,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,small capitals have been converted to ,,solid capitals4 ,illustrations have been moved so they do not break up paragraphs4 ,typographical errors have been silently corrected4 ,,an ,,introduction ,,to ,,nature ,,study4 ,illustration ,,macmillan ,,and ,,co41 ,,limited ,,london ,,bombay ,,calcutta ,,melbourne ,,the ,,macmillan ,,company ,,new ,,york ,,boston ,,chicago ,,atlanta ,,san ,,francisco ,,the ,,macmillan ,,co4 ,,of ,,canada1 ,,ltd4 ,,toronto ,,an ,,introduction ,,to ,,nature-,,study ,,by ,,ernest ,,stenhouse1 ,b4,,sc4 7,,lond47 ,,associate ,,of ,,the ,,royal ,,college ,,of ,,science1 ,,london2 ,,joint-,,author ,,with ,a4 ,t4 ,,simmons1 ,b4,,sc4 ,,of 8,,science ,,of ,,common ,,life0 ,,macmillan ,,and ,,co41 ,,limited ,,st4 ,,martin',s ,,street1 ,,london #aiaj ,first ,edition #aijc4 ,reprinted #aijd 7twice71 #aije1 #aijf1 7with additions7 #aijh1 #aiaj4 ,,glasgow3 ,,printed ,,at ,,the ,,university ,,press ,,by ,,robert ,,maclehose ,,and ,,co4 ,,ltd4 ,,preface4 ,one of the most encouraging of recent educational movements is the increasing importance attached1 both in this country and abroad1 to what is called ,nature-,study4 ,it is evident that the instruction contemplated differs as widely1 on the one hand1 from the traditional object-lessons on polar bears and ironclads1 as it differs from formal ,biology on the other4 ,this difference is abundantly shown1 not only by the circulars and syllabuses issued by our own ,board of ,education1 but by the publications of the leading educational authorities of ,europe and ,america4 ,the aim of ,nature-,study1 as thus laid down1 is not primarily the acquisition of the facts of natural history3 it is rather a training in methods of open-eyed1 close1 and accurate observation1 especially of familiar animals and plants1 which shall teach the student to see what he looks at1 and to think about what he sees4 ,it is in a spirit of entire agreement with these views that this book has been written4 ,no previous knowledge of ,biology on the part of the reader is assumed1 and technical terms have as far as possible been dispensed with4 ,in drawing up the course1 ,i have had in mind throughout the attitude of an intelligent youth of sixteen1 and the work will be found to be well within the powers of such a student4 ,teachers will1 however1 find no difficulty in adapting the exercises to the needs of younger pupils4 ,care has been taken to select1 as types for study1 animals and plants which are at the same time representative and easily obtainable1#a and ,i have been further guided in the selection by the ,board of ,education ,syllabuses of the ,king's ,scholarship ,examination and ,section ,i4 of the ,elementary ,stage of ,general ,biology1 the subjects of which are included in the volume4 ,the book has1 however1 a considerably wider scope than is indicated in these syllabuses1 and will therefore1 ,i hope1 be found useful not only in schools and training-colleges1 and to examination candidates1 but also to members of field clubs and to students of natural history generally4 ,it has been necessary to arrange the chapters with some attempt at logical sequence1 but it is not supposed that this order will be adhered to in practice2 by the aid of the monthly nature-calendar1 together with numerous cross-references1 it will be found easy to take up the work at any point4 ,the chapters are divided into sections1 each of which consists of two parts3 ,first1 precise instructions for practical observations and experiments1 designed to exercise the reasoning faculties of the students2 and1 second1 a descriptive portion1 in which the meaning and relation of the results obtained are discussed4 ,at the end of each chapter is a number of additional exercises1 either original or taken from past examination papers4 ,of the latter class1 questions to which dates are affixed have been set by the ,board of ,education1 while those marked 8,n4,f4,u40 are selected from ,national ,froebel ,union tests4 ,in many cases1 the exercises provide subjects for further observation and experiment1 as well as for written description4 ,much trouble has been taken in the selection of the illustrations1 many of which have been expressly drawn or photographed for this book4 ,through the kindness of the publishers ,i have been able to include illustrations from ,strasburger's ,text-,book of ,botany1 ,parker and ,haswell's ,text-,book of ,zoology1 ,the ,cambridge ,natural ,history1 and other books2 and ,mr4 ,ernest ,evans has courteously consented to the use of a number of figures from his ,botany for ,beginners4 ,the following illustrations have been prepared from photographs supplied by ,mr4 ,j4 ,c4 ,shenstone1 ,f4,l4,s41 ,vice-,president of the ,essex ,field ,club3 ,figs4 #bg1 #eg1 #fe1 #fg to #ga1 #gd1 #ge1 #hj1 #ha1 #hc1 #hd1 #he1 #hg1 #hi1 #ib1 #id1 #ie1 #ajb to #aaj1 #abj1 #acf1 #ade1 #adi1 #aeb and #aec2 while ,figs4 #ahj1 #aif1 #bjj1 #bja1 #bjc1 #bje1 and #baa are reproduced1 by permission1 from ,pike's ,woodland1 ,field1 and ,shore 7,religious ,tract ,society74 ,finally1 ,i must acknowledge gratefully the continuous help which1 at every stage in the preparation of the book1 ,i have received from ,professor ,r4 ,a4 ,gregory and ,mr4 ,a4 ,t4 ,simmons1 ,b4,sc4--help as valuable as it was generous4 ,the issue of a new edition has provided the opportunity of adding a section on ,school ,journeys1 originally contributed by me as an article to ,the ,school ,world1 and reprinted here by kind permission of the ,editors of that journal4 ,for the illustrative sketch-map 7,fig4 #bcg71 and for ,figs4 #ai1 #ba and #ach1 ,i am indebted to my friend ,mr4 ,t4 ,d4 ,tuton ,hall4 ,e4 ,,stenhouse4 ,,contents4 ,,part ,i4 ,,plant ,,life4 ,,chapter ,,page ,i4 ,,seeds ,,and ,,their ,,early ,,stages ,,of ,,growth1 #a ,,ii4 ,,how ,a ,,green ,,plant ,,feeds1 #bf ,,iii4 ,,the ,,forms ,,and ,,duties ,,of ,,leaves1 #cg ,,iv4 ,,buds4 ,,the ,,history ,,of ,a ,,twig1 #ee ,v4 ,,how ,,stems ,,do ,,their ,,work1 #fg ,,vi4 ,,some ,,common ,,flowers1 #hh ,,vii4 ,,grasses1 #abe ,,viii4 ,,common ,,forest ,,trees1 #adj ,,ix4 ,,fruits3 ,,how ,,seeds ,,are ,,scattered1 #afe ,x4 ,,ferns ,,and ,,horsetails1 #ahc ,,xi4 ,,mosses1 ,,mushrooms1 ,,and ,,moulds1 #aii ,,part ,,ii4 ,,animal ,,life4 ,,xii4 ,,the ,,rabbit3 ,a ,,typical ,,mammal1 #baa ,,xiii4 ,,how ,a ,,rabbit ,,lives1 #bbb ,,xiv4 ,,some ,,other ,,mammals1 #bdf ,,xv4 ,,the ,,pigeon3 ,a ,,typical ,,bird1 #bfe ,,xvi4 ,,the ,,development ,,and ,,education ,,of ,,the ,,chick1 #bhb ,,xvii4 ,,some ,,familiar ,,british ,,birds1 #cja ,,xviii4 ,,frogs ,,and ,,tadpoles1 #ccb ,,xix4 ,,the ,,habits ,,and ,,life-,,histories ,,of ,,common ,,insects1 #cdi ,,xx4 ,,some ,,crustaceans1 ,,molluscs1 ,,and ,,worms1 #cgb ,,xxi4 ,,field-,,work4 ,,the ,,school ,,journey1 #chh ,,monthly ,,nature ,,calendar1 #djj ,,part ,i4 ,,plant ,,life ,,chapter ,i4 ,,seeds ,,and ,,their ,,early ,,stages ,,of ,,growth4 #a4 ,,the ,,structure ,,of ,,seeds ,,with ,,two ,,cotyledons4 #a4 ,preparation of the seeds4--,obtain several seeds of the broad bean1 pea1 mustard1 yellow lupine1 vegetable marrow1 and sycamore2 soak them in cold or slightly warm water until they are soft enough to be cut through easily with a sharp knife4 ,the time necessary will vary with different seeds according to the size of the seeds1 and with the temperature of the water4 ,the beans should be left in the water for a few days4 ,when the seeds are soft enough1 examine one or two of each1 and in the meantime put about six of each 7except the mustard7 in damp sawdust in a warm place4 ,put the mustard seeds on damp flannel in a saucer4 #b4 ,the outside of a broad bean4--,notice the flattened oval shape1 with an indentation at one place 7,fig4 #a74 ,what is the colour of the skin 7seed-coat7 of the bean seed8 ,is all the skin of this colour8 ,a black scar extends along the edge from the indentation for about in4 ,what is this scar8 ,if beans in the pod can be obtained1 see that the scar is the place of attachment of the seed stalk4 ,make drawings to scale1 showing side and edge-views of the seed4 ,wipe the bean dry and then squeeze it gently4 ,notice that a drop of water comes out at a point at one end of the stalk scar4 ,there is evidently a little hole here4 ,this little hole is called the micropyle4 ,mark its position by a dot on the drawing4 #c4 ,the inside of a broad bean4--,with a sharp knife cut the seed-coat open1 beginning at the side of the seed furthest from the micropyle1 and carefully remove the seed-coat4 ,notice that near the micropyle the seed-coat forms a funnel-shaped depression1 and that the point of the funnel is at the micropyle4 ,does anything fit into the funnel8 ,a little cone may be seen to fill the funnel2 this conical body is called the radicle4 ,make a drawing of the seed after the removal of the seed-coat4 ,look at the edge opposite the radicle and notice that a crack divides the body of the seed into halves4 ,put the point of your knife blade into the crack1 and gently force the halves apart4 ,they come apart without tearing1 showing that they are naturally separate1 although they fit so closely together4 ,these two swollen bodies are called the cotyledons4 ,separate them and see1 at the point where they join the radicle1 a little curved rod1 evidently a continuation of the radicle1 lying between them4 ,this rod is the plumule4 ,take off one cotyledon1 and make a drawing of the inner face of the other cotyledon1 with the adhering plumule and radicle 7,fig4 #b74 #d4 ,starch present in the cotyledons of the bean4--,scrape the inner surface of a cotyledon and then pour on it a drop of iodine solution4#b ,is there any change8 ,pour also a drop of iodine solution on a piece of laundry-starch4 ,is a similar blue colour formed8 ,what substance is probably present in the cotyledons of the bean8 #e4 ,the pea4--,examine a pea in a similar manner4 ,make drawings showing the stalk-scar1 the micropyle1 and the plumule and radicle with their manner of connection with the cotyledons4 ,does the end of the radicle point towards the micropyle8 ,how many cotyledons has this seed8 ,what shape and colour are they8 ,do they contain starch8 #f4 ,the seed of the yellow lupine4--,compare this with the bean and the pea1 and find out how many cotyledons it has1 and whether they contain starch4 ,can you find the plumule8 ,it is very small1 but occupies a position similar to that of the plumule of the bean4 ,does the end of the radicle point to the micropyle8 #g4 ,the vegetable marrow seed4--,notice the peculiar shape 7somewhat like a pocket-flask7 of the seed1 and the thickened margin which runs round it4 ,carefully cut the seed-coat away so as not to injure the part inside4 ,how many cotyledons are present8 ,what is their colour8 ,do they contain starch8 ,can you see the plumule and radicle clearly8 ,if not1 do not decide that they are absent1 but leave the question to be settled later1 when you watch a vegetable marrow seed 8come up40 #h4 ,the mustard seed4--,notice how much smaller this seed is than the others4 ,with a balance1 find how many mustard seeds are equal in weight to one bean seed4 ,observe the stickiness of the seed-coat of the soaked seed1 and then remove it carefully with needles1 exposing two thin plates1 each one folded on itself1 and one tucked inside the other1 like two sheets of note-paper4 ,these are the cotyledons2 it seems that the smallness of the seed may be mainly due to the small size of the cotyledons4 ,what is their colour8 ,remember these characters and try1 when you watch the young plants come up later1 to find an explanation of them4 #i4 ,the sycamore fruit4--,the seed of the sycamore is enclosed in a case which has a wing attached to it4 ,the wing1 the case1 and the enclosed seed together constitute the fruit of the sycamore4 ,the fruits occur in pairs 7,fig4 #acg74 ,notice that a cord runs out to each fruit from the stalk on which the pair of fruits is borne4 ,make a drawing of a pair of fruits1 then separate the fruits4 #aj4 ,the sycamore seed4--,cut open a fruit4 ,can you see anything between the seed and the fruit-case8 ,would the hairy covering of the seed tend to keep it warm during the winter8 ,why8 ,why do you prefer to wear flannel in winter and linen in summer8 ,flannel is more fluffy than linen4 ,remove the seed-coat carefully4 ,running down one side you will see a little curved rod4 ,this is the radicle4 ,gently raise it with the point of your knife4 ,notice that the rest of the seed seems to consist of a green part1 which is curled up4 ,uncoil the curls carefully4 ,you find that they are two green leaves1 fixed at the top of the radicle4 ,these are the cotyledons4 ,in the seed each cotyledon is first folded in two across the middle and then coiled up4 ,make a sketch showing the coils 7,fig4 #d74 ,can you see the plumule8 ,it is just at the top of the radicle1 where the cotyledons are fixed on4 ,plants are living things4--,one of our foremost naturalists#c tells us that when he goes out into the woods1 or into one of those fairy forests which we call fields1 he finds himself welcomed by a glad company of friends1 everyone with something interesting to tell4 ,such a feeling would be quite impossible to one who did not vividly recognise the fact that plants are alive2 for it is precisely this recognition or its absence which makes the observation of the forms and habits of plants fascinating or the reverse4 ,let the ,nature-,student1 then1 at the outset of his work1 keep the idea of life inseparably bound up with his every thought about plants4 ,it may at first require a little effort1 but before long it will enable him to understand how the friendship of the more silent half of animate nature may form one of the great pleasures of life4 ,the study of seeds4--,the manifestation of life is so striking1 and the changes in form and size take place so rapidly1 in the germination of seeds1 that the study of plants cannot better be commenced than with this stage of their growth4 ,the method has also the logical virtue of beginning at the beginning1 or nearly so4 ,these early changes can be well observed by taking various common seeds1 soaking them in water until they are soft1 and then allowing them to germinate in damp sawdust1 taking a few out at intervals and noting their progress4 ,the growth of the seeds takes place more rapidly if they are kept in a warm room1 but in any case some days will probably elapse before much change is noticeable in them4 ,during the interval of waiting1 some of the seeds themselves should be carefully examined1 and drawings of all the parts should be made4 ,the drawing ought on no account to be omitted4 ,it compels the student's attention to details which would otherwise pass unnoticed2 and a careful sketch is a much better record of an observation than any amount of description alone could be4 ,the drawing need not be elaborate2 an outline pencil-sketch to scale will usually be sufficient4 ,illustration3 ,,fig4 #a4--;,a ,broad-,bean seed4 ,a1 side view2 ,b1 edge view3 st4 sc41 stalk-scar2 m1 micropyle4 7 47 ,the seed of the broad bean4--,the seed of the broad bean 7,fig4 #a7 is large1 having a diameter of perhaps an inch and a half1 and a thickness of half an inch4 ,in shape it is oval1 but at one region the edge is indented1 and a black scar 7st4 sc47 runs from the indentation along the edge for a distance of about three-quarters of an inch4 ,this scar is the place of attachment of the stalk which formerly carried the seed in the bean-fruit 7pod74 ,it may be called the stalk-scar4 ,if a soaked bean is wiped dry and then gently squeezed1 a small drop of water escapes from the end of the stalk-scar nearest the indentation4 ,the hole out of which the water comes is very small and difficult to see1 but its position is thus made clear4 ,this hole 7m7 is called the micropyle1--a word meaning the 8little gate40 ,the bean seed is covered by a tough brown skin1 the seed-coat 7,fig4 #b1 s4c471 a funnel-shaped depression in which leads to the micropyle 7m74 ,the depression is occupied by a part of the seed which is shaped like a conical peg and called the radicle 7,r72 the point of the radicle is directed toward the micropyle4 ,the great body of the seed is composed of two fleshy1 cream-coloured lobes1 easily wedged apart by inserting a knife-blade between them2 these fleshy lobes are the cotyledons 7,cot474 ,between them1 and continuous with the radicle1 is a small yellow body1 the plumule 7pl474 ,the relations of the radicle1 plumule and cotyledons are best seen by removing one cotyledon 7,fig4 #b74 ,illustration3 ,,fig4 #b4--;,broad-,bean seed1 seen from the inside1 after the removal of half the seed-coat and one cotyledon4 ,cot41 the inner face of remaining cotyledon2 ,c1 area of attachment of other cotyledon2 m1 micropyle2 pl1 plumule2 ,r1 radicle2 ,s4c41 seed-coat2 st4 sc41 stalk-scar4 7 #a47 ,a scraped cotyledon at once turns blue when a drop of dilute iodine solution is poured on it1 thus showing the presence of starch4 ,we shall see in ,chapter ,,ii4 what use the growing seedling makes of the starchy food which is stored in its cotyledons4 ,the seed of the pea4--,except in size and shape the seed of the pea is very similar to the bean seed4 ,its form is spherical1 and the scar left by the stalk which formerly attached it to the wall of the pea-pod 7,fig4 #c7 is plainly to be seen4 ,pointing towards the micropyle is the peg-like radicle2 the plumule lies between the hemispherical cotyledons4 ,as before1 the cotyledons can be proved to contain starch1 by the blue colour which is formed when a drop of iodine solution is poured on the scraped surface4 ,illustration3 ,,fig4 #c4--,pods and ,seeds of ,pea4 7 47 ,the seed of the yellow lupine4--,the seed of the yellow lupine is about as large as a pea1 but it is slightly flattened in shape4 ,the seed-coat is prettily mottled2 when it is removed1 the greater part of the seed is found to consist of two cotyledons4 ,they are somewhat swollen1 but the stored food is not starch4 ,the plumule and radicle occupy positions similar to those of the bean and pea4 ,the vegetable marrow seed4--,this seed has a rather curious shape1 and somewhat resembles a pocket-flask4 ,it is flattened1 and the border of the seed-coat is thickened and of silky appearance1 the rest of the 8skin0 having some resemblance to kid4 ,the two cotyledons1 which compose the greater part of the seed1 are white and only slightly fleshy4 ,the plumule and radicle are at the pointed end of the seed1 and are difficult to see4 ,the mustard seed4--,in comparing the mustard seed with those already described1 one is struck with the great difference in size4 ,an average broad-bean seed weighs about #fjj times as much as the mustard seed4 ,while the two fleshy cotyledons make up the bulk of the seed of the bean1 pea1 lupine and vegetable marrow1 the cotyledons of the mustard seed are thin and leaf-like4 ,they are folded on themselves1 one inside the other 7as at g1 ,fig4 #fa71 and enclose the radicle4 ,the characters of the cotyledons account very largely for the small size of the mustard seed4 ,it will be seen1 when the growth of the young plants is watched1 that the difference is associated with the special duties which the cotyledons perform in the various cases4 ,illustration3 ,,fig4 #d4--,sycamore ,fruit1 cut through in the plane of the wing4 s4c41 seed-coat 7indicated by a thick1 broken line72 f4w41 fruit-wall2 h1 layer of fine hairs2 ,r1 radicle2 pl41 plumule2 cot4 #a1 cot4 #b1 cotyledons 7diagrammatically shaded74 7 #b47 ,the sycamore seed4--,what is generally called the seed of the sycamore is really a fruit4 ,the fruits are in pairs 7,figs4 #cc and #acg71 and each half consists of a flat wing and a rounded case in which the seed itself is enclosed4 ,the round seed-cases of the two fruits are connected together4 ,when they come apart1 a scar marks the place where they were formerly in contact1 and a little cord runs out to each fruit from the stalk on which the pair of fruits is borne4 ,between the sycamore seed and the wall of its case is a layer of fine hair 7h1 ,fig4 #d71 which forms a warm nest for the seed in winter4 ,the seed is surrounded by a thin1 brown seed-coat1 and consists mainly of two cotyledons1 but these are very different from any yet described4 ,each is a green leaf1 measuring1 when unfolded1 about an inch in length4 ,it is first folded across the middle of its length1 and then rolled up into a close coil with its fellow4 ,the coils are very plainly to be seen when the seed coat is removed1 or when the whole seed is cut through1 by a sharp knife1 in the plane of the wing4 ,running down one side of the seed is a green rod1 the radicle 7,r1 ,fig4 #d74 ,the two cotyledons 7cot4 #a and cot4 #b7 spring from its upper end1 and between them is the tiny plumule 7pl47 ,the sycamore seed bears more resemblance to the mustard seed than to the others1 but it is on a much larger scale4 ,in each of these two seeds the cotyledons are plainly leaves1 while in the others their nature is disguised by the great accumulation of stored food in them4 #b4 ,,the ,,early ,,stages ,,of ,,growth ,,of ,,seeds ,,with ,,two ,,cotyledons4 ,if the seeds which were sown in damp sawdust and on flannel are kept warm they will soon be ready for study4 ,you should remember that at present your object is not so much to rear the plants as to find out how they grow4 ,as soon1 therefore1 as any sign of growth is to be seen when you take a seed out1 you should begin to examine them at regular intervals1 taking one or two out every day and leaving the rest to continue their development4 ,keep the sawdust damp1 but not wet4 #a4 ,the pea and bean4--7a7 ,general development4--,very soon the seed-coat splits at the micropyle-end of the stalk-scar1 and the end of the radicle protrudes4 ,does the radicle grow upwards or downwards8 ,observe that even if the seed was so planted that the micropyle was at the top1 the radicle turns over and grows straight down4 ,turn over a seedling and see if you can persuade the radicle to grow upwards4 ,open a seed when the radicle is about an inch long1 and see what the plumule is doing4 ,it is still enclosed in the seed-coat1 and lies between the cotyledons1 but is larger than at first4 ,as the growth proceeds the cotyledons begin to separate near the top of the radicle1 and you can get a glimpse of the plumule4 7b7 ,the growth of the radicle4--,day by day the radicle becomes longer4 ,is it all growing longer1 or does the increase in length take place more at one part than another8 ,to answer this question1 take five or six inches of cotton thread and moisten the middle part with ,indian ink4 ,lay the seed on a flat ruler1 so that the radicle lies over an inch divided into--say--tenths4 ,hold the thread tight1 and press the inked part gently on the radicle1 making about five marks at equal intervals from the point upwards4 ,the ink will dry almost immediately4 ,then carefully replant the seed1 taking care not to injure the radicle4 ,after a few days take it out again1 lay it once more on the ruler1 and measure the distance between the marks4 ,the radicle is evidently the young root4 7c7 ,the root-cap4--,hold up the radicle to the light1 and examine its tip with a lens4 ,try to see that the tip is covered by a little cap1 somewhat like a very small thimble4 ,this is called the root-cap4 7d7 ,the root-hairs4--,hold a seed1 with the radicle about an inch long1 against a dark surface4 ,is the surface of the radicle smooth1 or can you see any fluffiness on it8 ,is all the radicle fluffy1 or only a part8 ,which part8 ,as you examine older and older seedlings notice how much of the radicle is fluffy1 and where the fluffy part is4 ,the fluffy appearance is caused by fine1 closely-set hairs1 called root-hairs4 7e7 ,the plumule4--,how soon after planting does the plumule become free8 ,does it grow upwards or downwards8 ,the plumule is evidently the young stem4 ,as soon as the young stem is old enough mark it with ,indian ink as you marked the young root1 and replant it to find if there is any difference in the rates of growth of its different parts4 7f7 ,the fate of the cotyledons4--,from time to time examine the cotyledons and notice that as the seedling grows larger they become more and more shrunken4 ,something is evidently being taken from them1 perhaps to feed the young plant4 ,we shall inquire into this by further experiment 7,chapter ,,ii474 ,do the cotyledons remain in their original position1 or are they carried upwards with the growing stem or downwards with the growing root8 #b4 ,the yellow lupine4--,in the same way observe how this seed grows4 ,do the cotyledons shift their position or change in colour8 ,do they become leaf-like8 ,how do they differ from later-formed leaves8 ,what becomes of them at last8 ,what becomes of the seed-coat8 #c4 ,the mustard seed4--,notice that1 soon after the radicle has come out of the seed-coat1 a sort of hump forms at its upper end1 and at length the cotyledons are pulled out of the seed-coat and turn up towards the light4 ,what is their colour8 ,observe that the two cotyledons are soon raised on the end of a little stalk4 ,like the cotyledons of the yellow lupine they are plainly leaves4 ,notice their shape4 ,are they of equal size8 ,why not8 ,when they are about three inches above the seed-coat gently separate them and notice the little bud between them4 ,draw the seedling4 ,how large can you get a mustard seedling to grow on damp flannel8 ,plant a few mustard seeds on earth1 and notice the difference between the shape of the cotyledons or seed-leaves and that of the leaves which appear later4 ,what becomes of the cotyledons8 #d4 ,the vegetable marrow seed4--,make similar observations upon the vegetable marrow seeds1 noticing particularly whether the cotyledons remain in their original positions and shrink up as the plant increases in size1 or whether they are pulled out of the seed-coat by the elongating stem1 and become green and leafy4 ,how does the plant hold down its seed-coat whilst it pulls out its cotyledons8 #e4 ,the sycamore seed4--,from what you have seen of the cotyledons of the sycamore seed1 will you expect them to behave like those of the mustard seed1 or like those of the pea and bean8 ,even in the seed they are green1 and plainly leaves4 ,how do they escape from the seed-coat8 ,what is their shape8 ,do they come out before or after the radicle8 ,do they get any larger as the stem grows8 ,how large can you get a sycamore seedling to grow in damp sawdust8 ,as large as a seedling of pea or bean8 ,plant some sycamore seeds on earth and compare the shape of the cotyledons with that of the next-formed leaves4 ,how soon do the 8true0 leaves appear after the cotyledons have escaped from the seed8 ,do any 8true0 leaves grow on the plants in sawdust8 ,what becomes of the cotyledons at last8 ,the embryo4--,the plumule1 radicle1 and cotyledons1 which have now been seen in the seed1 form the embryo of the plant4 ,the adult plant will be wholly formed by the growth and development of these parts1 and we must now follow carefully the changes which take place when the seed germinates1 and try to find out what becomes of each part4 ,it is better to put the seeds at first in damp sawdust rather than in earth1 as the young roots can then be more readily cleaned and observed4 ,with small seeds the early stages of growth are better seen if damp flannel is used4 ,germination4--,under the influence of moisture and warmth the embryo in the seed begins to swell and unfold its parts4 ,the radicle makes its appearance first 7,fig4 #e71 breaking through the seed-coat at the micropyle2 it is the young root4 ,the radicle always grows downwards1 that is1 toward the centre of the earth4 ,if the seed lies in such a position that the micropyle is directed upwards1 the point of the radicle turns over and grows downwards as soon as it escapes from the seed-coat4 ,as the young root becomes longer and thicker 7,fig4 #f7 the seed-coat opens more and more1 showing the cotyledons beneath1 and these1 too1 are gradually forced apart4 ,illustration3 ,,fig4 #e4--;,an early stage in the germination of a ,broad-,bean seed4 ,r1 radicle2 s4c41 seed-coat4 7 47 ,,fig4 #f4--;,a slightly later stage in the germination of a ,broad-,bean seed4 cot41 cotyledon2 pl1 plumule2 ,r1 radicle2 s4c41 seed-coat4 7 47 ,illustration3 ,,fig4 #g4--,mustard ,seedling1 showing root-hairs and cotyledons4 7 47 ,the cotyledons4--,during the germination of various seeds1 a very marked difference in the behaviour of the cotyledons is to be seen4 ,in the case of the broad bean and pea the cotyledons remain in their original positions1 partially enclosed by the split seed-coat4 ,presently a hump 7,figs4 #f and #aa7 forms at the upper end of the radicle1 as if the plant were making an effort to pull its plumule out of the seed4 ,it soon succeeds 7,fig4 #ab71 and the plumule turns up to the light4 ,it is the young stem4 ,at its end is a little bud1 formed by a number of small1 overlapping1 green leaves which surround the growing point4 ,henceforth the stem grows upwards1 that is in a direction precisely opposite to that of the root's growth4 ,both stem and root are attached to the cotyledons1 which gradually shrivel up as the stem and root become larger and larger4 ,when1 however1 the seed of the mustard1 or sycamore1 germinates the cotyledons behave very differently 7,figs4 #g and #h74 ,soon after the root has become well established the cotyledons come quite out of the seed-coat and unfold themselves4 ,instead of remaining on or under the surface of the ground they are carried upwards at the end of a stalk toward the light1 and for some time the little plant appears to consist of root1 stalk1 and cotyledons only4 ,if1 however1 the cotyledons are gently pressed apart1 a tiny bud is seen between them4 ,this evidently corresponds to the bud at the end of the stem of the bean or pea4 ,in the case of the lupine 7,fig4 #i7 or vegetable marrow 7,fig4 #aj7 the cotyledons appear to combine these two conditions4 ,they are swollen and contain stored food2 yet they come out of the seed-coat early1 become green1 and open out to the light4 ,they are evidently leaves1 though their shape differs from that of the later leaves4 ,illustration3 ,,fig4 #h4--,three stages in the growth of a ,sycamore ,seedling4 cot41 cotyledons2 fol41 first pair of foliage leaves4 7,slightly reduced47 ,the germinating vegetable-marrow seed possesses a curious contrivance for pulling its cotyledons out of the seed-coat4 ,this is a peg 7p1 ,fig4 #aj7 which develops at the top of the radicle1 and holds down the lower half of the seed-coat whilst the other half is forced upwards to allow the cotyledons to be withdrawn4 ,illustration3 ,,fig4 #i4--,three stages in the growth of the ,yellow ,lupine4 ,on the right the cotyledons are still enclosed in the mottled seed-coat4 ,in the middle plant the cotyledons are spreading out2 the first foliage leaves have not yet unfolded4 ,on the left1 the first two foliage leaves are unfolding1 and the cotyledons have spread out flat4 7,slightly reduced47 ,after a little thought a possible explanation of these differences in the cotyledons suggests itself4 ,it may be that1 in the case of the mustard and sycamore1 leaves are required as early as possible1 while the bean and pea have no immediate need for leaves because their cotyledons contain so much stored food4 ,the cotyledons of these plants shrivel up as the seedling grows1 and this seems to indicate that during its early stages the plant lives upon this food4 ,in ,chapter ,,ii4 we shall make experiments to see if this explanation is the true one4 ,if so1 the lupine and vegetable-marrow seeds evidently rely partly upon their stored food and partly upon setting the cotyledons to work as leaves1 whilst the plant is still very young4 ,illustration3 ,,fig4 #aj4--;,germinating ,vegetable ,marrow seed4 p1 the peg by which the seed-coat 7s4c47 is held down to allow the cotyledons 7cot47 to be withdrawn4 7 #a47 7,after ,bailey47 ,illustration3 ,,fig4 #aa4--;,a germinating ,pea2 cot1 cotyledon2 pl1 plumule2 ,r1 radicle2 r4h41 root-hairs2 ,s4c41 seed-coat4 ,the radicle has been marked with ,indian ink at intervals of _/04 ,the true leaves4--,the cotyledons are really makeshift leaves1 which are already formed in the seeds4 ,even when they expand and become green they do not live long1 but as soon as the next few leaves are well established1 shrivel up and wither4 ,the true or 8foliage0 leaves first make their appearance as a bud which surrounds the growing point of the stem4 ,as this part of the stem increases in length1 the foliage leaves become separated from each other and spread out to the light and air4 ,the lengthening of the stem and root4--,unless an experiment to test the truth of the matter is really made1 it might be supposed that the different parts of the stem and root of the seedling grow in length at the same rate4 ,this can be tested by marking the stem and root with lines of ,indian ink at equal distances4 ,in one experiment with a pea seedling five lines were marked upon the young root at regular intervals of one-tenth of an inch1 beginning at the tip 7,fig4 #aa74 ,the seedling was carefully replanted and examined again a few days later4 ,between the tip and the first mark there was then 7,fig4 #ab7 a distance of seven-tenths of an inch2 that is1 this part had grown to seven times its former length4 ,the second interval was four times as long as before1 the third was one and a half times as long1 while the fourth and fifth intervals had not increased in length at all4 ,such experiments prove that the root grows in length either at or just behind the tip4 ,when a young stem is treated in the same way the lengthening is found to take place more evenly4 ,illustration3 ,,fig4 #ab4--,the ,pea seedling of ,fig4 #aa1 a few days later4 cot1 cotyledons2 pl1 plumule2 ,r1 radicle2 ,s4c41 seed-coat4 7 #a47 ,illustration3 ,,fig4 #ac4--,the tip of a root1 showing the root-cap4 7,magnified47 ,rootlets4--,after a time the radicle begins to put out branches called rootlets4 ,these come off the main root in rows4 ,in some cases rootlets make their appearance whilst the radicle is still very short1 as in the vegetable marrow of ,fig4 #aj1 but in others the radicle may be a few inches long before it produces rootlets4 ,the root cap4--,the tip of the root1 and of each of its branches1 is covered by a little cap1 shaped somewhat like a thimble 7,fig4 #ac74 ,this protects the tender growing point from the friction of particles of soil1 and is continually renewed by growth from within as its outer layers are worn away4 ,root hairs4--,when a young root is held against a dark background it appears fluffy4 ,this appearance is caused by a large number of very fine hairs upon its surface4 ,the hairs are not found all over the root and its branches1 but only for a short distance a little way behind the tips 7,figs4 #g and #aa74 ,these root hairs are of very great importance to the plant1 as will be seen in ,chapter ,,ii4 #c4 ,,the ,,structure ,,of ,,grains ,,of ,,maize ,,and ,,wheat4 #a4 ,preparation of the seeds4--,soak grains of maize 7,indian corn7 and wheat in water until they are soft4 ,the grains of maize will need soaking for several days4 ,plant about a dozen of each in damp sawdust1 and in the meantime examine others4 #b4 ,the maize grain4--,a grain of maize is really a fruit1 as a pea-pod is4 ,a pea-pod contains several seeds2 a maize fruit contains only one seed1 which fills it4 ,notice the shape of the grain--flattened1 rounded along one edge1 and bluntly pointed at the opposite edge 7,fig4 #ad74 ,notice a whitish patch on one of the flattened sides2 a ridge 7,e7 down the middle of this marks the position of the embryo4 ,cut through the grain lengthwise1 so as to divide the embryo into two equal parts1 and examine the cut surface 7,fig4 #ae74 ,identify3 7a7 ,the embryo1 lying somewhat obliquely1 and to one side4 ,the radicle 7rad47 is directed towards the pointed end of the grain1 and the plumule 7pl47 towards the rounded end4 7b7 ,the endosperm 7end73 a mass of material outside the embryo1 and forming at least half of the grain4 7c7 ,the scutellum 7scm73 a plate lying between the endosperm and the embryo4 7d7 ,the coats of the seed and fruit1 surrounding the whole4 ,draw4 ,add a drop of iodine solution to the cut surface of the half-grain4 ,the endosperm turns blue4 ,what does this indicate8 #c4 ,the wheat grain4--,a grain of wheat is also a one-seeded fruit4 ,notice the groove along one side1 and--on the opposite side near one end--the white patch marking the position of the embryo4 ,at the other end is a tuft of very fine hairs4 ,cut the grain lengthwise1 so as to divide the white patch into two equal parts1 and make out the embryo1 endosperm1 and scutellum 7,fig4 #af74 ,draw4 ,test the endosperm with iodine solution4 ,does it contain starch8 ,grains of maize and wheat4--,a grain of maize or wheat is really a one-seeded fruit4 ,in other words1 the grain consists not only of the seed with its seed-coat1 but also of the seed-case4 ,in this respect it resembles the fruit of the sycamore 7p4 #h74 ,when1 however1 a grain of maize or wheat is carefully examined1 it is found to differ greatly from all the seeds hitherto mentioned4 ,a maize grain is somewhat flattened1 and rather pointed along one edge 7,fig4 #ad74 ,on one flat side1 near the pointed end1 may be seen a whitish patch1 and1 along the middle line of this1 a ridge which marks the position of the embryo4 ,illustration3 ,,fig4 #ad4--,maize grain1 showing the position of the embryo 7,e74 7 #d47 ,illustration3 ,,fig4 #ae4--;,a longitudinal section of a ,maize grain1 through the middle line of the embryo4 end1 endosperm2 pl1 plumule2 rad1 radicle2 rt1 origin of a root2 scm1 scutellum4 7 #d47 ,a wheat grain has a different shape4 ,it is oval1 with a deep groove running down one side4 ,one end is clothed with a tuft of very fine hairs2 near the other end1 on the side opposite to the groove1 is a white patch beneath which is the embryo4 ,these differences in shape are of small importance1 for the two grains are really of very similar structure1 as may be seen when they are cut through lengthwise with a sharp knife1 in a direction which divides the embryo along its middle line4 ,it is then plain that each grain consists of two principal parts3 the embryo and the endosperm 7,figs4 #ae and #af74 ,the embryo lies to one side and in the lower half of the seed4 ,at its upper end the young stem and at its lower end the young root--each still enclosed in protecting sheaths--are easily seen4 ,the greater part of the seed is quite outside the embryo2 it is a mass of food called the endosperm1 which has been stored up for the use of the young plant during its earliest stages of germination4 ,this food mass at once turns blue when a drop of iodine solution is placed upon it1 showing that it contains a considerable amount of starch4 ,it is the endosperm which is made into flour when corn is ground4 ,lying between the embryo and endosperm is a flat plate called the scutellum4 ,covering embryo1 scutellum1 and endosperm is the seed-coat proper1 and outside that come the various layers of the fruit case4 ,illustration3 ,,fig4 #af4--;,diagram of a longitudinal section through the middle line of a wheat grain4 ,in the seeds previously examined1 the embryo--consisting of plumule1 radicle1 and cotyledons--was seen to fill the seed-coat completely4 ,in some cases the cotyledons were found to be more or less swollen with stored food-material4 ,in the maize and wheat1 however1 the embryo forms only a comparatively small proportion of the seed1 the bulk of which consists of stored food called endosperm4 ,this is a difference of some importance4 ,still more important1 however1 is the fact that the two cotyledons1 which were so conspicuous a feature of the other seeds1 cannot apparently be seen at all in these seeds4 ,are there then no cotyledons in the seeds of the maize and wheat8 ,if there are1 how and when do they appear1 and what is their number8 #d4 ,,the ,,early ,,stages ,,of ,,growth ,,of ,,maize ,,and ,,wheat4 #a4 ,the roots4--,watch for the appearance of the roots4 ,is there1 as in the seedlings previously studied1 one principal root1 or are there soon several1 all apparently of equal or nearly equal importance8 ,do the roots grow straight down as before1 or do they spread horizontally8 #b4 ,the stem and the cotyledon4--,notice that a rod1 somewhat thicker than a root1 grows out near the origin of the roots1 and curves upwards towards the light4 ,when this is about an inch long on a maize seedling1 slit it open carefully1 and observe that it consists of a pale outer sheath and a green core4 ,the sheath is the single cotyledon2 the green core is the young stem enclosed in a young foliage leaf4 ,cut open the grain and notice how the endosperm has shrivelled4 ,as the seedlings become larger watch the young stem growing out at the end of its sheathing cotyledon4 ,what is the length of the cotyledon when the stem first appears 7a7 in the maize1 7b7 in the wheat8 #c4 ,the foliage leaves4--,as soon as a foliage leaf unfolds make a drawing of its shape4 ,contrast it with the young foliage leaves of the other seedlings4 ,hold up the leaves to the light and compare the arrangement of their veins4 ,how maize and wheat seeds grow4--,when the maize and wheat fruits have been kept in damp sawdust for a few days1 the seeds--one in each fruit--begin to germinate4 ,as a rule the wheat plants have grown to a height of some inches before the roots and stems of the maize plant have emerged from the seeds4 ,the roots4--,as might be expected1 the first signs of life make their appearance at the white scar which indicates the position of the embryo or young plant4 ,instead of one main root growing out1 several little roots make their appearance almost at the same time4 ,they do not grow as directly downwards as the radicle of a pea or bean 7,fig4 #f71 but tend to spread in a horizontal direction 7,fig4 #ag74 ,it is clear that in this way the roots are more independent of each other than if they grew directly downward side by side4 ,the cotyledon and the stem4--,growing out from the seed close to the roots is another rod 7,fig4 #ag1 ,c71 rather thicker than the roots1 which at once curves upwards to the light4 ,it is pale green in colour4 ,this is the cotyledon or first leaf4 ,when it is carefully slit open1 it is found to be a hollow sheath1 enclosing a bright green core4 ,in the seedlings which are left undisturbed1 the core at last breaks through the tip of the cotyledon4 ,it consists of the young stem and its surrounding foliage leaves4 ,as the growth of the plant continues1 these sheathing leaves unfold themselves into the long narrow blades characteristic of grass leaves 7,fig4 #ih74 ,the bottom of each leaf is tubular and forms a sheath round the stem4 ,illustration3 ,,fig4 #ag4--,young wheat seedling4 ,c1 cotyledon2 r1 r1 r1 r1 roots4 7 #c47 ,the endosperm4--,the endosperm1 which at first made up more than half the seed1 gradually shrivels up as the little plant continues its growth4 ,the food material which it contains is absorbed by the scutellum and is passed on to afford the plant the necessary nourishment for those early stages when it is too young to feed itself4 ,by the time the first few foliage leaves are well developed1 all that remains of the grain is an empty husk4 ,comparisons and contrasts4--,the examination of these seeds and seedlings will enable the student to see that differences1 which at the first glance appear great1 are often of only minor importance2 while apparently small variations may prove1 on closer inspection1 to be caused by deeply-seated differences of structure and habits of life4 ,he should always set himself the questions1 8,in what ways do such and such objects resemble each other2 and in what ways do they differ from each other8 ,which of the differences and resemblances are of most importance80 ,he should also notice that a mere difference of size is often of very small consequence4 ,above all1 the student should get into the habit of asking the reasons for the differences and resemblances which he notices in his nature-study4 ,to learn what these reasons are he must observe closely1 think carefully1 and then make experiments to test the accuracy of his conclusions4 8,be sure you are right2 then look again0#d should be his motto4 ,it is at once plain that the seedlings fall into two classes1 according to the number of cotyledons or seed-leaves which they possess4 ,the wheat and maize have only one such seed-leaf1 while the mustard1 bean1 pea1 sycamore1 and vegetable marrow have two each4 ,we shall see later on that one-seed-leaved plants differ from those with two seed-leaves not only in the number of their cotyledons1 but also in the characters of their leaves and flowers and in their method of growth4 ,these differences are so constant and so important that botanists have agreed to call all plants of the first class 7such as maize and wheat7 ,monocotyledons1 and plants of the second class ,dicotyledons4 ,one of these differences is that the main roots of dicotyledons are formed directly by the growth of their radicles2 while in monocotyledons there is1 after a short time1 no such main root to be found1 but several roots of almost equal size spring from the base of the stem and spread outwards in all directions 7,fig4 #ag74 ,both maize and wheat seeds contain--outside the embryo--a large store of food called endosperm 7,figs4 #ae and #af71 which is not seen in any of the dicotyledonous seeds described in this chapter4 ,this is not a very important difference1 for1 if we examined a very large number of dicotyledon seeds1 we should find that most of them possessed endosperm4 ,on the other hand1 many monocotyledonous seeds are destitute of endosperm4 ,only after observing a very large number of facts is it safe to make general statements4 ,confining our attention to dicotyledons1 we are impressed by the great variation in size of the cotyledons4 ,those of the bean and pea are swollen with food material and form a large proportion