinal and cranial nerves usually bring special sensations4 ,examples of general sensations are hunger1 thirst1 satiety1 nausea1 faintness1 giddiness1 fatigue1 weight1 aching1 shuddering1 restlessness1 blues1 creepy feeling1 tingling1 sleepiness1 pain1 illness4 ,any nerve can convey the general sensation of pain1 if injured along its course4 ,if a nerve of touch is cut1 there is no sensation of touch1 but of pain4 ,touch sensations come only from the ends of the nerves4 ,general sensations are of many kinds4 ,we are only half conscious of some of them2 many of them are hard even to describe4 ,hygiene of the ,general ,sensations4--,general sensation is an invaluable aid to the health4 ,without it as a guide1 the body could not remain alive a single day4 ,pain should be heeded as our best friend1 and not killed with poisonous drugs as if it were our worst enemy4 ,we should not deaden the stomach ache with an after-dinner cigar4 ,if we do not go to bed when sleepy1 the desire for sleep may leave us1 and we will undergo untold suffering from sleeplessness4 ,thirst should be satisfied with cool water1 which quenches it the best2 he who makes his teeth ache with ice water will inflame his stomach and be continually thirsty4 ,he who does not stop eating when his hunger is satisfied1 will distend his stomach with food1 and the stretched organ will be harder to satisfy thereafter2 in fact1 eating after a feeling of satiety may cause indigestion so that the cells will not get the food4 ,a dyspeptic is always hungry1 for the cells are starving4 ,fatigue of body or mind gives us wise counsel2 but this feeling may be deadened by alcohol or tobacco1 and work continued until the body is injured4 ,we should heed the warning of pain or fatigue or restlessness as promptly as an engineer heeds a red flag on the railway track4 ,one who uses narcotics acts like a reckless engineer who removes the danger signal and goes ahead1 hoping by good luck to escape an accident4 ,most of the nerves of touch end in papill of the dermis as microscopic1 egg-shaped bodies 7,fig4 #abj74 ,there are also many in the interior of the mouth1 especially on the tongue4 ,on the palms they are arranged in curved lines1 and on the tips of the fingers they are in circular lines1 with one papilla in the center4 ,the delicacy of the sense of touch varies very much in different parts of the skin4 ,this delicacy refers to two things3 the ability to feel the slightest pressure and the ability to tell the exact point of the skin that is touched4 ,a lighter pressure can be felt on the forehead and temples than with any part of the body4 7,why is it best for this to be the case87 ,the greatest delicacy in locating the point of the skin touched is found to be located in the tip of the tongue1 the lips1 and the ends of the fingers 7,exp4 #a74 7,why is it best that this is so87 ,this delicacy is least in the middle of the back4 ,the delicacy varies with the number of touch corpuscles in different parts of the skin4 ,the sense of touch is capable of great cultivation1 as in the case of the blind4 ,illustration3 ,,fig4 #abj4--;,,different ,,kinds ,,of ,,touch ,,bodies ,,at ,,ends ,,of ,,nerves4 ,a1 from cornea of the eye2 ,b1 from the tongue of a duck2 ,c1 ,d1 ,e1 from the skin of the fingers4 7,jegi47 ,the temperature sense is given by special nerves called the thermic nerves 7,exp4 #b74 ,that the thermic nerves are easily fatigued is noticed soon after entering a bath of hot water2 it is also shown by the fact that in cold countries the nose or ears of a person may freeze without his feeling it4 ,the ,muscular ,sense4--,the special sense of touch gives some sense of weight4 ,a weight upon the skin must be increased by one third before it feels heavier1 but by lifting an object so as to bring into action the muscular sense residing in nerves ending in the muscles an increase of only one seventeenth of the original weight can be noticed 7,exp4 #c74 ,this sense gives us a continual account of the position of the limbs 7,exp4 #d74 ,the end organs of taste are located in the papill of the tongue4 ,the tongue has a fuzzy look because of the numerous papill4 ,the principal tastes are only four2 namely1 sweet 7tasted chiefly by tip of tongue71 sour and saline 7sides of tongue71 bitter 7tasted on the back of tongue7 7,exp4 #e74 ,the nerves of smell end in the mucous membrane of the upper half of the two nasal chambers2 the fibers are spread over the upper proportion of the walls4 ,the direct current of air does not pass as high as these nerve endings2 hence sniffing aids the perception of odors4 ,this sense is able to bring up the associations of early life more powerfully than any of the senses4 ,the odor of a flower like one that grew in an old garden can almost restore the consciousness of the past4 ,we smell gases only2 solids and liquids cannot affect this pair of nerves 7,exp4 #h74 ,flavors4--,the tastes that we call flavors are really smells4 ,we confuse them with taste1 because they accompany food that is in the mouth4 ,name some foods that seem 8tasteless0 when one has a severe cold in the head4 ,why is this8 ,some of the most repulsive drugs can be easily swallowed if the nose is held 7,exp4 #f and #g74 ,hygiene of the ,senses of ,taste and ,smell4--,a savage or a beast uses the senses of taste and smell to find out whether things are good to eat or not4 ,if a civilized man's senses are not perverted1 and he eats only simple foods that have a pleasant taste1 they will not injure him or cause him sickness4 ,things that are poisonous usually have unpleasant tastes and often have unpleasant odors4 ,these senses are naturally of wonderful delicacy4 ,they can be cultivated to a still more remarkable degree1 or they can be blunted and almost destroyed4 ,chronic catarrh dulls or destroys the sense of smell4 ,the loss or even the weakening of the perception of flavors is an injury to the working of the closely related sense of taste4 ,when a person loses the enjoyment of delicate flavors1 he wants food to have strong seasoning and more decided taste to prevent it from being insipid4 ,everything must be either very greasy or very sweet or very salty or very sour1 to please his degenerate senses4 ,wheat1 corn1 and other grains have