of the bulk of the seed4 ,as a consequence1 the seedling has enough food to enable it to grow into quite a sturdy little plant before it needs any foliage leaves4 ,the cotyledons of the mustard and sycamore1 however1 are thin1 and they unfold almost immediately into green leaves1 and set to work to help to maintain the plant until the first foliage leaves can be formed4 ,the cotyledons of the lupine 7,fig4 #i7 and vegetable marrow 7,fig4 #aj7 serve a double purpose4 ,they not only contain a store of food ready to hand1 but they also set to work early to make new food1 until the new leaves are sufficiently advanced to take up their duties4 ,it should be remembered that cotyledons are makeshift leaves4 ,,exercises ,,on ,,chapter ,i4 #a4 ,make a collection of the seeds of various trees2 try to find1 in each seed1 the cotyledons1 radicle1 and plumule4 ,which of the seeds contain stored starch8 #b4 ,soak pine and larch seeds in water for several days and then sow them1 with a covering of half an inch of soil4 ,make notes of the number1 shape1 size1 and behaviour of the cotyledons4 ,how large are the seedlings at the end of the first season8 #c4 ,make similar observations on the growth of sycamore1 ash1 and beech4 ,cover the seeds with an inch of soil4 #d4 ,plant seeds of oak and chestnut two inches deep1 and make drawings and notes of the stages of growth4 #e4 ,investigate the structure and method of germination of a barley seed1 and find out whether barley is a dicotyledon or a monocotyledon4 #f4 ,make experiments to discover the effects1 upon the germination of various seeds1 of differences of temperature1 moisture1 and light1 and write full accounts of the results obtained4 #g4 ,draw from memory a young seedling of maize1 and notice its chief peculiarities4 7#ahih7 #h4 ,draw the seedling of the sycamore in two or more stages1 and add short notes4 7#ahih7 #i4 ,draw the root of any seedling that you have studied1 giving its name4 ,mark the exact position of the root-hairs4 7#ahih7 #aj4 ,open the nut provided4 ,draw what is to be found in it in one or two positions4 ,name the parts and give short explanations4 7#aija7 #aa4 ,explain1 with drawings1 how certain seedlings withdraw their seed-leaves from the seed-coat4 7#aija7 #ab4 ,describe and explain as far as you can the principal changes to be observed during the germination of a bean or pea4 7#aija7 #ac4 ,describe the germination of a bean1 and compare it with that of a grain of wheat4 7#ahih7 #ad4 ,describe the structure of a grain of wheat1 and contrast it with that of an acorn4 7#ahif7 #ae4 ,plant seeds in wet1 sticky soil 7so that the air cannot easily get to them71 and compare their growth with that of similar seeds in a light1 open soil4 #af4 ,two acorns are allowed to germinate1 one in the neck of a bottle full of water1 and the other in an ordinary flower pot4 ,what differences will be noted in the two plants as they grow8 7,certificate1 #aijd7 ,,footnotes3 #a ,if any difficulty is found in procuring plant-specimens1 they may be obtained by post from the ,british ,botanical ,association1 ,ltd41 ,holgate1 ,york4 ,the names of dealers prepared to supply various animal-specimens are mentioned in the text4 #b ,made by dissolving one or two crystals of potassium iodide in about half a pint of water1 and then adding iodine in small quantities until the solution is the colour of sherry4 #c ,lord ,avebury1 ,the ,pleasures of ,life 7,macmillan74 #d ,prof4 ,comstock4 ,,chapter ,,ii4 ,,how ,a ,,green ,,plant ,,feeds4 #e4 ,,the ,,food ,,which ,a ,,green ,,plant ,,obtains ,,from ,,the ,,soil4 #a4 ,a plant cannot grow permanently in damp sawdust or clean sand4--,notice that the seedlings which were grown in damp sawdust presently wither and die1 while those which were grown in soil flourish1 and1 with proper care1 come to maturity4 ,obtain some clean sand1 and1 to be sure that there is nothing in it which water can dissolve1 wash the sand in several changes of clean water4 ,germinate some seeds in the sand1 keeping it damp4 ,the resulting plants in this case also wither and die4 ,evidently soil contains some plant-food which the plant cannot obtain from sawdust or clean sand4 ,what is this food8 ,illustration3 ,,fig4 #ah4--,porcelain crucible heated by ,bunsen burner4 #b4 ,the amount of water and mineral matter in plants4--,take a healthy plant1 say a bean plant1 and weigh it4 ,then dry it thoroughly in the oven and weigh it again4 ,it will be found very much lighter2 the difference in weight represents the water which has been driven off4 ,burn the dried plant4 ,when the flame goes out notice the black charcoal which is obtained4 ,continue the heating and observe that at last nothing is left but a little grey ash4 ,this experiment can be performed over an ordinary fire by using an old shovel or a tile1 but if you can use a porcelain crucible 7without lid7 and a ,bunsen burner 7,fig4 #ah7 you will get better results4 ,if a chemical balance is available1 weigh the ash and compare it with the weight of ash obtained from an ordinary bean seed1 such as that which gave rise to the plant you have used4 ,the ash from the plant is much greater than that got from the seed4 ,this extra ash must have been taken from the soil during the plant's growth4 #c4 ,a nutritive solution4--,make1 or ask a dispensing chemist to make1 the following solution3 ,potassium nitrate 7consists of potassium1 nitrogen1 and oxygen71 #a gram4 ,sodium chloride 7consists of sodium and chlorine71 0 ,calcium sulphate 7consists of calcium1 sulphur1 and oxygen71 0 ,magnesium sulphate 7consists of magnesium1 sulphur1 and oxygen71 0 ,calcium phosphate 7consists of calcium1 phosphorus1 and oxygen71 0 ,water1 #a litre4 7,a few drops of a dilute solution of sulphate1 or chloride1 of iron should be added47 ,water1 with this solution1 a plant growing in wet sand1 and when it is well grown1 dry and burn it4 ,as much ash is obtained as from a plant of the same size grown in soil4 ,notice the difference between such a plant and one which has had water only supplied to it4 #d4 ,water culture4--,fix two similar young plants in corks as shown in ,fig4 #ai1 and put the corks into two bottles1 the first of which contains pure water and the second the nutritive solution1 and let the roots of the seedlings dip into the liquids4 ,cover the outsides of the bottles with rolls of paper to keep out the light4 ,notice that the plant living in the nutritive solution thrives1 while the other presently withers4 ,dry and burn the former1 and observe that it yields more ash than does a seed such as that from which it sprang4 #e4 ,plants obtain their mineral food from the soil by their roots4--,as the roots are the only parts of the plant which are in contact with the nutritive solution1 or which 7under ordinary conditions7 are in the soil1 the mineral matter must be taken in by the roots4 #f4 ,the root-hairs4--,take up a seedling which has been growing in damp sand1 and observe the small particles of sand adhering to the root-hairs 7p4 #ag74 ,the hairs of a plant's root and rootlets apply themselves very closely to particles of soil 7,fig4 #bj71 and the mineral food 7dissolved in water7 passes into the hairs and so gets into the root and thence to the other parts of the plant4 #g4 ,roots as storehouses of food4--,examine1 before the plants flower1 the roots of a turnip1 a carrot1 and a radish1 and notice how greatly they are swollen4 ,you know that these roots are valued as foods2 of what use do you think the stored food is to the plants themselves8 ,the food of a young seedling4--,when such a seed as that of a bean is germinated in damp sawdust or wet clean sand1 and kept in a warm and light place1 it puts out a radicle1 which grows downwards and becomes the main root1 and a stem which grows upwards and bears green leaves4 ,after a time the main root branches1 giving off side roots1 which spread in all directions through the sawdust or sand4 ,the main root and the rootlets bear very fine fluffy hairs for a short length1 which is situated just behind their points 7,fig4 #aa71 and these root hairs come into very close contact with particles of damp sawdust or sand 7,fig4 #bj71 the moisture passing into them and thus reaching the main root1 from which it is distributed to the various parts of the plant4 ,the stem likewise flourishes1 growing in length and thickness1 and putting out new leaves4 ,all this time the young bean plant is living on the food material stored up in its cotyledons 7p4 #f72 and if the sand or sawdust is kept moist1 with even pure water1 this seed food is at first quite sufficient4 ,when at last the seed food is all used up1 however1 and all that remains of the cotyledons is a shrivelled skin1 the plant begins to droop and wither from lack of food4 ,plants obtain food from the soil4--,contrast this with the condition of a seedling which has been grown in soil4 ,it still flourishes1 even when the seed food is used up1 for it is drawing up food from the soil--food which could not be obtained from the damp sawdust or clean sand4 ,that the plant really has taken up some solid matter from the soil can be proved by a few simple experiments4 ,a plant which has been growing in soil for some time after its seed food is used up is dried and burnt1 and the ashes are weighed4 ,the weight of ash or mineral matter thus obtained is found to be considerably greater than that of the ash obtained from an ungerminated seed1 or from a seedling grown in damp sawdust or sand which has only been supplied with pure water4 ,the mineral food of plants4--,the composition of the ash obtained from various plants has been carefully determined by chemists1 and in this manner they have been able to find out what substances must be present in soil in order that the plant may obtain all the mineral food it requires4 ,a mixture of potassium nitrate 7nitre71 sodium chloride 7common salt71 calcium sulphate 7plaster of ,paris71 magnesium sulphate 7,epsom salts71 calcium phosphate1 and chloride 7or sulphate7 of iron--dissolved in water in the proportions specified on p4 #bg--;has been found to supply the necessary elements of the mineral food in a form which the plant can readily use4 ,that such a mixture is capable of supporting the plant1 while water alone is incapable of doing so1 may be seen by growing a plant--in the manner shown in ,fig4 #ai--;in this solution4 ,if1 in addition1 the plant is supplied with light and fresh air1 it will grow in a perfectly healthy and normal manner4 ,if any of the constituents 7except the common salt7 are omitted1 the plant will suffer4 ,on the other hand1 a plant which is growing in pure water will presently die1 from the lack of the necessary mineral food4 ,illustration3 ,,fig4 #ai4--,plant growing in a nutritive solution of salts4 ,the bottle should be covered with a roll of paper to keep out the light4 ,the work of the roots4--,these experiments show that water--of which a large proportion of a plant consists--and the mineral constituents of its food 7dissolved in the soil-water7 are taken up from the soil by the roots4 ,in ordinary soil the rootlets spread out on all sides1 dividing and subdividing1 seeking for this very weak solution of mineral salts4 ,even when soil appears practically dry1 a very thin film of moisture covers each little particle of earth1 and the root hairs become closely applied to these little particles 7,fig4 #bj71 so that the water passes through their walls and gradually makes its way to the main root1 the stem1 and the leaves4 ,illustration3 ,,fig4 #bj4--,tip of a root hair with adhering particles of soil4 7 #bdj47 ,roots sometimes perform other duties in addition to those of fixing the plant in the soil and providing it with water and mineral food4 ,it is usual1 for example1 for biennial plants--which produce flowers and seeds in their second year1 and then die--to take in much more food during their first season than they require at the time1 and to store up the surplus in readiness for the great effort of the second year4 ,these reserve materials are often stored in the roots1 which then become swollen and fleshy1 like those of the turnip1 radish1 and carrot4 #f4 ,,the ,,food ,,which ,a ,,green ,,plant ,,obtains ,,from ,,the ,,air4 #a4 ,plants contain much carbon4--,char a stick1 and notice the black charcoal which is formed4 ,charcoal is an impure form of carbon4 #b4 ,carbon dioxide gas is formed when wood burns4--,fasten a shaving or a splinter of wood on a piece of wire1 light it1 and lower it into a clean glass jar4 ,when the wood has burned for a few seconds take it out1 and pour a little clear lime-water into the jar4 ,the lime-water turns milky4 ,similarly1 pour a little lime-water into a jar in which nothing has been burning1 and notice that it remains clear4 ,there is evidently a difference in the nature of the air of the two jars4 ,the difference is caused by the burning of the wood1 during which some of the carbon unites with the oxygen of the air in the jar1 forming an invisible gas1 called carbon dioxide4 ,carbon dioxide can always be detected by the milkiness it causes in clear lime-water4 #c4 ,carbon dioxide present in ordinary air4--,pour some clear lime-water into a blue saucer and let it stand exposed to the air for half an hour1 then examine it4 ,a white scum has formed on the surface of the lime-water4 ,stir with a glass rod2 the solution becomes milky4 ,the scum and the milkiness are produced by the union of the lime with carbon dioxide from the air4 ,carbon 7in the form of carbon dioxide7 is therefore present in the air4 #d4 ,no carbon in the food solution4--,examine again the list of elements 7p4 #bg71 which compose the mineral salts which have been found to replace satisfactorily the food which a plant obtains from the soil4 ,there is no carbon in it4 ,a plant evidently does not depend on the soil for the carbonaceous part of its food4 ,from what other source can a plant obtain its carbon8 ,carbon has just been proved to be present in the air4 ,does the plant obtain its carbon from the air8 #e4 ,green leaves contain starch after exposure to sunlight4--,take a green leaf from a plant which has been exposed to the sunlight1 boil the leaf in water for a minute or two to kill it4 ,then put it in methylated spirit until the leaf-green is dissolved out4 ,when the leaf is bleached rinse it in water1 then put it into a dilute solution of iodine 7p4 #b7 and notice that it becomes blue or purplish brown4 ,the formation of this colour proves the presence of starch in the leaf4 #f4 ,starch contains carbon4--,char a piece of laundry starch and observe the charcoal formed4 #g4 ,green leaves do not contain starch after being left in the dark for #bd hours4--,keep a leafy plant in the dark for #bd hours and then test a leaf as in the previous experiment4 ,no starch can be detected4 ,put the plant in the sunlight for an hour or two and test another leaf4 ,it contains starch4 ,plainly1 starch is only formed in leaves if they are exposed to light1 and any starch previously present disappears when the plant is kept in the dark4 #h4 ,a green plant kept in air from which the carbon dioxide has been removed will not form starch in its leaves4--,obtain a large glass bottle1 such as those used by confectioners1 and fit it with a cork or india-rubber stopper through which passes a glass tube bent#e as in ,fig4 #ba4 ,care should be taken to make all the joints tight1 and it may be necessary to soak the cork in melted paraffin to ensure this4 ,pack the bend of the tube loosely with pieces of soda lime1 and in the bottle place a small jar containing lumps or a strong solution of caustic soda4 ,when the apparatus is ready1 place in the bottle a small plant or a leafy twig in water 7fuchsia answers very well71 which has been kept in the dark for #bd hours4 ,the caustic soda in the jar very soon absorbs all the carbon dioxide which is present1 and the soda lime in the bend of the tube prevents any carbon dioxide from getting into the bottle from the outside air4 ,place the jar in bright sunlight for a few hours and then test a leaf for starch4 ,none can be detected4 ,it is plain that one of the carbonaceous food stuffs--starch--is not formed in the leaves of plants unless the plant is grown 7in the light7 in air containing carbon dioxide4 #i4 ,seedlings are at first independent of light4--,germinate pea or bean seeds in wet sand or sawdust in the dark4 ,notice that for some time the seedlings grow almost as well as when in the light4 ,soon1 however1 the stem becomes long1 weak and straggling1 and the leaves are pale in colour1 even if the plant is supplied with mineral food4 #aj4 ,the formation of sugar in a germinating pea-seed4--,take up a pea-seedling when the stem is one or two inches long1 and chew the partly shrunken cotyledons4 ,notice the slightly sweet taste4 ,contrast this with the taste of an ungerminated seed4 ,a plant contains much carbon4--,when a piece of wood or other part of a plant is strongly heated it first blackens or chars1 showing the presence of a large proportion of charcoal or impure carbon4 ,on continued heating1 this carbon 8burns away40 ,in the process of burning it unites with some of the oxygen of the air1 and forms a colourless1 invisible gas known as carbon dioxide4 ,though this substance cannot be seen1 its presence can be easily detected by means of clear lime-water1 which1 when exposed to the gas1 absorbs it and becomes milky owing to the formation of a white precipitate of chalk4 ,if1 for example1 a splinter of wood is burnt in a glass jar1 and a little clear lime-water is immediately afterwards poured into the jar and shaken up1 a milkiness at once proclaims the presence of carbon dioxide4 ,the air contains carbon4--,if lime-water is poured into a blue saucer and left exposed to the air for half an hour1 a white scum of chalk is seen to have formed on its surface1 showing that carbon dioxide is present in the atmosphere4 ,it is important that the student should realise this presence of carbon--as invisible carbon dioxide gas--in the air4 ,although the proportion is very small1 amounting to only #c parts of carbon dioxide in #aj1jjj parts of fresh country air1 it is of incalculable importance to plants1 and indirectly to ourselves and all other animals4 ,a green plant obtains its carbon from the air4--,since the parts of a plant contain much carbon1 and the food which a plant obtains from the soil need not contain any carbon2 while the air1 on the other hand1 does contain carbon1 it seems likely that a plant obtains its carbonaceous food from the air4 ,this surmise is confirmed by experiments4 ,one of the most easily recognisable of plant products containing carbon is starch1 for it yields a very characteristic blue1 or purplish-brown1 colour when treated with iodine solution4 ,by means of this test starch can easily be proved to be present in the green leaves of a plant which has been exposed to the air and sunlight4 ,the leaf is first killed by being boiled in water for a minute or two1 and then its green colouring matter is dissolved out by immersion in alcohol 7methylated spirit74 ,the bleached leaf is rinsed in water and then put in iodine solution1 and the blue or purplish-brown colour which is formed shows the presence of starch4 ,there is a marked difference when a leaf1 which has been kept in the dark for twenty-four hours1 is similarly tested4 ,in this case no starch can be detected4 ,one compound of carbon--i4e4 starch--may thus be recognised easily2 and if we found that a leaf made no starch when supplied only with air from which the carbon dioxide had been removed1 this fact would be strong evidence in favour of the conclusion that a green plant obtains its carbon from the carbon dioxide of the air4 ,to test this1 a large bottle is fitted1 by means of a tightly fitting cork or stopper1 with a tube containing lumps of soda lime1 a substance which eagerly absorbs carbon dioxide from air4 ,a small jar of caustic soda is placed inside the bottle 7,fig4 #ba74 ,a green plant or a leafy twig1 which has been kept for twenty-four hours in the dark to free it from starch1 is then put in the bottle1 and the whole exposed to sunlight for a few hours4 ,at the end of this time it is found1 on testing the leaves1 that no starch has been formed4 ,by this1 and other experiments1 botanists have proved that green plants obtain all their carbon from the carbon dioxide of the air1 and that sunlight is indispensable for the process4 ,we shall examine this question more fully when we study leaves 7,chapter ,,iii474 ,illustration3 ,,fig4 #ba4--;,experiment to prove that leaves do not make starch unless the air with which they are supplied contains carbon dioxide4 ,s1 tube containing lumps of soda lime2 ,s1 jar containing a solution of caustic soda4 ,the carbonaceous food of a young seedling4--,just as a bean or pea seedling is for a time independent of an outside supply of mineral food--its roots needing only to be supplied with water--so there is enough carbonaceous food also stored up in the seed to satisfy for some time the needs of the growing plant--the stored starch being gradually changed into sugar and absorbed4 ,for this reason a young seedling will live healthily in the dark4 ,when1 however1 the seed food is exhausted1 or nearly so1 the plant draws upon the store of carbon1 which is present as carbon dioxide in the air1 for a renewal of the starch and allied substances which are necessary to it4 ,as it cannot make use of this atmospheric carbon in the dark1 it must henceforth be supplied with sunlight or it will not thrive4 ,plants kept in the dark after their seed-food is exhausted are pale in colour and unhealthy4 ,their stems grow long and straggling 7,fig4 #bb71 but are usually too weak to stand upright4 ,,exercises ,,on ,,chapter ,,ii4 #a4 ,make experiments to discover the effects1 upon seedlings growing in a nutritive solution 7p4 #bg71 of each of the following modifications in the composition of the solution3 7a7 omit the sodium chloride2 7b7 omit the potassium nitrate2 7c7 omit the compound of iron2 7d7 omit the magnesium sulphate2 7e7 substitute sodium nitrate for potassium nitrate4 #b4 ,explain how it is that a green plant cannot carry on its nutrition in darkness4 7#ahib7 #c4 ,what part of its food does a green plant obtain from the air8 ,in what form1 and under what conditions1 is it taken in8 7#ahhi7 #d4 ,describe the method of water cultures1 and give the general results of a set of experiments4 7#ahih7 #e4 ,give experimental proof that green plants require to be fed with combined nitrogen4 7#ahig7 #f4 ,what are the necessary conditions for the formation of starch in a plant8 ,mention experiments which support your statements4 7#ahif7 #g4 ,explain the influence of light on a growing plant4 ,illustrate your answer by reference to the changes in a ripening and germinating bean4 7,king's ,schol4 #aijc7 #h4 ,how can it be proved experimentally that a green plant draws some1 but not the whole1 of its nourishment from the air8 7#aijd7 ,illustration3 ,,fig4 #bb4--,two mustard seedlings of equal age4 ,e1 grown in the dark2 ,n1 grown in ordinary daylight4 ,,footnote3 #e ,cheap glass tubing can easily be made soft enough to bend by heating it in an ordinary batswing gas burner4 ,,chapter ,,iii4 ,,the ,,forms ,,and ,,duties ,,of ,,leaves4 #g4 ,,the ,,forms ,,of ,,leaves4 #a4 ,the shapes4--,make a collection of the leaves of a large number of different plants1 for example1 elm1 beech1 lime1 oak1 birch1 ash1 blackberry1 pine1 yew1 horse chestnut1 rose1 holly1 woodsorrel1 grass4 ,lay each in turn flat in your notebook and trace the shape of the leaf blade by passing the point of your pencil round the edge4 ,measure the length and greatest width2 write down these dimensions4 ,is the greatest width at1 above1 or below1 the middle of the leaf blade8 ,most of the leaves are flattened green plates4 ,those of the pine and yew are long and needle-shaped4 ,do you know any other leaves like these8 #b4 ,the veins4--,what enables the leaf to keep stretched out8 ,turn it over and notice the 8veins0 on the lower side4 ,do they act like the ribs of an umbrella8 ,fill in the positions of the main veins in your drawings4 ,are the veins parallel to each other in any of your leaves8 ,write a list of as many leaves as you can find which have parallel veins4 #c4 ,skeleton leaves4--,put some leaves in a saucer with a little soft water1 and allow them to rot4 ,clean away the soft stuff from time to time by gently brushing the leaves with an old tooth-brush4 ,notice the 8skeleton0 which remains4 ,skeleton leaves may be made much more quickly by soaking the leaves for some time in a weak solution of bleaching powder4 ,wash them well before drying4 #d4 ,the colour4--,is the green deeper on the upper or the lower surface of a leaf8 ,which surface usually receives more light8 #e4 ,the apex4--,in how many of your leaves is the apex 7a7 pointed1 7b7 blunt1 7c7 rounded8 #f4 ,the margin4--,examine the edge or margin of each leaf4 ,in how many is it 7a7 quite plain1 7b7 hairy1 7c7 wavy1 7d7 saw-edged1 7e7 doubly saw-edged1 7f7 spiny8 ,do you find spines on holly leaves which are so high on the tree as to be out of the reach of cattle8 ,what is the use of the spines8 #g4 ,blackberry leaves4--,gather several leaves from a blackberry bush4 ,notice that in addition to the 8saw cuts10 the margins of some are cut into slightly1 while others are divided quite to the midrib1 the leaf being thus cut into two or more leaflets4 ,select specimens which form a gradual series between the 8simple0 leaf and the 8compound0 leaf 7consisting of three or five leaflets7 and draw them4 #h4 ,the horse chestnut leaf4--,draw the compound leaf of the horse chestnut1 and draw an even curved line joining the points of the leaflets4 ,you can imagine that the compound leaf may have been formed by a leaf of this shape being cut into until it was divided into seven complete leaflets4 #i4 ,the rose leaf4--,draw an imaginary simple leaf such as may have been the original form from which the compound leaf of the rose was derived4 ,notice the difference in the arrangement of the main veins of the leaves of the horse chestnut and the rose4 ,does this account for the leaflets coming off at the sides of the midrib in the rose leaf1 and springing from one point1 like fingers from the palm of the hand1 in the case of the horse chestnut8 #aj4 ,sycamore and ivy leaves4--,if the large indentations in these leaves were continued to the midrib1 would the compound leaves thus formed be of the type of the rose leaf or of that of the horse chestnut leaf8 #aa4 ,the leaf-stalk4--,what attaches the leaf-blade to the stem or branch of the plant8 ,can you see signs of the main veins joining the top of the leaf-stalk8 ,do you know any plant with the blades of the leaves fixed directly on the stem1 i4e4 without any leaf-stalks8 #ab4 ,stipules4--,examine the rose leaf again and notice the two leaf-like outgrowths at the bottom of the stalk4 ,these are called stipules4 ,make a list of as many leaves as you can find which have stipules4 ,how many leaves can you find with a sheath at the bottom of the stalk8 #ac4 ,the leaf of the sweet pea4--,notice the large stipules of this compound leaf 7,fig4 #bh74 ,what are the tendrils8 ,do you think they may be mainly the larger veins of the upper leaflets8 ,is the leaf of the type of the rose or of the horse chestnut leaf8 #ad4 ,other compound leaves4--,compare and contrast ash1 lupine1 woodsorrel1 strawberry1 and other compound leaves with those of the rose and horse chestnut4 ,a leaf4--,the leaves of different plants vary much in size and shape1 but in general a leaf is a thin1 broad1 and more or less oval blade of green colour1 attached by a leaf stalk to the stem or branch4 ,in some cases1 however1 the leaf stalk is absent and the blade is attached directly to the stem or branch4 ,the veins4--,the leaf is kept taut by a number of branching ribs1 somewhat as the silk of an opened umbrella is stretched tightly by the ribs4 ,the ribs or 8veins0 of the leaf run beneath the skin1 but are generally nearer the lower surface than the upper1 and are easily seen when the leaf is turned over4 ,if a leaf is allowed to rot in a little soft water1 the skin and the soft green stuff of the interior decay and leave these veins as a white 8skeleton0 7,fig4 #bc74 ,the process may be assisted by gently brushing the leaf from time to time4 ,a skeleton leaf may be obtained still more quickly by putting the leaf in a weak solution of bleaching powder until the skin and interior are soft enough to be brushed away4 ,care should be taken to use a weak solution1 or the veins also will be rotted4 ,the skeleton should be well washed in water before drying4 ,the arrangement of the veins in a leaf varies widely1 but it falls broadly into two classes1 according as the main veins run parallel or nearly parallel to each other 7,fig4 #bd71 or form a less regular network 7,fig4 #bc74 ,the venation of a leaf is curiously associated with the number of cotyledons possessed by the seedling2 for nearly all dicotyledons 7p4 #bc7 have net-veined leaves1 while the leaves of monocotyledons are almost invariably parallel-veined4 ,careful drawings of several typical leaves should be made1 and the principal veins indicated on them4 ,illustration3 ,,fig4 #bc4--,net-veined leaf of a dicotyledon 7,white ,thorn74 7 7 ,illustration3 ,,fig4 #bd4--,parallel venation of the leaf of a monocotyledon 7,solomon's ,seal74 7 #a7 ,the shapes of leaves4--,although the blade of a leaf is most commonly flattened1 and roughly oval in outline1 there are several exceptions4 ,the leaves of pine1 spruce1 larch1 and yew are needle-shaped2 those of grasses 7,figs4 #ajb-aaj7 are very long in proportion to their width2 while the leaves of many moorland plants are rolled up into hollow cylinders4 ,there is some reason--could we find it--for every such variation1 and the significance of some of these shapes will be referred to later 7p4 #dg74 ,when the dimensions of leaves are carefully measured1 the proportion of the length to the width will be found to vary much in the leaves of different plants1 but will be found to be pretty constant for the same sort of plant4 ,this holds good1 too1 for the position of the greatest width 7e4g4 at1 above1 or below1 the middle of the blade71 the form of the apex of the blade 7blunt1 pointed1 spiny1 or rounded71 the nature of the margin 7smooth and 8entire10 hairy1 saw-edged1 doubly saw-edged1 lobed1 etc471 and the extent and positions of the larger indentations4 ,thus1 while any particular elm leaf 7,fig4 #abd7 is probably slightly different from every other elm leaf in the world1 it resembles every other elm leaf more than it does any leaf from any other plant than an elm4 ,no leaf of this shape ever grows on an oak tree or a sycamore4 ,thus1 in spite of minor variations there is a wonderful conformity to type1 and the student will find that by carefully examining the shape1 venation1 margin1 apex1 etc41 of all his leaves1 and above all by drawing them1 he will soon be able to recognise them at sight4 ,it is by doing this and noticing in each case the methods of folding and arrangement of young leaves in the bud that it may be possible in the future to explain some variations which are at present not understood4 ,it has already been seen that the peculiar forms of the leaves known as cotyledons are associated to some extent with the shape and size of the seeds containing them1 and with the amount1 if any1 of the food stored in them4 ,simple and compound leaves4--,blackberry leaves 7,fig4 #gf7 well repay close examination4 ,some of the leaves on the bush will be found to be simple--having one blade only on the leaf stalk4 ,here and there1 however1 a leaf may be discovered which is so deeply cut into along one side1 that it is almost completely divided into two leaflets2 and other leaves will easily be found which consist of three or five leaflets1 much resembling the leaves of the rose 7,fig4 #be71 a near relative of the blackberry4 ,here1 then1 we have a plant which produces simple or compound leaves according to its needs4 ,it seems as if the blackberry were still trying1 as an experiment1 a device which the rose tree has found so advantageous as to have adopted for good4 ,some other plants1 the ash1 for example1 have compound leaves broadly similar to the rose leaf--the leaflets springing in pairs from the sides of the midrib4 ,the compound leaf of the horse chestnut 7,fig4 #bf7 is of a different type1 for the seven leaflets all arise from one point2 and the leaves of the lupine 7,fig4 #i7 are arranged on the same plan4 ,when the venation is examined1 the reason for this becomes plain4 ,in these cases the main veins all diverge from the top of the leaf stalk2 whereas in the rose and ash the midrib gives rise to side ribs in pairs4 ,the leaflets are naturally arranged so that one of the larger veins shall support each4 ,the next question arising is1 8,what causes the differences in the methods of branching of the midrib80 ,at present this is a mystery4 ,compound leaves consisting of three leaflets are found in woodsorrel1 strawberry 7,fig4 #ej71 clover1 etc4 ,illustration3 ,,fig4 #be4--;,compound leaf of the ,rose4 ,l1 leaflets2 ,p1 leaf-stalk2 st1 stipules4 7 7 ,illustration3 ,,fig4 #bf4--;,compound leaf of the ,horse ,chestnut4 7 7 ,intermediate leaves4--,the ivy 7,fig4 #bg7 and sycamore 7,fig4 #cc7 have leaves which seem intermediate between truly simple and truly compound leaves4 ,from the arrangement of the veins it is seen that they approach the horse chestnut type more than that of the rose4 ,on the other hand1 if the deep indentations of the oak leaf 7,fig4 #aac7 were carried to the midrib1 the simple leaf would be divided into leaflets arranged1 somewhat like those of the rose or ash leaf1 along the sides of the midrib4 ,illustration3 ,,fig4 #bg4--;,ivy4 7 _/7 ,illustration3 ,,fig4 #bh4--;,compound leaf of ,pea4 ,fl1 flower-stalk2 ,sp1 stipules2 ,t1 tendrils4 7 7 ,stipules4--,at the bases of many leaf stalks1 close to the stem1 are leaf-like outgrowths called stipules4 ,they are well seen in the rose 7,fig4 #be7 and pea 7,fig4 #bh74 ,some leaves have a sheath at the bottom of the stalk1 partially enclosing the stem4 ,tendrils4--,the pea also affords an interesting case of leaflets being modified to do special work4 ,here the upper leaflets seem to have remained undeveloped except for their main veins1 and these have acquired a remarkable power of twining round suitable objects and so supporting the stem4 ,many other plants have tendrils1 but these are not always modified leaflets4 #h4 ,,how ,,leaves ,,are ,,arranged ,,on ,,the ,,stem4 #a4 ,opposite leaves4--,examine a deadnettle plant 7,fig4 #ib74 ,do the leaves come off the stem haphazard8 ,how many come off at each level8 ,are both leaves on the same side of the stem1 or opposite each other8 ,are the two leaves at the next level above just over these1 or do the directions cross8 ,do the leaves get as much light or more than they would if each pair were just over the pair next below8 ,how many other plants do you know which have leaves arranged in this manner8 ,examine leafy twigs of sycamore1 horse chestnut 7,fig4 #dj71 and ash4 ,are the stalks of the lower leaves of these twigs of the same length as those of the upper ones8 ,is it any advantage for the lower leaves to have longer leaf stalks8 #b4 ,box leaves4--,what is the arrangement in the box8 ,examine particularly the young leaves near the end of the twig4 ,are the lower ones twisted8 ,can you suggest a reason for this twisting8 ,can you find any twigs in which no twisting has taken place8 ,are these untwisted twigs so placed that they are equally exposed to the light on all sides8 #c4 ,alternate leaves4--,examine the arrangement of the leaves on a wallflower stem4 ,they come off alternately1 each springing from a rib on the stem4 ,how many ribs are there8 ,look at the bottom of the stem1 where the leaves have fallen off1 and notice that each has left a scar4 ,mark one of the scars with your pencil and then count how many scars you pass before coming to another on the same rib4 ,how many times do you wind round the stem in doing this8 ,you pass five leaves and wind spirally round the stem twice4 ,this is always the case in the wallflower4 ,examine leafy twigs of oak and pear trees4 ,here1 too1 the leaves are alternate1 and every sixth leaf is above the first1 and a line joining all the leaf-bases or scars between the first and sixth leaves would wind spirally round the stem twice4 ,what is the arrangement in the elm and lime8 #d4 ,leaves which form a rosette4--,examine plants of primrose 7,fig4 #ha7 and daisy4 ,the leaves in these cases spring from close to the ground and form a rosette4 ,notice that the bottom of the leaf blade is much narrower than the upper part4 ,is any saving of material obtained by this arrangement8 #e4 ,the position of branches and buds4--,look in the upper angle between a leaf and the stem in all your specimens4 ,this angle is called the axil of the leaf4 ,can you see a bud in the axil of the leaf8 ,can you find that a bud or a side branch ever arises in any other position8 7,the former positions of fallen leaves are marked by scars47 ,to the beginner in nature-study leaves seem in the majority of cases to be arranged on the stem of a plant in a haphazard and confusing manner1 and it is only after very careful observation that a definite order and regularity is seen to be always maintained4 ,nodes and internodes4--,the level at which a leaf springs from the stem is called a node 7,lat4 nodus1 a knot71 and the length between two consecutive nodes is called an internode 7,lat4 inter1 between74 ,opposite leaves4--,it is best to begin the study of leaf-arrangement by examining some such plant as the deadnettle 7,fig4 #ib74 ,the leaves come off in pairs3 two at the same level1 set opposite to each other4 ,the next pair above or below springs from the stem in a direction at right angles to the first--a device which allows the leaves to get a more equal share of light than if each pair were placed directly over the next below4 ,a similar arrangement is adopted by various other plants1 including the horse chestnut 7,fig4 #dj71 sycamore 7,fig4 #cd71 box1 privet1 etc41 but in some instances it is disguised4 ,box twigs afford an interesting example of this4 ,those twigs which are equally1 or almost equally1 illuminated on all sides1 have their leaves arranged in pairs at right angles to each other like those of the deadnettle4 ,some twigs1 however1 receive the light from one direction only1 and in these cases the leaves turn themselves until they face the light2 so that at a casual glance the pairs of leaves seem to lie all in the same plane4 ,one only needs to examine the end of the twig1 where the leaves are just unfolding1 to see that the arrangement is really in pairs alternately at right angles4 ,in the case of the privet the efforts of the leaves to face the light often cause the stem itself to be twisted between the leaf-levels4 ,the alternate1 or spiral1 arrangement4--,perhaps the commonest leaf-arrangement is one in which only one leaf is given off at any particular node1 the next leaf being a little further round the stem1 and so on4 ,as a result1 an ink line or a piece of thread joining the leaf-bases would wind spirally round the stem4 ,in the case of the wallflower1 oak1 pear1 and many others1 such a line would wind spirally twice round the stem before coming to a leaf vertically above the first1 and in so doing it would pass five leaves4 ,this may be shortly described as the _/ arrangement4 ,a less common one is 1 where in winding spirally round the stem #c times1 #h leaves would be passed4 ,efforts of leaves to obtain light4--,it would be difficult to imagine any order of insertion which would secure a more equal distribution of light to each leaf than the spiral arrangement2 but here also cases of leaves twisting in order to face the light are not uncommon4 ,lime leaves very often turn for this reason1 so as to lie in almost the same plane--adopting a device similar to that of the box and privet described above4 ,further1 the lime leaves arrange themselves at such angles that there is very little overlapping4 ,elm twigs also often exhibit similar instances of a mutual accommodation of leaves to each other's light supply4 ,the lower leaves on a horse chestnut twig have longer stalks than those nearer the end 7,fig4 #dj74 ,this enables the leaves to stand well out to the light and escape the overshadowing of those above4 ,the positions of branches4--,a branch of the stem of a flowering plant always arises as a bud in the upper angle between a leaf and the stem4 ,this position is called by botanists the axil of the leaf1 from the ,latin word axilla1 the arm-pit4 ,clearly1 then1 the arrangement of the branches is primarily dependent upon that of the leaves1 and we shall1 for example1 never find 8opposite0 branches on a tree which bears its leaves on the 8alternate0 system4 ,it is easy to notice1 however1 that not all the buds develop into branches4 ,in other words there are many buds which remain dormant1 and the final arrangement of the branches is often somewhat irregular on this account4 ,but wherever an ordinary bud or a branch occurs1 we may be perfectly sure that there was once a leaf immediately below1 even if the leaf-scar can no longer be seen4 ,economy of leaf surface4--,all these things seem to indicate that a good supply of light is of the greatest importance to leaves1 and this conclusion is supported by the fact that leaves are usually either narrow or actually cut away in places where the light cannot reach them4 ,the leaves of the daisy and of the primrose 7,fig4 #ha71 for example1 all spring from nearly the same point1 and form a rosette4 ,evidently there would be a certain amount of overlapping at the leaf-bases1 unless the blades there were very narrow1 as they are4 ,again1 the greatly-indented leaves of the ivy are often arranged so that a point of one leaf fits over an indentation of another--a beautiful example of plant economy4 #i4 ,,the ,,work ,,of ,,leaves4 #a4 ,in sunlight leaves make starch4--,expts4 #e1 #g1 and #h 7,sec4 #f7 have already proved 7a7 that leaves of a plant growing in ordinary air and exposed to the sunlight make starch2 7b7 that in the dark this starch somehow disappears2 7c7 that in air destitute of carbon dioxide leaves are unable to make starch even in sunlight4 #b4 ,the parts of a leaf which are not exposed to light do not make starch4--,keep a plant1 say of tropolum--or1 if not convenient1 a single leaf 7,fig4 #ca7--;in the dark for #bd hours to free the leaves from starch4 ,split a small cork and pin the halves on opposite sides of a leaf1 and then expose the plant to bright sunlight for an hour or two4 7,if a single leaf is used let the end of the stalk dip into water47 ,take off the cork1 kill the leaf with boiling water1 dissolve out the green colouring matter with methylated spirit1 rinse1 and test with iodine solution4 ,the part from which the light was excluded remains bleached1 and therefore contains no starch2 while the rest of the leaf becomes blue or purplish brown owing to the presence of starch4 #c4 ,parts of a leaf which are not green do not form starch in sunlight4--,take a variegated leaf from a plant 7e4g4 the variegated geranium or maple7 which has been in bright sunlight for some hours4 ,apply the usual test for starch4 ,the parts which were originally green contain starch2 the originally white parts remain bleached4 #d4 ,leaves supplied with carbon dioxide1 and exposed to sunlight1 give off oxygen gas4--7a7 ,take a bunch of fresh watercress or any green water-weed and put it in a beaker or glass jar4 ,cover the plant with an inverted funnel which is shorter than the beaker4 ,now fill the beaker with ordinary tap water or river water 7not distilled water71 so that the end of the neck of the funnel is covered4 ,completely fill a narrow test tube with water1 close it with the thumb1 and invert it over the neck of the funnel4 ,if this has been done carefully the test tube will still be full of water4 ,expose the arrangement 7,fig4 #bi7 to bright sunlight1 and notice the bubbles of gas which are given off from the plant and collect at the top of the tube4 ,when a few inches of gas have collected1 raise the test tube1 close it with the thumb whilst still under water1 and hold it mouth upwards4 ,in the meantime1 light a splinter of wood with the other hand4 ,when it is well burning1 blow out the light1 remove the thumb from the test tube1 and plunge the glowing splinter into the gas4 ,it bursts into flame again1 showing that the gas is oxygen4 ,illustration3 ,,fig4 #bi4--;,experiment to prove that green leaves supplied with carbon dioxide1 and exposed to sunlight1 give off oxygen gas4 ,illustration3 ,,fig4 #cj4--;,experiment to prove that tap-water1 or river-water1 contains dissolved carbon dioxide4 7b7 ,repeat the experiment1 7i7 placing the apparatus in the dark1 7ii7 without using any plant4 ,no gas collects in the test tube4 7c7 ,to show that the water used contains carbon dioxide in solution1 completely fill a gallon can or a large flask with similar water1 and attach a cork and a delivery tube which has also been filled with water--dipping the end of the tube into a little clear lime-water 7,fig4 #cj74 ,put the same quantity of lime-water into another vessel for comparison1 and then heat the can4 ,gas is given off1 and as it bubbles through the lime-water the liquid is gradually turned milky4 #e4 ,leaves wither in sunlight unless supplied with water4--7a7 ,cut off a leafy twig and leave it exposed to sunlight for an hour or two2 notice the change in the appearance of the leaves4 7b7 ,put a similar twig in the dark for the same length of time2 again notice the leaves4 ,is the difference due to a difference in light or to one of heat8 7c7 ,to test this1 keep1 if possible1 a similar twig in the dark in a warm place4 ,do the leaves wither as much as in 7a78 7d7 ,smear with vaseline the under surface of some of the leaves of such a twig and again expose to sunlight4 ,do the smeared leaves remain