each its own pleasant taste1 yet such persons must have lard in their bread because they are not capable of appreciating anything with a delicate taste4 ,in ,england1 butter is not salted and its delicate taste is enjoyed2 in ,america1 salt is added to preserve it1 and most people have come to prefer the strong taste of salty butter to the delicate taste of pure butter1 and do not like it unless its true taste is partly hidden by the taste of salt 7,exp4 #i74 ,deceiving the ,sense of ,taste4--,the habit of using narcotics like tea and coffee is usually begun by concealing the repulsive bitter taste of the substance by mixing sugar1 cream1 and other agreeable things with it4 ,licorice is sometimes mixed with tobacco to weaken its biting taste4 ,pure alcohol would never be drunk by any one who had the least respect for the sense of taste1 but the agreeable flavor of grapes1 apples1 and other fruit which still remains in wine1 cider1 and brandy1 conceals the repulsive taste of the alcohol4 ,beer has the insipid taste of grain which has undergone decomposition or partial rotting1 and hops are added because the strong bitter taste of hops is needed to hide the stale1 rancid taste of the rotted grain4 ,eggnog is made of eggs1 a nourishing food2 sugar1 which has an agreeable taste2 water1 a refreshing drink1 and alcohol1 a fiery poison4 ,a very good eggnog is often made without alcohol1 but a good one could hardly be made with any of the pleasant ingredients left out4 ,the best eggnog is made by using the fresh juice of lemon1 orange1 or grape1 instead of alcohol4 ,effect of ,narcotics4--,tobacco1 alcohol1 opium1 and other narcotics dull the senses of taste and smell and prevent the enjoyment of delicate flavors4 ,they accomplish this as much by their effect upon the brain as upon the nerves themselves4 ,it is ,wrong to eat ,food that is not ,relished4--,unpalatable food is not likely to be well digested4 ,it is a law of the body that the food which is enjoyed the most is digested the best4 ,this applies to a hungry person eating food with its own honest taste1 not to food disguised by the taste of something else4 ,the rule does not apply to a taste perverted by having been forced to become accustomed to poisonous things4 ,people who munch their food slowly enjoy the pleasures of taste the most1 and digest their food the best4 ,the nerves of taste and smell easily become fatigued4 ,the first whiff from a cologne bottle is the strongest4 ,highly flavored foods should be eaten moderately1 if we would obtain the greatest enjoyment from them4 ,,thought ,,questions4--#a4 ,interfering with the ,body4 ,what is the natural direction of growth of the big toe8 #b4 ,think of six evil results1 direct or indirect1 which will follow from displacing it by tight shoes 7p4 #dh74 #c4 ,which part of the spinal column1 designed in infinite wisdom to be most flexible1 do some people try to make the most inflexible8 #d4 ,the mobility of the false and floating ribs was intended as a blessing4 ,some people interpret the blessing as an opportunity to do what8 #e4 ,name six articles which warn us to avoid them by their bitter1 burning1 or nauseating tastes1 yet which are used by man4 #f4 ,name six feelings which are intended as warnings for our guidance1 but which are commonly disregarded4 ,the eyes on the rays of the starfish are mere spots of pigment4 ,insects have lenses in their eyes4 ,the eyes of vertebrates are all formed on the same general plan as the human eye4 ,the eyeballs are globes about an inch in diameter4 ,they are placed in deep1 bony sockets1 called orbits1 in the front part of the skull4 ,the optic nerve1 other nerves1 and several large blood vessels pass to the eye through a hole in the back of the orbit4 ,a soft cushion of fat is in the orbit behind the eyeball4 ,a pressure upon the eyeball causes the eye to sink into the socket1 for the fat yields to the pressure4 ,this is a protection to the eye4 ,the eyelids protect the eyes from dust1 and at times from the light4 ,they are aided in this by the eyelashes4 ,illustration3 ,,fig4 #aba4--,,tear ,,glands ,,and ,,ducts of right eye4 7,jegi47 ,the tears are formed by tear glands situated above the eyeball in the portion of the orbit farthest from the nose1 just beneath the bony brow where it feels the sharpest 7,fig4 #aba74 ,they are about the size of almonds4 ,a saltish liquid is continually oozing from the tear glands and passing over the eyeball2 it is carried into the nose through the nasal duct 7,fig4 #aba74 ,the tears reach this duct through two small canals1 which open into the eye in the little fleshy elevation at the inner corners of the eye 7,fig4 #aba74 ,the opening of one of the canals may be seen by looking into a mirror4 ,sometimes these canals are stopped up1 and what is called a 8weeping eye0 results4 ,a temporary stoppage may occur during a cold in the head4 ,tears prevent friction between eye and lid4 ,winking applies the tears to the ball4 ,small glands along the edges of the lids form a kind of oil which usually prevents the tears from flowing over the lids4 ,sometimes this oily secretion is so abundant1 especially during sleep1 as to cause the lids to stick together4 ,the mucous membrane of the eyelids continues as a transparent membrane 7the conjunctiva7 which passes over the front of the ball4 ,illustration3 ,,fig4 #abb4--,,the ,,anatomy ,,of ,,the ,,eye4 ,the globe of the eye consists of its outer wall and the soft contents 7,fig4 #abb74 ,the wall has three layers or coats4 ,the outer coat is the tough sclerotic 7,greek1 skleros1 hard71 composed of dense connective tissue 7,exp4 #ad74 ,it gives strength and firmness to the eyeball4 ,it shows between the lids as the 8white of the eye40 ,it is white and opaque except in front2 there it bulges out to form the transparent cornea4 ,this clear portion of the wall may be seen by looking at the eye of another from the side4 ,the second coat1 called the choroid1 consists of blood vessels and a loose connective tissue containing many dark brown or black pigment granules4 ,the choroid absorbs superfluous light4 ,cats' eyes shine at night because this coat in their eyes reflects some light4 ,the choroid separates from the sclerotic toward the front of the eye and