fresh longer than the others8 7e7 ,cut off the end of a twig with a sharp knife whilst it is under water1 and leave it exposed to sunlight1 dipping in water4 ,the leaves remain fresh4 ,how do you explain these differences8 #f4 ,in sunlight1 leaves give off water4--,take a piece of cardboard about #d in4 square and make a small hole in the middle4 ,pass the end of a leafy twig through the hole and make up with wax any chinks between the twig and the card4 ,put the card on a tumbler containing water1 so that the end of the twig dips under water2 and invert on the card--covering the leafy end of the twig--a second tumbler which is clean and dry4 ,put the apparatus in the sunshine and notice the mistiness 7or even visible drops of water7 forming on the inside of the upper tumbler4 ,where does this moisture come from8 #g4 ,the skin of a leaf is perforated by little pores4--,dip a fresh laurel leaf into boiling water in a beaker or tumbler4 ,can you see bubbles of air escaping from the leaf8 ,are they to be seen on both surfaces of the leaf1 or only on one8 ,which8 ,examine both surfaces of box leaves with a strong lens1 and try to see the little dots 7pores7 on the lower surface4 ,the student who has performed the experiments described in this section1 and who has thought about the results obtained1 cannot but have gained some insight into the main duties of leaves4 ,the meaning of these results must now be discussed4 ,the formation of starch in leaves4--,when the green leaves of a plant are exposed to sunlight in ordinary air--that is in air containing a certain proportion of carbon dioxide--the leaf forms starch in its interior1 and the starch can be detected by applying the iodine test 7p4 #cd74 ,when part of a leaf is protected from the light1 as by pinning the halves of a split cork on opposite sides of it 7,fig4 #ca71 no starch is formed in the shaded parts1 but only in the regions which are exposed to the light4 ,further1 if a variegated leaf is treated in the same way1 starch can be detected only in those parts of the leaf which were originally green2 the parts which were white are free from starch4 ,it is plain that it is the green colouring matter which puts the energy of the sunlight at the disposal of the leaf and enables it to manufacture starch4 ,illustration3 ,a ,b ,,fig4 #ca4--;,a1 ,tropolum leaf1 on which have been pinned the halves of a split cork 7,c74 7 47 ,b1 the same leaf tested for starch with iodine solution1 after exposure to sunlight for an hour4 ,the part shielded from the light remains bleached2 the rest of the leaf has turned blue4 ,at least three conditions are therefore necessary for the formation of starch in leaves3 7#a7 the green colouring matter2 7#b7 sunlight2 7#c7 carbon dioxide4 ,oxygen is liberated when leaves form starch4--,carbon dioxide gas1 which has been seen to be indispensable for the manufacture of starch in leaves1 consists of carbon1 or charcoal1 chemically united with the gas oxygen4 ,the green-stuff of the interior of the leaf makes the starch by causing this carbon to combine with water which has come up from the roots1 but it returns to the air the unnecessary oxygen4 ,water plants1 the leaves of which are not directly exposed to the air1 use carbon dioxide which the water has dissolved from the air4 ,they also give off the surplus oxygen1 after fixing the carbon4 ,this is the explanation of the bubbles of gas which1 in sunlight1 are often seen rising from the plants in an aquarium4 ,by such an arrangement as is described in ,expt4 #i1 #d1 this evolved gas can be collected1 and proved to be oxygen4 ,illustration3 ,,fig4 #cb4--;,experiment to prove that green leaves1 exposed to sunlight1 give off water4 ,the use of water to the leaves4--,it is common knowledge that if a twig is allowed to become dry its leaves hang limply and wither2 but if the twig is allowed to dip into water the leaves will keep fresh and crisp for a considerable time4 ,this necessity for supplying the twig with water seems to indicate that leaves give off water1 and that this is so may be proved by a few simple experiments4 ,two tumblers may be arranged as in ,fig4 #cb3 separated by a card through which passes the end of a leafy twig4 ,the end of the twig dips into water in the lower tumbler4 ,in order to prevent water vapour from passing from the lower tumbler to the upper1 the chinks between the twig and the card are sealed with paraffin wax4 ,when this arrangement is placed in the sunlight1 a dew soon collects on the inside of the inverted upper tumbler4 ,this water must have been given off in the form of vapour from the leaves4 ,that the loss of water from leaves is due rather to the light than to the heat of the sunshine may be shown by keeping leafy twigs in the dark4 ,the leaves keep fresh much longer than when placed in the light1 even if they are kept in as warm a place4 ,the pores of the leaf-surface4--,an ordinary leaf remains fresh much longer if its lower surface is smeared with vaseline4 ,the explanation of this lies in the fact that the waterproof skin of a leaf is perforated by a multitude of little pores1 especially on the lower surface4 ,in most leaves1 indeed1 the pores are confined to the lower surface4 ,smearing the surface with vaseline blocks up these pores and thus prevents the escape of water vapour from the interior of the leaf4 ,these little mouths 7known as stomata7#f open in the light and close in the dark4 ,during the daytime1 therefore1 the air 7containing its small proportion of carbon dioxide7 has free access to the interior of the leaf through the stomata1 and1 on the other hand1 any water which the leaf does not require can escape in the form of vapour4 ,a leaf requires water not only because all its mineral food 7p4 #bi7 is brought to it dissolved in water1 but also because water as well as carbon dioxide is required for the manufacture of the starch and other plant-foods4 ,how plant-food is distributed4--,the water which comes up from the roots is distributed to the various parts of the leaf through the veins4 ,these are therefore not only supports1 which stretch out the soft leaf-stuff to the light and air1 but they also form a very complete network of irrigating channels or water pipes4 ,further1 the starch and other foods which a leaf makes are drained off into the stem through other minute channels which are bound up with the water pipes4 ,the starch1 for example1 is changed into a kind of sugar which dissolves in water and drains away4 ,from the stem1 the food solutions are distributed to all the parts where growth is taking place4 ,,exercises ,,on ,,chapter ,,iii4 #a4 ,make drawings of as many cases as possible of economy of leaf surface4 #b4 ,grow various plants1 e4g4 ,tropolum1 ,geranium1 ,fuchsia1 ,mustard1 etc41 in the window1 and notice the effect which the direction of the light has upon the positions of the leaves4 #c4 ,smear with vaseline the lower surfaces of various growing leaves1 and on the following day test the leaves for starch1 comparing each with an unsmeared leaf from the same plant4 #d4 ,how is the transpiration of water from a green leaf effected and controlled8 ,discuss the uses of transpiration4 7#ahig7 #e4 ,put the same quantity of water into each of two similar test-tubes1 and let the end of a leafy twig dip into one4 ,weigh the tubes1 place them together in the sun for an hour1 weigh again1 and estimate roughly the weight of water lost by one square inch of leaf surface per hour4 ,compare various plants in this respect4 ,repeat the experiments1 7a7 in a moderate light1 7b7 in the dark4 #f4 ,make a list of plants in which the leaves are so arranged as 7a7 to conduct rain-water towards the base of the main stem1 7b7 to cause rain-water to fall to the ground from the outside of the foliage4 ,try to discover whether the difference has any relation to the arrangement of the roots4 #g4 ,under what conditions can plants use carbon dioxide as a source of food8 ,mention experimental and other proofs of the principal statements made4 7#aije7 #h4 ,what part of its food does a green plant obtain from the air8 ,in what form and under what conditions is it taken in8 7,king's ,scholarship1 #aije7 ,,footnote3 #f ,greek1 stoma1 a mouth4 ,,chapter ,,iv4 ,,buds4 ,,the ,,history ,,of ,a ,,twig4 #aj4 ,,the ,,structure ,,and ,,uses ,,of ,,buds4 #a4 ,a typical bud4--,split a cabbage1 or a lettuce 8heart10 down the middle1 and observe how the leaves are arranged round the conical end of the stalk4 ,the leaves which are fixed lowest on the stalk are the largest1 and they cover the outside of the bud4 ,the leaves are smaller and smaller as they are fixed nearer and nearer the end of the stalk1 until round the tip they are almost too small to be recognised as leaves4 ,a bud is the tip or 8growing point0 of a stem or branch1 together with the young leaves which crowd round it4 ,draw the section4 #b4 ,a sycamore twig4--,look in the axils 7p4 #dg7 of the leaves of a sycamore twig in summer or autumn1 and notice the buds4 ,can you see any buds on the lower parts of the twig--which bore leaves twelve months or longer ago8 ,did these also arise in the axils of leaves8 ,how can you be sure they did8 ,tie a piece of string1 or tape1 round this twig and look at it often1 making a note of every change which you see in it4 #c4 ,the fall of the leaf4--,on what date did you first notice that the leaves of the sycamore were falling8 ,did the first leaves fall from the twigs at1 or near1 the ends of the branches1 or lower down near the trunk8 ,examine the scar left by the first leaf which falls from your twig4 ,what is its shape8 ,what is the meaning of the dark dots on the scar8 ,gently take off the leaf nearest to the scar4 ,does it come off easily8 ,are there any dark dots on this scar8 ,can you see anything on the end of the leaf stalk corresponding to the dots8 ,do you think the dots are the ends of the food pipes referred to on p4 #ec8 ,make a drawing of a fallen leaf and write down on the drawing at the proper place1 the colour of that part of the leaf1 or better still1 colour the drawing with water-colour paints4 ,collect good specimens of the autumn leaves of as many other trees as possible1 and make coloured drawings of them4 ,on what date did you first notice that all the leaves were shed8 ,make similar notes for other trees4 #d4 ,the structure of a sycamore bud4--,in winter take off a sycamore twig which has a big bud at the end1 and examine it4 ,the bud is clothed with overlapping scales of a pale green colour4 ,make a drawing of the bud1 double the size1 and then take off the scales one by one and count them4 ,look with a lens at the upper end of one of the largest scales4 ,can you see any trace of a rudimentary leaf blade8 ,when the last scale is removed there remains on the end of the twig a tiny tuft of delicate green leaves surrounded by a little down4 ,count them1 and notice how each is folded up fanwise4 ,in some buds you may find a bunch of green flowers in the middle4 ,these buds are larger than those containing leaves only4 ,cut a bud across with a sharp knife1 and examine the cut surface with a lens to see more clearly how the scales and young foliage leaves are arranged4 ,draw what you see4 #e4 ,how the bud bursts4--,in spring watch your twig very carefully to be sure you do not miss any stage of the opening of the buds4 ,make drawings every day or two of the end bud1 when it has begun to unfold4 ,notice how the scales fall off--those on the outside first--and how the foliage leaves push open the upper scales and come out4 ,watch the way in which each leaf opens its folds and spreads itself out flat4 ,the buds may be made to open earlier by cutting off a twig about two or three feet long and keeping it in water in a warm room4 #f4 ,starch is stored up in the twigs4--,cut off a twig and pour a drop of iodine solution on the cut end4 ,what does the blue colour indicate8 #g4 ,the growth of the bud4--,watch your bud growing1 and notice that the tip of the twig--which was surrounded by the young leaves--elongates so that each pair of leaves is soon separated from the next pair4 ,notice the rings of scars which the scales left when they fell off4 #h4 ,a year's growth4--,look down the twig until you find the rings or scars which were left last spring1 when the scales fell off the expanding terminal bud4 ,a year ago the end of the twig was at this point1 so that the length between one such set of rings and the next marks a year's growth4 #i4 ,side branches4--,the buds on the length formed last summer but one may have grown out into side twigs4 ,try to find the leaf scars below each of these side twigs4 #aj4 ,a horse chestnut twig and its buds4--,examine in the same way a horse chestnut twig and trace its history4 ,the buds are larger than those of the sycamore1 and each is covered with a shining1 sticky layer of resin4 ,what do you think is the use of the resin8 ,put a bud in water1 and when you take it out notice how the water runs off and leaves the bud dry4 ,pull one of the terminal buds to pieces4 ,the scales will come apart more easily if the bud is soaked for some time in methylated spirit1 to dissolve out the resin4 ,notice the thick layer of down inside the scales4 ,what do you think is its use8 ,scrape the down gently1 and carefully clean it away from the little foliage leaves in the middle4 ,see how the leaflets of each leaf are folded4 ,in some terminal buds you may also find a little pink flower-spray4 ,tie a piece of string round a growing twig1 so that you can recognise it1 and watch all the stages of the expansion of the terminal bud1 the unfolding of the leaves1 and the elongation of the tip 7,figs4 #cg1 #ci and #dj74 ,cut off other twigs two or three feet long1 in ,february or early ,march1 and keep them in water in a warm room4 #aa4 ,other buds4--,examine the buds of the beech1 lilac1 violet1 dock1 fern1 etc41 and make drawings showing 7#a7 how the leaves are arranged with regard to each other1 and 7#b7 how each leaf is folded or rolled4 ,as a rule these points can be easily made out by examining with a lens the cut surface of a bud which has been cut across with a sharp knife2 but the buds should also be examined at frequent intervals when they are unfolding4 ,a typical bud4--,an excellent idea of the structure of a typical bud can be obtained by splitting down the middle an ordinary cabbage1 or a lettuce 8heart10 and examining the manner in which the leaves crowd round and cover the conical end of the stalk4 ,around the tip or 8growing point0 the leaves are extremely small and tender4 ,they are overlapped by slightly larger leaves1 which spring from the stalk a little lower down4 ,these in their turn are covered by still larger leaves1 inserted at a yet lower level1 and so on--the largest and oldest leaves folding over the smaller and more recently formed4 ,the growing point of a stem1 or of a branch of a stem1 surrounded by a cluster of immature leaves1 is called a bud4 ,the history of a sycamore twig4--,the student who would know the meaning of the various marks and scars on the surface of a twig1 should select one and follow carefully for a year the fate of the buds which it bears4 ,it is convenient to begin by studying a twig on a sycamore tree4 ,it may be marked for ease of recognition by tying a piece of tape on it4 ,if several students are working1 each should write his name or number on a luggage-label and fix this to his twig4 ,illustration3 ,,fig4 #cc4--,sycamore leaves and fruits4 7,from a photograph by ,mr4 ,a4 ,flatters47 7 _/47 ,the positions of the buds4--,in summer the younger twigs of the sycamore tree are covered with large five-pointed leaves 7,fig4 #cc74 ,the leaves come off in pairs1 each pair being at right angles to the pair next above or below4 ,every leaf is engaged throughout the day in building up--by means of the green stuff in its interior--starch and other foods 7p4 #ej71 and in giving off excess water1 in the form of invisible vapour1 through its stomata 7p4 #ec74 ,in the axil 7p4 #dg7 of each leaf is a little bud1 called from its position an axillary bud 7,fig4 #da1 ,b71 and at the very tip of the twig is a larger terminal bud4 ,autumn colours and the fall of the leaf4--,as the summer wanes1 the soil becomes colder1 and the chilled roots lose much of their power of absorbing moisture4 ,it is plain that if the leaves continued giving off water when no fresh supplies were forthcoming the tree would suffer4 ,how is the danger to be met8 ,starch and other foods have already been stored up in quantity sufficient to supply the needs of the winter and the early spring4 ,the leaves have finished their work1 and one by one they fall off4 ,but this does not take place until careful preparation has been made4 ,their green colouring matter breaks up2 the part which may still be useful to the plant drains into the stem1 leaving little heaps of yellow grains in the leaves4 ,or a special colouring matter may be formed1 which1 united in various ways with the materials of the dying leaf1 gives the warm shades of red1 orange1 and purple which make the woods so beautiful in autumn4 ,when all is ready1 a layer of cork 7,fig4 #da1 ,c7 forms at the junction of the leaf stalk and the twig so that no raw wound may be left2 the leaf-base splits across1 just above the cork layer1 and the leaf flutters to the ground1 there to rot and make rich leaf mould4 ,the leaf scars4--,the former position of each leaf is now marked by a curved scar 7l4s4 ,fig4 #cd71 and a row of brown dots 7v4b47 in the scar still shows where the food-pipes bent outwards from the twig into the leaf4 ,a line 7a7 stretches across and joins the two scars of each pair4 ,the buds4--,just above every scar is the bud which arose in the axil of the fallen leaf4 ,it is covered with overlapping scales of light green colour4 ,at the end of the twig is a single terminal bud1 similar in appearance to the axillary buds1 but of larger size4 ,it is instructive to take the terminal bud of a twig to pieces4 ,the outer scales are tough and green1 while the inner ones are thinner and have a beautiful silvery appearance4 ,usually there are fourteen scales4 ,each is long and narrow and bears at its upper end the rudiment of a leaf blade1 which cannot usually be seen well without a lens4 ,the scale is really a leaf which has been arrested in its development4 ,illustration3 ,,fig4 #cd4--,sycamore twig in winter4 l4s41 leaf-scars2 v4b41 ends of food-pipes2 ,r1 rings of scars left by scales of last winter's terminal bud4 7,slightly reduced47 ,illustration3 ,,fig4 #ce4--;,cross section of a ,sycamore bud4 7 #g47 ,when all the scales have been removed1 there remains a tiny tuft of delicate green foliage leaves surrounded by a little down4 ,each leaf is folded fanwise1 both for convenience of packing1 and to protect its tender tissues from the cold and the damp when the bud is expanding4 ,the complicated folding of these leaves is well shown in ,fig4 #ce1 which is a magnified sketch of a cross section through a sycamore bud4 ,the large sheaths surrounding the young leaves are four of the overlapping scales4 ,in a large terminal bud a bunch of green flowers may often be found4 ,the bursting of the buds4--,about the middle of ,april the tree wakens to new life4 ,the stored food makes its way to the terminal buds2 invigorated by the rich sugary sap the young leaves swell and push forward1 burst apart the scales1 and open out their folds to the light and air1 as if eager to get to work at the earliest possible moment4 ,the scales fall off to the ground1 leaving close-set rings of scars2 the growing point elongates1 and new leaves--which were indistinguishable in the bud--grow out and expand4 ,during the summer1 food is plentiful1 and a little bud appears in the axil of every leaf4 ,only with the autumn does the activity of the tree slow down4 ,except for some two pairs at the tip1 the newest leaves now remain stunted4 ,they form scales and close round the tender growing point protectingly1 in readiness for the winter4 ,illustration3 ,,fig4 #cf4--,sycamore twig in winter4 7 47 ,if necessary1 the axillary buds could have behaved as the terminal bud did1 in which case they would have grown out into side twigs4 ,they usually remain small1 however1 until next year 7,fig4 #cf71 for the leaves are so busy making food1 and the terminal bud is so busy growing in length1 that no energy can be spared for their further development4 ,if any accident had befallen the terminal growing point1 one or more of the axillary buds would have grown out into side twigs4 ,gardeners take advantage of such reserve buds when they clip off the ends of twigs to make a plant grow 8bushy40 ,illustration3 ,,fig4 #cg4--;,horse ,chestnut twig in winter4 7 _/47 ,illustration3 ,,fig4 #ch4--,the terminal part of a ,horse ,chestnut twig in winter4 l4s41 leaf-scars2 v4b41 ends of food-pipes4 7 47 ,a year's growth4--,when the bud scales drop off they leave1 as we have seen1 a series of closely-set rings of scars4 ,the distance between one set of rings and the next 7as at ,r41 ,fig4 #cd71 therefore represents a year's growth4 ,the student should get a twig two or three feet long and find out for himself1 by examining the marks on it1 what the twig did last year1 two years ago1 and three years ago4 ,with care he will be able to say definitely in which year any fairly recent side-twig began to grow out from its bud4 ,a horse chestnut twig4--,a winter twig of horse chestnut 7,fig4 #cg7 is very similar in its general features to what we have seen in the sycamore4 ,the buds are in pairs at right angles to each other1 and below each bud is a large corky leaf scar 7l4s4 ,fig4 #ch71 with the positions of the former food-pipes marked by black dots 7v4b474 ,these buds1 however1 are larger than those of the sycamore1 and each is covered with a shining layer of resin1 to keep out insects and the rain4 ,we may slip the end of a penknife under the bud scales and remove them one by one4 ,the first few are thin and papery1 and soaked in resin4 ,those next inside are woody and much thicker4 ,next comes a layer of papery scales1 inside that a coat of cottony down1 then another soft papery layer1 and lastly a thick pad of down4 ,when we carefully scrape away this down1 we find--warm and cosy in its midst--a tuft of little objects with a most quaint resemblance to hands clad in woollen gloves4 ,we remove one of these1 and on scraping it gently with a knife we see that the 8hand0 has seven fingers2 and it presently becomes clear that each finger is a tiny green leaflet folded on itself1 and that the hand is a young leaf4 ,if we take off these gloved leaves in turn one by one1 we find as we proceed that they become smaller1 until they are almost too small to be distinguished in their fluffy nest4 ,and when all the down and the baby leaves are scraped away1 the tender growing point of the twig is left alone at the summit of a little cone1 with steps showing where the leaves were4 ,had the twig been left undisturbed on the tree1 the bud would have awakened in spring and begun to grow 7,fig4 #ci74g ,the scales and the down would have been shed1 leaving only the rings of scars as a memento of the winter sleep2 the growing point would have pushed on and on1 lengthening perhaps a foot or more in three weeks2 the leaves would have opened their bright green fingers to the spring air1 and begun their work 7,fig4 #dj71 only to cease when in the autumn they too dropped off1 and the new buds tucked themselves up in their beds to go to sleep4 ,the leaves of the horse chestnut fall off1 as do those of the sycamore1 owing to a 8separation-layer0 arising at the base of the leaf stalk 7,fig4 #da71 and in this case each leaflet also becomes separately detached in the same way4 ,illustration3 ,,fig4 #ci4--,later stage of the ,horse ,chestnut twig of ,fig4 #cg4 7 _/47 ,illustration3 ,,fig4 #dj4--,the later development of the terminal bud of the twig of ,figs4 #cg and #ci4 7 47 ,other forms of buds4--,surrounding the young silky-fringed leaves of the beech bud are several crimson membranous scales which are really the stipules 7p4 #dc7 of undeveloped leaves4 ,the thin1 soft parts of the leaf blade are sharply pleated 7,fig4 #db7 between the side veins which spring from the midrib4 ,the way in which the branching of a tree depends on the buds is well shown in a lilac4 ,the terminal bud does not usually develop1 so that each of the two lateral buds just below grows out into a branch1 producing the characteristic 8forking40 ,in the lilac bud every gradation between scales and ordinary foliage leaves may be seen4 ,illustration3 ,,fig4 #da4--,longitudinal section of twig of ,sycamore4 ,a1 base of leaf2 ,b1 axillary bud2 ,c1 cork layer4 7 #b47 7,from a photograph by ,mr4 ,a4 ,flatters47 ,illustration3 ,,fig4 #db4--;,cross section through leaf-bud of ,beech4 7 #f47 ,in the violet bud the two margins of the leaf are rolled inwards towards the midrib2 while in the dock they are rolled backwards4 ,young fern leaves 7,fig4 #adf7 are not folded from side to side like the examples referred to above1 but are rolled into a tight coil from apex to base4 ,it is the upper surface of the leaf 7frond7 which is to the inside4 ,as the leaf grows1 the coil straightens out4 ,,exercises ,,on ,,chapter ,,iv4 #a4 ,where and when are the buds of common ,english trees formed8 7#aija7 #b4 ,show1 by describing and drawing one example1 that the branch of a tree may preserve a record of past seasons in the bark4 7#aija7 #c4 ,draw an unopened bud of sycamore4 ,of what parts is it composed1 and how are the parts arranged8 7#aija7 #d4 ,what can be seen inside a large bud of horse chestnut8 ,on what part of the branch are the largest buds to be found8 7#ahih7 #e4 ,upon what does the method of branching of a tree depend8 ,give examples4 #f4 ,examine pollarded trees2 what is the cause of their peculiarities8 #g4 ,examine buds of various trees in spring1 and try to discover in which cases the bud scales are 7a7 modifications of entire leaves1 7b7 modified leaf stalks1 and 7c7 modified stipules4 #h4 ,examine and describe the method of protection1 during the summer1 of the axillary buds of the plane4 #i4 ,take a poplar shoot during late summer1 and examine the corky separation-layer forming at the base of each leaf4 ,write an account of its use1 and make drawings of its appearance4 #aj4 ,the 8heart0 of a cabbage or lettuce is of lighter colour1 sweeter taste1 and more tender texture than the external leaves4 ,how do you explain these differences8 7,king's ,schol41 #aijb7 #aa4 ,describe and explain the effect of clipping a privet hedge4 #ab4 ,give an account of the changes in appearance in any common leaf during the whole period of its growth4 ,explain briefly what part the leaf plays in the life of the plant4 7,certificate1 #aijd7 #ac4 ,explain precisely how you would decide whether a given specimen consisted of 7a7 one compound leaf1 or 7b7 a twig bearing several simple leaves4 ,,footnote3 #g ,in a large terminal bud the cone often ends in a tiny pink spray1 which gives rise to a branch of beautiful flowers when the bud unfolds4 ,in this case no further growth of the main axis of the twig takes place4 ,,chapter ,v4 ,,how ,,stems ,,do ,,their ,,work #aa4 ,,the ,,duties ,,of ,,stems4 #a4 ,the shapes of stems4--,cut across a deadnettle stem and a wallflower stem and examine the shape of the sections4 ,the former is square1 the latter is five-ribbed4 ,is there any relation between the form of the stem and the arrangement of the leaves8 #b4 ,the 8bleeding0 of stems4--,cut through the lower part of a scarlet-runner plant in spring4 ,can you see any water escaping from that part of the stem still in the ground8 ,similarly1 cut back a sunflower stem when it is from to #a inch thick4 ,does the water exude from all parts of the cut surface equally1 or does it come from definite channels8 ,to see this better1 dry the cut end with blotting paper and examine the surface with a lens4 8,bleeding0 is best seen in vine stems2 if a young vine is available1 cut it back in spring and observe the large escape of water4 #c4 ,the water-current travels along definite channels4--,colour some water with red ink and put in it the stalks of cut white flowers such as snowdrops or narcissi4 ,the stalks and flowers soon become veined with red4 ,cut the stalks across and see that the strands in the interior are also coloured4 ,the coloured water has evidently travelled along definite channels4 #d4 ,the food-channels in a soft stem4--7a7 ,take a stout piece of the stem of a deadnettle1 including three nodes 7p4 #de71 and slit it down in a line between the end pairs of leaves4 ,then boil the stem in water until the internal tissue is soft4 ,take the stem out and carefully scrape away all the soft material until the woody strands can be well seen4 ,these are the food-channels4 ,notice their arrangement in the stem1 and the manner in which they run out to the leaves4 7b7 ,similarly1 examine the strands in a piece of sunflower stem1 and in an old cabbage stalk4 #e4 ,the path of the water-current in a woody stem4--,take a leafy twig of elder or laurel and1 from the part of the shoot below the leaves1 remove a ring of about an inch of the bark and the soft tissues which lie beneath it1 so as to expose the wood4 ,put the end of the twig 7below the ring7 in water4 ,the leaves remain fresh and crisp1 showing that the water travels either along the wood or the pith1 or along both4 #f4 ,the water travels along the wood4--,put a similar leafy twig of elder dipping in water which has been coloured by red ink4 ,expose to sunlight1 and after an hour or two cut open the twig and observe which parts are coloured4 ,the bark and the soft tissues between it and the wood are not coloured4 ,the wood is stained red4 ,the pith is not coloured4 #g4 ,the path of the leaf-made food4--7a7 ,take a leafy branch of a tree--e4g4 willow--and near the bottom remove a ring of the bark and the soft tissues lying between bark and wood4 ,put the twig in water1 so that the ringed part and a few inches above shall be immersed4 ,after a time roots are produced above the cut4 ,if any arise from the stripped part they are few in number and much shorter than those above4 7b7 ,place a similar but uninjured twig in water1 and notice that the new roots are produced at the end4 ,what is the reason for the difference8 ,the duties of stems4--,no one can study leaves without being impressed by the great importance to the plant of the work which they do4 ,even the casual observation that year after year thousands of fresh leaves make their appearance would indicate this4 ,and when it is learned that throughout the day every leaf is busily engaged in decomposing carbon dioxide1 and joining up the carbon with the water and mineral compounds which have come up from the root--thus forming sugars1 starch and a host of other valuable substances--some general idea is obtained that the trunk and spreading boughs of a tree may1 after all1 be of minor importance1 and may exist mainly to help the leaves to perform their duties as perfectly as possible4 ,this is the true view to take of the stem and its branches2 their duties are 7#a7 to bear the leaves and spread them out1 so that these will receive as much sunshine and fresh air as possible2 7#b7 to supply the leaves with the water and mineral substances which they require for their work2 and 7#c7 to receive from the leaves and distribute to the rest of the plant the food materials which the leaves have prepared4 ,a stem1 together with the leaves and branches which it bears1 is called a shoot4 ,it will be found that almost all the variations in the structure and habits of stems are connected with the arrangements of the leaves4 ,for example1 the weight of the mass of leaves borne by a forest tree is very great1 and they offer a great resistance to the wind2 the trunk and its branches1 therefore1 are correspondingly strong and stout4 ,again1 when a stem is ribbed or ridged in any particular manner it will generally be found that the ridges have a definite relation to the leaves and to their points of insertion on the stem4 ,this has been seen 7p4 #dd7 to be the case in the stem of the wallflower4 ,the tip of a stem or branch is occupied by a bud4 ,as the tip elongates 7,fig4 #dj71 the outer leaves of the bud become separated by internodes1 and new leaves continually arise around the growing point4 ,the path of the water in the stem4--,it may easily be shown that water travels up the stem to the leaves4 ,it is common knowledge that slightly withered leaves or flowers become fresh and crisp again if the twig or stalk is put in water4 ,if the stalks of white flowers--say snowdrops or narcissi--are put into water coloured with red ink1 the flowers become veined with red1 and1 if the stalks are cut into1 red strands may be seen4 ,this experiment not only shows that water has travelled up the stalk1 but it also shows that the water has passed along definite channels4 ,when a vine stem is cut back in the spring1 the water wells out rapidly from the end of that part of the stalk which is still in the ground4 ,this bleeding1 as it is called1 may also be seen1 though to a smaller extent1 in stems of sunflower1 scarlet-runner1 and other plants4 ,by drying the cut surface with blotting paper1 and then examining it with a lens1 it may be seen that the water escapes from the ends of certain little tubes2 and it is possible in a boiled or rotting stem 7,expt4 #aa4 #d7 to follow the distribution of the strands containing these tubes4 ,the strands run along the length of the stem1 outside the pith4 ,cross strands connect the main ones1 chiefly at the leaf-levels 7nodes72 and other strands run out into the leaves to form the veins4 ,the tubes which convey the water current are in that part of the strand which is nearest the pith1 and they become woody4 ,thus1 if the current year's growth of1 say1 a horse chestnut or an elder twig is cut across1 a thin ring of wood is seen surrounding the soft pith4 ,outside the wood are the softer tissues1 surrounded by the bark4 ,a ring of the bark and soft tissues beneath it may be entirely removed from a growing twig1 leaving the wood exposed1 but the leaves above remain crisp and fresh1 showing that this treatment has not interfered with their water supply4 ,the water1 therefore1 travels along either the wood or the pith4 ,that the wood and not the pith conducts the water may be shown by putting a leafy twig in water coloured with red ink4 ,only the wood is stained4 ,the path of the food made by the leaves4--,the plant food which the leaves make is drained off into the stem1 and distributed to the parts where growth is taking place4 ,this food travels in the soft tissue--called the bast--which lies below the bark4 ,this fact can be shown indirectly by removing a ring of bast from the lower part of a branch1 say of willow1 and putting the branch into water4 ,when at length the cutting puts out roots1 these spring from the top of the ring4 ,if any spring from the stripped part they are markedly smaller1 and fewer in number4 ,in an uninjured cutting1 which is of course supplied with prepared food along all its length by the bast vessels1 such roots spring from the cut end4 ,the supply of leaf-made food can also be cut off by ligaturing a twig below the leaves1 as by twisting a wire or cord tightly round it4 ,in such a case growth usually ceases in the part of the twig below the strangled part1 while the upper part of the twig1 to which the leaf-made food is now restricted1 grows much more luxuriantly than before4 ,gardeners often produce unusually fine fruits by ligaturing the lower parts of the twigs on which the fruits are ripening4 #ab4 ,,how ,,stems ,,are ,,strengthened4 #a4 ,the formation of wood4--7i47 ,in summer take a horse chestnut twig of three or four years' growth4 ,cut through it with a sharp knife at the following places1 and trim the cut ends flat3 7a7 ,near the apex2 7b7 at the middle of the current year's growth2 7c7 near the bottom of the current year's growth2 7d7 about the middle of last year's growth2 7e7 0 0 the previous year's growth4 ,make a drawing of what you see in each case3--,in 7a7 the twig is covered on the outside by a green skin4 ,in the middle is the soft pith4 ,between the two is a ring of separate strands4 ,in 7b7 and 7c7 the strands have joined up1 and a distinct1 though thin1 layer of wood surrounds the pith4 ,bast and other soft tissues lie between the wood and the bark4 7d7 has two layers of wood4 7e7 has three layers of wood4 7ii47 ,split each length longitudinally4 ,why is it easier to do this than to cut the twig across8 ,in which direction does the grain of the wood run8 ,make out in each piece the pith1 strands1 or layers of wood1 bast1 etc41 and skin or bark4 ,you can tear off the bast in ribbon-like shreds4 ,see how the strands run out into the young leaves4 ,cut lengthwise through the junction between the main twig and any side twigs1 and notice that corresponding parts are continuous4 #b4 ,the strength of a grass stem4--,notice the relatively enormous strength of a straw and other grass stems4 ,burn a straw and observe the tube of mineral matter which is left behind4 ,examine a piece of bamboo2 is it hollow or solid8 ,woody stems4--,to enable them to bear the weight of the leaves and branches1 and to withstand the force of the wind1 the stems of plants are strengthened in various ways4 ,most commonly this is effected by the formation of wood in the walls of the water-vessels4 ,even in succulent stems1 such as that of the sunflower1 the strands of vessels are stiffened by the long and narrow wood pipes which run along them2 and when the strands join up to form a complete cylinder a very strong column is the result4 ,engineers make use of the same device1 knowing that the same amount of material will bear a far greater stress when made into a hollow cylinder than it will in any other form4 ,the thickening of woody stems4--,in dicotyledons 7p4 #bc7 and gymnosperms 7p4 #afc7 the cylinder1 which is formed by the joining-up of the conducting strands1 consists of three layers4 ,the innermost of these is the wood1 and the outermost is bast4 ,between them is a very delicate layer called cambium1 which is continually dividing and forming more wood on its inner side and more bast on its outer side4 ,the wood is hard and resists pressure1 while the bast is soft and is squeezed against the inside of the bark by the expanding wood 7,fig4 #dc74 ,the formation of new wood and bast takes place vigorously during the summer1 at the expense of the food which is manufactured by the leaves and travels along the bast to the active cambium4 ,as autumn comes1 the activity of the tree slows down1 and the new wood is formed of closer texture4 ,in winter the process stops altogether2 but with the warmth and the plentiful food-supply of spring the formation of new1 open-textured wood is resumed4 ,illustration3 ,,fig4 #dc4--,portion of a four-year-old stem of the ,pine1 cut in winter4 #a1 #b1 #c1 #d1 the four successive annual rings of the wood2 b1 bast2 br1 bark2 c1 cambium2 f1 spring wood2 i1 junction of wood of successive years2 m1 pith2 ms1 medullary rays2 s1 autumn wood4 7 #d47 ,this difference in texture between the autumn wood and the later spring wood is quite visible to the naked eye 7,fig4 #dd71 and gives rise to a series of annual rings1 each of which represents a year's growth4 ,thus1 a cross cut through the four year old part of a branch 7,fig4 #dc7 shows four layers of wood1 one of which was formed each year4 ,the length formed last year has two layers of wood 7if we look in summer71 and the current year's growth has one layer1 all of which has been formed since spring4 ,the advantages of secondary thickening4--,the formation of secondary wood and bast is very important4 ,the new wood is required 7#a7 to provide additional water-vessels to supply the demands of an increasing number of leaves1 and 7#b7 to give the necessary increase of mechanical strength to the growing tree4 ,again1 the increase in the quantity of food manufactured by the leaves makes a larger quantity of bast necessary for its distribution4 ,last of all1 new tissues are required to take up the duties of those which are old and worn-out4 ,illustration3 ,,fig4 #dd4--;,cross section of ,larch stem1 showing annual rings4 ,in forest trees1 the central pith becomes almost obliterated and the old stem practically consists of wood1 bast1 and bark4 ,the various annual rings1 and the bast1 of a woody stem are joined together by a number of radiating horizontal spokes called medullary rays 7,fig4 #dc1 ms1 ms1 ms1 ms74 ,these conduct water and food materials across the stem from layer to layer4 ,the beautiful lines and patches called 8silver grain10 which may be seen in oak furniture1 consist of the medullary rays exposed in radial-longitudinal section4 ,bark4--,the very young stem is surrounded by a thin waterproof skin1 perforated by stomata 7p4 #ec7 as the skin of a leaf is2 and the part immediately below the skin possesses leaf-green1 and can therefore decompose carbon dioxide as a leaf does 7p4 #ea74 ,an old stem1 on the other hand1 is covered by a layer of tough bark 7br1 ,fig4 #dc71 which splits from time to time1 owing to the stretching which is caused by the increasing thickness of the wood4 ,the bark begins as a layer of cork1 which forms on the outer side of the bast4 ,the cork cuts off the food supply from all the external tissues1 which die4 ,bark1 therefore1 consists of the cork and the dead layers outside it4 ,grass stems4--,the great strength of grass stems--so apparent when we try to bend a straw--is largely due to silica1 the substance of which rock-crystal and ordinary sand are composed4 ,when a straw is burnt1 this remains as a hollow cylinder of mineral matter4 ,the great strength of the cylindrical form has already been referred to4 ,it is very well seen also in a bamboo stem1 and anyone who has blunted the edge of his knife on a piece of bamboo will appreciate the additional hardness which is given by the presence of mineral matter4 #ac4 ,,climbing ,,stems4 #a4 ,hooking stems4--,examine a bramble or a wild rose plant in a hedge4 ,why does it need to climb8 ,how does it climb8 ,pull a branch and notice by what means it resists the pull4 ,what is the shape of the prickles8 ,do they point upwards or downwards8 ,on what parts of the plant are the prickles found8 ,notice how easily a prickle may be pushed off1 sideways4 ,is it as easy to tear it off lengthways8 ,is the prickle a little branch1 or merely an extension of the rind8 ,contrast a prickle with the thorn of the hawthorn4 ,the thorn does not come off easily1 and it contains a woody core which is continuous with the wood of the branch4 ,cut lengthwise through the thorn and the branch which bears it to see this4 ,the thorn is a short pointed branch2 it arises in the axil of a leaf1 and sometimes bears leaves itself4 #b4 ,the ivy4--,observe how the climbing stem of the ivy is attached to a wall or tree4 ,it puts out a line of roots on its shaded side4 ,these roots give out a sticky fluid1 which1 on hardening1 fixes them to the wall4 #c4 ,twining stems4--,watch the growth of a convolvulus seedling4 ,at first the young stem grows straight up1 but soon the tip begins to move round and round4 ,try to find out how long it takes to describe one revolution4 ,put a long stick in the ground near the plant and notice how1 when the revolving stem touches the stick1 the spiral is henceforth described round the support and the stem consequently clings to it4 ,lay your watch face-upward1 and notice whether the stem moves in the same direction as the hands 7the 8clockwise0 direction71 or in the opposite 78counter-clockwise07 direction4 ,make similar observations on the hop1 honeysuckle1 and scarlet runner1 and note the results4 #d4 ,leaf climbers4--,examine a climbing tropolum 7often1 though wrongly1 called 8nasturtium074 ,which parts of the plant clasp the support8 ,watch a young plant coming up4 ,does the stem revolve before the leaf stalks come in contact with the support8 ,compare the clematis4 #e4 ,tendril climbers4--,examine plants of sweet pea1 bryony1 vine1 passion flower1 and cucumber4 ,try to find out in each case which part has been modified to form the tendrils4 ,watch a plant day by day until a free tendril grasps a support1 and notice how it becomes spirally coiled4 ,can you straighten the tendril by pulling1 without leaving any kinks8 ,why8 ,is the spiral of the tendril continuous1 or does it change its direction in the middle8 ,make a continuous spiral with wire1 and notice the kinks formed when the wire is straightened by pulling the ends4 ,which is better for the plant in a gale of wind1 a continuous or a reversed spiral8 ,why8 ,notice the sucker-like tendrils of the ,virginian creeper1 and the way in which they fix the plant to the wall4 ,plants whose stems are not strong enough to stand erect without support must adopt some special means of spreading out their leaves to the light and air4 ,one of the commonest devices of such plants is that of climbing up other and stronger plants1 walls1 trellis-work1 etc4 ,scramblers and climbers4--,in the simplest cases the plant simply scrambles over other plants4 ,many brambles and roses are merely scramblers1 but more often they are true climbers1 weaving themselves among their neighbours by the help of hooked prickles 7,fig4 #gf74 ,the prickles point backwards1 and therefore anchor the twigs firmly1 as is very evident on trying to pull a branch out of the hedge4 ,a prickle may easily be broken off by a side push1 for it is merely an outgrowth of the rind1 and does not contain any woody core4 ,it is so attached1 however1 that it resists much greater force in the lengthwise direction--a manifest advantage to the plant4 ,illustration3 ,,fig4 #de4--;,ivy climbing up a wall4 ,r1 arial roots4 7 47 ,the differences between such a prickle and a thorn like that of the hawthorn should be carefully noticed4 ,a thorn is really a little twig which has remained short and become pointed at the end4 ,it has a core of wood which is continuous with the wood of the branch bearing it4 ,that a thorn is really