forms the colored iris4 ,the iris makes the eyes beautiful1 and it also serves the useful purpose of regulating the amount of light4 ,the hole in the iris is called the pupil 7,exp4 #ae74 ,the third and innermost coat1 the sensitive pinkish layer called the retin-a1 is the most important and characteristic tissue in the eye4 ,it receives the light rays1 and retains the image for a fraction of a second 7,exp4 #aa74 ,hence the pictures in a kinetoscope 7,fig4 #abc7 appear as one moving picture4 ,the retina is made chiefly of the fibers of the optic nerve4 ,this nerve contains about five hundred thousand fibers1 and enters at the back of the ball4 ,the spot where it enters contains no nerve endings and is not sensitive to light4 ,it is called the blind spot4 ,the spot where the light most often falls is most sensitive to light4 ,it is the yellow spot 7,fig4 #abb74 ,illustration3 ,,fig4 #abc4--,,stroboscope1 the original of the kinetoscope4 ,the observer looks through the slits of a rapidly revolving disk and a new image falls on the retina before the last image has faded4 ,compare the pictures in the figure4 ,test for the ,blind ,spot4--,in this experiment shut the right eye and be careful not to let the left eye waver4 99 ,read this line slowly4 ,can you see the star all the time8 7,if so1 hold the book farther or closer and repeat47 ,within the coats of the ball1 like the pulp within the rind of an orange1 are the soft contents1 divided into three parts4 ,the first is a watery liquid in front1 which serves to keep the cornea bulged out 7,fig4 #abb74 ,it is called the aque-ous humor4 ,the main cavity of the ball is occupied by a clear1 jellylike substance called the vitre-ous humor1 which serves to keep the ball distended4 ,back of the iris1 and separating the two humors just named1 is the crystal-line lens1 a beautiful clear lens1 convex or rounded out on both sides 7,exp4 #ad74 ,it serves to bring the light to a focus on the retina1 thereby forming images of outside objects4 ,the eye1 like a camera1 has a dark lining1 the choroid2 the retina corresponds to the sensitive plate1 and the lens brings the rays to a focus on it and forms the image4 ,illustration3 ,,fig4 #abd4--;,,crossing ,,of ,,optic ,,nerves showing that one nerve reaches same half of both eyes4 ,the ,path of ,light in the ,eye4--,the light enters through the transparent cornea and passes through the aqueous humor4 ,as it goes through the pupil1 the iris shuts off all the light that is not needed4 ,the crystalline lens receives the light that has been allowed to pass1 and so bends the rays that by the time they have passed through the vitreous humor they fall upon the retina in just the right way to form a tiny image of anything outside 7,exp4 #aa74 ,the choroid absorbs any light that passes the retina4 ,the iris and choroid of albinos have no pigment2 hence albinos squint their eyes to shut out some of the light4 ,accommodation4--,in order to focus the light upon the retina1 the lens must change shape for every change in the distance of the object looked at 7see ,fig4 #abe74 ,the shape of the lens can be readily changed1 for it is elastic and has muscular fibers around its edges 7,exp4 #ag74 ,illustration3 ,,fig4 #abe4--;,change of lens in accommodation4 7,jegi47 ,defects in the ,eye4--,some eyeballs are too long1 and the lens brings the rays to a focus before they reach the retina4 ,such eyes are nearsighted 7,fig4 #abf7 and require glasses that round inward 7concave74 ,some eyeballs are too flat1 and the rays are not brought to a focus soon enough4 ,such eyes are farsighted and require glasses that round outward 7convex74 ,see ,fig4 #abg4 7,repeat ,exp4 #ae47 ,illustration3 ,,fig4 #abf4--7a7 ,,nearsighted ,,eye 7ball too long71 which only focuses rays for near objects 7#b7 when concave glasses are used 7#c74 ,illustration3 ,,fig4 #abg4--;,,farsighted ,,eye 7ball too short7 which needs convex lens to focus rays upon retina4 ,care of the ,eyes4--,because the eyes can do a large amount of work without giving pain1 they are often abused4 ,when reading or doing intricate work1 turn the eyes from the work occasionally and look at some distant object2 stop work before the eyes are tired4 ,twilight of early evening has ruined many good eyes4 ,you should always stop work before the twilight begins1 for the light fades so gradually that you will surely be straining the eyes before you know it4 ,do not work with the light in front2 the glare of the light makes objects appear dim4 ,the light should come from above1 and 7for right-handed people7 from the left4 ,do not read papers or books printed in fine type4 ,we should not read when convalescing from illness2 with the head bent down2 when the eyes are sore2 in jolting cars4 ,heating the eyes by a burner1 or drying the eyeballs in a dry1 stove-heated atmosphere1 using a light without a shade1 cause trouble with students' eyes4 ,of what are blood-shot eyes often a sign8 ,our eyes are best suited for seeing at a distance because primitive man had no houses1 books1 sewed clothes4 ,effort is required to shape the lens for seeing near objects4 ,most cases of nearsightedness begin when children are taught to read under eight years old4 ,the eyes are sometimes injured by the use of tobacco4 ,,thought ,,questions4 ,the ,eye4--#a4 ,the eye is shielded from blows by bony projections of 1 1 and 4 #b4 ,the hairs of the eyebrows lie inclined toward 1 in order to turn from the 4 #c4 ,i find by trying it that ,i 7can or cannot87 see the position of a window with my eyes closed4 #d4 ,the pupil appears to be black1 because no is from the interior wall of the eye4 ,i know that the iris is partly muscle1 because it the size of the 4 ,sound4--,anything that is sending off sound does so by vibrating1 or shaking to and fro1 very rapidly4 ,for instance1 a vibrating violin string sets every particle of air near it swinging to and fro4 ,the nearest particles of air strike the next ones and bounce back1 these in turn strike against others1 and thus vibrations called sound waves are sent through space in all directions from the sounding body4 ,we feel these waves with the ear4 ,the ear consists of three portions3 the external ear1 the middle ear 7or drum71 and the internal ear 7or