a little branch is shown by its origin in the axil of a leaf1 and by its often giving rise to leaves and buds4 ,illustration3 ,,fig4 #df4--;,climbing stem of ,honeysuckle4 7 47 ,illustration3 ,,fig4 #dg4--;,climbing stem of ,convolvulus4 7 47 ,the stem of the ivy climbs by means of little roots1 which it puts out on the side furthest from the light 7,fig4 #de74 ,these give out a sticky liquid which1 on drying1 cements them to the wall or tree4 ,twining stems are much in advance of these4 ,there seems to be something approaching intelligence in the manner in which the young stem of a hop1 honeysuckle1 or convolvulus1 which at first grows straight up1 begins to wander round and round1 tracing a spiral path in the air until it touches a support4 ,then1 however1 as if the plant could feel1 the movement below the point of contact stops2 but the upper part of the stem still revolves and therefore twines round the support4 ,the stems of the honeysuckle 7,fig4 #df7 and the hop turn in the same direction as the hands of a clock4 ,this is called the 8clockwise0 direction4 ,on the other hand the convolvulus 7,fig4 #dg7 and most other twining stems are 8counter-clockwise0 climbers4 ,the stem of the bittersweet revolves indifferently in either direction4 ,sensitive clasping organs in their simplest form are seen in the twining leaf stalk of the clematis and tropolum2 the stem itself revolves as if to give its leaf stalks every opportunity of finding suitable supports4 ,the leaf stalks seize these and twine round them4 ,most wonderful of all climbing organs are the tendrils4 ,they are well seen in ,fig4 #dh4 ,a part of the plant--sometimes a leaflet1 as in the pea 7,fig4 #bh72 sometimes a branch1 as in the passion flower2 or a flower stalk1 as in the vine--becomes modified into a thread1 slight but strong4 ,when the end of the thread touches and then twines round a support1 the whole tendril forms itself into a spiral which1 like a wire spring1 draws the plant up to the support1 and can yet lengthen and yield to the wind when necessary4 ,in the middle of the tendril the direction of the spiral is reversed1 so that the tendril can be straightened without being twisted4 ,the tendrils of the ,virginian creeper do not twine1 but on meeting a wall they form round red suckers at the end1 and attach the plant 7,fig4 #di74 ,illustration3 ,,fig4 #dh4--;,how a tendril grasps a support4 ,the spiral is reversed at x4 ,illustration3 ,,fig4 #di4--,virginian ,creeper4 ,r1 ,r1 stem tendrils4 7 47 #ad4 ,,creeping ,,and ,,underground ,,stems4 #a4 ,a creeping stem4--,examine a plant of the ground ivy4 ,is the stem strong enough to stand upright8 ,how does it spread out its leaves to the light and air8 ,the stem grows along the ground1 and at intervals it gives off a pair of leaves which grow upwards1 and a tuft of roots which grow down to the ground4 #b4 ,a runner4--,is the 8runner0 of the strawberry of the same nature1 i4e4 is it a continuous stem like that of the ground ivy8 ,when the plant is carefully examined1 the creeping 8stem0 is seen to be a branch arising in the axil of a leaf4 ,the branch runs along the ground for a little distance1 and then roots itself and gives off a number of leaves4 ,in the axil of one of these another branch arises and runs on in the same direction4 ,the same branch does not run on and on4 #c4 ,a stolon4--,follow carefully the underground part of the couch grass and make out its connection with the main shoot4 ,it is a branch like the runner of the strawberry1 which arises in the axil of a leaf1 and extends only to the next shoot4 ,compare the stolons of the cinquefoil4 #d4 ,a potato tuber4--,examine a potato tuber 7the part which is eaten74 ,notice the 8eyes40 ,these are buds1 with scale leaves4 ,leaves never occur on roots1 so that the potato must be an underground stem4 ,put a pin into every eye1 and wind a thread round the tuber along the bases of the pins4 ,it forms a spiral4 ,cut the potato into halves1 and pour a drop of iodine solution on the cut surface4 ,what is the meaning of the blue dots which at once make their appearance8 ,plant a potato in warm1 moist earth1 and when it has sprouted notice that each bud 7eye7 has given rise to a branch4 #e4 ,bulbs4--,cut an onion or snowdrop bulb down the middle1 and draw what you see1 marking on your drawing the outer scale leaves1 the swollen bases of last year's leaves1 the young leaves in the middle1 the short1 thickened stem1 and the roots4 ,also cut other bulbs across and again draw4 ,what is the similarity and what is the difference between these bulbs and such a bud as a cabbage8 ,also examine hyacinth1 tulip and daffodil bulbs4 ,put them in glasses with water touching their bases1 and watch them grow4 ,what do they live upon8 #f4 ,a crocus corm4--,obtain a few crocus 8bulbs0 in the early winter4 ,observe the tough outer tunic springing round the edge of a circular scar on the base4 ,if there are any roots they come off from the scar4 ,take off the tunics from one 8bulb0 and observe the bud or buds at the top of the white mass inside4 ,other tunics cover the buds4 ,cut lengthwise through the mass of the 8bulb0 so as to bisect the largest bud4 ,separate the parts of the bud with a needle and notice 7a7 the thin outer leaves1 7b7 the young foliage leaves1 7c7 the flower-sheath and flower4 ,pour a drop of iodine solution on the cut white mass 7the stem7 below the bud4 ,it turns blue4 ,why8 ,what is the principal difference between a crocus 8bulb0 and the bulb of an onion1 hyacinth1 or tulip8 ,a true bulb is mainly composed of swollen leaves or leaf bases2 in the crocus the thick1 rounded stem makes up most of the bulk4 ,it is better1 therefore1 to speak of a crocus corm1 to indicate the difference4 ,plant the remaining corms and examine them at intervals for a year4 ,notice the formation of the roots1 the lengthening of the buds1 the formation of the flowers1 the activity of the foliage leaves after flowering 7why871 the withering of the roots and leaves in summer1 and the growth of the enlarged base of the branch into next year's corm4 ,creeping stems4--,instead of climbing1 many stems find that the best method of spreading out their leaves is to creep along or under the ground1 and give off leaves and roots at intervals4 ,not only does this device prevent the leaves of one node from interfering with the light and air supply of those of the next1 but the plant is continually coming in contact with a fresh lot of soil4 ,the ground ivy is an instructive example of this method of growth4 ,the stem creeps along the ground1 and at every node it gives off a pair of leaves which grow upwards1 and a tuft of roots which grow down into the ground4 ,illustration3 ,,fig4 #ej4--,runner of ,strawberry4 7 47 ,the runner of the strawberry 7,fig4 #ej7 appears at the first glance to grow in a similar manner4 ,as a matter of fact1 however1 the apparent stem is a branch arising in the axil of one of the leaves of the last node4 ,the branch runs along the ground and gives rise to a new shoot1 and from this another branch1 springing from the axil of a leaf1 forms another runner4 ,the same branch does not run on from shoot to shoot4 ,the stolon of the couch grass 7,fig4 #ea7 is somewhat similar4 ,the erect stem of the plant is divided1 as usual1 into nodes or knots 7from which the narrow1 sheathing leaves arise7 and internodes4 ,branches 7stolons7 spring in the axils of the lower leaves1 turn downwards1 and run on underneath the soil1 taking root again at some distance from the parent plant4 ,illustration3 ,,fig4 #ea4--,stolon of ,couch ,grass4 7 47 ,illustration3 ,,fig4 #eb4--;,creeping underground stem of ,solomon's ,seal4 a1 bud of next year's arial growth2 b1 scar of this year's growth2 c1 d1 e1 scars of arial growth of previous years2 w1 roots4 7 47 ,underground stems4--,although the stem is usually that part of the axis of a plant which is above ground1 there are many exceptions4 ,the bracken fern1 daisy1 coltsfoot1 ,solomon's seal 7,fig4 #eb71 and many other plants have stems which are ordinarily buried in the ground1 giving off leaves above and roots below4 ,in some cases such underground stems become much swollen with stored food-material--manufactured by the leaves in excess of immediate requirements4 ,in the potato1 for example1 certain underground branches of the stem store up starch to such an extent that their ends become fleshy1 ovoid masses some inches in thickness 7,fig4 #ec74 ,the true nature of these tubers is revealed by the buds or 8eyes0 which spring upon them4 ,the buds are arranged spirally--as may be seen by sticking a pin into each and joining up the pins with thread--and when the tubers are kept in a warm1 moist place1 each bud grows out into a new leafy shoot4 ,illustration3 ,,fig4 #ec4--,part of a ,potato plant1 showing the old tuber 7dark7 and several new ones4 7 47 ,the structure of a bulb is easily made out in the onion1 tulip 7,fig4 #ed71 hyacinth1 or daffodil4 ,when such a bulb is cut down the middle1 it is seen to be mainly composed of leaves or leaf-bases1 swollen with stored food4 ,inside these are the young leaves and the flower bud1 which would have expanded next season2 and on the outside are a few thin scale leaves4 ,all these leaves spring from a fleshy button at the base1 which gives off roots below4 ,the button is the flattened stem4 ,when a plant produces a bulb it will generally be found that it flowers either very early or very late in the season2 that is1 at a period which would not be very favourable for the work of the leaves4 ,the flower 7,fig4 #ee7 is produced at the expense of the stored food in the bulb--made in excess of the requirements of the previous season4 ,after the plant has flowered1 the new leaves work until they have made enough food for next season's flower1 and then they also die4 ,illustration3 ,,fig4 #ed4--,longitudinal section of ,tulip bulb4 zk1 modified stem2 zs1 scale leaves2 v1 terminal bud2 k1 young bud2 w1 roots4 7 #a47 ,illustration3 ,,fig4 #ee4--;,daffodil4 7 _/47 ,the so-called bulb of the crocus is technically known as a corm 7,fig4 #ef74 ,it differs from a true bulb in consisting mainly of a fleshy1 rounded stem in which the surplus food made by last year's leaves is stored up4 ,the plant is thus able to flower early1 without waiting for the new leaves to supply food4 ,the swollen stem bears one or more buds1 and the whole is surrounded by tough tunics of scales4 ,when the corm begins to grow1 roots are put out from the base1 and the flowers and--later--the leaves of the buds expand4 ,the foliage leaves continue their work after flowering1 and the food which they make accumulates in the base of the former bud1 which becomes swollen to form the new corm for next year's flower4 ,the leaves then die down1 their bases becoming the tunics of the new corm4 ,illustration3 ,,fig4 #ef4--;,crocus corm1 seen from the side1 from below1 and in longitudinal section4 c1 base of bud1 which will grow into next year's corm2 fd4ch41 food channel2 flr1 flower bud2 l1 young leaves2 rts1 roots2 t1 t1 t1 t1 tunics4 7 47 ,,exercises ,,on ,,chapter ,v4 #a4 ,mention experiments1 which prove that organic substances are formed in the leaves1 and distributed to other parts of a green flowering plant4 ,by what channels are they distributed8 7#ahie7 #b4 ,draw a cross section through the stem of a flowering plant selected by yourself4 ,explain the uses of the chief things seen in the section4 7#ahig7 #c4 ,mention experiments or observations which show by what tissues water ascends to the leaves1 and nutritive substance descends from the leaves4 7#ahig7 #d4 ,by what tissues does water pass along the stem of a tree to the leaves8 ,give proofs of your statements4 7#ahih7 #e4 ,describe the effect of a tight ligature upon a growing hazel stem4 7#ahih7 #f4 ,what proofs can be given that the stem of a tree draws nourishment from the leaves8 7#ahih7 #g4 ,show1 by describing and drawing one example1 that the branch of a tree may preserve a record of past seasons in its wood4 7#aija7 #h4 ,mention an experiment which shows that organic substance formed in the leaves travels down the stem outside the cambium4 7#aija7 #i4 ,obtain thin sections 7e4g4 plane-shavings7 of as many different kinds of wood as possible1 and gum them into a book1 writing under each section the name of the wood and the direction 7transverse1 radial-longitudinal1 or tangential-longitudinal7 of the section4 #aj4 ,make yourself familiar with the appearance and characters of the different kinds of timber used in carpentry and joinery4 #aa4 ,notice the light-brown spots on the bark of twigs of apple and horse chestnut4 ,these are called lenticels2 they are breathing-pores4 ,in how many other trees can you find lenticels8 #ab4 ,observe whether an ivy stem puts out roots only where they can become fixed to a support1 or indiscriminately4 #ac4 ,make a list of plants which you have observed to climb by twining stems1 and note whether they are clockwise or counter-clockwise climbers4 #ad4 ,make careful drawings of all the tendrils you can find1 and try to discover which part of the plant has been modified to form the tendril4 #ae4 ,gently stroke a tendril of the passion flower and write an account of any resulting movement4 #af4 ,mention any three climbing plants which grow wild in this country1 and explain in each case how the plant climbs4 7#ahie7 #ag4 ,what is the difference between 7a7 a thorn1 7b7 a leaf-spine1 and 7c7 a prickle8 ,give examples4 7#ahif7 #ah4 ,enumerate and briefly describe the principal varieties of tendrils1 and explain how they act4 7#ahig7 #ai4 ,if a wire is fastened tightly about a growing branch of a common tree1 and left for two or three years1 what effect will be produced1 and how can the effect be explained8 7#aijd7 #bj4 ,what processes of vegetable growth are accompanied by the presence of sugar8 ,give examples from plants within your own experience4 7,king's ,scholarship1 #aijd7 #ba4 ,what are the chief uses of the vessels of a herbaceous stem8 ,mention observations and experiments in support of your statements4 7#aije7 #bb4 ,how can you demonstrate experimentally that food substances1 formed in the leaves of a tree1 descend to the branches below8 7#aije7 ,,chapter ,,vi4 ,,some ,,common ,,flowers4 #ae4 ,a ,,typical ,,flower4 ,i4 ,the wallflower4--,after noticing the general habit of growth of a wallflower plant 7,fig4 #eg71 and especially the shape and venation of the leaves1 make out the following parts in one of its flowers4 ,on the top of the flower-stalk 7called the receptacle7 are3 ,illustration3 ,,fig4 #eg4--,wallflower4 7 47 7a7 ,four small1 narrow1 purplish leaves1 called sepals4 ,the four sepals together constitute the calyx4 ,take off the sepals one by one4 ,notice that two opposite sepals are bulged out at their bases1 forming pouches containing nectar4 ,try to get out a small drop of nectar on the point of a pencil and taste it4 7b7 ,four showy leaves arranged in the form of a ,maltese cross1 called petals4 ,they are yellow1 or red1 or purplish in colour1 are delicately scented1 and have beautiful velvety surfaces4 ,the four petals together constitute the corolla4 ,take off the petals one by one4 7c7 ,six stamens1 each consisting of a greenish stalk or filament surmounted by a yellow1 boat-shaped body1 called the anther4 ,the anther is a four-chambered box containing an enormous number of tiny yellow grains called pollen grains4 ,two of the stamens are shorter1 and are fixed at a lower level on the receptacle than the remaining four4 ,take off the stamens one by one4 7d7 ,a central pistil1 shaped somewhat like a slender bottle4 ,at the top1 where the cork would come in a real bottle1 is the notched stigma1 slightly sticky4 ,the neck is called the style1 and the part corresponding to the body of the bottle is the ovary4 ,tear open the ovary with a needle to see the ovules1 which in an undisturbed flower would have become seeds4 ,watch bees visiting flowers4 ,does each bee confine itself to one kind 7species7 of flower at each journey1 or does it visit several kinds indiscriminately8 ,try to discover what the bees are doing4 ,avoid alarming them4 ,the work of flowers4--,the roots1 stem1 and leaves of a plant do a great deal of work1 but1 as it is performed for the benefit of the plant itself1 it is all1 in a sense1 selfish work4 ,plants1 however1 like animals1 grow old in time1 and at last die4 ,if they are not to become extinct it is evident that they must devote part of their energies to producing new individuals1 and to sending these forth into the world as well equipped as possible for the battle of life4 ,this unselfish and self-sacrificing part of a plant's life-work is called reproduction2 in the higher plants it is carried out by flowers4 ,the structure of a wallflower blossom4--,the flowers of different groups of plants vary greatly in structure1 but a good general idea of the arrangement of the parts of a flower can be obtained by examining the blossoms of a wallflower plant 7,fig4 #eh74 ,other flowers may afterwards be compared and contrasted4 ,illustration3 ,,fig4 #eh4--,wallflower4 ,a1 branch1 bearing leaves and flowers2 ,b1 flower2 ,c1 longitudinal section of flower2 ,d1 stamens and pistil2 ,e1 fruit2 ,s1 transverse section of stem1 7 47 ,there are evidently at least eight leaves in the flower1 but1 unlike the green foliage leaves1 these are not arranged spirally1 but stand at nearly the same level on the end--called the receptacle--of the flower-stalk4 ,the most external leaves are four in number1 small1 narrow1 and purplish in colour4 ,each of these leaves is called a sepal1 and the four sepals together constitute the calyx of the flower4 ,two opposite sepals are pouched at the base1 forming pockets1 in which a sugary fluid1 called nectar1 collects4 ,before the bud opens1 the calyx is the only part of the flower which is visible4 ,it is probably developed in the wallflower solely for the protection of the more delicate structures within4 ,next1 inside the sepals1 placed alternately with them1 and standing a little higher on the receptacle1 are four showy leaves arranged in the form of a ,maltese cross4 ,these leaves are called petals1 and the four petals together form the corolla4 ,the petals are delicately scented1 and their surfaces have a beautiful velvety sheen4 ,illustration3 ,,fig4 #ei4--;,cross section through a ,wallflower bud4 ,sep1 sepals2 ,pet1 petals2 lg4st41 anther of a long stamen2 sh4 st41 anther of a short stamen2 pol4sac41 pollen sacs2 ,ov1 wall of ovary2 ,ovl1 ovule4 7 #h47 ,when the sepals and petals are removed1 there remain standing on the receptacle six stamens surrounding a centrally-placed pistil 7,fig4 #eh1 ,d74 ,the stamens are the male part1 and the pistil is the female part1 of the flower4 ,each stamen consists of a greenish stalk or filament1 surmounted by a yellow boat-shaped body called the anther4 ,the anther is a box with four compartments 7,fig4 #ei74 ,when it is ripe1 each compartment contains an enormous number of tiny1 yellow grains called pollen grains2 and when the anther bursts 7as it does as soon as the flower opens7 its inner face is covered by the yellow dust of the pollen4 ,the pistil bears a rough resemblance to a slender bottle1 and consists of three distinct parts4 ,the neck of the 8bottle10 called the style1 is short in the wallflower1 and differs from an ordinary bottle-neck in being solid instead of tubular4 ,at the top of the neck1 where the cork would come in a real bottle1 is a body called the stigma4 ,the stigma of the wallflower pistil is hairy1 notched1 and slightly sticky1 from the presence of a sugary solution which forms upon it4 ,the part of the pistil1 corresponding to the body of the bottle1 is the ovary4 ,it contains four rows of little white ovules1 which are destined to become seeds capable of growing up and forming new wallflower plants4 ,the relations of the parts of the flower are well seen in ,fig4 #ei4 ,fertilisation4--,in order that an ovule may become a seed1 its contents must mix with the contents of a pollen grain4 ,the fusion of the two constitutes fertilisation4 ,for fertilisation to take place1 the pollen grain must first of all gain access to the stigma of the pistil4 ,if this be prevented the flowers will wither without forming ripe seeds4 7,this may be proved easily by ,expts4 #ah1 #c and #ba1 #b47 ,the sugary solution at the top of the stigma stimulates the pollen grains to growth1 and each puts out a long tube which grows down the style4 ,the living matter of the grains keeps near the tips of the tubes as these continue their journey down the style4 ,at length the tubes enter the ovary and find the ovules4 ,each ovule has at one end a minute pore 7the micropyle--p4 #f71 and a pollen tube finds this and enters it4 ,the living matter of the pollen tube fuses with that of the ovule in the neighbourhood of the pore1 and fertilisation is effected4 ,it is now easy to understand that the comparatively insignificant stamens and pistil are the all-important parts of a flower4 ,how the wallflower advertises4--,botanists have proved that a flower produces more1 and also better1 seeds when it is fertilised by pollen from another flower of the same species4 ,this is called cross fertilisation4 ,the wallflower relies upon bees for the transference of the pollen from one flower to another2 and it is solely to attract them that the petals are so delicately scented and brilliantly coloured1 and that sweet nectar collects in the sepal-pouches4 ,the gaily coloured petals are therefore advertisement placards which are hung out to attract the attention of bees4 ,a bee comes to a wallflower for the sake of both nectar and pollen--the 8bee-bread40 ,as the bee thrusts its proboscis down between stamens and pistil in search of the sweet liquid in the pouches1 its head is pretty certain to come in contact with1 and to brush off1 some of the pollen dust hanging loose on the inner faces of the anthers4 ,when the bee flies off to another wallflower and continues its search for nectar1 it almost invariably leaves some of the pollen1 from the first flower1 on the hairy and sticky stigma of the second4 ,in almost all cases when a flower is brightly coloured it depends upon the help of insects for cross fertilisation4 #af4 ,,the ,,wallflower ,,family4 ,illustration3 ,,fig4 #fj4--,shepherd's ,purse4 7 47 #a4 ,shepherd's purse4--,compare the shepherd's purse 7,fig4 #fj7 with the wallflower4 ,the flower is very much smaller1 and white1 but the parts have the same arrangement as in the wallflower1 viz41 four sepals1 four petals arranged in the form of a cross1 six stamens 7two short and four long71 and a central pistil1 all arranged separately on the receptacle4 ,look down the plant1 and notice that in the oldest 7lowest7 flowers1 everything but the pistil has dropped off1 and that this has become greatly enlarged to form a fruit4 ,cut some fruits open1 both lengthwise and crosswise1 and observe that each consists of two pocket-like chambers1 separated by a thin partition on which the seeds are borne4 ,notice the manner in which the oldest fruits have opened naturally4 #b4 ,other relatives of the wallflower4--,compare also the flowers and fruits of the stock and candytuft1 and also cress1 mustard1 radish 7,fig4 #fa71 cabbage1 and turnip1 which have been allowed to 8run to seed40 ,examine the roots of the turnip and radish4 ,make a note of the earliest dates on which you see the above plants in flower4 ,the wallflower family4--,the plants of the family to which the wallflower belongs are of very great importance to mankind2 for while not one of them is poisonous1 many are extremely valuable as food-crops4 ,they are all dicotyledons2 that is1 their seeds contain two cotyledons or 8makeshift leaves10 as has already 7,chapter ,i47 been seen in the case of the mustard4 ,the net-like venation of the leaves of the full-grown plant also indicates this4 ,there is a great family likeness between the flowers of this group1 and they are easily recognised 7,fig4 #fa a1 c7 by the cross-shaped corolla and the six stamens 7two short and four long74 ,all the parts of the flower--sepals1 petals1 stamens1 and pistil--are fixed separately on the top of the flower stalk or receptacle4 ,the cross-arrangement of the petals has led to these plants being called ,crucifers 7cross-bearers74 ,the shepherd's purse 7,fig4 #fj7--so-called from the shape of its fruit--is a common weed with small1 white flowers4 ,all stages of the flower may generally be found on the same plant4 ,while at the top the buds may still be unopened1 the flowers below have been fertilised 7in this case generally self-fertilised72 the sepals1 petals1 and stamens--having fulfilled their duties--have fallen off2 the ovules have become seeds1 and the ovule-box or ovary has become a seed-box or fruit1 consisting of two bags separated by a partition which bears two rows of seeds on each side 7,fig4 #fb74 ,illustration3 ,,fig4 #fa4--,wild ,radish4 a1 flower 7nat4 size72 b1 petal2 c1 stamens and pistil 7 #b72 d1 pistil 7 #b72 e1 fruit 7 #a72 f1 cross section of fruit2 g and h1 embryo 7mag47 ,illustration3 ,,fig4 #fb4--;,a1 ,fruits of ,shepherd's ,purse 7 72 ,b1 a single open fruit 7mag472 ,c1 cross section of ,b4 ,illustration3 ,,fig4 #fc4--,root of ,turnip4 7 47 ,illustration3 ,,fig4 #fd4--,root of ,radish4 7 47 ,useful crucifers4--,the turnip and the radish are largely cultivated for their roots 7,figs4 #fc and #fd71 and are then taken out of the ground at the end of their first season4 ,as these plants naturally flower in their second year of growth and then die1 they are called biennials4 ,the production of flowers and fruit is a great strain on a plant1 and it is to prepare for the effort that the turnip and radish store so much food in their roots during the first year as to give them a globular and spindle shape respectively4 ,a carrot is not a crucifer1 but it also adopts this device4 ,the cabbage is grown for its leaves4 ,varieties of the cabbage are ,brussels sprouts1 broccoli1 and cauliflower2 it is the very small flower-buds of the last two which are eaten4 ,cress and white mustard are eaten in the seedling stage4 ,the seeds of the black mustard are ground and eaten as a condiment4 #ag4 ,,the ,,buttercup ,,family4 #a4 ,the buttercup4--,notice the habit of growth1 characters of the leaves1 etc4 ,is the buttercup a dicotyledon8 ,make this observation with all flowering plants4 7,see1 however1 ,chap4 ,,viii41 p4 #afc47 ,in the flowers of a buttercup 7,fig4 #fe7 make out3 7a7 ,the calyx of five green1 separate sepals2 they are the only parts to be seen in young1 unopened buds4 ,take off the sepals of a fully-opened flower one by one4 7b7 ,the corolla of five1 golden-yellow1 separate petals1 alternate with the sepals4 ,notice the nectary--a little pocket--near the base of the upper surface of each petal4 ,take off the petals one by one and observe that they are fixed on the receptacle1 a little higher than the sepals4 7c7 ,the large number of separate stamens1 inserted still higher on the receptacle4 7d7 ,on the top of the receptacle the large number of separate1 flask-shaped bodies1 which together make up the pistil4 ,each of these is called a carpel4 ,watch bees and other insects visiting buttercups and notice how they stand on the flower to obtain the nectar from the nectaries4 ,does a bee on leaving go to another buttercup1 or does it change to another kind of flower8 ,in a flower from which the sepals1 petals1 and stamens have fallen1 notice the compound fruit 7,fig4 #ff71 consisting of ripened carpels4 ,open a carpel with a needle and pick out the single seed4 #b4 ,other plants of the buttercup family4--,notice that in the anemone 7,fig4 #fg7 and marsh marigold 7,fig4 #fh71 the sepals appear to be absent 7the three leaves under the anemone flower are not parts of the flower2 they are called bracts74 ,the apparent petals are really the sepals2 it is the corolla which is absent4 ,observe the large number of stamens1 and notice that the pistil consists of several separate carpels4 ,in what kind of ground have you seen these plants growing wild8 ,illustration3 ,,fig4 #fe4--;,buttercup4 7 _/47 ,the buttercup family4--,the buttercup 7,fig4 #fe7 and its relatives resemble the crucifers 7#a7 in being dicotyledons 7as is indicated 7p4 #dj7 by the venation of the leaves71 and 7#b7 in the fact that1 of the parts which compose the flower1 each group is arranged separately on the receptacle4 ,for example1 the stamens are not connected with either the calyx1 the corolla or the pistil4 ,having noted these points of resemblance1 however1 we are met by some important differences4 ,in the buttercup there are usually five sepals and five petals2 there may be twenty or more stamens2 and the pistil is not a single structure1 but consists of a number of separate parts1 each of which is called a carpel1 and contains a single ovule4 ,the pistil of a crucifer consists of only two carpels2 these are welded together into a single structure1 and until the fruit ripens a slight notch in the stigma is the only external indication that the pistil is in two parts4 ,illustration3 ,,fig4 #ff4--;a1 ,compound fruit of ,buttercup 7 #b72 b1 a carpel 7 #d72 c1 carpel in longitudinal section 7 #d74 ,illustration3 ,,fig4 #fg4--;,anemone4 7 47 ,insects visit buttercups for the sake of nectar and pollen1 and whilst creeping about the flower transfer pollen to the stigmas of the carpels4 ,the insects may have brought some of this pollen from other flowers1 and then cross-fertilisation is caused4 ,if the pollen is derived from the same flower self-fertilisation is the result4 ,after fertilisation the ovules become seeds2 the sepals1 petals1 and stamens drop off2 and the carpels swell up1 forming a dry compound fruit 7,fig4 #ff71 consisting of several nutlets4 ,two other common plants of this family are the anemone 7,fig4 #fg7 and marsh marigold 7,fig4 #fh74 ,in neither of these cases has the flower any petals1 but the calyx has taken on the appearance of a corolla4 ,in the marsh marigold it is large and yellow2 in the anemone it is white or purple4 ,the three green leaves immediately beneath the flower of the anemone are called bracts4 ,they should not be mistaken for sepals4 ,illustration3 ,,fig4 #fh4--,marsh ,marigold4 7 47 ,the plants of the buttercup family are as generally poisonous as the crucifers are wholesome4 ,monkshood is especially poisonous1 and its root has been mistaken1 with fatal results1 for that of horse-radish4 ,it is often noticed that grazing cattle avoid the buttercups in a field4 ,the bitter and disagreeable taste of the leaves is of course a valuable protection to the plant4 #ah4 ,,the ,,pea ,,family4 #a4 ,the garden pea4--,notice again the habit of the plant3 its compound1 net-veined leaves with large stipules1 and its method of climbing by tendrils which are modified leaflets4 ,examine the flower and make out 7a7 the calyx of five united sepals2 7b7 the curiously shaped corolla4 ,the large upper petal is called the standard1 the two at the side are the wings1 and the lowest 7really two locked together7 is the keel2 7c7 the ten stamens4 ,one 7opposite the standard7 is separate2 the remaining nine have the lower parts of their filaments united to form a tube4 ,slit open the filament-tube and remove the stamens1 noticing how they are attached to the other parts of the flower2 7d7 the pistil4 ,slit open the ovary and see the ovules in it4 ,watch the various stages of the formation of the fruit 7pod74 ,illustration3 ,,fig4 #fi4--,vetch4 7 47 ,watch bees visiting the flowers4 ,the insect alights on the wings1 and its weight pulls them down and lowers the keel1 bringing the stamens against the bee's body4 ,cut a complete flower down the middle with a sharp knife1 and notice that calyx1 corolla1 and stamens seem not to be inserted separately on the receptacle1 but to spring from a common base4 #b4 ,other plants of the pea family4--,examine also bean1 vetch 7,fig4 #fi71 meadow vetchling 7,fig4 #gj71 clover 7,fig4 #ga71 laburnum 7,fig4 #gc71 and broom4 ,compare the habits of growth of the plants1 and notice that they all have the same peculiar shape of flower4 ,dissect a flower of each4 ,notice that in laburnum and broom the ten stamens are all united4 ,in clover the flowers are in heads4 ,notice how the leaflets of the clover plant close at sunset4 #c4 ,fertilisation4--,dig up several red clover plants in early summer and pot them4 ,cover about half the plants with gauze1 so fixed on wire frames that insects cannot get inside1 and then put all the plants together where they will get plenty of sun4 ,water them regularly1 and notice which plants ripen seed4 ,how do you account for the differences8 ,illustration3 ,,fig4 #gj4--,meadow ,vetchling4 7 47 ,illustration3 ,,fig4 #ga4--,red ,clover4 7 47 ,illustration3 ,,fig4 #gb4--;,bird's-foot ,trefoil4 #a1 flowering branch 7 72 #b1 flower2 #c1 pistil and stamens2 #d1 pistil 7 #a_/72 #e1 fruit 7 72 #f1 corolla2 a1 standard2 b1 wings2 c1 keel2 #g1 diagram of flower4 ,illustration3 ,,fig4 #gc4--;,flowering branch of ,laburnum2 st1 standard2 w1 wings2 k1 keel2 #a1 #b1 #c1 the flower from different points of view4 7 47 ,the pea family4--,plants of the pea family are found in all quarters of the earth4 ,they are of very diverse size and habit of growth2 the laburnum1 for example1 is a tree2 the gorse is a bush2 the broad bean has a strong1 erect1 herbaceous stem2 the pea is a weak-stemmed climbing plant2 the clovers are small herbs with flowers forming 8heads40 ,most of the members of the family agree in having a 8butterfly-shaped0 corolla 7,figs4 #gb and #gc71 which consists of three well-marked parts1 viz41 a large standard1 a pair of wings1 and two closely-connected petals which form a boat-shaped keel4 ,there are ten stamens1 and the filaments of nine of these usually cohere to form a tube surrounding the ovary4 ,in the laburnum1 gorse1 and a few others1 all the ten stamens are united4 ,when a bee visits the flower1 in search of nectar1 it alights on the 8wings0 of the flower1 and its weight depresses these and pulls down the keel4 ,the anthers of the stamens are so placed with respect to the keel that this results in a mass of pollen being scraped off the anthers and forced out at the beak of the keel1 or in the stamens being suddenly liberated and scattering pollen on the bee4 ,the pollen sticks to the bee's body1 and some of it is almost certainly transferred to the stigma of the next flower visited4 ,the quaint shape of the corolla is thus definitely adapted to the visits of insects2 for the nectar is so placed that to obtain it the insect must carry off some of the pollen4 ,the calyx1 corolla1 and stamens are not obviously--as in the wallflower and buttercup--inserted separately on the receptacle1 but seem to spring from a common base4 ,the fruit is a pod 7,fig4 #c71 which opens when ripe along both margins and liberates the seeds4 ,laburnum seeds are poisonous1 but the seeds of many other plants of the family 7peas1 beans1 lentils1 etc47 are valuable foods4 #ai4 ,,the ,,rose ,,family4 #a4 ,the wild rose 7,fig4 #ge74--,with a sharp knife cut vertically through the middle of a wild rose4 ,notice that the receptacle forms a deep cup1 and that the carpels of the pistil are enclosed in the cup4 ,from the edge of the cup spring the five sepals1 five petals1 and numerous stamens4 ,what is the great difference between a rose and a buttercup8 ,trace the formation of the succulent fruit or hip from the receptacle cup of the flower4 ,cut through a rose hip1 and observe the ripened carpels in the interior4 #b4 ,the blackberry4--,similarly examine a blackberry flower 7,fig4 #gf74 ,this is still more like a buttercup1 but--as in the rose and the pea--the calyx1 corolla1 and stamens seem to spring from a common base1 and not to be inserted separately on the receptacle4 ,trace the formation of the compound fruit1 and notice that each part is like a little plum or cherry4 #c4 ,the cherry4--,similarly examine cherry blossom 7,fig4 #gg74 ,the pistil consists of one carpel1 and is fixed at the bottom of the receptacle-cup1 while the calyx1 corolla1 and stamens are fixed on the margin of the cup4 ,trace the origin of each part of the fruit4 ,compare the plum and apricot4 ,illustration3 ,,fig4 #gd4--;,apple ,blossom4 7 47 ,illustration3 ,,fig4 #ge4--,wild ,rose4 7 47 #d4 ,the apple and pear4--,cut vertically through an apple blossom 7,fig4 #gd7 or pear blossom 7,fig4 #gh71 and notice that the ovary is embedded in the receptacle1 and that calyx1 corolla1 and stamens are fixed on the top of this4 ,cut across the ovary and see the five divisions 7carpels74 ,the eatable part of the fruit is the swollen receptacle4 ,compare the hawthorn4 ,the wild rose4--,the plants of the rose family are1 most commonly1 woody trees or shrubs4 ,the leaves are provided with stipules in nearly all cases4 ,the wild rose 7,fig4 #ge7 may be taken as a type of the group4 ,it bears a superficial resemblance to a buttercup1 but on dissection considerable difference in the arrangement of the parts is seen4 ,in the rose1 the receptacle is urn-shaped2 from the margin of the urn spring the five sepals1 five petals1 and numerous stamens2 while inside the urn the separate carpels of the pistil are inserted4 ,in the blackberry 7,fig4 #gf71 raspberry1 and strawberry the receptacle is knob-shaped1 and the carpels are arranged on the outside of the knob1 somewhat as in the buttercup4 ,here again1 however1 the calyx1 corolla1 and stamens differ from those of the buttercup in seeming to arise from a common base4 ,illustration3 ,,fig4 #gf4--;,blackberry4 #a1 flowering branch 7 72 #b1 longitudinal section of flower 7 #a72 #c1 fruit 7 72 #d1 diagram of flower4 ,illustration3 ,,fig4 #gg4--;,cherry4 #a1 flowering branch 7 72 #b1 longitudinal section of flower2 #c1 longitudinal section of fruit4 ,the differences between the rose1 blackberry1 raspberry1 and strawberry are more marked when the pistil has become a fruit4 ,the fleshy part of the rose hip is the urn-shaped receptacle which encloses the ripened carpels4 ,in the case of the blackberry and raspberry the receptacle is dry1 and is surrounded by the compound fruit 7,fig4 #gf1 #c7 of the several bodies like little plums or cherries4 ,the eatable part of the strawberry fruit 7,fig4 #add7 is the swollen receptacle1 on the outside of which are the little yellow nutlets derived from the carpels of the flower4 ,in the cherry 7,fig4 #gg71 plum1 and apricot the pistil consists of only one carpel1 which is enclosed in the urn-like receptacle4 ,after fertilisation1 the greater part of the wall of the ovary becomes fleshy1 and one of the two ovules contained in it becomes a seed4 ,the 8stone0 is formed from the innermost part of the ovary wall4 ,the apple 7,fig4 #gd7 and pear 7,fig4 #gh7 have their five carpels embedded in the receptacle1 and the rest of the flower stands on this part4 ,the eatable portion of the fruit is the swollen receptacle4 ,the hawthorn has usually only two carpels1 and in the fruit the part derived from the receptacle becomes hard and horny4 ,in other respects it is very similar to the apple4 ,illustration3 ,,fig4 #gh4--,pear4 #a1 flowering branch 7 72 #b1 longitudinal section of flower2 #c1 longitudinal section of fruit2 #d1 diagram of flower4 ,the rose family is widely distributed1 especially in temperate regions4 #bj4 ,,the ,,parsley ,,family4 #a4 ,the poison hemlock4--,examine this plant 7,fig4 #gi7 very carefully1 remembering that it is poisonous4 ,notice the general habit of growth2 the characters of the sheathing1 compound leaves2 the hollow ribbed stem2 and also the arrangement of the flowers1 which is characteristic of the family4 ,from the top of a main flower-stalk several smaller stalks come off together1 like the ribs of an umbrella4 ,from the top of each of these spring the stalklets which bear the small white flowers4 ,notice the bracts at the points of origin of the stalks4 ,examine the flowers1 and watch insects visiting them4 ,which insects are most commonly found on the flowers8 ,compare the cow parsnip1 the water hemlock1 carrot1 parsley1 parsnip1 and celery1 carefully noting the points of resemblance and difference4 ,illustration3 ,,fig4 #gi4--,poison ,hemlock4 7 47 ,illustration3 ,,fig4 #hj4--;,hedge ,parsley4 7 47 ,the parsley family4--,the plants of this family may be recognised easily by the arrangement of the flowers4 ,several stalks spring together from the top of the main flower stalk and each of these again gives rise at its tip to a number of smaller stalks1 at the ends of which the small flowers are borne 7,figs4 #gi and #hj74 ,the flowers are fertilised by the aid of insects1 and as the nectar is on the surface it is accessible to small insects such as flies1 beetles1 etc4 ,the flowers are rendered more conspicuous by being placed close together4 ,the stems are usually hollow1 and the leaves are alternate1 and generally compound1 with sheathing bases4 ,many of the plants of this family are very poisonous1 and such should be carefully distinguished and whenever possible exterminated4 ,the poison hemlock 7,fig4 #gi7 varies in height from two to seven feet4 ,it has a hollow stem which is spotted with purple in the lower part1 and when bruised the leaves give off a smell like that of mice4 ,cattle are often poisoned by eating the plant in hay1 and children have been poisoned even by blowing whistles made from the stem4 ,the water-hemlock is extremely poisonous4 ,it grows along the sides of pools4 ,the stem is hollow1 and the leaflets of the compound leaves are finely toothed4 ,the root is a cluster of fleshy swellings1 and has unfortunately a rather pleasant taste4 ,other poisonous plants of the family are the water dropwort and the fool's-parsley4 ,among the harmless and useful members of the group are celery 7when cultivated71 carrot1 parsnip1 and parsley4 #ba4 ,,the ,,primrose ,,and ,,cowslip4 #a4 ,the primrose4--,examine the habit 7,fig4 #ha7 of the plant1 its underground stem1 its spoon-shaped leaves--arranged in a rosette--and the manner in which the flowers spring from the stem4 ,in the flower make out 7a7 the calyx1 #e-pointed and with united sepals2 7b7 the corolla1 consisting of #e petals united below into a tube4 ,tear down the corolla-tube to see 7c7 the #e stamens inserted on the corolla-tube4 ,in some 78thrum-eyed07 flowers the anthers are at the top of the tube2 in others 78pin-eyed071 they are halfway down2 7d7 the pistil1 consisting of stigma1 style1 and ovary4 ,in thrum-eyed flowers the style is short and the stigma is halfway down the corolla-tube2 while in pin-eyed flowers the style is long and the stigma is at the top of the tube4 ,do you find both pin-eyed and thrum-eyed flowers on the same plant1 or does one plant bear only one kind8 #b4 ,fertilisation4--,cover up a plant of each kind with gauze1 to keep insects from the flowers1 and notice whether the covered flowers ripen seeds like the others4 #c4 ,the cowslip4--,compare the cowslip 7,fig4 #hc71 and notice that the main stalk gives off from the same point several smaller stalks1 each of which bears a flower4 ,observe that the cowslip also has both pin-eyed and thrum-eyed forms of flowers4 ,illustration3 ,,fig4 #ha4--,primrose4 7 47 ,the primrose and cowslip4--,in the primrose we have flowers of a type differing from all those previously considered in this chapter4 ,not only are the sepals joined together to form a five-toothed calyx-tube1 but the five petals are also joined together to form a corolla-tube1 and the stamens are fixed on the corolla-tube4 ,there are two kinds of primroses1 known to country children as pin-eyed and thrum-eyed flowers respectively 7,fig4 #hb74 ,the two forms grow on separate plants4 ,in a pin-eyed primrose the style is long1 and the stigma--looking somewhat like the head of a pin--is at the top of the corolla-tube2 while the stamens are halfway down4 ,the thrum-eyed primroses have their stamens at the top1 while the stigma of the pistil is halfway down the tube1 exactly opposite the place where1 in the pin-eyed form1 the stamens are inserted4 ,this curious state of things was a great puzzle to botanists until ,darwin cleared up the mystery4 ,a bee1 thrusting its proboscis down a pin-eyed primrose in search of the nectar at the bottom1 dusts it with pollen about halfway down--just in the place which will come in contact with the stigma when the animal visits a thrum-eyed flower4 ,and the pollen from the thrum-eyed form adheres to the part of the bee which will presently touch the stigma of a long-styled flower4 ,this beautiful and simple arrangement makes it practically certain that each primrose shall be fertilised by pollen from the other form4 ,in the thrum-eyed form1 however1 it is possible for pollen to fall upon the stigma and produce self-fertilisation4 ,illustration3 ,,fig4 #hb4--;,chinese ,primrose4 ,l1 long-styled 78pin-eyed07 flower2 ,k1 short-styled 78thrum-eyed07 flower2 ,g1 stigma2 ,s1 anthers4 ,illustration3 ,,fig4 #hc4--;,cowslip4 7 47 ,it is obvious that the cowslip 7,fig4 #hc7 is closely related to the primrose4 ,the difference lies chiefly in the character of the flower-stalk4 ,in the cowslip this is long1 and it bears at its top several stalklets1 each of which ends in a flower4 ,as in the primrose1 cross-fertilisation is secured by some flowers being pin-eyed 7long styled7 and others thrum-eyed 7short styled74 #bb4 ,,the ,,daisy ,,and ,,its ,,relatives4 #a4 ,the daisy4--,take up several daisy plants 7,fig4 #hd7 entire1 and wash away the soil from the roots4 ,notice how the stems--some of which are underground--are connected together4 ,draw a leaf4 ,what advantage is it to the plant to have leaves of the shape noticed8 ,cut vertically through the 8head10 and notice that what is usually called the 8flower0 really consists of a large number of small flowers4 ,illustration3 ,,fig4 #hd4--;,daisy4 7 47 ,the central or disc flowers are tubular4 ,which disc flowers open first1 those near the middle or those nearer the edge of the disc8 ,pick off a flower and notice the #e-toothed corolla4 ,tear the corolla down with a needle1 and observe the tiny stamens 7#e7 fixed on the corolla-tube4 ,the anthers are joined together4 ,notice the divided stigma of the pistil4 ,the white and pink ray flowers have strap-shaped corollas4 ,they have no stamens1 but each has a pistil like that of a disc flower4 ,what do you think is the object of the ray flowers being so conspicuous8 ,why do they close over the disc at night8 ,notice the large number of green bracts below the disc4 #b4 ,the dandelion4--,compare the dandelion 7,fig4 #he74 ,notice that all the flowers are strap-shaped1 like the ray flowers of the daisy4 ,pull one out1 and make out the strap-like corolla1 the five stamens with joined anthers1 and the double stigma 7,fig4 #hf1 #b74 ,notice the tuft of fine hairs below the corolla and above the knob-like ovary4 ,the tuft of hairs is the top of the calyx-tube4 ,when the flowers have been fertilised1 the yellow corollas wither1 and each calyx-tube elongates until it is about an inch long1 the tuft of fine hairs being still at the top 7#d74 ,blow a 8clock10 and notice how easily the fruits are detached from the disc and how slowly they settle4 ,what advantage is this to the plant8 ,illustration3 ,,fig4 #he4--;,dandelion4 7 47 #c4 ,the thistle4--,compare the thistle 7,fig4 #hg74 ,the bracts are very prickly4 ,is this an advantage8 ,are the flowers tubular or strap-shaped8 ,examine the fruits 78thistle down07 and compare with those of dandelion4 ,the daisy4--,what is generally called the 8flower0 of the daisy 7,fig4 #hd7 really consists of a very large number of small separate flowers set close together on a flattened disc or receptacle4 ,the group of flowers is called a head4 ,on the lower surface of the head are several green leaves1 or bracts1 which protect the bud before it opens4 ,the flowers of a daisy-head are of two kinds4 ,the white or pink straps set round the edge of the head are the corollas of the ray flowers4 ,they have no stamens1 but a pistil with a divided stigma is present in each4 ,the disc flowers are yellow and tubular4 ,the corolla consists of five united petals4 ,on it are fixed five stamens1 the anthers of which are joined together4 ,the pistil is like that of a ray flower4 ,no calyx is present in either the ray or disc flowers of the daisy4 ,the daisy is fertilised by the aid of insects which are attracted by the strap-like corollas of the ray flowers4 ,illustration3 ,,fig4 #hf4--;,dandelion4 #a1 two heads and a leaf 7 72 #b1 a single flower 7 #b72 #c1 fruit 7 _/72 #d1 receptacle1 with one fruit4 ,the dandelion 8flower0 7,fig4 #he7 is also really a head consisting of a great many separate flowers4 ,there are often between two and three hundred of these little flowers present in one head4 ,below the head are several green bracts1 and these protect the flowers both in the bud and at night 7,fig4 #hf74 ,the flowers of the dandelion are all of one type4 ,the corolla is strap-shaped 7,fig4 #hf1 #b71 and of a beautiful yellow colour to attract insects4 ,on the end of the strap may be seen five small teeth which indicate that it really consists of five united petals4 ,at the base of the corolla is a tuft of fine hairs1 which is the top of the calyx-tube1 and at the bottom of the flower is a little white knob--the ovary4 ,the five stamens are fixed on the inside of the corolla tube4 ,their anthers are united to form a tube through which the upper part of the style1 and the forked stigma protrude4 ,illustration3 ,,fig4 #hg4--,thistle4 7 47 ,illustration3 ,,fig4 #hh4--,tubular flower of ,thistle 7magnified74 ,it will be noticed that a dandelion flower is practically like a ray flower of a daisy1 with the addition of calyx and stamens4 ,the thistle 7,fig4 #hg7 is another common member of the family4 ,its bracts are prickly1 and are a protection from the attacks of animals4 ,the flowers 7,fig4 #hh7 are all tubular4 ,the common thistle distributes its fruit by a plume of radiating fine hairs--the calyx4 ,the fruit is commonly known as 8thistle down40 ,the ,compositae1 as plants of this family are called1 are found in all parts of the world4 ,the family is the largest in the vegetable kingdom1 and many of the plants included in it are of considerable importance4 #bc4 ,,the ,,foxglove ,,family4 #a4 ,the foxglove4--,examine a flowering plant of foxglove 7,fig4 #hi74 ,notice the general habit of growth4 ,in the flower make out the five-lobed calyx1 the irregular corolla with five petals joined to form a tube1 the four stamens 7two long and two short7 fixed on the corolla tube 7,fig4 #ij71 and the form and attachment of the pistil4 ,watch bees visiting the flower4 #b4 ,the speedwell4--,compare the speedwell 7,fig4 #ia71 and notice that the corolla is more nearly regular than is the case with the foxglove1 that it consists of four combined petals1 and that two stamens are fixed upon it4 #c4 ,the musk4--,compare the musk4 ,dissect a flower and notice the forms and positions of the parts4 ,especially examine the pistil with its two-lobed stigma4 ,with a hair1 carefully touch one of the lobes of the stigma of a growing flower and watch how the lobes close4 ,do the lobes open again8 ,put a little pollen on1 and watch to see if this time the lobes open again after closing4 ,watch insects visiting the flowers and try to make out how the pollination of the stigmas is brought about4 ,the foxglove family4--,in the primrose and the disc-flowers of the daisy are seen examples of regular1 dicotyledonous flowers with five petals fused to form a corolla-tube1 and with five stamens inserted on the corolla4 ,in the strap-shaped flowers of the dandelion the corolla is irregular1 but still consists of five fused petals and bears the five stamens4 ,illustration3 ,,fig4 #hi4--;,foxglove1 7 47 ,the foxglove 7,fig4 #hi7 and its relatives have also irregular corollas of joined petals on which the stamens are fixed2 but the stamens are usually only four in number1 two being long and two short as in ,fig4 #ij1 b4 ,in the foxglove the stamens ripen and shed their pollen before the pistil of the same flower is mature4 ,this prevents self-fertilisation1 but bumble bees in passing from one flower to another convey the ripe pollen of the younger flowers to the stigmas of flowers which are ready for fertilisation4 ,illustration3 ,,fig4 #ij4--;,foxglove4 a1 flower2 b1 corolla cut open and spread out2 c1 calyx and pistil2 d1 fruit2 e1 section of fruit4 7 47 ,the pretty blue speedwell 7,fig4 #ia7 is closely related to the foxglove1 but its corolla has only four lobes instead of five1 and some times these seem of almost equal size at the first glance4 ,generally1 however1 the corolla is very plainly irregular4 ,the speedwell has only two stamens1 while mullein has five4 ,illustration3 ,,fig4 #ia4--,speedwell4 7 47 ,calceolaria1 musk1 gloxinia1 and snapdragon--other members of the family--are often cultivated in gardens4 ,the flowers of the musk are especially interesting1 because they show so well what is called irritability1--the power which all living things possess of acting in a definite manner in response to a definite irritation or stimulus4 ,we have already seen good examples of plant-irritability in the way a climbing stem winds itself round a support4 ,the stigma of the musk flower has two flaps4 ,if these are touched with a hair or bristle they quickly close together1 but presently open again as if they had found out that they had been tricked4 ,when1 however1 a little pollen is put on the flaps they close finally1 for their whole object is accomplished4 ,some of the plants in this family are poisonous1 the foxglove being especially so in all its parts4 #bd4 ,,the ,,labiates4 #a4 ,the deadnettle4--,examine a deadnettle plant 7,fig4 #ib74 ,notice the habit of growth1 and write down a description of the shape and appearance of the stem and leaves4 ,what is the shape of the flower8 ,how many sepals1 petals1 and stamens has it8 ,do the stamens ripen first1 or does the pistil8 ,what insects do you find visiting the flower8 ,try to find out how they pollinate the stigma4 ,illustration3 ,,fig4 #ib4--,white ,deadnettle4 7 47 #b4 ,other labiates4--,compare the sage 7especially in respect of its relation to bees71 rosemary1 thyme1 marjoram1 and mint1 and distinguish between their various flowers1 leaves1 and scents4 ,the labiates4--,the deadnettle is a type of an easily recognisable family of plants4 ,the stem is square in section1 and the leaves are arranged upon it in opposite pairs at right angles to each other4 ,the plants are hairy and have distinctive odours4 ,the aroma of thyme1 mint1 marjoram1 sage1 etc41 has led to the plants being used for flavouring food4 ,none of the labiates is poisonous4 ,the shape of the flower is very characteristic1 and is specially adapted to the visits of bees4 ,the flowers are so modified that the lowest part of the corolla forms a platform on which the bee may conveniently alight1 while the upper petals unite into an arched roof which protects the pistil and stamens4 ,illustration3 ,,fig4 #ic4--,pollination of the ,sage by a bumble bee4 ,for explanation see text4 7 #a47 ,the mechanism of cross-pollination is particularly well shown in the case of the sage 7,fig4 #ic74 ,the flower contains four stamens1 but two of these have lost their use1 and the others are modified in a strange manner4 ,the whole stamen has somewhat the shape of a capital ,t1 and at each end of the cross-piece is a pollen box4 ,usually the cross-piece 7c1 ,fig4 #ic1 #c7 is not at right angles to the filament1 but is swung up--the junction acts as a hinge--until it is nearly vertical 7,fig4 #ic1 #d74 ,the pollen box s1 which is at the lower end of the cross-piece c when this is vertical1 contains hardly any pollen4 ,the entrance to the honey tube is thus guarded by two pillars1 the filaments 7f7 of the stamens2 and the lower pollen box 7s7 of the cross-piece of each stamen is directly in front of the bee's head as it stands on the lower lip of the flower4 ,when it pushes forward its head to reach the nectar it comes in contact with the lower pollen boxes1 and the cross pieces swing round on their hinges1 bringing the upper pollen boxes down with a smack on the bee's back 7,fig4 #ic1 #a71 and sprinkling it liberally with pollen dust4 ,having shed their pollen the stamens shrivel up1 and the pistil comes to maturity4 ,as the pistil ripens1 the stigma arches over 7,fig4 #ic1 #b7 so as to scrape along the back of any bee visiting the flower for the nectar1 and thus to wipe off the pollen which has been brought from a younger flower4 #be4 ,,the ,,lily ,,and ,,snowdrop ,,families4 #a4 ,the hyacinth4--,take up a plant 7,fig4 #id7 entire and notice the underground bulb with roots springing from its lower surface1 and the long narrow leaves4 ,is the venation of the leaves parallel or net-like8 ,is the hyacinth a monocotyledon or a dicotyledon8 ,see the bract at the base of each flower-stalklet4 ,examine the flower4 ,its leaves cannot be distinguished into calyx and corolla1 but are quite similar to each other in size1 shape1 and colour4 ,they are therefore called the perianth4 ,the perianth leaves are united to form a tube4 ,tear down the tube to see the six stamens fixed on it4 ,are they all on the same level8 ,examine the pistil and cut the ovary across to see the ovules in the three joined carpels4 ,which is fixed at the higher level1 the perianth or the base of the pistil8 #b4 ,other plants of the lily family4--,examine also the white lily1 tulip1 star of ,bethlehem1 and lily of the valley1 and notice that in spite of small differences they are all monocotyledons 7how do you know this87 and all have the perianth fixed below the ovary4 #c4 ,the snowdrop4--,compare and contrast the snowdrop 7,fig4 #ie74 ,make out that it is a monocotyledon1 but that its perianth is inserted above the ovary4 ,this is the great point of difference from the lily family4 ,notice also how the stamens are fixed4 ,illustration3 ,,fig4 #id4--,wild ,hyacinth4 7 _/47 ,illustration3 ,,fig4 #ie4--,snowdrops4 7 47 #d4 ,other plants of the snowdrop family4--,examine the daffodil 7,figs4 #ee and #if7 and narcissus4 ,arising from the short perianth tube of the daffodil is a longer one which is often mistaken for a corolla2 it is called the corona4 ,none of the flowers hitherto described contains anything corresponding to a corona4 ,the corona in the narcissus is short4 ,as in the snowdrop1 the perianth is fixed above the ovary4 ,observe how the stamens are fixed1 and notice the dry leaf beneath the flower4 ,the lily family4--,either the wild hyacinth 7,fig4 #id7 or the cultivated single hyacinth may be taken as a good representative of this family4 ,the first point which strikes the student on examining the general 8habit0 of the plant is the character of the long sheathing leaves4 ,their veins do not form an obvious network1 such as is seen in the leaves of dicotyledons1 but run lengthwise and roughly parallel to each other in the manner characteristic of grasses and other monocotyledons 7p4 #dj74 ,the leaves are narrow1 and are not divided into blade and stalk2 they and the flower stalk spring from an underground bulb 7p4 #hd7 which consists chiefly of the swollen leaf-bases of a previous season4 ,a separate calyx and corolla are not to be distinguished in the flower2 the six leaves being all alike in size1 shape1 and colour4 ,these six leaves hence receive a special name1 and are called the perianth4 ,the perianth leaves are united into a tube1 on the inside of which the six stamens are arranged in two series of three each4 ,in the middle of the flower1 and fixed above the insertion of the perianth1 is the pistil1 which consists of three united carpels4 ,illustration3 ,,fig4 #if4--;,daffodil flower1 cut down the middle4 7 47 ,it will be noticed that the parts of the flower are in threes4 ,there are six united perianth leaves 7three inner and three outer71 six stamens 7also in two series71 and three united carpels4 ,this is very common--though by no means universal--in monocotyledons4 ,all the plants of the lily family--including the tulips1 the true lilies1 lily of the valley1 asparagus1 onion1 etc4--agree in being monocotyledons1 and in their flowers having a conspicuous perianth 7for attracting insects7 and six stamens1 and in the ovary being above the insertion of the perianth4 ,the snowdrop family4--,plants of this family are very similar to those of the lily family2 in fact in only one respect can any sharp line of demarcation be drawn between the two groups2 in the snowdrop and its relatives the other parts of the flower stand upon the ovary 7,fig4 #if74 ,the flowers of some plants of the family1 e4g4 the daffodil1 possess a tubular outgrowth of the perianth1 which is called a corona4 ,it is often mistaken for a corolla4 #bf4 ,,the ,,arum ,,lily4 #a4 ,the cuckoo-pint4--,examine the habit of the plant1 and then cut open the 8flower40 ,you will probably find a number of small flies inside4 ,examine the central rod and make out the stamens and pistils on it4 ,which ripen first8 ,the arum 8lily10 with its humble relative the cuckoo-pint 7,fig4 #ig71 merits special mention2 for1 in the first place1 it is not a lily at all1 and secondly1 it furnishes an extremely interesting example of pistils coming to maturity before anthers1 which is rather rare4 ,what is generally called the 8flower0 of the cuckoo-pint1 or 8lords and ladies10 consists of a big curled leaf with a purple rod sticking up in the middle4 ,near the bottom of the rod1 but hidden from sight by the lower part of the leaf1 the true flowers arise4 ,the chamber containing them is shut in by a series of stiffish hairs which point downwards4 ,below the hairs the rod supports a series of anthers and1 near the bottom of the chamber1 several pistils4 ,on cutting open the chamber one nearly always finds a number of small flies1 covered with pollen1 which they have brought from another arum4 ,the flies get in easily enough1 but once in they are prisoners1 for the down-pointing hairs prevent them from getting out again4 ,the pistils near the bottom of the rod ripen1 and are fertilised by the pollen the flies have brought4 ,after a time the anthers above ripen and shed their welcome pollen on the hungry captives4 ,soon after this the hairs at the top of the chamber shrivel up1 and the flies1 once more covered with pollen1 are at liberty to return to the outer world and1 untaught by experience1 to repeat the experiment on another 8flower40 ,illustration3 ,,fig4 #ig4--;,a1 ,cuckoo-pint4 7 47 ,in ,b1 the front of the leaf is cut away to show the rod sp 7,c74 ,f1 female flowers2 ,m1 male flowers2 st1 undeveloped male flowers4 ,,exercises ,,on ,,chapter ,,vi4 #a4 ,describe the arrangement of the stamens in the wallflower1 the sage1 and the primrose4 #b4 ,describe the pistil of the deadnettle1 the primrose1 and the shepherd's purse4 7#ahie7 #c4 ,in what respects does the flower of the buttercup differ from that of the wild rose8 #d4 ,explain the arrangement and form of the stamens in some flower selected by yourself4 ,describe the structure and contents of the anther4 7#ahig7 #e4 ,where is the pollen of a flower formed8 ,what is its use8 7#ahih7 #f4 ,name one or two plants which do not ripen seed if insects are excluded1 and show why they do not4 7#ahih7 #g4 ,name two plants which would be in flower in each of the months from ,march to ,august inclusive1 and state in what localities they would be found8 7,n4,f4,u47 #h4 ,in what ways are insects attracted to visit flowers8 ,give examples1 with an explanation and drawing in each case1 of any special structure which may be a means of attraction4 7,n4,f4,u47 #i4 ,name ten flowering plants which may be found1 7a7 in a shady wood1 7b7 in a meadow1 in late spring4 #aj4 ,name any fresh specimens of flowers which usually could be obtained growing wild in ,march1 ,june1 and ,october respectively4 7,n4,f4,u47 #aa4 ,what wild flowers would you expect to find in early ,april in your part of the country8 ,in what kinds of places would you look for them8 7,n4,f4,u47 #ab4 ,name the parts of any flower you have examined which are concerned with the production of seed4 7,king's ,scholarship1 #aijd7 ,,chapter ,,vii4 ,,grasses4 #bg4 ,,the ,,everyday ,,life ,,of ,a ,,grass4 #a4 ,general features4--,pull up a sod of couch grass or of ,yorkshire fog and clear away the earth as well as possible4 ,notice the fibrous1 creeping branches or stolons1 and the bunches of fine roots4 ,in summer the plant sends up also erect branches called haulms1 which bear leaves and flowers4 ,examine the shape of the leaves and notice their parallel venation1 which indicates 7p4 #dj7 that the plant is a monocotyledon4 ,observe how the leaves are borne on the haulms4 ,each leaf arises at a knot 7node7 which is slightly swollen4 ,the first part of the leaf is a sheath which encloses the haulm up to perhaps the next knot4 ,then the leaf-blade stands out from the haulm4 ,turn back the blade slightly and notice at this point a little strap1 the ligule 7,fig4 #ih71 on the upper surface of the leaf-blade4 ,notice the variation in the size and shape of the ligules of different kinds of grass4 ,pull the haulm until it gives way1 and draw the broken part out of the leaf-sheaths4 ,chew the end1 and notice the taste of sugar4 ,cut across haulms of various ages4 ,the young haulms are solid2 the old ones are hollow except at the nodes1 where there is a horizontal shelf4 ,notice this also in a bamboo cane1 which is the haulm of a large tropical grass4 ,in spring1 mark a young haulm1 so that you can recognise it1 and measure it day by day4 ,note the measurements made on various days1 and also the date of opening of the flowers4 #b4 ,different grasses4--,learn to recognise different grasses1 not only by the way in which the clusters of flowers are borne on the haulms 7,figs4 #ajb to #aaj7 and by their colours1 but also by the general appearance of the plant when it is not flowering2 the size and shape of the leaves1 the character of the ligules1 the manner of rooting1 etc4 ,again germinate grains of wheat1 and especially notice the single cotyledon1 the leaves1 and roots 7p4 #ba74 ,importance of grasses4--,it is impossible to over-estimate the value to man of the various grasses4 ,from the earliest times he has obtained his staple food from the grains of such cereals as wheat1 barley1 oats1 rice1 and maize2 and his flocks and herds have grazed upon the nutritious herbage of the plains4 ,the numberless applications of such large tropical grasses as the bamboo and the sugar-cane are also well known4 ,sugar occurs very generally in grasses4 ,it can easily be recognised even in ordinary meadow-grass by pulling out the upright 8stem0 from the sheathing leaves1 and chewing the tender end4 ,illustration3 ,,fig4 #ih4--,part of a ,grass ,stem and ,leaf4 h1 haulm2 s1 part of leaf-blade2 l1 ligule2 v1 leaf-sheath2 k1 node-like swelling at the base of the leaf-sheath4 7 474 ,the general characters of grasses4--,in this country1 grasses are usually herbs not more than three or four feet high4 ,they have abundant leaves1 which are long1 narrow1 and pointed at the end2 they have parallel veins like the leaves of most other monocotyledons4 ,the roots1 too1 are of the usual monocotyledonous type--springing in bunches from the base of the stem1 not branching from a main tap-root4 ,most grasses spread by prostrate creeping branches or stolons 7p4 #hc71 which spring from the axils of leaves and then run along beneath the soil4 ,at some little distance from the parent shoot1 the stolon forms roots below and a new shoot above4 ,other stolons arise in the axils of the leaves of the new shoots1 and so the process is repeated4 ,in this way such grasses become thoroughly established in the soil1 and--if they are of the undesirable species which are classed as 8weeds0--cause much trouble4 ,this habit of growth is1 however1 useful in binding together the sand and earth of embankments1 etc41 into a compact mass4 ,the new shoots of stolon-bearing grasses are of two kinds4 ,throughout the greater part of the year they consist of tufts of leaves2 but1 in the spring and summer1 there are also produced erect branches--commonly known as stems1 but better called haulms--which bear leaves in the 8alternate0 manner4 ,the point at which a leaf springs from the haulm is called a knot or node2 it is usually swollen4 ,the distance between two knots is1 of course1 an internode4 ,extra roots are often given off from the lower nodes of the haulm4 ,the lowest part of the leaf is a cylindrical1 and generally split1 sheath 7,fig4 #ih71 which closely embraces the haulm for some distance--often for the length of an internode4 ,the sheath protects and supports the soft1 growing internode1 inside it4 ,at the top of the sheath is the blade of the leaf1 which stands out from the haulm4 ,at the junction of the blade and sheath1 on the upper surface of the leaf1 is a little membranous outgrowth called a ligule 7,fig4 #ih1 l74 ,it often varies greatly in size and shape in different species of grasses1 and is a valuable means of distinguishing between them4 ,its use is not certainly known4 ,the student should examine the ligule of every grass he studies4 ,the haulm1 or flowering branch1 is for some time short and solid1 and its nodes are so close together that the sheath of a lower leaf may overlap several upper leaves4 ,the haulm is thus protected from the rough weather of the early spring4 ,in the meantime1 the flowers have been developing at its upper end4 ,when they are almost ready to open1 the haulm begins to grow very rapidly2 its internodes elongate so quickly that the internal tissues are torn and the haulm becomes a hollow straw1 except at the nodes1 where there are horizontal shelves4 ,the haulm hardens and stiffens as it grows1 so that1 when the spikelets of flowers at its upper end open1 they are carried high above the leaves on a slender but very strong rod1 which bends and dances in the wind1 and allows the pollen to be detached and blown to the stigmas of other flowers4 #bh4 ,,the ,,reproduction ,,of ,a ,,grass4 #a4 ,the arrangement of the spikelets4--,gather ears 7flowering haulms7 of several different kinds of grasses and notice the arrangement of the flowers4 ,in the oat 7,fig4 #ii71 the meadow grasses 7,fig4 #ajc71 fescues 7,fig4 #ajb71 and others1 the nodding oval bodies1 called spikelets1 are borne on delicate stalks which spread outwards from the haulm4 ,in the foxtails 7,figs4 #ajd and #aje71 timothy 7,fig4 #ajf71 and sweet vernal grass 7,fig4 #aaj7 the spikelets are on short stalks1 which can1 however1 be seen on bending the ear sharply on itself4 ,in wheat1 barley1 couch grass1 rye1 and rye grasses 7,fig4 #aji7 the spikelets are devoid of stalks and are set close along the haulm4 ,be quite sure you understand what is meant by a spikelet4 #ci spikelets are shown in ,fig4 #ii4 ,illustration3 ,,fig4 #ii4--,panicle of ,oats4 7 47 #b4 ,the arrangement and structure of the flowers4--,take an open spikelet from the ear of a grass 7e4g4 oat7 which has large flowers1 and examine it4 ,at the bottom are two boat-shaped leaves--really bracts--called glumes4 ,remove them carefully4 ,above them will be found two or more flowers1 each flower enclosed in two other leaves4 ,the outer of these two leaves is called the outer pale2 the inner is the inner pale4 ,from the middle of the back of the outer pale of the oat springs a bristle called an awn4 ,remove the outer pale and make out the three anthers on long filaments1 and the ovary with two branching feathery stigmas and short styles4 ,fig4 #ajj is a diagram of a spikelet1 which makes clear the relation of the glumes1 pales1 and flowers4 ,fig4 #aja1 ,a1 is a spikelet of meadow fescue4 ,its outer pales differ from those of the oat in not bearing awns4 ,otherwise it is very similar4 ,fig4 #aja1 ,b1 shows the appearance 7magnified7 of a flower of meadow fescue from which the outer pale has been removed4 ,the two little scales seen in front of the ovary possibly represent a perianth4 ,be careful not to confuse the terms ear1 spikelet1 and flower4 ,the ear consists of a number of spikelets1 and each spikelet consists of glumes and one or more flowers4 ,similarly dissect spikelets and flowers of other grasses1 making notes of the lengths of the stalks of the spikelets1 and the presence 7and lengths7 or absence of awns4 #c4 ,the use of the awns4--,try to find out the use of the awns4 ,are they generally rough or smooth8 ,have you ever seen grass 8seeds0 sticking in the wool of sheep8 ,what kept them attached8 #d4 ,grain4--,examine several kinds of grass 8seeds0 and make out that they not only consist of the entire ripened ovary and are therefore fruits1 but that usually the pales also remain attached to them4 #e4 ,the embryo and endosperm4--,again cut through soaked grains of maize and wheat1 and make out the embryo and endosperm 7p4 #ai74 ,grass flowers4--,grasses are true flowering plants2 but because they depend on the wind for the transference of pollen to the stigmas1 they do not pander to the taste of bees and butterflies by secreting nectar1 and hence have no need to display those advertisement placards which we call petals4 ,for this reason their flowers are not generally recognised as such4 ,it requires a little care to make out the parts of the flower and to understand the manner in which the flowers are arranged among themselves4 ,illustration3 ,,fig4 #ajj--;,diagram of a ,grass ,spikelet4 g1 the glumes2 p and p1 the outer and inner pales2 ,b1 flower4 ,the whole group of flowers borne by any one haulm is generally called the ear or panicle4 ,the ear in its turn consists of several bodies called spikelets4 ,the appearance of the ear varies greatly in different grasses 7,figs4 #ajb to #aaj7 according as the stalks of the spikelets are long and spread outwards from the haulm1 as in the meadow-grasses 7,fig4 #ajc71 oats 7,figs4 #ii and #ajh71 fescues 7,fig4 #ajb71 and others2 short1 as in the foxtails 7,figs4 #ajd and #aje71 timothy 7,fig4 #ajf71 and sweet vernal grass 7,fig4 #aaj72 or absent altogether1 as in the wheat1 barley1 rye1 rye grasses 7,fig4 #aji71 and couch grass4 ,a single spikelet of a grass is shown diagrammatically in ,fig4 #ajj4 ,at the bottom are two boat-shaped bracts called glumes 7g1 g71 which almost or entirely cover the spikelet before it opens4 ,when the glumes have been removed a few flowers remain4 ,each one is protected by two leaves called pales3 outer 7p7 and inner 7p7 respectively4 ,the flower 7,b71 as a rule1 has three stamens1 the anthers being borne on long filaments and dangling out to the wind 7,fig4 #aja71 and a pistil with two branching feathery stigmas4 ,in many grasses the outer pale bears a bristle called an awn1 well seen in 8bearded0 wheat1 barley1 and upright brome grass4 ,fig4 #aja1 ,a1 represents a single spikelet of meadow fescue1 with two open flowers4 ,the outer pales of this grass are not awned4 ,fig4 #aja1 ,b1 shows a single flower of the same grass from which the outer pale has been removed4 ,the two little scales seen in front of the ovary 7and at e in ,fig4 #ajj7 possibly represent all that is left of a perianth 7p4 #aba74 ,fertilisation4--,by the time the flowers have opened1 the haulm has usually grown so tall that they are lifted well above the leaves4 ,the stamens hang their anthers loosely out to the wind1 and1 as the slender haulm sways in the breeze1 the pollen is readily detached and carried to other flowers1 perhaps miles away4 ,it is in order to catch the wind-borne pollen-grains that the stigmas of grasses are branched and feathery4 ,a great waste of pollen is obviously entailed by this method4 ,but on the other hand it must be remembered that insect-pollinated flowers have to pay for their privileges by storing nectar in cunningly hidden pockets1 and by advertisement-expenses1 all of which the grasses avoid4 ,illustration3 ,,fig4 #aja4--,meadow ,fescue4 ,a1 spikelet with two open flowers 7 #a72 ,b1 a flower from which the outer pale has been removed 7 #f74 ,the ovule is fertilised in the usual way1 by a pollen tube growing down the style from a grain on the stigma4 ,as a result of fertilisation the ovary becomes a fruit containing one seed which fills it4 ,in many cases 7e4g4 barley and oats7 the pales still remain in position and adhere to the fruit4 ,when the awn is present it may play an important part in distributing the 8seeds0 by clinging to the hides of animals1 etc4 ,sometimes the awn is of use in fixing the grain in position on the ground until the seed has germinated4 ,the structure of a grass seed has already 7p4 #ai7 been studied in the wheat and maize4 ,the developing embryo 7p4 #ba7 lives upon a store of food called the endosperm 7,fig4 #af7 until its roots and leaves are sufficiently advanced to make food for themselves4 #bi4 ,,some ,,common ,,grasses4 #a4 ,the fescues4--,gather plants of meadow fescue1 and examine the habit of growth 7in tufts71 the broad leaves1 and the nodding panicles and the flowers4 ,also examine the 8seeds40 ,compare sheep's fescue 7,fig4 #ajb71 and notice the very fine leaves4 ,the outer pales are awned4 #b4 ,the meadow grasses4--,examine the various species of meadow grass 7,fig4 #ajc74 ,they can be distinguished from each other by the characters of the ligules4 ,notice the tree-like habit of the panicles and compare them with the fescues4 ,the meadow grasses never bear awns4 ,notice the woolly 8webs0 at the bases of the 8seeds40 #c4 ,the foxtails4--,in meadow foxtail 7,fig4 #ajd7 notice the prostrate stolons and large succulent leaves4 ,does the grass grow in tufts8 ,why not8 ,what is the earliest date on which you have seen it in flower8 ,double the ear on itself to see the short stalks of the spikelets4 ,how many flowers are there in each spikelet8 ,notice the silky awns of the flowers4 ,compare the slender foxtail 7,fig4 #aje71 which is a troublesome weed4 #d4 ,timothy4--,compare the leaves and flowers of timothy or 8meadow catstail0 7,fig4 #ajf7 with the meadow foxtail4 ,the ear is green and rough1 and the flowers are awnless4 ,what is the date of flowering8 #e4 ,yorkshire fog4--,notice the woolly covering of this weed 7,fig4 #ajg74 ,this covering and its bitter flavour make it distasteful to cattle4 ,observe the 8kneed0 awn of the flower4 ,dig up and shake off the earth from a sod to see the stolons4 #f4 ,wild oat 7,fig4 #ajh74 ,examine the large spikelets and make out the long twisted awn of the flower4 ,compare this weed with the cultivated oat 7,fig4 #ii7 and with the yellow oat grass4 #g4 ,the perennial rye grass4--,notice that the ear is flattened1 and that the spikelets are without stalks and have only one glume4 ,the leaf is glossy and has a prominent midrib and a flattened sheath4 ,illustration3 ,,fig4 #ajb4--,sheep's ,fescue4 7 47 ,illustration3 ,,fig4 #ajc4--,smooth-stalked ,meadow ,grass4 7 47 #h4 ,sweet-scented vernal grass4--,notice the tufted habit of growth and the characters of the leaves4 ,chew the stalk and notice the sweet odour of new-mown hay4 ,what is the date of flowering8 ,make out that the flower has two stamens only4 #i4 ,rushes and sedges4--,rushes and sedges are sometimes mistaken for grasses4 ,examine the stems1 the flowers1 and the leaves 7look for ligules71 and tabulate as many differences from the true grasses as possible4 ,the student should learn to recognise the common grasses and to distinguish the useful species from the weeds4 ,when the grasses are in flower there is not much difficulty in doing this1 but the habit of growth--the characters of the leaves and roots1 and of the stolons of the perennial species--should also be noticed carefully1 as during the greater part of the year these alone can be depended upon4 ,illustration3 ,,fig4 #ajd4--,meadow ,foxtail4 7 47 ,illustration3 ,,fig4 #aje4--,slender ,foxtail4 7 47 ,the fescues fall into two groups according as their leaves are broad or narrow4 ,the meadow fescue is a good example of the former group4 ,it is found in meadows and pastures and has long broad leaves4 ,sheep's fescue 7,fig4 #ajb7 is a good example of the second group of fescues4 ,it has very fine--almost bristle-shaped--leaves4 ,like the meadow fescue it grows in tufts2 it inhabits high lands and downs1 especially in limestone districts4 ,the nodding spikelets are borne on fairly long stalks1 and the panicles are somewhat like those of the meadow grasses 7,fig4 #ajc74 ,the flowers of sheep's fescue1 however1 bear short awns4 ,the meadow grasses much resemble the fescues in general appearance1 but the panicles 7,fig4 #ajc7 are rather more tree-like--the stalks of the spikelets spreading more horizontally--and the flowers are never awned4 ,the various species can be distinguished by their ligules2 for example1 the ligule of the smooth-stalked meadow grass 7,fig4 #ajc7 is blunt1 while that of the rough-stalked species is long and pointed4 ,the annual meadow grass is a weed to be found almost everywhere4 ,illustration3 ,,fig4 #ajf4--,timothy ,grass4 7 47 ,the foxtails are easily recognised by the tail-like appearance of the ears 7,figs4 #ajd and #aje74 ,the meadow foxtail 7,fig4 #ajd7 is a valuable grass with broad1 long1 and succulent leaves4 ,it spreads by means of prostrate stolons4 ,the spikelets have short stalks1 as can be seen on bending the ear on itself1 and each spikelet contains only one flower4 ,the silky awns give the ear a silvery grey colour4 ,the grass flowers in early spring4 ,the slender foxtail 7,fig4 #aje7 is a most injurious weed of cornfields4 ,it can be distinguished from the meadow foxtail by its less vigorous appearance1 by the thinner and more pointed ear1 and by the black patches on the ear4 ,it is often called 8black bent40 ,timothy grass or 8meadow catstail0 7,fig4 #ajf7 has a general resemblance to meadow foxtail1 but its ears are rough to the touch and green in colour4 ,it also flowers much later in the year 7,july7 and its pales are awnless2 the two grasses are therefore easily distinguished4 ,timothy grows abundantly in clay soils1 forming fairly close tufts4 ,illustration3 ,,fig4 #ajg4--,yorkshire ,fog4 7 47 ,illustration3 ,,fig4 #ajh4--,wild ,oat4 7 47 ,yorkshire fog 7,fig4 #ajg7 is a rank weed which is distasteful to cattle1 partly because it is covered with hairs and is difficult to wet1 and partly because it has a bitter flavour4 ,it is pale in colour and soft4 ,it spreads rapidly by means of creeping stolons4 ,oat grasses are of several species2 one is cultivated as a cereal1 others are valued as forage for cattle1 while others still are troublesome weeds4 ,the wild oat 7,fig4 #ajh7 is a common weed in cornfields4 ,it is an annual1 from two or three feet high1 with large spikelets forming a loose panicle1 the flowers having awns twice as long as the spikelets4 ,the cultivated oat is supposed to be a variety of the wild oat4 ,the panicle of the yellow oat grass is oblong1 and has erect spikelets4 ,illustration3 ,,fig4 #aji4--,perennial ,rye ,grass4 7 47 ,illustration3 ,,fig4 #aaj4--,sweet-scented ,vernal ,grass4 7 47 ,the perennial rye grass 7,fig4 #aji7 is very easily recognised by its flattened ears of alternate1 stalkless spikelets4 ,each spikelet has only one glume4 ,the leaves are dark-green and glossy1 and the leaf-sheaths are flattened instead of being round1 as is the case with most grasses4 ,this is one of the most valuable of forage grasses4 ,sweet-scented vernal grass 7,fig4 #aaj7 does not occur very abundantly in meadows and pastures1 but the fragrance of new-mown hay is almost wholly attributed to it4 ,the odour can be distinctly perceived when a stalk of the grass is chewed4 ,the leaves are somewhat hairy and are broad and flat4 ,the spikelets are borne on short stalks4 ,the flowers open early and are remarkable in possessing only two stamens instead of three4 ,rushes and sedges are monocotyledonous plants which are often erroneously called grasses4 ,the stems of rushes are vivid green1 round1 and pointed1 and contain a distinct pith4 ,the flowers 7,fig4 #aaa7 are never in spikelets2 they contain six stamens1 and the pistil has three long stigmas4 ,the sedges1 like grasses1 have narrow1 pointed leaves1 but the ligules are either very small or absent1 and the leaf-sheaths are not split4 ,the flowers are often in spikelets with glumes1 as are grass flowers4 ,the stems of sedges are solid and triangular4 ,illustration3 ,,fig4 #aaa4--;,a ,rush4 a1 flowering part of stem2 single flower 7b7 and pistil 7c7 more highly magnified4 ,the flowers of rushes in many respects resemble those of the lily family4 ,indeed it is supposed that the ancestors1 not only of the lily family1 but also 7along a different line7 of the grasses and sedges1 were primitive and now extinct rushes4 ,the lilies have developed the rush perianth more and more as they have increasingly depended on insects for pollination2 while in the grasses and sedges the perianth has gradually dwindled because these plants found that wind-pollination was sufficient for their needs4 ,,exercises ,,on ,,chapter ,,vii4 #a4 ,what grasses are grown as corn in your part of the country8 ,how can you recognise the grasses 7a7 before flowering1 7b7 in the ear1 7c7 by the straw8 #b4 ,what forage grasses are most cultivated in your part of the country8 ,make a list of the earliest dates on which you have seen each in flower4 #c4 ,examine grains of wheat1 barley1 oats1 and rye1 as harvested4 ,in which of these are the pales present8 ,what is the 8beard0 of barley8 #d4 ,make a collection of 8seeds0 of various grasses1 and write down the characters by which they may be distinguished from each other4 #e4 ,what are the commonest weeds you have seen in corn fields8 ,do the corn and the weeds flower at the same time or not8 ,is the time of flowering an advantage 7a7 to the weeds1 7b7 to the farmer8 #f4 ,in what important respects do wind-fertilized flowers differ from insect-fertilized flowers8 ,give examples of each4 7#ahih7 ,,chapter ,,viii4 ,,common ,,forest ,,trees4 #cj4 ,,the ,,oak ,,family4 #a4 ,the oak4--7a7 ,habits of growth4--,examine an oak tree growing in an exposed situation4 ,what is its approximate height8 ,estimate the diameter of the trunk at 7a7 the ground level1 7b7 at heights of #a1 #b1 #c1 #d1 etc41 feet4 ,at what height do the principal boughs come off8 ,about what angle do the boughs make with the trunk8 ,are they straight1 evenly curved1 or zig-zag8 ,contrast in these respects an oak growing in a plantation4 ,try to account for the differences observed4 7b7 ,the bark4--,examine the barks in oaks of various ages4 ,do the ridges and furrows caused by the splitting of the bark form any definite pattern1 or are they arranged anyhow8 ,find a piece which shows the pattern well1 and make a drawing of it4 7c7 ,method of branching4--,carefully observe the tree from a distance1 and notice how the great boughs spring from the trunk1 and in their turn give rise to smaller and smaller branches4 ,notice the shape of a tuft of the smallest twigs against the sky2 then close your eyes and try to recall the picture4 ,a still better way is to make a careful drawing of the tree1 not attempting to put in details1 but paying special attention to the trunk and main branches1 and to the general massing of the twigs4 ,what is the general 8expression0 of the tree8 ,would you call it1 e4g41 graceful1 formal1 sturdy1 delicate1 stiff1 or sombre8 ,the method of branching is best seen in the winter or spring1 when the tree is leafless4 ,examine a twig in winter or spring1 and notice the position of the buds4 ,round the tip there may be three or more crowded buds4 ,the one at the tip generally dies1 and those just behind grow out into lateral branches4 ,can you see any trace of this having been the case with the big boughs8 ,on a twig make out--from the marks on the outside--the growth of last year1 two1 three1 and four years ago4 ,cut these lengths across with a sharp knife1 and count the rings of wood4 7d7 ,the leaves4--,watch a marked twig from spring to summer1 and notice how short are the new shoots which come from the buds1 and consequently how close together the new leaves are4 ,does this account for the crown of foliage on the tree being so dense8 ,make a drawing of an oak leaf4 ,at what time of the year do 7i7 the leaf-buds open1 7ii7 the leaves fall from the tree8 ,in winter1 try to find an oak which has not shed its leaves2 is it a young tree or an old one8 7e7 ,the flowers4--,in ,may notice 7i7 the hanging catkins1 each of which is a bunch of male flowers containing stamens1 but no pistil2 7ii7 the groups of small female flowers which arise in the axils of two or three of the upper foliage leaves2 each contains a pistil1 but no stamens4 ,notice the cup of scaly bracts1 which surrounds the lower part of a female flower4 ,does the tree flower before or after the leaf buds have expanded8 7f7 ,the fruit4--,trace the development of the acorn from the female flower1 and the change of the covering of scales into the woody cup4 ,if possible1 compare for some years the yield of acorns by a selected old oak4 ,germinate an acorn4 7g7 ,associated animals4--,make as full a list as possible of the animals which you have seen obtaining food or shelter from the oak4 ,what was each doing when you saw it8 ,look for galls--the so-called 8oak apples0--and cut them open to see the insect inside4 ,also examine the other kinds of galls found on the leaves and catkins4 ,make similar observations1 sketches1 and notes of other forest-trees1 in addition to the special observations mentioned below1 and learn to recognise their 8expressions10 methods of branching1 bark1 leaves1 flowers1 and fruit4 #b4 ,the beech4--,notice the smooth1 olive-grey bark1 and the 8fluted column0 appearance of the base of the trunk of many beeches2 the long1 wavy boughs2 the brown1 sharp leaf-buds2 the smooth1 silky-fringed leaves2 the scarcity1 or absence1 of vegetation beneath the tree2 the hanging1 globular catkins of male flowers2 the pairs of female flowers1 surrounded by prickly scales4 ,make notes of the dates of flowering and opening of the leaf-buds4 ,trees may be considered in flower when the stamens can be seen4 ,trace the development of the fruit or 8mast40 ,each pair of flowers gives rise to two three-sided nuts1 enclosed in a woody cup or husk4 ,it is covered with hard bristles1 and splits into four parts when ripe4 ,compare the sweet chestnut4 #c4 ,the birch4--,observe the graceful appearance of the tree2 the slender trunk1 with its bark streaked with brown1 yellow1 and silver2 the purple-brown colour and wiriness of the young twigs2 the shape and size of the dark green leaves1 and the cylindrical1 many-flowered catkins4 ,the male catkins appear in the autumn1 the smaller female catkins in the following spring4 ,examine the two kinds of flowers4 ,find an old birch-cone and break it open to see the winged fruits4 ,what is the use of the wings8 #d4 ,the hazel and alder4--,in what situations do these trees grow8 ,compare them with the birch4 ,notice that in both hazel and alder the male flowers are in long1 dangling catkins4 ,the groups of female flowers of the hazel look almost like leaf-buds1 but can be recognised by the spreading red stigmas4 ,the female flowers of the alder form distinct cones4 ,is the flowering part of the twig of this year's or last year's growth8 ,look in the autumn for the cones and catkins which will expand next spring4 ,trace the development of the fruit4 ,the oak4--,the student cannot better commence the study of forest trees than by selecting one as a type1 and making himself thoroughly familiar with its life-history1 and with its appearance at all times of the year4 ,other trees should then be compared and contrasted point by point1 is and with each other4 ,the oak answers admirably as such a central type4 ,it is perhaps the best-known of all ,british forest trees1 not only from its wide distribution1 but also from its historical and legendary associations4 ,illustration3 ,,fig4 #aab4--,the ,oak4 ,the oak 7,fig4 #aab7 flourishes in exposed and sunny situations1 especially where the soil is well drained4 ,it can be recognised by the zig-zag and wide-spreading boughs1 which often spring from the trunk almost horizontally4 ,a very strong form of trunk is plainly necessary to support such branches1 and in an old solitary oak it may often be seen that the bole is very thick at the ground line1 and then rapidly narrows1 until at a height about equal to the base-diameter it may be only half or one-third the thickness4 ,above this point it is practically cylindrical up to the origin of the boughs1 where it is swollen4 ,an oak growing in a wood1 or plantation1 is of very different form4 ,its trunk is tall and straight1 and the larger boughs are not given off until near the top4 ,to secure the necessary light1 the tree used its energy in growing in length1 and in keeping pace with its neighbours rather than in spreading laterally4 ,in such a crowded oak the lateral buds generally remain undeveloped1 while the end of the shoot pushes onwards and upwards to the light4 ,the opposite is the case when there is plenty of room and light on all sides4 ,then it is usually the terminal bud which dies1 while the lateral buds grow out into branches1 forming the 8knee-joints0 which were once so greatly valued for shipbuilding4 ,the bark of the oak is very rugged1 with ridges and furrows running almost vertically4 ,illustration3 ,,fig4 #aac4--,the ,oak2 leaves1 flowers and fruit4 ,a1 flowering branch 7 72 ,b1 a male flower 7magnified72 ,c1 stamens 7magnified72 ,d1 a female flower 7magnified72 ,e1 acorns2 ,f1 cup of acorn2 ,g1 ,h1 seed4 ,the young shoots which are formed when the buds expand in spring are short1 and the leaves are set closely together4 ,as a result1 the oak's foliage is characteristically dense and thick4 ,the leaves are very distinctive2 their general shape is oval1 and the margin is deeply and irregularly lobed 7,fig4 #aac74 ,if in early spring we go out in the woods and fix on an old oak tree 7the oak hardly ever flowers before it is #ej years old71 we shall probably see the flowers on some of the young twigs4 ,the female flowers--one to five on each flower-stalk--are near the end of the twig1 while the male flowers arise lower down4 ,the female flowers are destitute of stamens1 each consisting practically of a single pistil1 partially enclosed in two envelopes1 the lower of which ultimately becomes the familiar 8cup0 of the acorn4 ,the stigma has three spreading lobes for receiving pollen4 ,the male stalks or catkins1 hang down from the lower part of the twig1 and every stalk bears about a dozen flowers4 ,the male flowers have each from #e to #ab stamens1 but they have no pistil4 ,the stamens produce pollen in the usual way1 and when they burst1 the wind blows the loose pollen from the stamens and scatters it in the air4 ,some of the pollen dust is almost certain to be wafted to the stigmas of the female flowers1 and the pollen grains put out tubes1 and in due course fertilise the ovules4 ,illustration3 ,,fig4 #aad4--,the ,beech4 ,most of our forest trees resemble the oak in being pollinated by the aid of the wind4 ,it is evident that for the process to be successful the trees must flower early in the spring1 before the foliage has become so thick as to be in the way of the pollen and prevent it from reaching the stigmas of the female flowers4 ,it is also important that the pollen may be easily detached1 and it is for this purpose that the male flowers of the oak and similar trees hang down in the familiar catkin fashion4 ,illustration3 ,,fig4 #aae4--,the ,beech4 #a1 flowering branch 7 72 #b1 a male flower 7 #d72 #c1 a female flower cut through longitudinally 7 #b72 #d1 cross section of ovary2 #e1 cup and fruits 7 72 #f1 fruit4 ,after fertilisation the female flower changes into an acorn 7,fig4 #aac1 ,e71 a nut enclosed in a cup4 ,the nut contains a single large seed1 which on germination grows up into a new oak4 ,galls of various kinds are to be found on most oaks4 ,these are excrescences caused by certain insects having laid their eggs in the soft tissues beneath the surface4 ,more than fifty species of insects obtain their food from the oak4 ,some of these will be referred to in a later chapter4 ,illustration3 ,,fig4 #aaf4--,the ,birch4 ,the beech4--,the beech 7,fig4 #aad7 is easily recognised by the olive-grey1 smooth bark1 and by the shape of the base of the trunk1 which usually has the appearance of being formed by the union of several separate columns4 ,when well grown the tree is lofty1 and bears a wide-spreading crown of branches which1 when clothed with leaves in summer1 casts a dense shade4 ,the ground beneath the tree is generally destitute of other vegetation4 ,the winter-buds are long and pointed2 they expand in ,may1 the new shoots at first drooping1 but straightening out in a fortnight or so4 ,the leaves 7,fig4 #aae7 are broad1 thin1 and glossy1 and are fringed with fine1 silky hairs4 ,young beeches1 like young oaks1 often retain their leaves through the winter4 ,the tree is in flower by the time the foliage has fully developed4 ,the male flowers are borne in small1 rounded catkins 7a1 ,fig4 #aae74 ,the female flowers 7#c1 ,fig4 #aae7 are in pairs4 ,each pair is surrounded by prickly scales1 and gives rise after fertilisation to two three-sided and pointed nuts enclosed in a woody cup or husk4 ,the husk is covered with hard1 blunt prickles1 and when ripe splits into four parts4 ,beeches do not harbour many insects1 but squirrels frequent them for the sake of the nuts4 ,the prickly husks protect the fruit from being eaten before it is ripe4 ,illustration3 ,,fig4 #aag4--,the ,birch2 leaves1 flowers and fruit4 #a1 branch with male 7b7 and female 7a7 catkins 7 72 #b1 bract with three male flowers 7 #b72 #c1 bract with three female flowers 7 #d72 #d1 ripe cone 7 72 #e1 fruit 7 _/74 ,the ,spanish1 or sweet chestnut is allied to the oak and beech4 ,it has long1 narrow leaves2 it flowers in ,july4 ,its fruit is enclosed in a prickly husk1 which splits into four when the nuts are ripe in ,october4 ,the birch4--,the birch 7,fig4 #aaf7 is a slender1 graceful tree1 with bark streaked with brown1 yellow1 and silvery patches4 ,its leaves 7,fig4 #aag7 are rather small1 and their glossy1 dark-green colour contrasts pleasantly with the brownish-purple of the young twigs4 ,both male and female flowers are arranged in catkins 7,fig4 #aag74 ,the male flowers appear in autumn1 but do not open until spring1 when the newly-formed female flowers are ready4 ,the female catkins 7a1 ,fig4 #aag7 are much smaller than the male 7b74 ,illustration3 ,,fig4 #aah4--,the ,hazel2 leaf1 flowers and fruit4 #a1 a flowering branch 7 72 #b1 a male flower 7 #b72 #c1 a stamen 7 #d72 #d1 a female flower cut through longitudinally2 #e1 fruit with cup 7 72 #f1 fruit without cup2 a foliage leaf4 ,illustration3 ,,fig4 #aai4--,the ,alder2 leaf1 flowers and fruit4 #a1 ,branch with male catkins 7a7 and female cones 7b7 7 72 #b1 male flowers 7 #b72 #c1 female cone2 #d1 two female flowers2 #e1 ripe cone 7 72 #f1 a fruit 7 #a74 ,the hazel and alder develop their flowers in the year preceding their opening4 ,the female flowers of the hazel 7,fig4 #aah7 look somewhat like buds1 but may be distinguished by the red stigmas4 ,the fruit is a nut1 enclosed by a sheath of soft bracts4 ,the seeds are largely dispersed by squirrels4 ,the alder grows on the banks of streams2 its female flowers 7,fig #aai1 b7 are arranged in short catkins1 which may be called cones4 ,the ripe cone 7#e1 ,fig4 #aai7 contains two nuts at the base of each scale4 ,the fruits fall into the stream1 and float away1 perhaps to germinate at a considerable distance4 #ca4 ,,the ,,willow ,,and ,,the ,,poplar4 #a4 ,the willow4--,about the third week in ,march1 examine willow trees1 and notice the soft1 round1 silky bodies which spring alternately on the young twigs4 ,on some trees these are broad and yellow2 they are male catkins 7,fig4 #abj74 ,pick off a flower and see the stamens 7generally two stamens to each flower7 inserted on a small silky bract 7,fig4 #aba1 ,b74 ,with a lens look for the honey cup at the bottom of the bract4 ,on other trees notice the long1 narrow1 silvery female catkins4 ,pick off a flower to see the single pistil with the forked style1 also on a small1 honeyed bract4 ,have you ever seen bees visiting the flowers8 ,are the catkins as conspicuous when the trees are in leaf8 ,is it an advantage to the trees to flower before the leaves come out8 ,in ,june1 examine the ripened female catkins4 ,pull out a tuft of the hairy seeds and dry it in the sun1 noticing how they form a fluffy mass4 ,blow the mass of seeds4 ,how do you think the seeds are dispersed8 #b4 ,the poplar4--,find male and female poplars and examine their flowers4 ,are the female flowers pollinated by insects or by the wind8 ,is self-fertilisation ever possible with willows and poplars8 ,why not8 ,which appear first1 the flowers1 or the leaves of poplars8 ,why8 ,examine the leaves of the ,english poplar4 ,why do they turn over so easily1 even with a very slight breeze8 ,are both sides of the leaf of the same colour8 ,compare the ,lombardy poplar with the ,english poplar4 ,the willow4--,many species of willow are known1 but the sallow willow--called the saugh tree in ,scotland--is common in coppices and hedges4 ,it has purplish brown branches1 and large1 broad1 downy leaves4 ,in the willow the male and female flowers are produced on different trees1 so that self-fertilisation is obviously impossible4 ,the flowers of the male willow form broad yellow catkins which cling closely to the twig 7,fig4 #aba74 ,they are often called 8golden palms40 ,each flower consists of two stamens1 borne on a silky scale which has a tiny honey cup at the base4 ,the female flowers form long1 narrow1 and silvery catkins2 each flower is merely a single pistil with a forked stigma1 and1 like a male flower1 is supported on a small honeyed bract4 ,the flowers appear in ,march1 before the leaves1 and the catkins are very conspicuous4 ,they are visited by bees for the sake of the honey and pollen1 pollination being thus effected4 ,in ,june1 the female catkins are ripe4 ,each ovary has now become a fruit1 which opens and liberates the silky seeds4 ,when the seeds dry1 their fine hairs cling together so that a light fluffy mass is formed1 which can be blown to great distances by the wind4 ,illustration3 ,,fig4 #abj4--,twig of male ,willow1 with catkins4 7 7 ,illustration3 ,,fig4 #aba4--,the ,willow4 ,a1 flowering male-shoot 7 72 ,b1 male flower with bract 7magnified72 ,c1 female cone2 ,d1 ,e1 female flowers 7magnified72 ,f1 fruit 7 72 ,g1 the same magnified2 ,h1 seed 7magnified74 ,the poplar4--,the various poplars are also completely unisexual1 that is1 any one tree bears either male or female flowers1 but not both4 ,in this case also the flowers appear before the leaves2 but the flowers are pollinated by the aid of the wind1 not by insects1 and nectaries are therefore not formed4 ,the catkins are not very much like those of the willows in appearance1 but the fruit and seeds are very similar4 ,both willows and poplars are fond of the banks of streams4 ,the ,english poplars are graceful trees which can be recognised at a distance by the manner in which the broad leaves turn on their long stalks1 exposing the lighter-coloured under-surface at the slightest breath of wind4 ,this is especially noticeable with the aspen or trembling poplar 7,fig4 #abb74 ,the ,lombardy poplar is a tall1 stiff tree4 ,illustration3 ,,fig4 #abb4--,the ,poplar4 #a1 male catkin 7 72 #b1 female catkin 7 72 #c1 male flower 7 #b72 #d1 female flower 7 #d72 #e1 the same in longitudinal section2 #f1 fruit2 #g1 the same after opening2 #h1 seeds 7 #c72 #i1 diagram of male flower4 #cb4 ,,the ,,elm1 ,,lime1 ,,and ,,ash4 #a4 ,the elm4--,notice the straight trunk1 rough bark1 and slender branches of the common elm4 ,examine the flowers in early spring and notice that each contains both stamens and pistil4 ,when do the flowers open8 ,when do the leaves expand8 ,draw a leaf and a fruit4 ,what is the use of the broad plate of the fruit8 #b4 ,the lime4--,observe the straight trunk1 smooth bark1 and general pyramid shape of the tree4 ,draw a leaf1 and notice that it is pointed and is larger on one side of the midrib than on the other4 ,notice that the flower stalks spring from leaves 7bracts7 differing in shape 7,fig4 #abf7 and colour from ordinary leaves4 ,draw one of these leaves with its attached flower stalk4 ,when do the flowers open8 ,try to discover whether bees haunt the flowers4 ,find out what is the use to the fruit of the long leafy bract4 #c4 ,the ash4--,look in winter for the black buds and the flattened tips of the twigs4 ,when do the flowers open8 ,notice their rich purple colour4 ,examine a flower and make out the two stamens and the pistil4 ,trace the formation of the fruit1 which is winged and hangs in bunches called keys4 ,what is the use of the wing8 ,when do the leaves expand8 ,are they simple or compound8 ,draw one4 ,what is its colour8 ,when do the leaves fall8 ,illustration3 ,,fig4 #abc4--,the ,elm4 ,the elm4--,the elm 7,fig4 #abc7 is usually a lofty tree1 easily recognised at a distance by its straight trunk1 slender branches1 and rounded masses of foliage4 ,the bark is rough and very corky4 ,the tree flowers early in the spring before the leaves are expanded4 ,the flowers are purple and contain both stamens and pistil4 ,each fruit 7,fig4 #abd7 is a flat plate with a rounded seed box in the middle2 it is distributed by the wind4 ,the seeds of the common elm do not often ripen in this country4 ,the leaves 7,fig4 #abd7 are rough to the touch1 and have very prominent veins4 ,they do not fall until late autumn4 ,illustration3 ,,fig4 #abd4--,the ,elm2 leaves1 flowers and fruit4 #a1 flowering branch 7 72 #b1 branch with leaves2 #c1 a flower 7 #b72 #d1 the same1 cut through longitudinally2 #e1 a fruit 7 74 ,the lime4--,the lime tree 7,fig4 #abe7 has a straight smooth trunk4 ,the tree generally spreads at the base1 and tapers to a blunt apex4 ,the leaves are bright green1 heart-shaped1 and pointed1 and plainly larger on one side of the midrib than on the other4 ,the yellowish-green flowers are in bunches1 carried on a stalk which springs from the middle of a long1 narrow bract 7,fig4 #abf74 ,the flowers are complete--calyx1 corolla1 stamens1 and pistil being all present--and are pollinated by bees1 which visit them for the sake of nectar1 being attracted by the sweet scent4 ,illustration3 ,,fig4 #abe4--,lime ,trees4 ,illustration3 ,,fig4 #abf4--,the ,lime4 ,a1 group of flowers on stalk 7a71 springing from bract 7b7 7 72 ,b1 longitudinal section of fruit 7magnified74 ,illustration3 ,,fig4 #abg4--,the ,ash4 ,the ash 7,fig4 #abg7 is a very graceful tree1 and its compound leaves1 with leaflets springing from the sides of the midrib1 give the foliage a characteristically feathery appearance4 ,the bark is ashen-grey in colour4 ,the tips of the twigs are curiously flattened1 and the winter buds are jet black4 ,the flowers are small1 with two purple-black stamens and a pistil4 ,they open in ,april before the leaves appear1 forming close clusters4 ,the fruits are long and flat1 and hang together in bunches which are popularly called keys4 ,they are only detached by high winds1 and are then blown to considerable distances4 ,the leaves appear rather late--about the end of ,may--and are shed early4 ,they are compound1 each consisting of seven or more leaflets arranged in opposite pairs along the midrib1 with a single leaflet at the end4 ,the mountain ash or ,rowan tree has leaves somewhat like those of the ash proper1 but in other respects it is quite different1 as it belongs to the rose family 7p4 #ajc74 #cc4 ,,the ,,sycamore ,,and ,,horse ,,chestnut4 #a4 ,the sycamore4--,observe the size and general shape of the tree4 ,examine the twigs in winter and watch the buds open in spring4 ,draw a leaf4 ,why are the leaves usually so sticky in warm weather8 ,notice the hanging sprays of green flowers4 ,are both stamens and pistil present in the same flower8 ,are the flowers visited by bees8 ,why8 ,follow the development of the fruit4 ,draw a pair of fruits4 ,what is the use of the wing on a fruit8 ,do the fruits fall off themselves or are they torn off by gales8 ,look for seedling sycamores in the woods2 also germinate seeds in garden soil and again observe the various stages4 ,compare the plane1 and notice the pyramidal shape of the tree4 ,the leaves are very similar in outline to those of the sycamore1 but the flowers are clustered into balls which dangle on long stalks4 ,in summer1 pull off a leaf and observe how the axillary bud is covered by the cup-shaped base of the leaf-stalk4 #b4 ,the horse chestnut4--,notice the general shape and method of branching4 ,these characters1 the large buds in winter1 and the shape and size of the leaves in spring and summer1 render the tree easily recognisable at all seasons4 ,trace the connection between the method of branching and arrangement of the leaves and buds on the twigs4 ,note the date of flowering1 and of the unfolding and shedding of the leaves4 ,examine the flowers2 are they pollinated by insects or by the wind8 ,trace the development of the fruit4 ,illustration3 ,,fig4 #abh4--,the ,sycamore4 ,the sycamore 7,fig4 #abh7 is one of the best-known trees in this country1 and often grows to a great height4 ,its leaves 7,fig4 #cc7 are large and five-pointed1 the main veins spreading from the top of the leaf stalk4 ,when young they are of a beautiful red colour4 ,in hot weather the leaves become very sticky with a sugary syrup called honey-dew4 ,the sycamore is indeed a species of maple1 and is closely related to the sugar maple of ,north ,america4 ,in ,may1 the flowers hang from the twigs in drooping green clusters4 ,they contain both stamens and pistils1 and are visited by bees for the sake of the honey in which they abound4 ,the fruits or keys 7,figs4 #acg and #d7 occur in pairs1 or sometimes three together4 ,each has a flat1 membranous wing1 by means of which it is easily transported by the wind4 ,in ,scotland the sycamore is often called the plane4 ,the leaves of the plane and sycamore are somewhat similar in shape1 but the trees belong to different families4 ,the plane can be identified by its globular heads of flowers and subsequent balls of seeds1 which hang on long stalks from the twigs4 ,illustration3 ,,fig4 #abi4--,the ,horse ,chestnut4 ,the horse chestnut4--,the horse chestnut differs from all our other forest trees of equal size in bearing brilliantly coloured and conspicuous flowers4 ,the flowers are complete1 containing not only stamens and pistil1 but also a calyx and a beautiful pink or white corolla4 ,the tree has a striking appearance at all seasons of the year4 ,in winter1 the thick twigs1 the large terminal buds1 and the opposite lateral buds already described on pp4 #fb-fd are very conspicuous1 and give an instructive clue to the method of branching4 ,the buds open early and the new shoots rapidly lengthen1 so that the tree is a mass of foliage whilst most neighbouring trees are still bare4 ,the leaves 7,fig4 #bf7 are compound1 consisting of seven large1 spoon-shaped leaflets which spring from a common point at the end of the leaf-stalk4 ,the flowers open in ,may4 ,the fruit is ripe in ,october and then falls to the ground1 its prickly husk splitting into three parts to liberate the rounded seeds4 ,the leaves fall early1 leaving large scars 7,fig4 #ch71 which have some resemblance to the hoof-marks of a horse4 #cd4 ,,cone-,,bearing ,,trees4 #a4 ,the ,scotch pine4--,notice the shape of the tree3 the tall straight stem and rugged bark1 and the dark tufts of foliage4 ,does the tree bear leaves all the year round8 ,does it ever shed its leaves8 ,are they shed at any special time of the year8 ,examine a leafy twig2 observe that the leaves are needle-shaped and come off in pairs4 ,at the apex is a terminal bud which will continue the length of the twig next season2 the lateral buds below will grow out into twigs at the same time4 ,try to make out which parts of the twig grew during last year1 and which during the two previous years4 ,notice the cones4 ,the young female cones 7b1 ,fig4 #acj1 #a7 are erect1 and their scales separate slightly in spring to allow the pollen to enter4 ,afterwards they hang down 7c7 whilst the seeds are ripening4 ,three years after pollination the scales come apart again to let the seeds fall out4 ,examine the seeds from a ripe cone and notice the attached wings 7,fig4 #acj1 #d74 ,examine cones of various ages4 ,in spring look for the pointed cones of male flowers 7,fig4 #acj1 #a1 a7 which produce the abundant pollen4 #b4 ,the spruce fir4--,compare the spruce fir4 ,notice the conical ,christmas tree shape and the large spreading branches near the ground4 ,compare the leaves and cones with those of the pine4 #c4 ,the larch4--,compare the larch with the pine and spruce4 ,notice the drooping boughs1 the alternate tufts of leaves1 and the small cones arranged in a row along the twig4 ,is the larch an evergreen8 ,cone-bearing trees4--,the cone-bearing trees1 such as the pines and firs1 are true flowering plants1 but of a type which is very different from any hitherto described4 ,the flowers are peculiar1 and form cones1 the male flowers producing pollen and the female flowers ovules4 ,the ovules1 however1 are not enclosed in ovaries1 but are naked1 so that the pollen gains access to the ovule directly1 and is not received on a stigma4 ,the female cone consists very largely of smooth scales1 a pair of ovules being borne by each scale near its base4 ,the pollen grains of these trees are rendered particularly buoyant by being blown out at the sides into little air-filled bladders1 and are thus easily carried by the wind4 ,when the pollen falls on the female cone1 the grains slide down the smooth scales and very likely come in contact with the ovules at the bottom4 ,each ovule has a sticky drop of gum at its end1 and the pollen is caught in the gum4 ,such pollen grains as roll off the upper scales are almost certain to fall on a lower one and reach the ovules4 ,the ,scotch pine4--,this is a large tree1 with a dome-shaped crown of foliage4 ,the bark is rough and scaly4 ,its foliage leaves 7,fig4 #acj7 are long and needle-shaped1 and occur in pairs1 each pair being carried by a very short branch4 ,the leaves do not fall off each winter1 as do those of most forest trees1 but remain on the branches for three years or more1 so that the younger twigs are clothed with foliage at all seasons4 ,the cones of male flowers 7,fig4 #acj1 #a1 a7 are found at the base of some of the shoots of the current year4 ,the female cones 7,fig4 #acj1 #a1 b7 are formed round the ends of the young twigs4 ,they consist mainly of overlapping woody scales1 each being knobbed on its exposed surface and bearing a couple of ovules near the base1 where it springs from the axis of the cone4 ,the young cones are erect1 and in spring 7when clouds of pollen are blowing about7 their scales separate slightly to admit the pollen in the chinks between them4 ,after pollination the scales close again and the cone hangs down 7,fig4 #acj1 #a1 c74 ,the ovules receive the pollen in ,may1 but the actual union1 or fertilisation1 does not take place until ,june of the following year4 ,the seeds become mature two years after fertilisation4 ,when they are ripe each bears a thin wing which has split off from the upper surface of the scale4 ,the scales now separate1 and the winged seeds fall out1 to be distributed by the wind4 ,when all the seeds have fallen1 the empty cones drop off the tree4 ,illustration3 ,,fig4 #acj4--,the ,scotch ,pine4 #a1 branch with male 7a7 and female 7b1 c7 cones2 c1 cone 7 73 #b1 two views of a stamen 7 #b73 #c1 scales bearing two ovules 7 #b73 #d1 scale with two seeds 7a71 wing 7b71 seed 7c73 #e1 seed in longitudinal section 7 #a74 ,owing to the length of time necessary for the ripening of the seeds1 cones of various ages may be found on the tree all the year round4 ,the spruce fir4--,the spruce has a characteristic conical shape1 which is familiar in ,christmas trees4 ,the branches are long1 and spread horizontally4 ,the foliage leaves are needle-shaped and four-sided in section1 but are shorter than those of the pine1 and are borne singly4 ,the tree is 8evergreen0 in the sense that the pine is so1 that is1 the leaves are not shed all together1 but gradually4 ,the method of pollination1 fertilisation1 and distribution of the winged seeds is similar to that of the pine4 ,in the spruce1 however1 the seeds are ripe in ,october of the year in which the cones are pollinated4 ,the larch4--,the larch is a cone-bearer1 and a near relative of the pines and firs1 but it differs from them in shedding its leaves annually4 ,the leaves are 7as is usual in cone-bearing trees7 needle-shaped1 but they are very thin and they grow in tufts on short alternate spurs4 ,the cones are small and are arranged in a row on the twig4 ,their scales do not fit so closely together as those of the pine and fir cones4 ,the larch tree has a conical form1 but can readily be distinguished from the spruce by its drooping boughs1 and absence of leaves in winter4 ,gymnosperms4--,the pines1 firs1 and larches are neither dicotyledons nor monocotyledons1 but belong to a class of plants which botanists call gymnosperms1 in allusion to the fact that their ovules are not enclosed in ovaries1 like those of other flowering plants1 but are naked4 ,this is the most ancient and primitive group of flowering plants known4 ,in fact they form a connecting link between higher flowering plants and the group to which the ferns and horsetails--which are still more primitive--belong4 ,,exercises ,,on ,,chapter ,,viii4 #a4 ,what trees are the first to put on leaves in ,england8 ,which flower before leafing8 ,which trees are the latest to come into leaf8 ,when do evergreens1 for the most part1 change their leaves8 7,n4,f4,u47 #b4 ,describe the fruit and seed of four of our commonest trees1 explaining in each case how the seeds are distributed4 7,n4,f4,u47 #c4 ,make observations to find which of the following trees endure shade most readily--oak1 beech1 elm1 sycamore1 chestnut4 #d4 ,what do you suppose are the advantages and disadvantages of shading and crowding trees1 as regards the quality of the resulting timber8 #e4 ,study young pines and firs1 and find out during which period of life they grow most rapidly4 #f4 ,which trees have you found growing 7a7 in heavy clay soils1 7b7 in sandy soils8 #g4 ,describe any observations upon six common ,british trees which could be made during a walk in early spring4 7,n4,f4,u47 ,,chapter ,,ix4 ,,fruits3 ,,how ,,seeds ,,are ,,scattered4 #ce4 ,,plants ,,which ,,sow ,,their ,,own ,,seeds4 #a4 ,the fruit of the wallflower4--,examine wallflower fruits and make out that each consists of the ripened pistil4 ,does the fruit open of itself8 ,how many chambers does it consist of8 ,where are the seeds attached8 ,are they blown off at last by the wind8 ,draw the fruit4 ,it is called a siliqua4 #b4 ,compare with this the fruit of shepherd's purse 7,fig4 #fb71 and penny cress 7,fig4 #acb71 and notice that they are of the type of the wallflower fruit1 but are much broader in proportion to the length4 ,such a fruit is called a silicula4 ,draw4 #c4 ,the fruit of the pea4--,examine a ripe pea-pod and compare it with 7a7 the pistil of an unfertilised flower1 7b7 a half-ripe pod4 ,how many carpels have taken part in forming the pod8 ,how many seeds 7peas7 does the pod contain8 ,leave a pod on the plant until the shell becomes dry1 to find out how the fruit opens4 ,does it open along one edge only1 or along both8 ,how are the seeds attached8 ,such a pod is called a legume4 ,draw it4 ,compare and draw the legumes of the broad bean1 ,french bean1 scarlet runner1 laburnum 7remember its seeds are poisonous71 and bird's foot trefoil4 ,the legume of the bird's foot trefoil bursts open suddenly and scatters the seeds in the air4 ,is the scattering of the seeds any advantage8 ,why8 #d4 ,the fruit of the field geranium4--,make out that five carpels are grouped around a central rod4 ,examine fruits which have opened4 ,about noon on a bright1 sunny day gently touch a ripe fruit with a small brush1 and watch the carpels spring back from the rod and jerk the seeds into the air4 ,compare and contrast this fruit with a siliqua1 silicula1 and legume respectively4 #e4 ,the fruit of the poppy4--,examine a poppy head4 ,the top of the fruit is the stigma4 ,observe below this a line of small holes running round the fruit4 ,draw4 ,shake the fruit1 and notice that seeds fall out through the holes4 ,cut the fruit across to see the large number of small seeds inside4 ,how does the fruit hang on the growing plant8 ,does the wind shake it and liberate the seeds8 #f4 ,the fruit of the pansy and violet4--,watch the ripening of the fruits on the plants4 ,observe that the ovary swells up into an egg-shaped body which afterwards splits into three boat-shaped valves containing seeds4 ,try to make out why the seeds are one by one shot out as the sides of the valves dry4 ,put a ripe fruit before the fire and watch the process4 ,imitate it by placing a pea between two flat rulers and pressing the rulers together4 ,the origin of a fruit4--,when the ovules of a flower have been fertilised 7p4 #ib7 by the pollen tubes they change into seeds which have the remarkable power of growing up--in favourable circumstances--into plants resembling that which produced the seeds4 ,this is not1 however1 the only result of fertilisation4 ,whilst the ovules are changing into ripe seeds1 those parts of the flower--the stamens1 corolla1 and calyx--which have finished their work wither and fall off1 though the calyx sometimes remains4 ,other parts--the pistil and sometimes the receptacle 7p4 #ij7--take on new duties1 and become gradually modified in order to protect or scatter the seeds4 ,thus1 the tender wall of the pistil often becomes a woody1 leathery1 or juicy seed-case2 while the receptacle1 or top of the flower stalk1 may become fleshy and swollen with sugary pulp1 as a bait for birds and other animals4 ,in any case we give the name of fruit to all such altered and persistent parts together with the seeds which accompany them4 ,a pea pod1 for example1 is as truly a fruit as a plum1 and a poppy-head as a strawberry4 ,what a fruit is like depends to a great extent upon the characters of the pistil which gave rise to it4 ,if1 for example1 the pistil consists of several separate carpels1 the ripened carpels or fruits will also be separate4 ,when1 on the other hand1 the pistil is composed of united carpels1 these will remain united1 at least until the fruit is ripe4 ,then in some cases they come apart4 ,illustration3 ,,fig4 #aca4--;,a1 fruits of wallflower 7 72 ,b1 siliqua 7 #a72 ,c1 siliqua open4 ,illustration3 ,,fig4 #acb4--;,fruits 7siliculae7 of ,penny ,cress4 7,nat4 size47 ,the part of a fruit which is derived from the walls of the pistil is called the pericarp4 ,the fruit of the wallflower4--,after fertilisation the stamens1 petals1 and sepals of the wallflower drop off1 leaving the pistil alone on the top of the flower stalk4 ,the pistil increases greatly in size 7,fig4 #aca1 ,b7 during the ripening of the seeds4 ,at last its wall 7the pericarp7 splits into two flaps4 ,these become free at the bottom1 exposing a central plate which bears the rows of seeds4 ,when the seeds are quite ripe1 a slight breeze is sufficient to shake them off1 and they fall to the ground to take their chance of finding a place favourable for germination4 ,a fruit with a dry pericarp1 which opens of itself when the seeds are ripe1 is called a capsule4 ,this particular kind of capsule--consisting of two carpels which come apart at maturity1 leaving a central partition bearing seeds--is known as a siliqua4 ,when it is short in proportion to its length1 as in the shepherd's purse 7,fig4 #fb7 and penny cress 7,fig4 #acb71 it is distinguished as a silicula4 ,the fruits of the pea tribe4--,the pod of the pea 7,fig4 #c7 and its relatives is a capsule of another kind4 ,it consists of one carpel only1 and opens1 when ripe1 along both back and front margins to liberate the seeds4 ,such a fruit is called a legume4 ,in the young fruit the pericarp is somewhat fleshy and succulent1 but it becomes dry during ripening4 ,the legume of the bird's foot trefoil bursts open suddenly1 and throws the seeds to a considerable distance4 ,the fruit of the field geranium 7,fig4 #acc7 is a long capsule composed of five carpels arranged round a central column 7,a74 ,when the seeds are ripe1 the carpels suddenly spring from the rod1 remaining attached only at their upper ends 7,b71 and fling the seeds into the air4 ,the method may be watched by stroking the fruits very gently with a small brush1 when they open in the manner described4 ,the experiment is most likely to succeed in dry1 sunny weather1 about the middle of the day4 ,the fruit of the poppy4--,the pistil of the poppy swells during ripening into a large1 globular capsule known as the poppy head4 ,the top of the fruit 7,fig4 #acd7 is the persistent stigma4 ,just below this1 a line of small holes like windows runs round the head4 ,as the fruit hangs inverted on the top of the flower stalk it is shaken about by the wind1 and the tiny seeds fall out through the windows4 ,illustration3 ,,fig4 #acc4--;,field ,geranium 7 74 ,illustration3 ,,fig4 #acd4--;,a1 capsule of poppy2 ,b1 cross section of capsule 7 72 ,c1 seeds4 ,the fruit of the violet or pansy4--,the arrangement by which the violet 7,fig4 #acd7 or pansy sows its seeds is most interesting4 ,after fertilisation the ovary swells into a great egg-shaped capsule1 in the inside of which the seeds are arranged in three rows4 ,when the seeds have become ripe and hard1 the capsule splits down the side along three lines1 and is thus divided into three parts4 ,these open outwards1 and bend back as shown in ,fig4 #ace4 ,each is a boat-shaped valve4 ,the seeds inside are thus exposed to the air1 and they soon dry and become ready for scattering4 ,illustration3 ,,fig4 #ace4--,violet4 ,f1 explosive fruit2 ,s1 seeds being shot out of fruit4 ,then the curved sides of each valve begin to straighten and come together1 and naturally allow less and less room for the hard1 smooth seeds inside4 ,the pressure of the sides of each valve on the seeds inside it becomes greater and greater1 until one by one they are shot out to a considerable distance4 ,if a ripe violet ovary be warmed before the fire the whole operation may easily be watched4 ,the process may be imitated by putting a pea between two flat rulers and pressing the rulers together1 when the pea may be shot to a distance of several yards4 ,why fruits are scattered4--,a flowering plant is practically confined for life to the place where it first sprang up1 so that it is unable to go about and select favourable situations for its offspring4 ,on the other hand1 if the seeds simply fell to the ground beneath the parent plant1 the seedlings would generally be so crowded together that they would interfere very much with each other's growth4 ,in addition1 they would often be under a great disadvantage1 because the parent plant would keep so much light from them4 ,hence1 very many plants have some special arrangement for scattering their seeds1 so that some at least of the seeds will have a chance of falling in a place where they will obtain plenty of light1 air1 and good soil4 ,in this section we have studied examples of devices by which plants sow their own seeds4 ,we shall see next that other plants call in the help of the wind and of animals4 #cf4 ,,seeds ,,sown ,,by ,,the ,,wind4 #a4 ,the fruit of the dandelion4--,examine the manner in which the tiny flowers of the dandelion are grouped together to form the head 7p4 #aac72 and make out the various parts of the flower1 especially the ovary--a little white knob at the bottom of the flower1 and the calyx-tube--forming a tuft of fine hairs above the ovary4 ,trace the development of the fruits3 the withering of the corollas and stamens1 the elongation of the calyx-tube1 and the expansion of the tuft of hairs to form a parachute4 ,blow a dandelion 8clock0 7the head of fruits71 and notice how the parachutes float the fruits in the air4 ,examine 8thistle down0 and contrast it with the dandelion fruit4 #b4 ,the fruit of the willow4--,examine the ripened catkins of a female willow in ,june1 and notice how each fruit has split into halves1 which come apart and expose the silky seeds inside4 ,pull a tuft of seeds out and dry them in the sun4 ,notice that they wriggle and writhe about and gradually become entangled together into a woolly mass1 which is easily blown away4 #c4 ,the elm fruit4--,about the end of ,april look for elm fruits4 ,notice the flat green plate 7wing7 with the rounded swelling near the middle 7,fig4 #abd1 #e74 ,cut open the fruit and see that the swelling is caused by a single seed4 ,how does the flat wing aid in the distribution of the seed8 ,compare the winged fruits of the ash and sycamore 7,fig4 #acg74 ,do these winged fruits drop from the trees easily1 or are they torn off by gales8 ,take a pair of sycamore fruits4 ,cut off the wing from one and let it and an uninjured fruit fall at the same instant from a height4 ,which reaches the ground first8 ,why8 #d4 ,pine and fir cones4--,examine and compare pine and fir cones of various ages4 ,break open a ripe cone and see the scales with the pairs of naked seeds1 each seed bearing a thin1 papery wing which has split off from the upper surface of the scale4 ,illustration3 ,,fig4 #acf4--8;,clock0 of ,dandelion ,fruits4 7 47 ,wind-sown seeds4--,many plants depend on the wind for the dispersal of their seeds1 and consequently the seeds are provided with outgrowths of various kinds1 which increase the surface greatly without adding much to the weight1 and1 acting like parachutes1 offer increased resistance to the air and thus prevent the seeds from falling quickly to the ground4 ,in some cases the outgrowth is part of the pericarp1 in others it is an appendix carried by the seed itself1 while in the lime it is the bract upon which the flowers were formerly borne4 ,the dandelion fruit4--,the fruit of the dandelion 7,fig4 #acf7 affords one of the best possible examples of wind-dispersal4 ,it will be remembered 7p4 #aac7 that what is commonly called the flower of the dandelion is really a head of perhaps #cjj complete flowers3 each with a hairy calyx-tube1 a yellow1 strap-shaped corolla1 five stamens1 and a pistil4 ,when the flowers have been fertilised1 the yellow corollas and the stamens wither1 the ovary increases in size with the ripening of the single nutlet in its interior1 and each calyx-tube elongates until it is about an inch in length1 the tuft of fine hairs being still at its upper end4 ,the attachment of the fruit 7,fig4 #hf1 #d7 to the disc 7receptacle7 is so slight when the seed is ripe that a very gentle puff of air is sufficient to overcome it4 ,the tuft of hairs at the upper end has by this time expanded until it acts like a parachute1 which supports the tiny fruit for a long time in the air4 ,the common thistle--a relative of the dandelion--also distributes its fruit by means of a tuft of fine hairs derived from the calyx4 ,in this case the hairs radiate from the seed4 ,such 8thistle down0 is commonly found floating through the air in summer4 ,illustration3 ,,fig4 #acg4--;,a pair of ,sycamore ,fruits4 7 47 ,the willow fruit4--,the catkins of the female willow are ripe in ,june4 ,each catkin consists of a large number of tiny pods derived from the ovaries of the flowers 7p4 #aea74 ,each fruit splits into halves1 which bend back from each other 7,fig4 #aba1 ,f71 exposing the silky seeds within to the warmth of the sun4 ,the seeds 7,h7 turn and twist about as they dry1 and gradually entangle themselves together into a light1 woolly mass1 which is easily blown to great distances by the wind4 ,the willow and the dandelion1 therefore1 use very similar devices to ensure the dispersal of their seeds1 although these plants are not at all nearly related4 ,the fruits of the elm1 sycamore1 and ash4--,these common forest trees bear fruits with the seed attached to a flat plate1 which is an outgrowth of the pericarp 7p4 #afg74 ,in the elm fruit 7,fig4 #abd1 #e7 the plate is green and oval1 and the seed forms a rounded swelling at1 or near1 its middle4 ,the fruits of the sycamore generally grow in pairs 7,figs4 #cc and #acg74 ,each half consists of a single seed with an attached membranous plate1 and the two seed-boxes of each pair are in contact4 ,the fruits of the ash hang from the twigs in bunches called 8keys10 each fruit on a separate little stalk4 ,the plates which bear the seed are long1 narrow1 and oval in shape4 ,it is plain that such plates1 or wings1 expose a relatively large surface to the air and prevent the fruit from falling to the ground as quickly as it otherwise would4 ,the fruit is thus often blown to a great distance before it finally settles and the seed germinates4 ,the action of the wing may be well shown by cutting off the plate from a sycamore fruit and letting it and one with an attached wing fall at the same instant from a height4 ,the seed without a wing comes straight down as a pea would2 but the winged seed spins in the air and settles more slowly4 ,in the case of the round downy fruits of the lime1 a similar service is performed by the bract 7,fig4 #abf71 upon which the flowers were carried4 ,pine and fir cones4--,if a ripe pine1 or fir cone is broken open1 it will be seen that each seed is attached to a thin1 papery wing 7,fig4 #acj1 #d71 which has split off the upper surface of the scale bearing the seeds4 ,the winged seeds are shaken out of the cone by the wind1 and blown away4 ,trees alone bear winged seeds4--,winged seeds would be useless to any but fairly high trees1 because if they were formed on the low plant they would fall to the ground long before the wind could catch them properly4 ,it is also interesting to find that such seeds are generally attached so firmly that they are only broken off by gales strong enough to carry them a considerable distance4 ,on the other hand1 the tiny plumed fruit of the dandelion or thistle is so very light in comparison with the surface exposed to the air that it takes quite a long time to fall even a few inches4 #cg4 ,,seeds ,,which ,,are ,,scattered ,,by ,,animals4 #a4 ,hooked fruits4--,examine plants of herb bennet 7wood avens7 in summer and autumn1 and find the fruits4 ,brush your sleeve against the fruits1 and notice how they cling to the cloth4 ,examine them with a lens and observe the hooks at the ends of the styles4 ,compare goosegrass 7cleavers7 and find the hooks on the fruits4 #b4 ,nuts4--,examine a hazel nut4 ,notice the sheathing bracts at the base of the fruit4 ,crack the nut and examine the broken edge of the shell 7pericarp7 with a lens4 ,make out the three layers which compose it4 ,how many seeds are present8 ,cut the seed 7kernel7 across and see that the bulk of it consists of two cotyledons 7,chap4 ,i474 ,does the fruit open of itself1 if undisturbed8 ,compare the acorn of the oak4 ,trace the development of the acorn from the female flower1 noticing that the cup is developed from a wrinkled disc surrounding the lower part of the flower4 ,cut across the ovary in ,june and notice that there are six ovules in it4 ,in the ripe fruit observe that the cup separates easily from the nut4 ,remove the shell 7pericarp7 of the nut4 ,how many seeds does it contain8 ,what do you think has become of the other five ovules8 ,cut through the seed and observe the two cotyledons4 ,compare the fruits of the beech4 ,notice that they are three-sided nuts 7each being a seed enclosed in a woody pericarp72 and that two nuts occur together1 surrounded by a bristly woody cup which splits1 when the nuts are ripe1 into four valves4 #c4 ,stone fruits4--,examine a ripe plum4 ,cut it open and crack the stone to see the single seed4 ,notice that the pericarp consists of three layers as in the hazel nut1 but that here the middle layer is soft and fleshy1 and the outer layer is the 8skin40 ,the stone is the inner layer of the pericarp4 ,is there any special means of liberating the seed8 ,compare the cherry1 and examine the seed and the three layers of the pericarp4 ,examine the fruits of the blackberry and raspberry1 and observe that each consists of several small stone-fruits arranged on the receptacle4 #d4 ,berries4--,the gooseberry4--,notice the stalk at the bottom of the fruit1 and1 at the top1 the withered remains of the calyx4 ,cut across a half-ripe gooseberry and observe the thick1 fleshy pericarp enclosing the seeds4 ,treat a ripe gooseberry in the same way1 and observe that the pericarp has now for the most part become a soft pulp1 in which the seeds are embedded4 ,the rest of the pericarp is a membranous skin4 ,is there any special means of liberating the seeds8 ,compare grapes1 currants1 oranges1 and vegetable marrow fruits1 and notice that the structure of these resembles that of the gooseberry4 #e4 ,the apple4--,cut across the receptacle of the flower 7apple blossom7 and notice how the five carpels are buried in it 7p4 #ajf74 ,trace the formation of the fruit1 and see how the receptacle becomes larger and larger during ripening4 ,at the top of the ripe fruit observe the withered remains of the calyx4 ,cut the apple through across the middle to see the core4 ,this consists of the horny walls of the five carpels and the contained seeds 7pips74 ,from what part of the flower is the fleshy1 eatable part of the apple derived8 ,compare the pear4 #f4 ,the rose hip4--,examine fruits of the wild rose4 ,notice that they are urn-shaped4 ,on the flat rim of the urn observe the five scars left by the sepals 7or1 in some cases1 the sepals themselves74 ,in the opening of the urn see a tuft of greyish hairs4 ,cut the fruit down from top to bottom through the middle to see the thick1 fleshy wall of the urn and the contained nutlets4 ,from what part of the flower is the fleshy wall of the hip derived8 ,examine a nutlet4 ,what does the tuft of hairs seen in the mouth of the urn consist of8 ,open a nutlet with a needle and pick out the seed4 #g4 ,the strawberry4--,cut a strawberry down the middle and notice at the base the persistent calyx1 in the inside the fleshy receptacle1 and on the outside the yellowish nutlets4 ,open a nutlet with a needle and pick out the seed4 ,the help of animals4--,it has been seen in ,chapter ,,vi4 