labyrinth1 see ,fig4 #abh74 ,the cranial nerve connecting the ear with the brain is called the auditory nerve4 ,the outer and middle ear pass on the vibrations of air to the ends of the fibers of the auditory nerve in the internal ear4 ,illustration3 ,,fig4 #abh4--,,middle ,,and ,,internal ,,ear 7greatly enlarged74 ,the external ear consists of a large wrinkled cartilage on the exterior of the head and a canal leading from it1 called the meatus4 ,this passage is closed at its inner end by the drum membrane or drum skin4 ,it is often called the drum1 but this name is properly applied to the whole middle ear4 ,a trial will show that the drum skin cannot be seen even with the aid of a bright light1 for the passage is slightly curved 7see ,fig4 #abh74 ,hence a missile or a flying insect cannot go straight against the ear drum4 ,the skin lining this passage contains wax glands1 which secrete a bitter sticky wax1 which helps to keep the passage flexible4 ,this wax catches dust and usually stops insects that may enter4 ,if an insect enters the ear1 it may often be coaxed out by a bright light held close to the ear4 ,the ear wax in a healthy ear dries with dust and scales of epidermis and falls out in flakes1 thus cleansing the ear4 ,it is unwise to probe into the ear with a hard object or even with the corner of a towel4 ,it is not necessary to insert the finger in the meatus to cleanse it2 it is one inch long1 but only about one fourth inch across4 7,how large is the little finger87 ,the cartilaginous ears on the sides of the head should be carefully washed because of their many crevices4 ,if ear wax is deposited too fast1 it will cause temporary deafness and earache4 ,it may be syringed out with warm water4 ,earache is usually caused by a small boil which requires time to relieve itself by bursting4 ,warm water poured into the upturned ear1 or hot flannels or compresses applied to the side of the head will lessen the suffering4 ,each ear has three muscles for moving it4 ,once they were doubtless useful to all1 but like the scalp muscle they have become so weakened by disuse as to be useless to most people4 ,they are vestigial organs4 ,the middle ear1 or drum chamber1 contains air 7,fig4 #abh74 ,it is separated from the outer ear by the drum membrane4 ,it contains three bones which stretch across it and conduct the sound waves from the drum membrane to the inner ear4 ,state the order in which they are placed 7see ,fig4 #abh74 ,the middle ear is connected with the pharynx by a tube 7the ,eustachian tube2 pronounced yoo-stakee-an1 see ,fig4 #abh74 ,this tube is opened every time we swallow4 ,it allows the air from the throat to enter the middle ear and keep the air pressure equal on each side of the drum skin4 ,this tube and the middle ear are lined with mucous membrane4 ,a cold in the head or a sore throat may extend through this tube to the middle ear and affect the hearing4 ,this occurs because the tube is closed by congestion of its lining2 the air of the middle ear may be partly absorbed1 and the pressure of the outside air may cause the drum membrane to bulge inward1 and to be stretched so tight that it cannot vibrate freely4 ,the inner ear is called the labyrinth1 because of its winding passages4 ,there is a spiral passage called the snail shell and three simpler passages called the loops 7,fig4 #abh74 ,the inner ear is filled with a limpid liquid which conveys the vibrations to the ends of the auditory nerve found in the snail shell4 ,if the auditory nerve or labyrinth becomes diseased1 the deafness is probably incurable4 ,quinine and other drugs may cause deafness4 ,sense of ,equilibrium4--,some fibers of the auditory nerve end in the loops and are not believed to be used in hearing4 ,it is believed that each loop acts like a carpenter's level1 and the varying pressure of the fluid upon the nerves in the loops tells us the position of the body and constitutes the sense of equilibrium4 ,there are how many of these loops in each ear8 7,fig4 #abh47 ,,chapter ,x ,,bacteria ,,and ,,sanitation ,experiment #a4 ,yeast ,plants4--,with a microscope examine a drop from a glass of water in which you have washed grapes or apples 7,fig4 #abi74 ,experiment #b4 ,fermentation4--,put a tablespoonful of sugar into this water and set the glass in a warm place for a day or two4 ,do you see any bubbles of gas8 ,have the odor and taste changed8 ,does the microscope show that the yeast plants are now more abundant8 ,by fermentation1 or the growth of yeast in sugar1 sugar is changed into carbon dioxid1 a gas1 and alcohol1 a liquid4 ,experiment #c4 ,a ,sanitary ,map4--,construct a sanitary map of the community4 ,indicate houses where consumption1 typhoid fever1 or other transmissible diseases have occurred1 with number of cases4 ,mark location of stagnant waters where mosquitoes breed1 mark garbage dumps1 unclean streets4 ,suggest where improvements may be made in drainage1 dust1 noises1 sunshine1 shade1 etc4 ,illustration3 ,,fig4 #abi4--,,yeast ,,cells magnified #bjj diameters1 or #dj1jjj areas4 ,yeast plants multiply by budding4 ,notice small cells growing on larger and older ones4 ,bacteria1 or microbes1 the smallest living things1 are visible only under a microscope of high power4 7,see 8,plant ,biology10 p4 #ahb47 ,they obtain food either from dead tissue or from degenerate tissue of living plants and animals4 ,the green plants and the animals now upon the earth have proved their fitness to survive by successfully resisting these one-celled vegetable germs1 or bacteria4 ,microbe diseases attack only the weaker individuals of the human species1 or those who have gone to regions where there are microbes which their bodies have not yet acquired the power of resisting4 ,usefulness of ,bacteria4--,their chief work is to destroy dead tissue and return it to the soil and air for the use of green plants again1 otherwise the earth would be filled with carcasses1 etc4 ,they are indispensable in soil formation4 ,they give the agreeable flavors to butter and cheese1 and cause milk to sour4 ,a rod-shaped bacterium is called a bacillus 7,fig4 #acj72 a spherical one is a coccus4 ,multiplication of ,bacteria4--,this is by division or fission4 ,sometimes1 instead of dividing1 a little rounded mass known as a spore appears4 ,the spore breaks out and the bacterium itself perishes4 ,species which do not produce spores are readily destroyed1 but spores have a hard1 tough shell1 and they may be dried or heated even to boiling without being killed4 ,spores float through the air and start new colonies4 ,most common bacteria grow best between #gj and #ie ,f4 ,they render it difficult to preserve foods1 especially proteid foods 7cheese1 lean meat1 eggs1 etc474 ,food decays slowly if at all below #gj and above #abe4 ,direct sunlight1 or the temperature of boiling water 7#bab ,f47 kills bacteria but not spores4 ,pantries1 kitchen1 and sickrooms should have bright walls and all the light possible4 ,boiling water should be poured into the sink1 and dish cloths should be thoroughly washed in boiling water4 ,diseases due to ,bacteria4--,a germ disease is usually due partly or wholly to substances called toxins produced by the bacteria4 ,most disease germs attack a single organ of the body4 ,diphtheria is caused by a species 7,fig4 #acj7 that grows on the mucous membrane of the throat2 this germ produces a powerful toxin4 ,the germs of typhoid fever 7,fig4 #aca7 and ,asiatic cholera multiply in the small intestine4 ,in both these diseases the source of infection is the diarrhal discharges from the alimentary canal4 ,flies may carry the germs on their feet from the discharge to food4 ,sometimes typhoid fever cases occur throughout a town because the water supply has become contaminated by sewage4 ,cases may occur only in families that buy milk from a certain dairy1 because the milk cans have been washed in contaminated water4 ,in caring for a typhoid patient all suspicious material should be disinfected or burned4 ,germs of tuberculosis 7called consumption if the disease is in the lungs7 may float through the air4 ,recent investigations indicate1 however1 that infection usually occurs through the alimentary canal1 the germs being swallowed1 then absorbed and taken to the lungs in the blood or lymph4 ,to prevent a patient from reinfecting himself in new parts of the lungs or elsewhere1 he should carefully cleanse his teeth1 mouth1 and throat 7by gargling with formal or lysol7 before eating4 ,illustration3 ,,fig4 #acj4--;,,bacillus ,,of ,,diphtheria4 ,illustration3 ,,fig4 #aca4--;,,bacillus ,,of ,,typhoid ,,fever4 ,illustration3 ,,fig4 #acb4--;,,culex ,,or ,,common ,,mosquito1 above 7possibly carries dengue fever74 ,,anopheles ,,or ,,malarial ,,mosquito1 below 7not always infected74 ,body of malarial mosquito is never held parallel to the supporting surface 7unless a leg is missing72 it has five long appendages to the head1 the culex 7above7 has only three4 7,draw47 ,illustration3 ,,fig4 #acc4--,,protective ,,white ,,corpuscle 7phagocyte7 digesting a microbe4 ,mosquito ,fevers4--,malaria1 yellow fever1 and probably dengue are transmitted each by a different genus of mosquito 7,fig4 #acb74 ,a mosquito of the malarial genus may bite a patient and suck into its body blood-corpuscles containing spores of the malarial parasite 7a protozoan animal1 see 8,animal ,biology10 p4 #g74 ,afterwards a spore 7in another stage7 may be transmitted by this mosquito when it bites another person4 ,the germ enters a red corpuscle1 grows1 and finally divides into many little spores4 ,at this moment the corpuscle itself breaks up1 setting free in the blood the spores and toxin formed4 ,this causes the chill and fever4 ,this development usually takes forty-eight hours1 hence the fever occurs every other day4 ,these mosquitoes begin to fly at dusk4 ,how are they recognized8 7,fig4 #acb47 ,they should be kept out of houses by screens or from the beds by netting4 ,kerosene should be poured on breeding places at the rate of one ounce for fifteen square feet of standing water4 ,this should be repeated twice a month4 ,cactus macerated in water may be used1 and forms a permanent film on the water4 ,stagnant pools may be filled or drained 7,exp4 #d74 ,malarial patients should themselves be screened1 as the chief source of danger to others2 for only mosquitoes who suck the blood of malarial patients will transmit the disease4 ,even then it is only transmitted to those whose white blood corpuscles are unable to protect them 7,fig4 #acc74 ,further ,means of ,protection against ,disease ,germs4--,the best protection is physical vigor4 ,there are certain substances called opsonins which exist in the plasma of the blood of disease-resisting persons2 these opsonins give the white corpuscles the power to devour disease germs4 ,the serum of the blood also develops antitoxins which neutralize the toxins formed in disease4 ,not only can the white corpuscles and serum kill bacteria1 but most of the secretions of the healthy body 7gastric juice1 nasal secretions1 etc47 are bacteria-killing as well4 ,persons in a low state of health most readily succumb to disease4 ,excess in eating may lessen the germicidal power of gastric juice and inactivity that of the lymph4 ,the same germ disease does not usually attack the same person twice1 as the body becomes immune2 that is1 an opsonin1 or an antitoxin1 is developed which cures the first attack and remains to protect the body in future4 ,the periods of quarantine or isolation for several common germ diseases are given in the following table3-- ,,from ,,exposure ,,name ,,of ,,till ,,first ,,patient ,,is ,,infectious ,,disease ,,symptoms ,,to ,,others ---------------------------------------- -------------------------- ,diphtheria #b days #ad days after membrane disappears4 ,mumps #aj-bb days #ad days from commencement4 ,scarlet fever #d days ,until all scaling has ceased4 ,smallpox #ab-ag days ,until all scabs have fallen4 ,measles #ad days #c days before eruption till scaling and cough cease4 ,typhoid fever #aa days ,until diarrha ceases4 ,whooping cough#ad days #c weeks before until #c weeks after beginning to whoop4 ,water ,supply4--,bacteria are more abundant in flowing streams than in water standing in lakes or reservoirs 7contrary to the usual belief74 ,they are most abundant in rivers that flow through populous regions4 ,they are comparatively scarce in dry1 sandy soils1 and very numerous in moist1 loamy soils4 ,the water of cities should never be taken from a stream or lake