that insects play a very important part in the fertilisation of many flowers4 ,very many plants also call in the aid of animals at a later stage for the dispersal of the seeds1 and the devices by which this aid is obtained are often very ingenious4 ,hooked fruits4--,sometimes after a country walk the reader has probably found small fruits and seeds sticking to his clothes4 ,they have become attached to the cloth by means of small hooks which they carry4 ,the fruit of the herb bennet 7wood avens7 is a good example of this device4 ,when the stigma of the fruit breaks away1 a little hook is left at the top of the style 7,fig4 #ach74 ,goosegrass or cleavers--a common hedgerow plant--and many others have also hooked fruits4 ,sheep or cattle1 grazing near such plants are very likely to brush against them and carry off the fruits and seeds in their hair4 ,they may not again reach the ground until they have been carried far from the place where they grew4 ,the position of hooked fruits4--,it is evident that these little hooks would be quite useless if the fruits grew out of the reach of animals4 ,such hooked fruits are never found1 for instance1 on high trees4 ,illustration3 ,,fig4 #ach4--;,a1 ,aggregate ,fruit of ,wood ,avens 7nat4 size72 most of the stigmas have broken off4 a1 a1 a1 fruits with stigmas still attached2 c1 calyx2 ,b1 single fruit with stigma still attached 7magnified72 ,c1 single hooked fruit after loss of stigma 7magnified74 ,nuts4--,a fruit which has a dry1 woody pericarp and does not open of itself is called a nut4 ,the fruits of the hazel1 oak1 and beech are good examples4 ,the shell 7pericarp7 of the hazel nut 7,fig4 #aci7 is composed of three layers1 and encloses a single seed1 or kernel4 ,the nut of the oak 7,fig4 #aac7 is called an acorn4 ,its lower part lies in a cup developed from a wrinkled disc by which the lower part of the female flower was surrounded4 ,when the fruit is ripe the nut easily separates from the cup4 ,the acorn contains one seed only1 which consists largely of two swollen cotyledons4 ,if the ovary of the female flower of the oak is cut across in ,june six ovules are found in it4 ,as in the case of the hazel only one ovule is allowed to reach maturity2 the rest are sacrificed in order that the remaining one may be more perfectly developed4 ,in the beech1 two three-sided nuts occur together1 surrounded by a bristly1 woody cup1 which splits into four valves when the nuts are ripe4 ,illustration3 ,,fig4 #aci4--;,a1 group of ,hazel ,nuts 7 72 ,b1 longitudinal section of fruit4 ,the dispersal of nuts4--,squirrels and other nut-eating animals are instrumental in the dispersal of the seeds in a somewhat indirect manner4 ,they have a habit of storing up nuts and seeds in holes2 but in their active life these animals often forget where their larder is4 ,the seeds1 thus left to themselves1 sprout and grow into trees4 ,the unripe nuts of the beech are protected from the attacks of squirrels by the hard bristles on the outer husk4 ,illustration3 ,,fig4 #adj4--;,a1 ,plum2 ,b1 longitudinal section2 ,c1 cross section2 ,e1 ,m1 ,en1 outer1 middle1 and inner layers of pericarp2 ,s1 seed4 7 47 ,stone fruits4--,a ripe plum 7,fig4 #adj7 or cherry 7,fig4 #gg71 like a nut1 consists of a seed and a pericarp2 but here the pericarp is specially modified to tempt animals and at the same time to protect the seed from them4 ,the inner pericarp-layer is a hard1 woody shell called the stone2 the middle part swells up to form a juicy1 sweet mass2 while the outer layer constitutes the 8skin10 and is often beautifully coloured4 ,illustration3 ,,fig4 #ada4--;,blackberry4 7 #a47 ,blackberries 7,fig4 #ada7 and raspberries consist of several small fruits of the plum type1 which are arranged round an axis derived from the receptacle of the flower4 ,berries4--,the gooseberry 7,fig4 #adb7 is a type of this class of fruit4 ,it contains several seeds4 ,the pericarp is thick and fleshy before the fruit is ripe1 but during ripening the greater part of it becomes a soft1 sweet pulp in which the seeds are embedded4 ,the rest of the pericarp is a membranous skin4 ,grapes1 currants1 oranges1 and vegetable marrow fruits are also berries4 ,the vegetable marrow has obviously a general resemblance to a half-ripe gooseberry but is on a much larger scale4 ,illustration3 ,,fig4 #adb4--;,a1 ,gooseberry2 ,b1 longitudinal section2 ,c1 cross section4 7 47 ,the apple4--,in the apple 7,fig4 #adc7 we have an example of a fruit in the formation of which the receptacle has taken a large share4 ,even in the flower1 the five carpels of the pistil are buried in the receptacle1 and as the seeds 7pips7 ripen1 the receptacle swells until it composes the greater part of the fruit and at last becomes sweet and fleshy4 ,the carpels with the contained seeds constitute the core4 ,the withered sepals are still to be seen at the top of the fruit4 ,the structure of the pear is quite similar to that of the apple4 ,illustration3 ,,fig4 #adc4--;,a1 ,apple2 ,b1 longitudinal section2 ,c1 cross section4 7 47 ,illustration3 ,,fig4 #add4--;,a1 ,strawberry2 ,b1 longitudinal section2 ,ac1 carpel1 ,r1 swollen receptacle4 7 47 ,the fruit of the wild rose4--,the fruits of the wild rose are called hips4 ,they are urn-shaped1 and on the flat rim of the urn five scars show the former position of the sepals4 ,in some cases the sepals themselves have remained4 ,the narrower mouth of the urn is filled by a tuft of greyish hairs which1 when the fruit is cut open1 are seen to be the styles of the carpels4 ,the carpels are hairy1 and stand on the bottom and sides of the urn-cavity4 ,each carpel contains a seed4 ,comparison with the flower shows that the red1 fleshy urn is the developed receptacle4 ,the strawberry4--,in the strawberry 7,fig4 #add7 the eatable part of the fruit is again the swollen and juicy receptacle4 ,in this case it has grown up on the inside of the carpels--the little1 yellow nutlets 7carpels7 lying on the surface4 ,each carpel contains a seed4 ,why some fruits are sweet4--,the delicious flavours of sweet fruits have been developed as baits for the allurement of such animals as are likely to scatter the seeds to the best advantage4 ,consider such fruits as cherries1 currants1 and rose-hips4 ,birds--such as thrushes--find them very nice to eat1 and are ready to carry them away to consume at their leisure4 ,the birds eat the sweet1 fleshy part1 but in the case of a stone-fruit they drop the stone and leave the seed to germinate4 ,a seed which is in danger of being swallowed is either hairy like the rose-carpels 7and therefore rejected because it irritates the mouth unpleasantly71 or it is enclosed in a hard or horny case1 upon which the animal's digestive juices are unable to act4 ,when the seed is dropped it is no worse for its experience1 and with good luck grows up into a plant4 ,illustration3 ,,fig4 #ade4--;,holly4 ,the red colour of the fruits contrasts strongly with the dark-green of the leaves4 7 47 ,eatable fruits generally conspicuous4--,in order that birds and other animals may easily find the luscious fruits which they may eat as a reward for scattering the seeds1 such fruits are almost always displayed very conspicuously1 and are brilliantly coloured4 ,oranges1 plums1 red currants1 apples1 etc41 illustrate this fact well4 ,red is perhaps the commonest colour of eatable fruits1 because it contrasts so strongly with the green colour of the foliage 7,fig4 #ade74 ,,exercises ,,upon ,,chapter ,,ix4 #a4 ,name and define the different kinds of self-opening fruits4 ,from what common plants could you collect examples of these during an ,autumn walk8 7,n4,f4,u47 #b4 ,describe any rough1 prickly1 or hairy seeds or fruits1 explaining the form and nature of the outgrowths and their use4 7,n4,f4,u47 #c4 ,what wild fruits and wild flowers would you expect to find in ,september in your part of the country8 ,in what kinds of places would you look for them8 7,n4,f4,u47 #d4 ,describe and draw the fruit of a field geranium1 and point out the uses of some of its peculiarities4 7#ahih7 #e4 ,describe the seed vessels of a pansy4 ,draw one entire1 and also burst open4 ,how does it scatter the seeds8 7#ahih7 #f4 ,shortly describe the fruit of an apple or pear1 and of a cherry or plum4 ,point out the chief differences between them4 7#aija7 #g4 ,how are the seeds of cherry1 field geranium1 and pine or birch dispersed8 7#aija7 #h4 ,give examples of seeds which are dispersed by the aid of birds or other animals1 explaining in each case how the dispersal is effected4 7#ahic7 #i4 ,why is it an advantage to some fruits to be 7a7 brightly coloured1 7b7 sweet8 ,give examples4 #aj4 ,a school museum contains1 among other things1 some dandelion fluff1 a dish of marrowfat peas1 a few nodules of garlic1 and some hawthorn berries4 ,how could you employ these to illustrate a lesson on plant germination8 7,certificate #aijc7 ,,chapter ,x4 ,,ferns ,,and ,,horsetails4 #ch4 ,,ferns4 #a4 ,the male-fern4--7a7 ,habit of growth4--,in summer dig up a plant of the common male-fern 7,fig4 #adf7 and wash the soil from the roots4 ,make out the short1 stumpy1 creeping stem1 covered with the hairy bases of old leaves2 the slender matted roots springing from the leaf-bases2 the large1 compound leaves or fronds of the current year1 and the coiled young leaves which have not yet expanded4 7b7 ,the stem4--,remove the large leaves1 leaf-bases1 and roots from the stem1 and examine it4 ,notice how the youngest leaves are grouped round the apex of the stem4 ,cut across the other end of the stem1 and notice the cut ends of the conducting strands embedded in a softer ground-tissue4 ,cut the stem in halves lengthwise and carefully scrape away the ground-tissue of one half to see how the harder conducting strands are connected together4 ,if you spoil this1 try again on the other half1 after boiling it until it is softened4 7c7 ,the leaves4--,make a drawing of one of the expanded leaves4 ,notice that the leaf consists of a number of leaflets1 and that these are again cut up into segments1 or are at least deeply lobed4 ,notice the brown hairs clothing the leaf-stalk and the midrib4 ,notice the crozier-like coiling of the young fronds1 and make out that when they uncoil the inside of the coil becomes the upper surface of the leaf4 7d7 ,the reproductive organs4--,examine the lower surface of full-grown fronds1 and notice the brown rounded patches4 ,dry some leaves bearing these patches and shake them over a sheet of paper4 ,collect the brown dust which falls from the patches2 it consists of minute grains called spores4 7e7 ,the prothallus4--,sow some spores on damp soil sheltered from the direct rays of the sun4 ,keep the soil moist1 and notice that in a few weeks the spores have grown into small1 flat1 green1 heart-shaped plants4 ,each of these is called a prothallus4 ,pick off prothalli of different ages with a needle1 float them in water1 and compare the various stages of growth4 ,in old prothalli notice a young fern plant springing up from the lower surface4 ,observe that as these become larger the prothalli which bear them shrivel up and die4 #b4 ,the bracken1 fern4--,dig up a bracken fern1 wash the earth from the roots1 and compare it1 point for point1 with the male-fern4 ,notice3 7a7 ,the long cylindrical1 branching1 underground stem4 ,does it lie deeper in the ground than the stem of the male-fern8 ,cut the stem across and compare the section with ,fig4 #adh1 noting 7i7 the two concentric rings of separate vascular strands 7s74 7ii7 ,the strengthening material1 arranged as a brown zone 7lp7 just below the skin1 and as an incomplete ring 7ll7 between the two rings of vascular strands4 7iii7 ,the softer ground-tissue 7,r71 in which the vascular and strengthening strands are embedded4 ,draw the external appearance of the stem 7natural size71 and also the cross section 7#d times natural size74 7b7 ,the roots4--,describe the roots4 ,do they appear to arise from any particular region of the stem8 7c7 ,the leaves4--,from what part of the stem do the leaves arise8 ,how many come up each year8 ,what is the appearance of a young leaf before it expands8 ,how does it differ from that of the male-fern8 ,draw a young leaf1 and also an expanded one4 ,is the leaf simple or compound8 ,does it branch8 ,does the leaf of the male-fern branch8 7d7 ,the spores4--,examine the under side of the leaf1 and notice the absence of the brown patches seen in the male-fern4 ,notice that the edge of the bracken frond is folded over like a hem4 ,dry a frond1 and then run the point of your pencil under the fold and observe the brown dust 7spores7 which is removed4 7e7 ,the prothalli4--,sow some bracken spores on damp earth and keep in a shaded place4 ,notice that the prothalli produced are very similar to those of the male-fern4 ,watch their development and the growth1 on old prothalli1 of a new generation of ferns4 #c4 ,the hart's tongue fern4--,examine the hart's tongue fern1 and notice how it differs from the two previous types4 ,are the leaves simple or compound8 ,observe the brown trenches on the lower surface of the leaf4 ,try to get out some spores by running the point of a pencil along the trenches of a dried leaf4 ,sow the spores and try to raise prothalli4 ,the daily life of a fern4--,the everyday life of a fern is very similar to that of a flowering plant2 for the organs by which it obtains food are--broadly speaking--of the same type4 ,ferns are lovers of damp and shady situations4 ,the plant obtains its mineral food from the soil by means of its roots2 and its spreading green leaves1 or fronds1 enable it1 with the help of the sunlight1 to decompose the carbon dioxide of the air and to build up starch1 sugars1 and other carbonaceous compounds4 ,the male-fern4--,the common male-fern 7which1 by the way1 has no sex whatever7 may be taken as a type of the group4 ,it occurs abundantly in woods and hedgerows4 ,the stem1 or rhizome1 is short and stumpy2 it grows obliquely upwards1 and does not branch4 ,it is covered with old leaf-bases1 which are clothed with brown1 scaly hairs4 ,the stem consists of a rather soft ground-substance1 in which is embedded a hollow cylindrical network of conducting strands4 ,in a cross section these appear as a somewhat irregular ring of dots 7,fig4 #adf1 #b1 a74 ,when the soft ground-tissue is carefully scraped away1 the network of strands is left as a skeleton1 with large diamond-shaped meshes4 ,the thin wiry roots spring from the bases of the leaf-stalks1 just where these come off the stem4 ,illustration3 ,,fig4 #adf4--,the ,male-,fern4 #a1 ,illustration showing general habit 7 _/72 a1 young leaves3 #b1 cross section of stem showing conducting bundles a3 #c1 portion of leaf2 b1 spore-boxes2 a1 covering scale3 #d1 longitudinal1 and #e1 cross section of group of spore-boxes2 a1 leaf2 b1 scale2 c1 spore-boxes3 #f1 a single spore-box2 a1 stalk2 c1 spring2 d1 spores4 ,the leaves or fronds of the male-fern arise near the growing-point 7the upper end7 of the stem4 ,leaves of almost all ages are present4 ,those which surround the growing-point are mere rudiments2 while slightly older ones 7,fig4 #adf1 #a1 a7 are tightly rolled up into a coil4 ,during their growth the coils unfold1 the inside of the coil becoming the upper surface of the leaf4 ,a fully expanded leaf is roughly triangular in shape4 ,the leaf-stalk and the midrib are covered with brown1 scaly hairs2 and the blade of the leaf is divided into several distinct leaflets1 which are arranged on the midrib in two rows4 ,the leaflets are also in many cases sub-divided into separate segments4 ,the spores4--,on the lower surface of many of the segments of a male-fern frond may be seen a number of small1 brown1 kidney-shaped scales 7,fig4 #adf1 #c1 a74 ,each scale is attached to the leaf by a short stalk1 and the structure thus bears a rough resemblance to a little umbrella4 ,attached to the bottom of the short 8handle0 of the 8umbrella0 are several tiny boxes1 somewhat like pill-boxes4 ,these are shown at b 7,fig4 #adf1 #c71 and highly magnified at #d and #e4 ,fig4 #adf1 #f1 represents a single box1 more highly magnified4 ,when ripe1 each box contains about fifty minute grains1 which may thus be likened to the pills in the pill-boxes4 ,these 8pills0 are called spores4 ,summing up thus far1 we may say that the spores are formed in spore-boxes1 which are attached by stalks to the lower surface of the frond1 each group of spore-boxes being covered by a protective scale4 ,the scattering of the spores4--,when the spores are ripe1 each box 7,fig4 #adf1 #f7 becomes dry1 and is ultimately burst by the sudden straightening of a spring 7c7 which is coiled round its edge4 ,the force of the uncoiling of the spring is sufficient to jerk the spores 7d7 out of the box into the air1 and they may be carried for some distance by the wind before they at length reach the ground4 ,once there1 however1 each spore1 under favourable conditions1 begins to grow1 and gives rise to a plant which1 curiously enough1 is not in the least like the parent fern plant which produced the spore4 ,the difference between a spore and a seed4--,it is important to notice that the spore is produced by a purely non-sexual process4 ,in this respect it differs widely from the seed of a flowering plant1 which1 it will be remembered 7p4 #ib71 results from the union of the living matter of a pollen grain with that of an ovule4 ,illustration3 ,,fig4 #adg4--,the ,male-,fern4 ,a1 ,prothallus seen from below2 an1 male organs2 ar1 female organs2 rh1 hairs4 ,b1 ,prothallus with young fern attached to it2 b1 the first leaf2 w1 the primary root 7about #e times nat4 size74 ,the prothallus4--,the new plant1 which is produced when a fern spore germinates1 is called a prothallus 7,fig4 #adg1 ,a74 ,it is a flat1 filmy little plant1 of the form which is generally called heart-shaped4 ,it has neither stem nor roots1 but1 as it contains green colouring matter like that of leaves1 and as it puts out on its lower surface little hairs 7rh7 which take up watery solutions from the soil1 it is in no danger of starvation1 and is quite capable of taking care of itself and leading an independent existence4 ,this tiny plant 7a large fern prothallus is perhaps half the size of a #c;d4 piece71 in contrast with its parent1 produces sexual organs4 ,some of these organs 7an7 give rise to male cells and others 7ar7 to female cells4 ,the male cells are excessively small1 and can only be seen by high powers of the microscope4 ,when they are ripe they swim about in a drop of rain or dew1 as if they were little animals1 and find their way to the female cells1 which they fertilise4 ,the embryo which results from the union grows up 7,fig4 #adg1 ,b7 into an ordinary fern plant1 one being borne by each prothallus4 ,in its young stages it is parasitic on the prothallus1 i4e4 it depends entirely upon the prothallus for its nutrition2 but it soon develops a little leaf 7b7 and a root 7w71 and henceforth feeds itself4 ,when the young fern is well established in independent life1 the prothallus shrivels up and dies4 ,the subsequently-formed roots of the fern are not branches of the primary root1 but spring from the bases of the leaves4 ,alternation of generations4--,in the life-history of the fern there are thus two very different generations4 ,the first generation--the ordinary fern1 which is non-sexual--produces1 by means of spores1 the sexual generation1 called the prothallus4 ,the prothallus gives rise1 in its turn1 by a sexual process1 to the obvious fern plant4 ,each generation therefore resembles1 not its parent1 but its grandparent4 ,illustration3 ,,fig4 #adh4--;,cross section of underground stem 7rhizome7 of ,bracken ,fern4 s1 ,conducting strands2 l1 lp1 strengthening tissue2 ,r1 ground-tissue2 e1 skin4 7 #g47 ,illustration3 ,,fig4 #adi4--,leaf of the ,bracken ,fern4 7 _/47 ,the bracken or brake fern differs in several respects from the male fern4 ,its cylindrical stem 7rhizome7 creeps along horizontally beneath the ground1 branching at intervals1 by a division of its growing point into two4 ,conducting strands run along the stem and into the leaves and may be seen in cross section 7,fig4 #adh1 s7 to form two somewhat irregular1 concentric rings4 ,strands and plates of strengthening tissue 7l7 accompany them1 and a cylindrical zone 7lp7 of similar material also occurs just beneath the outside skin 7e7 of the stem4 ,the great advantage of having supporting structures arranged as hollow cylinders has already 7p4 #gb7 been referred to4 ,the rest of the stem consists of softer packing or ground-tissue1 in which starch is often stored4 ,illustration3 ,,fig #aej4--;,hart's ,tongue ,fern4 7 47 ,illustration3 ,,fig4 #aea4--;,hart's ,tongue ,fern4 ,part of a section through the fertile portion of a leaf2 sg1 spore-boxes2 i1 i1 protecting flaps4 7 #be47 ,the sappy stalk of a young bracken leaf is very sturdy2 when it is only six inches high the stalk may be already half an inch across at the bottom1 and half that thickness where it curls over at the top to form a crook4 ,the end of the leaf-stalk divides into three1 each bearing a frond which1 at this stage1 is coiled up tightly1 looking somewhat like a green caterpillar4 ,at a later stage1 the middle one of the three branches commonly divides again into three1 and the branching may continue until the fully expanded leaf 7,fig4 #adi7 is very complex4 ,the spore-boxes and contained spores of the bracken are very similar to those of the male fern1 but they are not collected in patches1 like those shown in ,fig4 #adf1 #c4 ,instead1 they are arranged in a row along the margin of the lower surface of the frond-segment2 and the margin is turned over--like a hem--so as to cover them in4 ,the spores are liberated in the usual way 7p4 #ahg7 when ripe2 and each germinates1 under favourable conditions1 to form a sexual prothallus4 ,each prothallus gives rise to an embryo1 which is at first parasitic upon it1 but presently grows up into an ordinary bracken4 ,the hart's tongue fern 7,fig4 #aej7 has simple and undivided leaves1 which1 as usual1 bear spore-boxes upon the lower surface4 ,in this case the spore-boxes are produced in trenches1 which appear to the naked eye as oblique brown lines4 ,each trench is covered in by a pair of thin flaps 7i1 ,fig4 #aea74 ,the life-history closely resembles that already described for the male-fern and bracken4 #ci4 ,,the ,,common ,,horsetail4 #a4 ,habit of growth4--,carefully dig up a plant of the common horsetail4 ,notice 7a7 the deep1 creeping1 underground stems2 7b7 the thin wiry roots springing from the stem2 7c7 the two kinds of upright shoots or haulms3 one kind 7,fig4 #aeb7--to be found in summer--being thin1 and giving rise to tiers of green branches1 which come off like the ribs of an umbrella2 the other kind 7,fig4 #aec71 coming up in ,march1 being paler in colour1 without branches1 and bearing little cones at the apex4 #b4 ,the underground stem4--,make out that the stem is distinctly divided into nodes--marked by toothed leaf-sheaths--and internodes4 ,does it branch8 ,notice that some of the branches are swollen1 forming tubers4 #c4 ,the roots4--,these are thin and wiry1 and come off from the stem4 ,do they come off at the nodes or at the internodes8 #d4 ,the branched haulms4--,observe that each is divided into nodes--marked by toothed leaf-sheaths--and internodes4 ,are the internodes smooth or ridged8 ,from what parts of the haulms do the lateral branches arise8 ,carefully tear down a leaf-sheath to see its relation to the branches4 ,notice that the branches themselves branch repeatedly4 ,what is the colour of the branches8 #e4 ,the cone-bearing haulms4--,do these haulms appear earlier or later than the others8 ,what is their colour8 ,does a cone-bearing haulm give rise to branches at the nodes8 ,examine the cone with a lens and see that it is covered with hexagonal scales4 ,does the hexagonal shape allow the scales to be more closely packed8 ,take off a scale with a needle and notice1 with the help of a lens1 the spore-boxes attached to its inner surface4 ,illustration3 ,,fig4 #aeb4--,sterile ,haulms of ,horsetail4 ,illustration3 ,,fig4 #aec4--;,fertile ,haulms of ,horsetail4 #f4 ,the prothallus4--,dry a ripe cone and shake it over paper to collect the spores4 ,sow these on moist soil1 and try to raise prothalli4 ,the general appearance of the horsetail4--,the common horsetail 7,fig4 #aed71 which may be found in hedgerows and cornfields1 is not in any respect showy4 ,it rarely exceeds a few feet in height1 and does not attract attention by any display of bright colours4 ,the plant has stiff1 jointed stems or haulms1 standing gracefully erect and bearing rings of small united leaves at intervals4 ,the branches arise just above the leaves1 and alternate with them3 several coming off at each level1 somewhat like the ribs of an umbrella4 ,the whole plant has thus a rather stiff and formal aspect4 ,illustration3 ,,fig4 #aed4--;,common ,horsetail4 7 47 #a1 ,fertile haulms1 terminating in cones 7a73 #b1 a sterile haulm2 a1 tubers3 #c1 scale of cone with spore-boxes 7mag473 #d1 scale with ruptured spore-boxes 7mag473 #e1 #f1 #g1 spores 7mag474 ,the haulms are very plainly of two kinds2 for some1 which are of a pale colour1 do not branch1 and are developed merely to bear the pretty little cones 7,fig4 #aed1 #a1 a7 which appear at their upper ends4 ,as the purpose of the cones is to give rise to the next generation1 the haulms which bear them may be called the fertile haulms4 ,they will be described presently1 when the reproduction of the plant is considered4 ,the sterile haulms4--,the erect branching shoots 7,fig4 #aed1 #b71 bear no organs of reproduction1 and are hence referred to as the sterile haulms4 ,their work is to provide the whole plant with carbonaceous food1 and it is on this account that their branches are of the characteristic green tint4 ,in most green plants the manufacture of carbonaceous food 7,chapter ,,iii47 takes place mainly in the leaves4 ,in the horsetail1 however1 the leaves are small and of very little importance in this respect1 and the work is carried on by the sterile haulms and their branches4 ,the underground stem and roots4--,a large part of the horsetail plant is hidden beneath the surface of the ground1 and often penetrates to a great depth4 ,in ordinary language these underground parts are called roots4 ,they are1 however1 subterranean stems1 as is shown quite plainly by the fact that they bear small leaf-sheaths like those on the stems above ground4 ,in the common horsetail the underground stems often become swollen in parts by the formation of tubers 7,fig4 #aed71 as is the case with the potato4 ,the true roots are very slender and thread-like1 and spring from the nodes 7p4 #de7 of the underground stems4 ,they penetrate the soil in all directions1 seeking for water1 which they take up by the fine hairs which clothe them1 like velvet-pile1 a little behind their points4 ,the stem and its haulms1 like those of grasses1 are stiffened by silica1 which is deposited in the outer layers4 ,this is of course obtained from the soil4 ,it is not absolutely necessary to the life of the plant1 but it is nevertheless very useful1 as it enables the haulms to stand upright and spread out their branches to the light and air4 ,the sterile branches are thus concerned with the horsetail's daily life4 ,the roots provide it with water and mineral food1 and the green branches supply the necessary carbonaceous matter4 ,stem1 branches1 and roots are permeated with a complete system of canals1 through which the food substances find their way to the various centres of activity4 ,the reproduction of the horsetail4--,it has been seen that some of the haulms do not bear branches1 but are set aside for the production of the cones4 ,these fertile haulms come up in ,march1 before the green sterile haulms appear4 ,when the cones are carefully examined they are seen to be covered by a number of shield-shaped scales4 ,to the inner side of each scale 7,fig4 #aed1 #c1 #d7 are attached from five to ten boxes1 each containing a large number of little grains or spores4 ,the boxes burst open when they are ripe1 about the end of ,march1 liberating the spores2 and the fertile haulms1 having performed the one duty for which they were developed1 at once die down4 ,if the spores fall in a favourable situation they germinate1 and each gives rise to a new plant4 ,the new plant is1 however1 not a horsetail1 but a small filmy prothallus1 somewhat like the prothallus of a fern4 ,some of the prothalli produce male cells1 while others give rise to female cells4 ,when the minute male cells are ripe1 they are set free1 and are able1 by means of fine1 lashing threads1 to swim towards the female cells of a neighbouring prothallus1 through a drop of dew or rain4 ,the two cells fuse together and give rise to a little embryo1 which in due course grows up into a new plant--an ordinary horsetail with stems and branches and roots like its grandparent4 ,the advantage of an alternation of generations4--,the life-history of the horsetail is evidently very similar to that of a fern1 each exhibiting a well-marked alternation of generations4 ,there is reason for believing that the prothallus-generation is the original form1 and that the ordinary fern and horsetail were developed simply to scatter spores at intervals1 and so to give new plants the advantages of fresh soil4 ,illustration3 ,,fig4 #aee4--;,calamite3 an extinct plant allied to the ,horsetails 7greatly reduced74 ,living and extinct horsetails4--,none of the ,british horsetails is of great height1 although one species may attain to six feet4 ,some of the tropical members of the family1 however1 are very much larger than this1 reaching even forty feet4 ,in spite of the last-named fact it is quite plain that the horsetails have had their day1 and are dying out4 ,if we wish to form an idea of what they were at the height of their prosperity1 we must carry our minds back to the long distant age when our coal was being formed2 when so much of this country as then existed was low-lying swamp1 covered with exuberant vegetation4 ,then the horsetails and their relatives were stately forest trees1 and at the head of the vegetable kingdom4 ,some of them towered to a height of over ninety feet4 ,nor did mere height constitute the only difference between them and their degenerate descendants4 ,many of these old-world giants had already found out the device1 since invented afresh by more modern plants1 of thickening their stems and roots with secondary wood1 and of giving rise to bark like that of our present-day forest trees4 ,the wood of these ,calamites 7,fig4 #aee71 as they are called by geologists1 had already reached much the same stage of development as is found to-day in such a tree as the yew4 ,the cones often show great variation from the comparatively simple form found in the modern horsetail1 but they are essentially of the same type4 ,flowering and flowerless plants4--,botanists divide plants into two great groups--flowering plants1 which reproduce themselves by means of pollen grains and ovules2 and flowerless plants1 which still retain the primitive marriage customs of their ancestors4 ,the flower is a comparatively recent invention in the history of plant life1 and its success is shown by the dominant position in the plant world which the flowering plants now occupy4 ,many of the flowerless plants--like the horsetails--have fallen behind their competitors4 ,the ferns1 in spite of their conservatism1 still hold their own1 and seem in no danger of extinction4 ,many other flowerless plants maintain their position by sheer force of numbers4 ,yet others have become completely extinct1 and can now be known only by their fossil remains4 ,but these latter are sometimes so distinct that stems1 roots1 and spore-boxes can be seen with all their sharpness of outline unimpaired2 the delicate tracery of frond and leaf is visible1 as clear and fresh as if made yesterday4 ,and such rocky herbaria tell us in unmistakable terms that our forest trees and other flowering plants are after all mere parvenus and upstarts4 ,,exercises ,,on ,,chapter ,x4 #a4 ,explain the formation of the green scales which are frequently seen on the surface soil of a fernery4 ,whence do they arise8 ,what happens to them if they are allowed to grow8 7,king's ,scholarship1 #aijb7 #b4 ,point out the differences between the fronds of a fern and the leaves of most flowering plants4 7#aija7 #c4 ,show how the spore-producing plant of a fern is attached to the prothallus1 and trace the early development of the former4 #d4 ,make a list of the ferns which you have seen growing wild1 and state exactly in what kinds of places they were growing4 #e4 ,make experiments to prove that the prothallus of a fern is capable of manufacturing starch4 #f4 ,make drawings of the spore-bearing leaves of all the ferns you can find1 marking in each case the position of the spore-groups4 #g4 ,in what situations have you found horsetails growing8 ,what other plants were growing near8 #h4 ,what is the difference between a seed and a spore8 #i4 ,describe the situation in which the main stem of the bracken is found1 its mode of growth1 and the simpler facts of its structure4 7#aijd7 #aj4 ,in what respects do you consider the rhizome of a fern 7a7 similar2 7b7 dissimilar to the root of a tree8 7,certificate1 #aije7 #aa4 ,where are the spores of a fern formed1 and how are they dispersed8 ,what do they produce on germination8 7#aije7 ,,chapter ,,xi4 ,,mosses1 ,,mushrooms1 ,,and ,,moulds4 #dj4 ,,liverworts ,,and ,,true ,,mosses4 #a4 ,a common liverwort4--,look along the sides of a brook or a well1 and try to find a flat green plant with numerous lobed and overlapping branches4 ,each branch is perhaps half an inch across4 ,this is one of the commonest liverworts 7,pellia74 ,notice the prominent midrib running along each branch4 ,in spring1 observe the 8frilled0 appearance of the end1 caused by the small new branches4 ,pull the plant up1 and notice that it is attached to the soil by a large number of fine hairs which spring from the lower surface of the midrib4 ,in ,february1 or ,march1 examine the upper surface of the growing plant with a lens1 and notice the small1 dark-green balls1 mounted on short1 thick stalks4 ,examine these at intervals until ,may1 and notice that the stalks then grow rapidly until they are two or three inches long4 ,each is white1 and still bears the black ball 7the capsule7 on its summit4 ,when the stalk is full-grown1 the capsule opens--its wall splitting into four parts--to liberate the spores4 ,how soon1 after the liberation of the spores1 do the capsule and its stalk die down8 #b4 ,a common moss4--,separate a single plant from a tuft of the common moss 7,funaria7 which grows1 almost everywhere1 on the ground and on walls4 ,notice that the plant consists of a stem perhaps half an inch high1 thickly covered with small simple green leaves4 ,the moss is fixed in the soil by a tuft of fine hairs4 ,on some of the plants notice a thin stalk 7about half an inch long7 springing from the top of the stem2 and on the end of the stalk an ovoid capsule or spore-box4 ,in cases where the stalk is not yet full-grown1 notice that the capsule is covered by a conical hood1 somewhat like a candle-extinguisher4 ,select a plant bearing a ripe capsule1 and warm it gently before the fire--holding it over a sheet of paper--to dry it4 ,examine the mouth of the capsule with a lens1 and try to see the teeth which surround the opening4 ,then shake the capsule over moist soil in a small flower-pot to scatter the spores2 cover with a sheet of glass and keep in a warm room4 ,in a few days notice that the soil is covered with fine green threads4 ,ultimately new moss plants will grow from these4 ,the life-history of a liverwort4--,one of the commonest and simplest of this class of plants is known to botanists as ,pellia4 ,it may generally be found growing by the sides of streams or old wells4 ,it has neither stem1 leaves1 nor root1 but consists of flat1 green1 overlapping lobes which fork at their ends4 ,it branches very freely1 and in spring the new branches give the ends of the lobes a frilled appearance4 ,a rather prominent midrib runs along each branch4 ,the plant is attached to the soil by a large number of fine hairs which spring from the lower surface of the midrib4 ,the whole appearance of this liverwort is very suggestive of the prothallus 7,fig4 #adg7 of a fern2 and1 indeed1 it corresponds to a prothallus1 not only in its general structure and mode of life1 but also in bearing sexual organs of a very similar type4 ,it was seen in ,chapter ,x4 that a fern prothallus at length produces an embryo1 which grows up and forms the spore-bearing generation which is what people usually understand by a 8fern04 ,the liverwort also gives rise to a spore-bearing generation1 but in this case it consists merely of a small1 round1 spore-box1 dark-green in colour1 which is carried on the summit of a white stalk--the whole looking somewhat like a stout pin4 ,in ,february1 or early ,march1 the spore-boxes may be seen upon the upper surface of the plant as small balls1 perhaps one-sixteenth of an inch in diameter1 protruding from the mouth of a little pocket in which their early stages are passed4 ,about ,may1 their stalks lengthen so rapidly that in a few days the spore-boxes are lifted to a height of two or three inches4 ,then each box opens by its wall splitting into four1 and the spores are liberated to germinate and form new liverworts4 ,having thus shed the spores1 the box and stalk die down4 ,the complete life-cycle of a liverwort thus includes two unlike generations1 as that of a fern does2 but it is a different generation which attains the greater development in the two cases4 ,the ordinary fern is the spore-bearing generation2 the 8ordinary0 liverwort is the sexual generation1 and its sporing offspring is not a separate plant at all1 but a mere stalked box1 almost entirely dependent upon its parent4 ,illustration3 ,,fig4 #aef4--;,a ,moss4 ,a1 a plant with spore-case still covered by hood 7c7 7 #a74 ,b1 a plant with ripe spore-case 7k72 s1 stalk2 d1 lid2 rh1 hairs 7 #a74 ,c1 mature spore-case with lid 7d7 removed2 p1 fringe of teeth 7 #c74 ,the mosses4--,a moss-plant appears at first sight to be very similar in its general features to one of the higher plants2 for it has a little stem1 bearing flattened green leaves which build up carbonaceous food in the usual way4 ,it has no true roots1 but fine hairs penetrate the soil and do the work of roots by taking up solutions of mineral food4 ,it is all the more remarkable1 therefore1 to find from its method of reproduction that the moss-plant belongs to the generation which corresponds to the prothallus stage of a fern's life-history1 and not to the leafy1 sporing generation which it somewhat resembles superficially4 ,the sexual organs of a moss are essentially of the same type as those which a prothallus bears1 and here also the tiny male cells gain access to the female cells by swimming through a drop of rain or dew4 ,the result of fertilisation is an embryo which1 however1 grows up to form1 not a plant with stem and leaves1 but a stalked spore-case only4 ,in a tuft of the moss ,funaria1 which is so common in all country places1 several stages of development of the spore-cases may usually be seen4 ,fig4 #aef represents a moss which is very similar to ,funaria but larger4 ,in ,a1 the spore-case is still covered by a conical hood 7c74 ,in ,b1 the stalk 7s7 has grown much longer1 and the hood has dropped off4 ,the spore-case or capsule 7k7 is now seen to be a pear-shaped body1 closed by the lid 7d74 ,when the spores are ripe1 the lid becomes detached4 ,the mouth of the nodding capsule is still blocked1 however1 by a number of teeth 7,fig4 #aef1 ,c1 p7 which remain close together in damp weather4 ,in dry weather the teeth separate1 and allow the spores to fall out4 ,when a moss spore falls in a favourable situation it germinates to form a fine1 branching network of green threads1 from which new moss-plants arise as buds4 ,the obvious plant of a moss--like that of a liverwort--therefore corresponds to the prothallus generation of a fern or horsetail4 ,its sporing generation1 corresponding to the obvious fern-plant or horsetail1 is a stalked spore-case1 which is always more or less dependent on its parent and dies down as soon as its work of scattering the spores is accomplished4 #da4 ,,the ,,common ,,mushroom4 #a4 ,habit of growth4--,in what situations do you find mushrooms growing8 ,in what kinds of weather and at what time of the year are they most abundant8 ,take up a mushroom with a trowel1 and carefully wash the earth from the lower part to see the tangle of white threads 7called the mycelium71 which is the underground part of the plant4 ,see that several of these run into the bottom of the stalk4 ,on the underground mycelium look for young mushrooms in the 8button0 stage4 ,look around1 and try to get a series of mushrooms showing all stages from the smallest buttons to fully-opened specimens4 #b4 ,structure4--,draw a side view 7natural size7 of a full-grown mushroom1 showing the stalk and cap4 ,running round the stalk notice a ragged flap1 called the collar4 ,what is the height of the collar from the base of the stalk8 ,examine younger mushrooms to find what the collar really is4 ,notice that in young specimens a membrane or veil stretches from the edge of the cap to the stalk1 and that as the mushroom grows larger this veil is torn away from the cap 7,fig4 #aeg71 and remains as a ragged flap 7the collar7 on the stalk4 ,in young specimens1 therefore1 the lower side of the cap is completely shut in by the veil1 while in fully-grown ones it is exposed4 #c4 ,the gills and spores4--,cut the stalk across at the top1 and make a drawing of the lower surface of the cap4 ,notice the radiating vertical plates 7the gills71 and their flesh-coloured or dark-brown tint4 ,be careful to show the exact arrangement of the gills in1 say1 a quarter of the drawing4 ,cut off the cap of a mushroom which has brown gills and lay it1 gills down1 on a sheet of paper2 cover it with a tumbler to shield it from draughts1 and leave it for a day4 ,then take off the cap 7being careful not to smear it along the paper71 and observe the radiating brown lines4 ,on touching them1 it will be seen that the lines consist of fine brown dust4 ,the particles of dust are spores4 ,they have evidently fallen from the gills4 #d4 ,the source of the mushroom's food4--,what is the colour of the mushroom8 ,cut through the stalk and cap in various directions and notice the pure white 8flesh0 of the interior4 ,do you think it likely that the plant can obtain carbonaceous food from the air8 ,why not8 ,dry a mushroom and burn it carefully4 ,does it contain carbon8 ,where must the carbon have come from1 if not from the air4 ,can you find any decaying vegetable or animal matter in the soil in which mushrooms grow8 #e4 ,toadstools4--,carefully compare the common mushroom with other gilled fungi which look somewhat like it4 ,notice particularly the following characters3 the colour1 shape1 and texture of the surface of the cap2 the colour and arrangement of the gills2 the proportions of the length and thickness of the stalk to the diameter of the cap2 the presence or absence of a collar on the stalk2 the presence or absence of a cup1 or scaly swelling1 at the base of the stalk4 ,the following precautions are necessary in selecting mushrooms for food3 ,never eat a 8button0 mushroom2 in this stage wholesome and poisonous mushrooms cannot be properly distinguished from each other4 ,reject all mushrooms which show signs of a cup or a scaly swelling at the base of the stalk--especially if they have also white spores and a collar4 ,the common meadow mushroom4--,the common mushroom 7,fig4 #aeg7 may easily be found in meadows1 especially in autumn and after damp weather in summer4 ,the part which rises above the surface of the ground consists of a stout stalk1 about three inches long and perhaps three-quarters of an inch thick4 ,on the upper end of the stalk is a circular horizontal cap1 convex and smooth above and concave below2 with a diameter about equal to the length of the stalk4 ,the interior of the stalk and cap is composed of a firm white fleshy substance4 ,the underground part of the plant consists of a tangle of fine white threads1 most of which are woven together into strands2 and it is easy to see that several of these strands run into the base of the stalk4 ,each of the fine threads is called a hypha1 and the network which they together compose is known as the mycelium4 ,it has indeed been found by microscopic examination that the whole plant is built up of such hyphae--closely packed together in the stem and cap1 more loosely aggregated in the underground strands4 ,the stalk of the full-grown mushroom bears1 a little above its middle1 a ragged ring of tissue--the collar4 ,this ring is the remains of a membrane or veil which in the younger stages reached to the edge of the cap1 completely enclosing its lower surface2 but which was torn off the cap 7,fig4 #aeg7 as the stalk of the 8button0 mushroom elongated4 ,illustration3 ,,fig4 #aeg4--;,common ,meadow ,mushroom4 ,to the right1 mushroom in 8button0 stage 7 74 ,the reproduction of the mushroom4--,the lower side of the cap of a mature mushroom bears a very large number of radiating plates called the gills4 ,these are at first pink1 but the colour afterwards changes to a dark brown4 ,each gill produces an immense number of extremely fine spores1 too small to be seen individually by the naked eye4 ,when1 however1 the cap of a mushroom is laid1 gills down1 on a sheet of paper and protected from draughts1 a 8spore print0 is obtained2 the dust of the fallen spores marks the positions of the gills in brown radial lines4 ,quite recently it has been found possible to raise new mushroom plants by germinating the spores1 and there can be no doubt that this is the natural method of reproduction4 ,the method of life of the mushroom4--,the mushroom1 like all the plants we have studied1 thus consists of parts which perform one or other of two duties2 that of feeding