into which sewerage flows unless it is thoroughly filtered4 ,filters are constructed thus3 first a layer of small stones1 next a layer of coarse sand1 lastly a layer of very fine sand on top1 the total thickness being four or five feet4 ,beneficial microbes live upon the grains of sand and destroy all1 or nearly all1 of the dangerous microbes as the water slowly soaks through4 ,the construction of such waterworks is left to sanitary engineers1 of course1 and the average citizen does not need to know the details4 ,the department of street cleaning should receive the willing coperation of all citizens4 ,banana peelings1 paper1 etc41 should not be thrown upon the street or school grounds4 ,garbage1 ashes1 and rubbish should be placed in separate cans1 as the rules provide4 ,garbage cans1 if not thoroughly cleaned1 acquire unpleasant odors and breed flies and bacteria4 ,they should be thoroughly washed with very hot water and sal soda and scalded with boiling water and scrubbed with an old broom4#aa #aa ,the chief ,disinfectants are3 fresh air1 sunshine1 heat1 formaldehyde1 etc4 ,airing and sunning will destroy some germs in bedding and clothing as effectually as chemicals4 ,boiling and steaming are the best ways of applying heat4 ,formaldehyde is a volatile liquid4 ,after room is sealed and strips of paper pasted all over cracks1 a specially constructed generator is applied to keyhole1 and room kept closed for #ab hours4 ,mercuric chloride 7corrosive sublimate7 is used #a part to #ajjj parts of water for disinfecting soiled clothing1 towels1 utensils1 surgeon's instruments1 and wounds4 ,in place of this1 carbolic acid1 #e per cent solution1 may be used1 but it is not so good a germicide4 ,the chief duties of the ,health ,department are3 quarantine isolation and disinfection1 with the purpose of preventing or controlling contagious and infectious diseases2 inspection of dairies1 slaughterhouses1 and other sanitary work2 inspection of milk#ab and other food stuffs2 the department gathers vital statistics2 it enforces the rules for disinfection of public buildings4 #ab ,milk may be sterilized by boiling1 but boiled milk is not digestible nor nutritious4 ,milk may be ,pasteurized by immersing bottles of milk in water which is kept nearly 7but not quite7 at boiling point 7#afj ,f47 for five minutes4 ,but this makes the milk less valuable than fresh milk1 and destroys beneficent microbes4 ,buttermilk has many such microbes1 which kill injurious microbes and purify the stomach4 ,cleanliness1 or an aseptic condition1 is far preferable to antiseptics4 ,importance of ,coperation with the ,health ,department4--,only an ignorant and short-sighted person would fail to coperate promptly and cheerfully with local or state health officers4 ,it is for the benefit and protection of every one that the truth concerning contagious diseases be reported promptly4 ,only in this way may outbreaks of disease be prevented and many lives saved4 ,he is a bad citizen and a public enemy who will conceal a case of disease dangerous to the community4 ,outbreaks of fatal diseases may be easily prevented or stamped out if the health officer is sustained and his directions carried out4 ,,index ,i1 ,v1 ,x1 etc4 ,introduction3 ,p ,plant ,biology3 ,a ,animal ,biology3 ,h ,human ,biology4 ,aboral surface1 ,a #ce4 ,aborted seeds1 ,p #aff4 ,absorption1 ,h #ajf4 ,abutilon1 ,p #aef4 ,accessory fruit1 ,p #afd1 #afi4 ,accommodation in eye1 ,h #adc1 #aec4 ,acephala1 ,a #ajg4 ,acid1 ix4 ,adaptation to environment1 ,p #f1 ,a #adh1 #ahe1 #bja1 #bje1 #bjg1 ,h #ai1 #ajh1 #aji1 #aaj4 ,adenoid growths1 ,h #hf4 ,adipose tissue1 ,h #ab4 ,adulteration of food1 ,h #ic4 ,adventitious roots1 ,p #cf2 buds1 ,p #aad4 ,aerial roots1 ,p #cd4 ,aggregate fruit1 ,p #afh4 ,air cells1 ,h #ge4 ,air plants1 ,p #ce4 ,akenes1 ,p #afe4 ,albinism1 ,h #af1 #ah4 ,albumen1 ,h #ib4 ,albumin1 ,h #ib4 ,alcohol and circulation1 ,h #fg2 and fermentation1 ,h #aeh2 and food1 ,h #aac2 and muscles1 ,h #ej2 and nerves1 ,h #ace2 and skin1 ,h #bj4 ,algar1 ,p #agi1 #ahc1 #aie4 ,alkaline1 ix4 ,alternation of generation1 ,p #agi1 ,a #cj1 #ca4 ,ambulacral1 ,a #cf4 ,ameba1 ,a #aj4 ,americans1 ,h #a4 ,anadon1 ,a #ih4 ,anatomy1 ,h #i4 ,anemophilous1 ,p #adi4 ,animal food1 ,h #ie1 #aaj4 ,annual plant1 ,p #ag4 ,antelope1 ,a #bae4 ,antenn1 ,a #fh1 #hg4 ,anther1 ,p #ace1 #add1 #ahj4 ,antheridium1 ,p #agh1 #ahf1 #aih1 #bjj1 #bjb1 #bjc4 ,ant-eater1 giant1 ,a #aii2 spiny1 ,a #aif4 ,ant-lion1 ,a #ia4 ,ape1 ,a #bbj4 ,apical dehiscence1 ,p #aff4 ,appendicitis1 ,h #ajf4 ,appendix1 vermiform1 ,h #ajf4 ,appetite1 ,h #id1 #aaj4 ,aptera1 ,a #hb4 ,apteryx1 ,a #agd4 ,aquarium1 ,a #ag4 ,archegonium1 ,p #agh1 #aih1 #bjj1 #bjb1 #bjc4 ,argonaut1 paper1 ,a #ajg4 ,arm1 ,h #cc4 ,armadillo1 ,a #bjj4 ,arrowhead1 ,h #b4 ,arteries1 ,h #ea1 #ec1 #ed1 #fa4 ,arthropoda1 ,a #i1 #abe4 ,arum family1 ,p #adj4 ,ash1 ,p #ib4 ,asiatic cholera1 ,h #afj4 ,assimilation1 ,p #ig1 ,h #ij4 ,association fibers1 ,h #abc1 #abf4 ,asthma1 ,h #hf4 ,astigmatism1 ,h #add4 ,athletics1 ,h #df1 #dg4 ,atwater's experiments1 ,h #aac4 ,auricle1 ,h #ec4 ,automatic action1 ,h #abc4 ,axil1 ,p #aab4 ,axis1 plant1 ,p #ae4 ,axon1 ,h #aai4 ,bacillus1 ,h #aeh1 #aei4 ,bacteria1 ,p #ci1 #aji1 #ahb1 ,h #aeh1 #aei1 #afj1 #afa4 ,bandage1 ,h #fb4 ,barberry1 ,p 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#abi4 ,sea anemone1 ,a #cc4 ,sea fan1 ,a #cb4 ,sea horse1 ,a #abd4 ,sea urchin1 ,a #ch4 ,seed1 ,p #bj1 #afc1 #ahj2 coat1 ,p #ba4 ,selaginella1 ,p #bjd4 ,selection1 natural1 ,p #h2 artificial1 ,p #h4 ,sense1 muscular1 ,h #adc2 thermic1 ,h #adb4 ,senses of insects1 ,a #gf4 ,sensory1 cell1 ,h #abj2 fiber1 ,h #abj1 #aba4 ,sepal1 ,p #acc1 #afi4 ,septicidal capsule1 ,p #aff4 ,serum1 ,h #fa4 ,sessile1 ,p #gg4 ,set1 ,a #dc1 #dh4 ,sexual selection1 ,a #agd4 ,shark1 ,a #aba4 ,shelf fungus1 ,p #aid4 ,shoes1 ,h #dh4 ,shoulder1 ,h #cb4 ,shrub1 ,p #ai4 ,sick headache1 ,h #acc4 ,sieve tubes1 ,p #ff4 ,silicle1 ,p #afg4 ,silique1 ,p #afg4 ,silkworm1 ,a #hd1 #hf1 #ie4 ,silver scale1 ,a #hc4 ,siphon1 ,a #aja4 ,siphonoptera1 ,a #hb4 ,skeleton1 of bird1 ,a #aeb2 cat1 ,a #ahh2 frog1 ,a #aca2 of fish1 ,a #aac2 man1 ,h #bh2 chart of1 ,a #bah4 ,skin1 ,h #af4 ,skull1 ,h #fc2 mammalian1 ,a #aid4 ,sleep1 ,h #acj4 ,slipper animalcule1 ,a #ac4 ,sloth1 ,a #aii4 ,slug1 ,a #aje4 ,smell1 ,h #adg4 ,snail1 ,a #aje4 ,societies1 ,p #i4 ,soil1 ,p #dj1 #dg1 ,a #dh4 ,soredia1 ,p #aif4 ,sori1 ,p #agg1 #aib4 ,souring of milk1 ,h #aeh4 ,spadix1 ,p #adj4 ,sparrow1 ,a #ahb2 ,english1 ,a #agj4 ,spathe1 ,p #ach1 #adj4 ,specialization1 ,a #bj1 #bg1 #ff1 #baj1 ,h #h4 ,species1 ,a #h4 ,spermary1 ,a #be1 #bg4 ,spermatophytes1 ,p #ahj4 ,spicule1 ,a #ah4 ,spider1 ,a #id4 ,spike1 ,p #aeg4 ,spinal cord1 ,h #abj1 #aba4 ,spinal deformities1 ,h #cg4 ,spine1 ,h #ca4 ,spiracle1 ,a #gg1 #hg4 ,spirogyra1 ,p #ahd4 ,sponges1 ,a #ag1 #abe2 glass1 ,a #ai2 horny1 ,a #ai2 limy1 ,a #ai4 ,spontaneous combustion1 xiii4 ,sporangium1 ,p #agg1 #ahf1 #ahh1 #bja1 #bjc1 #bjd4 ,spore1 ,p #agf1 #agh1 #aha1 #ahd1 ,h #aei4 ,sporophyll1 ,p #ahj1 #bja4 ,sporophyte1 ,p #agg4 ,sports1 ,a #adh1 #bbd4 ,sprain1 ,h #ch4 ,squash bug1 ,a #ic1 #ie4 ,squid1 ,a #ajf4 ,stamen1 ,p #ace4 ,starch1 x1 ,p #ie1 #aja1 ,h #hh1 #ia4 ,starvation1 ,h #ach4 ,stem1 ,p #di2 endogenous1 ,p #ei2 exogenous1 ,p #fa2 kinds of1 ,p #di4 ,sterilizing wounds1 ,h #afc4 ,stickleback1 ,a #aai4 ,stigma1 ,p #ace1 #add1 #ade4 ,stimulant defined1 ,h #acg4 ,stipule1 ,p #gf1 #hd4 ,stock1 ,p #abe4 ,stomate1 ,p #hg4 ,stone age1 ,h #b4 ,stone fruit1 ,p #afh4 ,storage of food1 ,p #ii4 ,street cleaning1 ,h #afc4 ,struggle to live1 ,p #d1 #f1 ,a #adg1 ,h #d4 ,study1 comparative1 ,a #hb1 #adi1 #bbc4 ,style1 ,p #ace1 #afc4 ,sugar1 ,h #ia1 #ajj4 ,sulphur1 vii4 ,summer-spore1 ,p #aia4 ,sun energy1 ,p #ie1 ,a #b1 ,h #ia4 ,sunlight1 ,a #b1 ,h#ah4 ,survival of fittest1 ,p #g1 ,a #adg1 ,h #d1 #ada4 ,sutures1 ,h #ce4 ,swarm-spores1 ,p #ahf4 ,sweat gland1 ,h #bj4 ,symbiosis1 ,p #aif4 ,sympathetic system1 ,h #abg1 #abi4 ,syngenesious1 ,p #ada4 ,synovial fluid1 ,h #cf4 ,tadpole1 ,a #abf1 #acd4 ,tanner1 ,dr41 ,h #ach4 ,tapeworm1 ,a #di4 ,tarantula1 ,a #id4 ,taste1 ,h #aaj1 #adc1 #adf4 ,tear gland1 ,h #adi4 ,teeth1 ,h #hh1 #ih1 #ii1 #aaa2 of frog1 ,a #acj4 ,teleutospores1 ,p #aib4 ,temperature1 ,h #ba2 nerves of1 ,h #adb1 #adf4 ,tendon1 ,h #da4 ,tendril1 ,p #aja4 ,terrapin1 ,a #adc1 #add4 ,thallophyte1 ,p #aha1 #ahd4 ,thallus1 ,p #ahd1 #aig4 ,thompson1 ,sir ,henry1 on smoking1 ,h #hg4 ,thoracic duct1 ,h #fd1 #fe1 #aje4 ,thorns1 ,p #aja4 ,thought questions1 ,h #bj1 #bg1 #gi1 #ajg1 #aji1 #aaf4 ,thyrse1 ,p #afj4 ,thyroid gland1 ,h #ig4 ,tillandsia1 ,p #aaj4 ,timber1 decay of1 ,p #aie4 ,tissue1 ,h #g1 #aj1 ,p #fj1 #fb4 ,toad1 ,a #acg4 ,toadstool1 ,p #aid4 ,tobacco1 and heart1 ,h #fg2 and lungs1 ,h #hf2 and taste1 ,h #adh2 when enjoyable1 ,h #hg4 ,tortoise1 ,a #adj1 #adc1 #add4 ,torus1 ,p #acd1 #afi4 ,touch1 ,h #ade1 ,a #aai4 ,toxin1 ,h #afj1 #afa4 ,toyi ,niku1 ,madame1 quoted1 ,h #ada4 ,trachea1 ,h #gd4 ,tracheid1 ,p #fe4 ,transpiration1 ,p #ih1 #ajc4 ,trap-door spider1 ,a #id4 ,tube feet1 ,a #ce4 ,tuberculosis1 ,h #e1 #afj4 ,tumble bug1 ,a #ij1 #ia4 ,turtle1 ,a #adj1 #adc1 #add4 ,twiners1 ,p #abi1 #aca4 ,typhoid fever1 ,h #aei4 ,umbel1 ,p #aei4 ,umbo1 ,a #ih4 ,undergrowth1 ,p #ab4 ,ungulate1 ,a #bab4 ,urea1 ,h #id4 ,uric acid1 ,h #aad4 ,urinary tubule1 ,h #bg4 ,vacuole1 ,a #aa1 #ab1 #ad4 ,valve1 ,p #afd1 ,h #ea1 #ec1 #eg4 ,vampire1 ,a #bjc4 ,variation1 ,a #adg1 ,p #b4 ,variety1 ,a #h4 ,vaso-motor nerves1 ,h #bc1 #fh4 ,vaucheria1 ,p #ahf4 ,vegetables1 ,h #ie1 #aab4 ,venomous snakes1 ,a #adc4 ,vent1 ,a #db4 ,ventilation1 ,h #ga1 #hb1 #hc4 ,ventral1 ,a #dc4 ,ventricle1 ,h #ec4 ,vermes1 ,a #i1 #abe4 ,vermiform appendix1 ,h #d1 #ajf4 ,vertebra1 ,h #ga1 #hb1 #hc4 ,vertebrates1 ,a #i1 #abe4 ,vertebrate skeletons1 ,a #bah4 ,verticellate1 ,p #hd4 ,vestigial organs1 ,h #ajf4 ,villi1 ,h #ajd4 ,vinegar1 ,h #id4 ,viscera1 ,h #abg2 of bird1 ,a #afc4 ,vitreous humor1 ,h #aeb4 ,voluntary act1 ,h #abb1 #abd4 ,warning sound1 ,a #adg4 ,wasps1 digging1 ,a #hi4 ,water-pore1 ,p #hh4 ,waterworks1 ,h #afc4 ,weevil1 ,a #ij1 #ia1 #if4 ,whale1 ,a #bjh4 ,wheat rust1 ,p #aib4 ,white corpuscles1 ,h #ei2 origin of1 ,h #fa2 work of1 ,h #fj1 #afa1 #afb4 ,white weed1 or ox-eye daisy1 ,p #aee4 ,whorled1 ,p #hd4 ,willow mildew1 ,p #aij4 ,wind travelers1 ,p #agc4 ,wings1 of grasshopper1 ,a #fg2 of bird1 ,a #aec1 #aeh4 ,woodpecker1 ,a #ahj4 ,woody fiber1 ,p #ag4 ,worms1 ,a #db4 ,wounds of plants1 ,p #ef4 ,written exercises1 ,h #ae1 #ej1 #aaf4 ,yeast plants1 ,p #aij1 ,h #aeh4 ,yellow fever1 ,h #afj4 ,yellow spot1 ,h #aea4 ,zoology defined1 ,a #a4 ,zoophytes1 ,a #cc4 ,zygnema1 ,p #ahe4 ,zygospore1 ,p #ahe1 #ahi1 #aij4 ,,lessons ,,in ,,hygienic ,,physiology ,by ,w4 ,m4 ,,coleman4 x #bga pages4 #aih illustrations 7#af colored1 #ac full-page plates74 #fj cents net4 ,in ,lessons in ,hygienic ,physiology the study of physiology is simplified without weakening the presentation of its three essential principles--the biological principle of environment1 the chemical principle of oxidation1 and the physical principle of energy4 ,the subject is approached throughout from the standpoint of health1 because this is the most useful as well as the most interesting point of view4 ,the question of temperance is treated fully1 but at the same time in a conservative manner4 ,the book is fully illustrated1 one hundred and ninety-eight figures being furnished1 sixteen of which are colored4 ,the ,lessons is suited to the needs of teachers who may find the ,elements somewhat too advanced for their classes4 ,,elements ,,of ,,physiology ,by ,w4 ,m4 ,,coleman4 xii #cfd pages4 ,a very full course in ,physiology and ,hygiene4 ,profusely illustrated in black and white and in colors4 #ij cents net4 ,this book has an exceptionally large number of illustrations--two hundred and forty-eight1 of which eight are full-page colored plates4 ,the need for a compound microscope is largely obviated by sixty microscopic views of cells and tissues4 ,the ,elements is provided with a ,colored ,manikin arranged to show every important organ in its natural position with reference to the organs before it1 behind it1 and around it4 ,since every pupil has the manikin while studying each lesson1 it is really more serviceable than the manikins usually found in schools4 ,this book contains twenty-five ,thought ,lessons of about ten questions each1 logically developing different lines of thought2 also three hundred questions in ,applied ,physiology4 ,,the ,,macmillan ,,company ,sixty-four and ,sixty-six ,fifth ,avenue1 ,new ,york ,,botany ,an ,elementary ,text for ,schools4 ,by ,l4 ,h4 ,,bailey1 ,director of the ,college of ,agriculture1 and ,professor of ,rural ,economy in ,cornell ,university4 ,revised and enlarged4 ,illustrated4 #abmo4 ,half leather4 xiv #cee pages4 #a4aj net4 ,the subjects treated are four in number3 the nature of the plant itself1 the relation of the plant to its surroundings1 the minute structures of plants1 and the determination of the kinds of plants4 ,each of these subjects is practically distinct1 so that the teacher may begin where he will4 ,the five hundred illustrations in the book are an important as well as an attractive feature4 ,they are not pictures merely--they are illustrations of the subject-matter2 many of them are reproductions of photographs4 ,a flora containing descriptions of more than six hundred common wild and cultivated plants1 with keys to the natural orders1 completes the book4 ,,lessons ,,with ,,plants ,suggestions for ,seeing and ,interpreting ,some of the ,common ,forms of ,vegetation4 ,by ,professor ,l4 ,h4 ,,bailey4 ,illustrated4 #abmo4 ,half leather4 xxxi #dia pages4 #a4aj net4 ,the book is based upon the idea that the proper way to begin the study of plants is by means of plants1 instead of formal ideas or definitions4 ,instead of a definition as a model telling the pupil what he is to see1 the plant shows him what there is to be seen1 and the definition follows4 ,in this way the pupil soon begins to generalize1 and the conclusion reached is the true definition4 ,,the ,,macmillan ,,company ,sixty-four and ,sixty-six ,fifth ,avenue1 ,new ,york ,transcriber's ,notes ,inconsistent and obsolete spelling1 hyphenation1 etc4 have been retained1 except as listed below4 ,depending on the hard- and software used to read this text and their settings1 not all elements may display as intended4 ,scales and factors of enlargement or reduction as given in illustration captions are not necessarily correct4 ,page ,p #fe1 legend with ,fig4 #gh3 reference letter f does not appear in the illustration4 ,page ,p #ajg1 7b1 ,fig #acb73 reference letter b does not appear in the illustration4 ,page ,p #aaa3 the text refers to an apple bud in ,fig4 #acg1 the illustration caption refers to an apricot bud4 ,page ,a #af-;,a #ag3 there is no ,fig4 #bj in the source document4 ,page ,a #if3 there is no caption or other explanation with the third illustration 7hazelnut leaf1 fruit and insect74 ,page ,h #h1 444 canals instead of railroads for their commerce 7see ,fig4 #hd73 it is not clear which illustration is referred to2 ,fig4 #hd does not show this distinction4 ,page ,h #aa1 444 called nerve fibers 7,fig4 #adb73 there is no ,fig4 #adb1 nor is it clear to which figure showing nerve fibers this phrase refers4 ,page ,h #hh1 ,practical ,question #f3 the reference to ,chapter ,,vi is included in ,chapter ,,vi4 ,page ,h #aje1 444 fresh milk is an emulsion of cream 7,fig4 #ih73 ,fig4 #ih shows something unrelated4 ,page ,h #afa1 ,page ,h #afa3 ,stagnant pools may be filled or drained 7,exp4 #d73 there are only three experiments with this chapter2 ,experiment #c mentions stagnant water4 ,changes made3 ,footnotes1 tables and illustrations have been moved out if text paragraphs4 ,some minor typographical errors and missing or extraneous punctuation have been corrected silently2 where relevant1 illustration captions have been standardised4 ,blanks to be filled out have been standardised to a series of underscores4 ,the parts of the book have been included in the page numbering3 lower case ,roman numerals for the index1 prefixes ,i1 ,p1 ,a and ,h for the ,introduction and the parts on plants1 animals1 and humans respectively4 ,page ,i ix3 page number ,p #a inserted in ,table of ,contents for ,part ,i ,chapter #a4 ,page ,i xi3 page number ,h #bi 7section ,the ,skeleton7 changed to ,h #bh4 ,page ,i xvii3 ,see also experiments with candle and breath1 in ,introduction to ,human ,biology4 and related hyperlinks changed to ,see also experiments with candle and breath1 in ,the ,principles of ,biology4 and relevant hyperlinks4 ,page ,p#ca3 ,fig4 ,b has been rotated #ij4 ,page ,p #hi3 444 at their middles on either side the opening1 444 changed to 444 at their middles on either side of the opening1 4444 ,page ,p #ia3 444 the table on page #hh 444 changed to 444 the table on page #hh 4444 ,page ,a#h3 7,fig4 #chi47 changed to 7,fig4 #cij47 ,page ,a #db3 444 a test with live worm 444 changed to 444 a test with a live worm 4444 ,page ,a #ia3 ,parenthesis deleted from 444 ,where does a ,scarab 7or sacred beetle 4444 ,page ,a#ic3 ,illustration caption ,fig4 #agg added4 ,page ,a #id3 parenthesis deleted from 7,does the size of its nerve ganglia 4444 ,page ,a #adc1 caption with ,fig4 #bgj3 444 lr1 liver 444 changed to 444 le1 liver 4444 ,page ,a #agd3 ,describe the molting process 7page #abj7 changed to ,describe the molting process 7page #aeg74 ,page ,a #agg3 ,d ,bill hooked1 444 changed to ,d ,bill hooked1 4444 ,page ,a #aic3 ,c ,head large2 444 changed to ,c ,head large2 4442 ,c ,five toes1 444 changed to ,c ,five toes1 4442 ,dolphin 7#cgi1 #cig7 changed to ,dolphin 7,figs4 #cgi1 #cig74 ,page ,a #bjj3 7,see ,fig4 #cdg47 changed to 7,see ,fig4 #cdi47 ,page ,h #ag3 question mark deleted from 444 a cotton cloth of same weight and texture8 ,page ,h #be3 444 keeping the body cool during the exertion 7,exp4 o7 changed to 444 keeping the body cool during the exertion 7,exp4 #e74 ,pahe ,h #ch3 444 sit far back in the chair 7,figs4 #fj1 #fa1 #fb7 444 changed to 444 sit far back in the chair 7,figs4 #di1 #ej1 #ea7 4444 ,page ,h #ed3 444 blood vessels must have these three properties8 changed to 444 blood vessels must have these three properties4 ,page ,h #ef3 ,fig4 #eg rotated #ahj4 ,page ,h #gj3 7,see ,animal ,biology1 p4 #ad47 changed to 7,see ,animal ,biology1 p4 #d47 ,page ,h #gb3 ,make a model like sketch 444 changed to ,make a model-like sketch 4444 ,page ,h #aaj1 ,fig4 #aja3 individual elements rotated #ij clockwise4 ,page ,h #adj 7footnote73 closing quote mark inserted after 444 how to harmonize color with herself4 ,page ,h #aeh3 parenthesis deleted after 444 #bjj diameters1 or #dj1jjj areas74 ,index3 some page numbers corrected and book 7,i1 ,p1 ,a or ,h1 see above7 letters added4