the plant1 and that of continuing the race4 ,in this case the food is supplied entirely by the underground mycelium2 while the arial part1 consisting of stalk and cap1 is concerned only with the work of scattering the spores4 ,there is nothing corresponding to the leaf-green of the higher plants1 and the mushroom is therefore unable to make use of the carbon dioxide of the air 7p4 #cd7 as the source of the carbonaceous food which is necessary for its life4 ,carbonaceous and mineral food alike are obtained from the soil by the underground mycelium4 ,the plant is1 in short1 dependent upon carbonaceous food which has been previously built up by some other plant or animal1 and can therefore grow only in soil containing decaying animal or vegetable matter4 ,it would be quite unable to subsist upon the nutritive solution of salts which was seen 7p4 #bi7 to suffice 7when supplemented by fresh air7 for green plants4 ,fungi4--,the mushroom belongs to a class of plants called the ,fungi1 all of which obtain their carbonaceous food ready-made from some other plant or animal1 living or dead4 ,for this reason many fungi are parasitic upon other living plants4 ,most of the diseases of crops and of forest trees are due to fungi4 ,the moulds which destroy food are fungi1 and the dry rot which ruins timber is caused by organisms of the same class4 ,toadstools4--,the common meadow mushroom is a justly-esteemed article of food1 but some other gilled fungi1 which are intensely poisonous1 bear a sufficiently close resemblance to mushrooms to render them dangerous4 ,the student should therefore take every opportunity of examining these1 and of comparing them with the edible mushroom in the manner described on p4 #bjd4 #db4 ,,moulds4 #a4 ,the growth of moulds4--,damp three small slices of bread1 and cover them with tumblers to prevent them from drying4 ,expose one slice to ordinary daylight2 keep another in a dark place at about the same temperature2 and submit the third to the direct rays of bright sunlight as much as possible4 #b4 ,white mould 7,mucor74--,in one or two days observe that the bread is covered with white fleecy threads4 ,some of these may grow to a height of an inch or more1 and end in small black knobs which can be seen with the naked eye4 ,the knobs contain spores4 ,examine the mould with the help of a lens4 ,on which of the three pieces of bread is there most mould1 and on which the least8 ,mix freshly-boiled and strained juice of stewed fruit 7preferably colourless or nearly so7 with an equal quantity of water4 ,half fill a small glass with the mixture1 and with the point of a needle add a few spores from the mould on the bread4 ,cover the glass1 avoid shaking it1 and examine day by day4 ,notice the delicate threads 7hyphae7 of the mycelium which spreads over the liquid and sends down branches below the surface4 ,observe also the hyphae which grow up into the air and bear spore-knobs at the end4 ,similarly1 sow some of the spores on a little of the nutritive solution of salts 7p4 #bg7 contained in a clean glass4 ,do these spores also develop into moulds8 ,why not8 ,scratch through the skin of a ripe fruit 7e4g4 plum1 apple1 grape1 etc47 with a needle1 and lay the fruit aside with the scratch upward4 ,scratch a similar fruit in the same way1 and rub into the scratch a few mould-spores before laying it aside4 ,with these put a third fruit which has a perfectly whole skin4 ,compare the fruits after a few days4 #c4 ,blue mould 7,penicillium74--,after some days the white mould on the bread will probably be crowded out by a blue or greenish velvety mould called ,penicillium4 ,examine it with a lens4 ,as with ,mucor1 make experiments as to the action of light upon this mould2 the germination of its spores 7which form a greenish powder on the ends of the short arial hyphae7 in fruit-juice2 and the action of the spores upon ripe fruits4 ,common moulds4--,in the dust floating about in the air the spores of certain moulds are almost always present4 ,when these spores fall upon materials which--like bread1 fruit1 old leather1 etc4--are capable of affording them suitable food-substances1 they germinate and form the woolly growths which are familiar to everyone4 ,the white mould 7,mucor74--,what is known familiarly as white mould1 and botanically as ,mucor1 is very convenient for study on account of its abundance and large size4 ,if a piece of bread is kept in a damp atmosphere it generally becomes covered1 after a day or two1 with a fleecy growth of the white threads of this mould4 ,these may attain a height of an inch or more1 and many of them bear at their ends a small black knob1 in which the spores are formed4 ,when mature1 the knobs burst open1 and the fine spores are scattered in the air4 ,the various parts of the mould are best seen in position by scattering some of the spores1 or a little dust from a shelf1 upon the surface of clear1 colourless fruit-juice in a glass vessel1 and following the stages of growth with a lens4 ,it then becomes clear that the mould--like the mushroom--consists of 7a7 a buried tangle or mycelium of hyphal threads which take in the plant's food1 and of 7b7 an arial part which scatters the spores4 ,the mould also resembles the mushroom in not containing the green colouring matter possessed by the higher plants1 and therefore in being dependent upon ready-made organic food4 ,provided with this1 it can grow freely even in the dark4 ,illustration3 ,,fig4 #aeh4--,penicillium4 ,an arial hypha with its terminal spore-brushes4 7 #cfj74 ,blue mould 7,penicillium74--,it is generally found that the fleecy hyphae of ,mucor1 which first cover the damp bread1 are crowded out in a short time by the growth of another mould1 which is known to botanists as ,penicillium4 ,this also consists of a mycelium1 which penetrates the nutritive substance1 and of arial hyphae which produce spores4 ,here1 however1 the spores are not borne in cases1 but break off from the ends of brush-like branches of the arial hyphae 7,fig4 #aeh74 ,the spores of ,penicillium are greenish-blue in colour1 and it is from this circumstance that the mould receives its common name4 ,the colour is1 however1 quite different from the leaf-green which gives the higher plants the power1 in sunlight1 of decomposing the carbon dioxide of the air and building up their own carbonaceous food--a power which neither ,penicillium nor any other fungus possesses4 ,the smallest plants4--,the description of microscopic organisms is beyond the scope of this book1 but the student ought to realise that by far the greater number of plants are quite invisible to the naked eye4 ,some of these--to be found in every pond and ditch--are green1 and1 though they are of very simple structure1 they obtain their food in a manner substantially resembling that adopted by a flowering-plant or a fern4 ,others1 like the yeast plant1 are fungi1 and are subject to the limitations in food-supply which are characteristic of that class4 ,the smallest of all plants are the bacteria2 they are almost inconceivably minute1 yet they possess an influence upon the health and wellbeing of mankind which it is impossible to over-estimate4 ,,exercises ,,on ,,chapter ,,xi4 #a4 ,explain in what respects a moss plant resembles and differs from the prothallus of a fern4 #b4 ,what structure in a moss corresponds1 as regards reproduction1 to an ordinary fern plant8 #c4 ,what do you mean by the term 8alternation of generations08 ,explain your answer by references to ferns and mosses4 #d4 ,how does a mushroom resemble and differ from a green plant in its method of obtaining food8 #e4 ,why does a piece of damp bread become mouldy when it is exposed to the air8 #f4 ,describe simple experiments which prove that the dust of ordinary air contains living particles4 #g4 ,mention common plants which are wafted about by currents of air in a dwelling-house1 and point out changes which such plants may set up in articles of human food4 7#aije7 ,,part ,,ii4 ,,animal ,,life ,,chapter ,,xii4 ,,the ,,rabbit3 ,a ,,typical ,,mammal4 #dc4 ,,the ,,rabbit3 ,,habits ,,and ,,appearance4 #a4 ,the habits of the wild rabbit4--,in what places have you known wild rabbits to have a warren8 ,in what kind of ground is a rabbit warren generally found8 ,how can you recognise it8 ,are all the holes of the warren of similar size1 or can you distinguish between main entrances and 8bolt-holes08 ,look for smooth paths1 perhaps nine inches wide1 which lead to the main entrances and intersect each other1 so as to form 8runs40 ,watch the animals feeding and playing2 to do this successfully it will be necessary to keep very still and silent2 avoid walking on the runs4 ,what do the rabbits eat8 ,do they walk1 or hop8 ,how do they run8 ,notice how conspicuous is the white tail of a running rabbit4 ,in ,june look for a nest of young rabbits4 ,the position of such a nest may often be recognised1 when the doe is away from home1 by a smooth patch of earth with which she has covered up the hole4 ,dig up this very carefully and notice how the nest is lined4 ,examine the young ones without hurting them1 and then cover them up again4 ,what is the colour of a wild rabbit8 ,does the colour render the animal less conspicuous8 ,are tame rabbits so often of this colour8 ,why not8 ,watch a tame rabbit1 noticing especially the movements of its nostrils1 whiskers1 and ears1 and its method of feeding4 ,try to see how it gnaws the bars of its hutch4 #b4 ,fur4--,examine a dead rabbit4 ,with what is the skin covered8 ,what are the differences between the fur of a rabbit1 the hair of a dog1 and the wool of a sheep8 ,is fur curly8 ,does it lie flat on the skin8 ,does it consist of different sizes of hair--short1 fine hairs and long1 thicker ones8 ,what other animals do you know which have fur8 #c4 ,the head4--7a7 ,the whiskers4--,on what parts of the head are the longest hairs found8 ,how do these differ1 apart from length1 from ordinary hairs8 ,what other common animals have whiskers8 ,do such animals often make their way through narrow passages8 ,what do you suppose is the use of the whiskers8 7b7 ,the skull4--,feel the bones of the head through the skin1 and make out the rounded brain-case1 the ridge above and the arch below each eye1 and the positions of the jaws4 7c7 ,the external ears4--,examine the large ear-flaps4 ,notice that the upper parts are thin and almost transparent1 and that the lower parts are gristly and lead into the interior of the head4 7d7 ,the eyes4--,notice that the eyes are at the sides of the head4 ,is this position an advantage to the rabbit8 ,examine1 in each eye1 the upper and lower lids2 and also1 in the angle of the eye next the nose1 the third eyelid--a fold of white skin4 ,take hold of this fold with the forceps and see that it is easily pulled over the eyeball4 ,look in a mirror and see the little fleshy body which occupies a similar position in your own eye2 this corresponds to the rabbit's third eyelid4 ,in the visible part of the rabbit's eyeball notice the round dark pupil in the middle 7contrast the pupil of a cat's eye72 the coloured ring 7the iris7 surrounding the pupil2 and the 8white0 7called the sclerotic7 surrounding the iris4 7e7 ,the lips and nostrils4--,notice how the upper lip is split in the middle line1 so as to show the front teeth4 ,what is the use of the split8 ,notice the grooves passing from the upper lip to the nostrils4 7f7 ,the inside of the mouth4--,open the rabbit's mouth and notice3 7i7 ,the two gnawing or incisor teeth in the lower jaw1 and the pair of strongly-grooved incisors which are so conspicuous in the upper jaw4 ,just behind the large1 upper incisors two smaller incisors may be felt with the finger4 ,separated by a wide space from the incisors are the grinding teeth--six on each side in the upper jaw1 and five on each side in the lower jaw4 7ii7 ,the tongue1 lying between the halves of the lower jaw4 7iii7 ,the hard ridges running across the fore half of the roof of the mouth4 7iv7 ,the hairiness of the inside of each cheek1 between the incisor and grinding teeth4 #d4 ,the neck4--,notice how the neck enables the head to be turned freely in various directions without the body being moved4 ,feel through the skin and identify3 7a7 ,in front of the neck1 the trachea or windpipe1 with the larynx or 8voice box0 at its upper end between the halves of the lower jaw4 7b7 ,the bones of the neck-part of the spine4 #e4 ,the trunk4--,feel through the skin and make out the spine1 the breast-bone1 and the curved ribs which connect these4 ,the spine1 breast-bone1 and ribs together form a bony cage which encloses the fore-part 7the thorax7 of the body4 ,the hinder and larger part of the body 7the abdomen7 is not protected by ribs1 but the bones of the spine are largest and stoutest in this part of the body4 #f4 ,the limbs4--,how many limbs has the rabbit8 ,which pair is the longer8 ,is the difference in length an assistance in leaping8 ,make out the main divisions of each limb1 and1 by feeling through the skin1 the manner of attachment of its bones to the bones of the body 7,fig4 #afa74 #g4 ,the tail4--,notice the length1 shape1 position1 and colour of the tail4 ,the chain of bones inside it is a prolongation of the spine4 ,methods of studying animals4--,in studying animals1 methods similar in principle to those described in previous chapters for plants should be employed4 ,a real knowledge of the habits of animals can only be obtained by watching them as closely as possible in their natural surroundings4 ,it is often very difficult to get sufficiently close to shy animals to see them distinctly without causing alarm1 and a good field-glass is a valuable help in such cases4 ,a great deal of first-hand knowledge of wild life can1 however1 be gained without such aids if the student will learn to move quietly and silently1 and to remain motionless as soon as he is in a good position for observation4 ,the books of such masters of woodcraft as ,richard ,jefferies1 ,william ,j4 ,long1 ,ernest ,thompson ,seton1 and ,w4 ,h4 ,hudson give charming descriptions of the methods of tracking and studying wild animals1 and should be carefully read by every field-naturalist4 ,observations made in the field should be at once recorded1 with the date1 in a note book4 ,many animals can be kept for some time1 without cruelty1 in confinement2 and a more intimate knowledge of certain of their habits can be thus obtained4 ,the practice of keeping pets is1 however1 to be encouraged only when every possible care is taken to secure the comfort of the captives4 ,to understand the internal structure of an animal1 dissection is necessary4 ,this consists in exposing and separating the internal organs of the dead animal from each other1 in order to notice their mutual relation4 ,a careful outline drawing of every dissection should be made and preserved4 ,the student should make it a rule never to kill any animal unless for some useful purpose1 and then to do so in the quickest and most painless manner4 ,the habits of the rabbit4--,wild rabbits live in burrows or underground passages which they excavate1 by means of their strong feet1 in the soil of sandbanks1 fields1 woods1 etc4 ,the animals are sociable1 and the burrows belonging to any one community are collectively known as a warren4 ,the passages of the warren communicate with the outside world by means of openings1 some of which are in common use1 while others seem to be used mainly as 8bolt-holes0 in cases of sudden alarm4 ,a rabbit which is bolting to its burrow exposes the white underside of its tail1 and thus acts as a danger signal and guide to its fellows4 ,when a rabbit is startled1 or puzzled by seeing some unusual object1 it generally thumps the ground smartly with its long hind-foot2 other rabbits in the neighbourhood are thereby warned4 ,illustration3 ,,fig4 #aei4--,rabbits4 ,it is common to find1 outside a rabbit warren1 a number of intersecting paths1 perhaps nine inches wide1 and worn smooth by the patter of little feet4 ,these are the highways1 or 8runs10 which lead from the holes of the warren to the various feeding-grounds4 ,rabbits breed very rapidly2 it has been estimated that in five years a single pair might have about a million descendants1 were it not for the countless mishaps to which rabbits are exposed4 ,the young are born and suckled in a special shallow burrow1 which the doe excavates and lines with dry leaves1 fur1 etc4 ,when she leaves the nest for any purpose she covers up the entrance with soil4 ,the proportions of the parts of the body of a very young rabbit are markedly different from those of the adult4 ,the head is relatively larger1 the tail longer1 and the ears shorter2 while the hind limbs and fore limbs are of almost equal length4 ,during the first six months of its life the animal gradually takes on the proportions of the adult--with small head1 long ears1 large hind legs with long feet1 and small1 upwardly-turned tail4 ,a rabbit is able to stand upright on its hind legs1 and to maintain itself in this position for a considerable time4 ,it thus obtains a wider view and a greater choice of food4 ,the great difference in the length of the fore and hind legs gives the animal a characteristic gait4 8,in a freely moving rabbit10 says ,jefferies1 8both fore-feet stop when the hinder come up--one hinder foot slightly behind the other1 and rather wide apart40 ,rabbits are exclusively vegetarian feeders1 living on green herbs and on the tender shoots and bark of shrubs and young trees4 ,the external characters of the rabbit4--,the outside of the rabbit's body is almost entirely covered with fur4 ,this consists of two kinds of hair--coarse and fine4 ,the coarser hairs are fewer in number and longer than the fine ones1 which they protect from wet4 ,the fine hairs are extremely closely-set1 and stand straight out from the skin4 ,in a seal-skin coat only the short hairs of the fur are to be found2 the longer hairs have been removed by the dressing process4 ,the great warmth of furs is due to the air which is entangled between the fine1 close hairs4 ,it is generally the case that fur-bearing animals are exposed to either mud or wet by their method of life2 in spite of this fact1 while the hair of a dog soon becomes wetted by rain1 and the wool of a sheep retains a great deal of dirt1 furred animals are noted for keeping their coats clean and dry4 ,the longest hairs of the rabbit are the stiff whiskers which stand out from the upper lip1 the cheeks1 and above the eyes4 ,they are extremely sensitive to touch1 and are of great assistance to the animal in finding its way through the dark burrows4 ,the colour of the wild rabbit is greyish brown1 except on the belly and under the tail1 where it is white4 ,this colour harmonises well with the surroundings1 and renders the animal much less noticeable4 ,wild rabbits are exposed to so many enemies1 that individuals which happen to be born with conspicuously coloured fur have generally but a poor chance of surviving and leaving offspring to inherit their disadvantages4 ,there is thus in each generation a natural selection of the animals which are best protected1 by their colour1 from observation4 ,among tame rabbits1 on the other hand1 protective colouration is of very little importance1 and one variation of colour is as likely as another to be transmitted by heredity to the next generation4 ,the regions of the body4--,for convenience and precision in describing animals it is customary to use the words anterior and posterior to indicate the fore1 or head1 end1 and the hind1 or tail1 end respectively4 ,the belly-surface is said to be ventral1 and the back dorsal4 ,the body of a rabbit obviously consists of head1 trunk1 a short tail1 and four limbs4 ,the general arrangement of the bony framework1 or skeleton1 7,fig4 #afa7 which supports the softer parts may be felt through the skin4 ,the skeleton consists of 7#a7 the skull2 7#b7 the spine or vertebral column 7generally spoken of as the backbone71 placed dorsally1 and reaching from the anterior end of the neck into the tail2 7#c7 the ventral sternum or breast-bone1 which is connected with the vertebral column by means of curved ribs2 7#d7 the bones of the two pairs of limbs1 with the shoulder-and hip-bones to which they are attached4 ,the bones will be studied in more detail in the next chapter4 ,the trunk is divided into two regions--an anterior thorax1 or chest1 7enclosed in the bony cage formed by the ribs1 sternum1 and the adjoining part of the vertebral column71 and a posterior abdomen4 ,the two cavities are divided from each other by a fleshy partition called the diaphragm4 ,organs of special sense4--,in addition to the sense of touch which is possessed by the whole surface of the body1 the rabbit has organs which enable it to distinguish objects by sight1 sounds1 scents1 and taste4 ,its sense of smell is so keen that1 to be successful in snaring rabbits1 8in walking to the spot selected for the snare it is best to avoid even stepping on the run1 and while setting it up to stand back as far as convenient and lean forward4 ,the grass that grows near must not be touched by the hand1 which seems to impart a very strong scent4 ,the stick that has been carried in the hand must not be allowed to fall across the run2 and be careful that your handkerchief does not drop out of your pocket on or near it4 ,if a bunch of grass grows very tall and requires parting1 part it with the end 7not the handle7 of your stick40#h ,the shape of the ear-flaps1 which can be turned in different directions 7,fig4 #aei71 enables the rabbit to catch very slight sounds4 ,the eyes are placed on the sides of the head1 so that the animal has a wide field of view1 and an enemy approaching from behind is not likely to be unnoticed4 ,the eye of the rabbit is very similar in structure to our own1 but it possesses one useful adjunct which ours has lost1 in the shape of a third eyelid--an opaque flap of skin which lies in the inner angle1 and can be drawn over the eyeball at will4 ,the little fleshy nodule in the corresponding position of the human eye is a rudiment of a similar structure4 ,the rabbit a gnawing animal4--,rabbits are much addicted to gnawing young trees for the sake of the bark and the softer juicy tissues between bark and wood4 ,even tame rabbits exhibit the same instinct by gnawing their wooden hutches1 although these are of no use as food4 ,the gnawing is done by the sharp teeth1 called incisors1 which are conspicuous in the middle of both upper and lower jaw4 ,in the upper jaw two incisors 7which are so deeply grooved that they look like four7 are visible even when the mouth is closed1 owing to the split in the middle of the upper lip4 ,the hardest part of the tooth 7a substance called enamel7 is at the front4 ,behind this the tooth is composed of a softer1 bony material called dentine2 and the back of the tooth consists of still softer dentine4 ,the result of these differences in the composition of the various parts of the tooth is that the gnawing of hard substances wears away the back of the tooth most1 the middle part next1 and the front least of all2 and thus a sharp chisel-edge is always maintained4 ,moreover1 the teeth of the rabbit never stop growing1 so that they never become appreciably shorter through use4 ,immediately behind the two visible incisors of the upper jaw1 another and smaller pair can be felt by the finger2 the enamel-faces of these are directed backwards towards the cavity of the mouth4 ,the softer and more easily worn faces of the two pairs of upper incisors are thus in contact1 and are continually worn down to form a groove4 ,into this groove the two incisors of the lower jaw bite4 ,the incisor teeth stand well out from the jaws1 and the split upper lip can be drawn back1 so that the lips are not injured by gnawing4 ,in the hinder part of the mouth1 where the chewing1 or mastication1 of the food takes place1 are six flatter but cross-ridged grinding teeth on each side of the upper jaw1 and five on each side of the lower jaw4 ,the insides of the cheeks are protected from sharp splinters of wood by a patch of hair on each side1 which extends from the region of the incisors to the grinding teeth behind4 ,the roof of the mouth is protected by hard cross-ridges1 and the tongue by tough skin4 ,rodents4--,rabbits and hares1 rats and mice1 and squirrels are said to be rodents 7,lat4 rodo1 ,i gnaw71 as they not only agree in the gnawing habit1 but also in other very important respects4 ,mammals4--,rodents1 and all other animals which suckle their young1 are included by naturalists in the class ,mammalia4 ,these animals agree further in breathing air1 in having warm blood1 and in being more or less completely covered with hair4 ,vertebrates4--,mammals1 birds1 reptiles1 amphibians1 and fishes are grouped together to form the sub-kingdom ,vertebrata4 ,they are given this name because they all possess a spinal1 or vertebral1 column 7which usually consists largely of a chain of bones71 running below the dorsal surface 7p4 #bag7 of the body1 from neck to tail4 ,the position of the rabbit in the animal kingdom4--,it is clear from the above that the rabbit is1 in the first place1 a vertebrate animal2 it belongs1 secondly1 to the mammalian class of vertebrates1 and thirdly1 to the rodent-order of mammals4 ,,exercises ,,on ,,chapter ,,xii4 #a4 ,in what respects does the hind-foot of a rabbit differ from the fore-foot8 ,what is the use of the difference8 #b4 ,describe the way in which a rabbit runs4 ,what precautions does it take when feeding in an open place8 7#aija7 #c4 ,make observations of the habits and external characters of hares1 and compare them1 point for point1 with those of rabbits4 #d4 ,describe the inside of a rabbit's mouth1 and explain the advantages of any peculiar features to be seen in it4 #e4 ,mention the two chief constituents of a rabbit's tooth4 ,describe by what means the edges of a rabbit's incisor teeth are kept sharp4 #f4 ,make a list of all the vertebrate animals with which you are acquainted4 ,why are they called vertebrates8 #g4 ,by what external characters would you recognise that an animal was a mammal8 ,,footnote3 #h ,jefferies1 ,the ,amateur ,poacher 7,smith1 ,elder ,co474 ,,chapter ,,xiii4 ,,how ,a ,,rabbit ,,lives4 #dd4 ,,the ,,skeleton ,,and ,,muscles #a4 ,the examination of the bones4--,in a boiled rabbit clear away the flesh from the bones4 ,before separating a bone1 notice carefully how it is attached to neighbouring bones4 ,notice also1 especially in the limbs1 the attachment of the bundles of flesh 7muscles7 to the bones1 the ends of each muscle being fixed to separate bones4 ,notice that the places of attachment of the largest muscles are marked by ridges or roughnesses on the bones4 #b4 ,the skull4--,observe the two rounded knobs at the back of the skull1 which fit into hollows on the first bone 7vertebra7 of the vertebral column4 ,in the skull notice the saw-like boundaries of the various bones1 and make out3 the great1 rounded brain-case2 the external openings of the ears2 the eye-sockets2 the snout1 with the two nasal chambers2 and the upper and lower jaws4 ,before separating the lower jaw observe carefully how it is hinged on the arches which run below the eyes1 and notice the great muscle on each side which moves it4 ,examine the teeth in detail1 and remove them one by one from their sockets4 ,notice the bony shelf or palate separating the nasal chambers from the cavity of the mouth4 ,draw a side view of the skull4 ,shave off the top of the brain-case with a sharp knife1 and examine the brain4 #c4 ,the vertebral column4--,make out that each of the bones 7vertebrae7 which compose the vertebral column is really a ring1 and that the whole column is therefore a bony tube4 ,in this tube is enclosed the spinal cord1 a backward continuation of the brain4 ,examine and draw vertebrae from the various parts of the column1 and notice how they vary in shape and size4 ,compare vertebrae from 7a7 the neck1 7b7 the region of the chest 7notice the attachment of the ribs71 7c7 the abdominal region1 7d7 the region of the hips 7four united vertebrae2 leave these for the present in position between the hip-bones71 7e7 the tail4 #d4 ,the ribs and sternum4--,examine the manner of attachment of the anterior 7p4 #bag7 pairs of ribs to the sternum or breast-bone4 ,some of the more posterior ribs are free at their ventral ends4 #e4 ,the bones of the fore-limb4--,examine the bones in order and make out3 7a7 the triangular shoulder-blade1 7b7 the single long bone of the upper arm 7its upper1 rounded end fitting into a socket in the shoulder-blade2 its lower end forming1 with the bones of the fore-arm1 the elbow joint71 7c7 the two bones of the fore-arm 7these lie side by side2 notice the peg which makes it impossible for the hinged elbow-joint to be bent back beyond a straight line71 7d7 the small bones of the wrist1 7e7 the bones of the hand4 #f4 ,the bones of the hind-limb4--,notice that the limb as a whole is divided into parts--upper leg1 leg1 ankle and foot--which correspond to the divisions of the fore-limb4 ,make out3 7a7 that as the bone of the upper arm fits into a socket in the shoulder-blade1 so the bone of the upper leg has a ball-shaped end which works in a socket of the hip-bone4 ,notice that the two hip-bones are joined together ventrally1 and that they are fixed to the welded vertebrae of the hip-region4 ,does this give increased strength to the hind-limb8 ,identify3 7b7 the two bones of the leg 7between knee and ankle7 and notice that they differ from the corresponding bones of the arm in being fused together in the lower part2 7c7 the bones of the ankle1 and 7d7 the bones of the foot4 #g4 ,the structure of a long bone4--,take the long bones of the upper arms and upper legs1 and examine them further4 ,break one across the middle4 ,is it solid or hollow8 ,what is the advantage of its being hollow8 ,is the tube empty or does it contain marrow8 ,are the ends of the bone hollow or solid8 ,place one of the bones on a bright hot fire4 ,is there any sign of burning8 ,does all the bone burn away8 ,carefully remove what is left1 and compare the brittleness of the 8burnt0 bone with that of an unburnt bone4 ,place another bone for several days in a cupful of water to which has been added about two teaspoonfuls of strong hydrochloric acid4 ,then take it out1 wash it2 and try to bend it4 ,continue the treatment until the bone is soft enough to tie in a knot4 ,can you tie an ordinary bone in a knot8 ,why not8 ,put a 8burnt0 bone in similar dilute acid4 ,does it dissolve8 ,what do you think gives a bone its hardness8 #h4 ,bones moved by muscle4--,stretch out one of your arms and grasp the middle of the upper arm firmly with the other hand4 ,now bend the elbow1 and notice that the great muscle 7the biceps7 of the front of the upper arm thickens and becomes shorter4 ,straighten the arm again1 and notice that the muscle becomes thinner and longer again4 ,examine ,fig4 #afj1 which shows how the upper end of the biceps is attached at a to the shoulder-blade and its lower end to one of the bones of the fore-arm at ,p4 ,if the biceps muscle shortens1 the fore-arm must be pulled up1 because the shoulder remains stationary4 ,carefully notice the various movements of which your arm is capable--e4g4 extension of the arm2 bending 7flexure7 on the elbow-joint2 rotation of the fore-arm1 so that either the palm or the back of the hand can be turned upwards2 and grasping4 ,observe your power of touching the tip of the little finger with that of the thumb4 ,if a human skeleton is accessible watch how one 7which87 of the two long bones of the fore-arm rotates when the hand is turned over4 ,how many of these movements can the rabbit make8 ,the uses of the skeleton4--,the bodies of vertebrate animals 7p4 #bbj7 are supported1 and their more delicate parts protected from injury1 by an internal framework called the skeleton4 ,in some of the simpler fishes this is composed of gristle or 8cartilage02 but in more highly developed animals it consists almost entirely1 in the adult state1 of bone4 ,further1 almost all the bones are connected with strands or bundles of red flesh called muscle1 which the animal is able to shorten or 8contract0 at will4 ,when a muscle shortens1 the bones to which its ends are fixed are of necessity pulled nearer to each other4 ,if the bone at one end of the muscle remains stationary1 that at the other end is moved into a new position4 ,this is1 generally speaking1 the manner in which the numberless movements of the limbs1 head1 etc41 are made4 ,illustration3 ,,fig4 #afj4--,the action of the ,biceps muscle4 a1 the attachment of the muscle to the shoulder-blade2 ,p1 attachment of the muscle to the fore-arm2 ,f1 elbow2 ,w1 hand4 ,the movements of the limbs4--,an excellent illustration of this relation between the bones and muscles is seen in the bending of the arm at the elbow4 ,when the arm is bent1 a great mass of flesh1 the biceps muscle1 in front of the upper arm may be observed to become much thicker4 ,the muscle 7,fig4 #afj7 thickens because it becomes shorter4 ,its upper end is attached to the corner of the shoulder-blade 7a71 which remains stationary2 while its lower end is connected at ,p with one of the bones of the fore-arm4 ,the shortening of the muscle therefore draws up the fore-arm4 ,the elbow-joint1 about which the motion takes place1 is a very perfect hinge4 ,several other forms of joint are also found in various parts of the body4 ,it is seen1 when the skeleton is examined1 that in every case the characters of the joints and the attachment of the muscles are most admirably adapted to the movements with which they are associated4 ,the study of the skeleton4--,the study of the rabbit's skeleton is not only highly interesting in itself1 but necessary for the intelligent appreciation of the animal's life4 ,and when it is compared with the skeletons of other familiar animals1 a common plan of structure is found which illustrates in the most convincing manner the kinship which often exists between very dissimilar creatures4 ,such a comparison shows that1 almost bone for bone1 the skeleton of a rabbit corresponds with that of a man or a horse1 and even with that of a bird or a frog4 ,mounted skeletons are shown in most natural-history museums1 and the student should1 whenever possible1 examine and compare them4#i ,he can himself1 however1 easily separate the bones from a boiled rabbit1 and make out their main features and relationships4 ,the rabbit's skull and backbone--,the bones of the head are collectively known as the skull4 ,this consists of 7#a7 a large brain case2 7#b7 the cavities for the organs of special sense1 viz41 7a7 a pair of nasal chambers 7in which the organ of smell is located7 in front3 their hinder ends open into the top of the throat2 7b7 the eye-sockets at the sides1 and 7c7 the flask-shaped chambers for the internal ears at the sides of the hinder end of the brain-case2 7#c7 the jaws3 the upper jaw is rigidly attached to the brain-case1 but the lower jaw is hinged at each side on the hinder end of the bony arch which runs below the eye4 ,both upper and lower jaws bear teeth1 which are fixed in sockets4 ,on each side the upper jaw contains two incisor teeth 7p4 #bai7 and--much further back--six grinding teeth4 ,in the lower jaw are one incisor and five grinding teeth on each side4 ,illustration3 ,,fig4 #afa4--,the ,rabbit4 ,the skeleton in position1 seen from the left side4 ,the vertebral column or backbone is a chain of bony rings or vertebrae which runs dorsally 7p4 #bag7 from the hinder end of the skull to the tail1 and forms a long tube containing the spinal cord--a backward continuation of the brain4 ,on the anterior face of the first vertebra are two hollows into which a pair of knobs on the skull fit4 ,although1 with the exception of the first and second1 all the vertebrae are formed on essentially similar lines1 there is considerable variation in shape and size in the different regions of the spine1 as may be seen from ,fig4 #afa4 ,there are seven neck vertebrae1 and this number is remarkably constant in mammals 7p4 #bbj74 ,following these are the chest vertebrae1 which bear pairs of ribs4 ,the majority of the ribs curve round and join on to a ventral bar of bone called the sternum or breast bone2 so that the cavity of the chest1 containing those very important organs the heart and lungs1 is enclosed in a protective bony cage4 ,the vertebrae of the abdominal region of the body are very large and stout4 ,between them and the tail-bones are four fused vertebrae1 forming a mass which on each side gives attachment to the large hip-bone4 ,the bones of the rabbit's limbs4--,the fore and hind-limbs of the rabbit are obviously comparable3 the upper arm corresponding to the upper leg1 the elbow to the knee1 the fore-arm to the 8leg10 the wrist to the ankle1 and the fore-foot to the hind-foot4 ,this similarity becomes even more apparent when the limb-skeletons are examined4 ,commencing in each limb at the end nearest the body we find a single long bone4 ,in the fore-limb the rounded1 upper end of this bone works in a socket at the anterior angle of the shoulder-blade1 a triangular plate on each side which overlies the chest dorsally2 in the hind-limb the rounded end of the corresponding bone works in a cup in the hip-bone4 ,again1 between the elbow and the wrist are two bones lying side by side2 and between the knee and the ankle are two corresponding bones1 although here they are only separate in their upper parts4 ,similarly1 the wrist bones correspond to the ankle bones1 and the bones of what may be called the fingers to those of the toes4 ,certain of the ankle bones are1 however1 much elongated3 obviously a great advantage to an animal which progresses by a series of hops--owing to the increased leverage which is thereby given to the hind-foot4 ,the rabbit's fore-foot bears five toes1 the hind-foot four4 ,the structure of a long bone4--,the long bones of the limbs are hollow except at the ends4 ,strength and lightness are thus secured by a device 7the hollow cylinder71 which has already 7p4 #gb7 been seen to be adopted by the supporting structures of plants1 and is also copied by human engineers4 ,the cavity of the tube is filled by marrow1 which supplies the bone with food4 ,the hard1 bony tube itself is partly composed of mineral matter and partly of animal matter4 ,the mineral matter is left as a white1 brittle framework when the animal matter is burnt away2 while on the other hand the mineral part--which gives the bone its rigidity--may be dissolved out by immersing the bone in dilute hydrochloric acid1 leaving the organic tissue as a soft flexible substance having the shape of the original bone4 #de4 ,,how ,,the ,,rabbit ,,digests ,,its ,,food4 ,illustration3 ,,fig4 #afb4--;,experiment to show that starch solution will not pass through a thin membrane4 b1 beaker2 w1 water2 p4p41 parchment paper2 t4t41 stem of thistle funnel2 s1 starch solution in head of thistle funnel4 #a4 ,a solution of starch will not pass through a thin membrane4--,rub up with water as much starch as will lie on a shilling1 so as to form a thin 8cream10 and then pour on it about a cupful of boiling water4 ,the starch swells up and largely dissolves in the water4 ,add a few drops of the starch solution to about half a pint of water1 stir1 and test it by adding a little iodine solution 7p4 #b1 footnote74 ,a beautiful blue colour is obtained1 showing that the test is a very delicate one4 ,now take a thistle funnel and with a file cut through the stem about six inches below the head4 ,wet a piece of parchment paper or thin bladder 7having previously held it up to the light to be sure there are no holes in it71 and tie it tightly across the mouth of the funnel4 ,fill the head and about an inch of the stem with the starch solution4 ,this can easily be done by means of a 8canula10 such as is used for filling fountain pens4 ,now put the funnel into a beaker of water1 in the manner shown in ,fig4 #afb1 and put the arrangement aside for a few hours4 ,after that time add iodine solution to the water in the beaker4 ,no blue colour is formed1 showing that no starch has passed through the membrane4 #b4 ,a solution of sugar will pass through a thin membrane4--,a delicate test for certain varieties of sugar 7not1 however1 table sugar7 is a liquid known as ,fehling's solution4#aj ,place a particle of honey in a test tube with a teaspoonful of ,fehling's solution1 and put the test tube into a vessel of boiling water4 ,notice that in a short time the blue colour of the solution disappears and the liquid becomes red and turbid4 ,now repeat ,experiment #de1 #a1 but instead of starch solution use honey dissolved in water4 ,to show that some of the honey-sugar has passed through the membrane1 take about a teaspoonful of the water in the beaker1 and put it in a test tube with twice as much ,fehling's solution4 ,heat as before1 and notice the red turbidity4 ,if table sugar is used it may be recognised by the sweet taste of the water after the experiment4 #c4 ,the action of saliva on starch4--7a7 ,chew a piece of india-rubber to induce a free flow of saliva1 and collect the liquid4 ,in one test tube put half a teaspoonful of starch solution2 in a second tube put a mixture of equal quantities of starch solution and saliva2 in a third put saliva alone4 ,keep the tubes at blood heat for twenty minutes4 ,then add a little water to each tube and divide its contents into two parts4 ,test one part of each for starch with iodine solution1 and the other part for sugar with ,fehling's solution4 ,the first tube contains only starch4 ,the second now contains no starch1 but shows the presence of sugar4 ,the third contains neither starch nor sugar4 ,evidently the saliva has changed the starch of the second tube into sugar4 7b7 ,repeat the experiment1 but keep the mixture of starch and saliva in a cold place4 ,no sugar is produced4 7c7 ,repeat the experiment as in 7a71 but use saliva which has been heated to boiling in a test tube4 ,no sugar is formed4 ,the necessity for food4--,it is common knowledge that a rabbit1 like every other animal1 must have a regular supply of food if it is to continue healthy1 and that it would soon die outright if food were withheld4 ,the reason for this is that the living substance of the animal's body is incessantly wasting away4 ,the rabbit cannot move a muscle except at the expense of the living substance of the muscle1 and the more active is its life1 the more rapidly does its body waste4 ,it is to counteract this continual waste by continual formation of new living substance that food is taken4 ,but the succulent plants which the rabbit eats are not suddenly transformed into animal muscle and bone1 and so forth1 when they are swallowed4 ,they have first of all to undergo a process which is called digestion4 ,this takes place in a tube--the digestive canal--which runs from end to end of the body4 ,the digestive canal of the rabbit is coiled in a somewhat intricate manner4 ,that of the frog is1 however1 much simpler and more typical of vertebrates 7p4 #bbj7 generally1 and will serve equally well in so elementary a consideration of digestion as the present4#aa ,the frog's digestive canal4--,the hinder end of the frog's mouth opens 7,fig4 #afc7 into the gullet 7gul471 a short wide tube which leads to a capacious bag called the stomach 7st474 ,the termination of this is continuous with a coiled narrow tube called the small intestine 7s4 in471 which passes suddenly into a much wider large intestine or rectum4 ,the rectum opens to the exterior1 at the hinder end of the body1 by an aperture 7an47 known as the anus4 ,in addition to the digestive tube proper1 two large digestive glands1 the liver and the pancreas1 should be carefully noticed4 ,the liver 7lr47 is a large1 dark red organ1 consisting of two lobes which lie at the sides of the stomach4 ,it makes a digestive fluid called bile4 ,the pancreas 7pn47 is an elongated body which lies in the loop between the stomach and the first portion--called the duodenum 7du47--of the small intestine4 ,it makes a digestive fluid called the pancreatic juice4 ,in the frog both the bile and the pancreatic juice are discharged into the duodenum by one tube or duct 7b4d474 ,small digestive glands also occur in the inner wall of the stomach2 these discharge a fluid called gastric juice into the cavity of the stomach4 ,illustration3 ,,fig4 #afc4--,the ,frog1 dissected from the left side4 gul1 gullet2 st1 stomach2 du1 duodenum2 s4 int1 small intestine2 an4 anus2 lr1 liver2 pn1 pancreas2 b4d1 bile duct2 bl1 urinary bladder2 c4art1 l4au1 s4v1 v1 parts of the heart2 cn4 #c1 8body0 of #crd vertebra2 eus t4 ,eustachian tube2 gl1 glottis1 leading to l4lng1 left lung1 and r4lng1 right lung2 n4a4 #a1 arch of #ast vertebra2 p4na1 internal opening of nostril2 sp4cd1 spinal cord2 spl4 spleen2 tng1 tongue2 kd1 kidney2 ur1 ureter2 vo4t1 vomerine teeth4 ,the rabbit's digestive canal--,in its main features the digestive canal of the rabbit resembles that of the frog2 here also the mouth opens into a long tube consisting of gullet1 a bag-like stomach1 a small intestine1 and a large intestine4 ,there are also a liver and a pancreas which discharge their fluids--by separate ducts1 however1--into the first part of the small intestine2 and the stomach is supplied with gastric juice by small glands in its inner wall4 ,there are1 however1 certain differences besides those of size in the digestive tubes of the two animals4 ,in the first place1 a fluid called saliva is poured into the rabbit's mouth by the ducts of salivary glands which occur near the mouth4 ,secondly1 the coils of the small intestine are very much more complicated than in the frog4 ,and lastly1 at the junction of small and large intestines there is given off1 in the rabbit and in herbivorous mammals generally 7when these have simple stomachs1--p4 #bfa71 a great1 spirally-constricted tube which ends blindly in a finger-like process4 ,how the rabbit digests its food4--,a rabbit needs food to repair the constant waste of substance which the activities of its life entail2 and the same is true of every other living thing1 be it plant or animal4 ,now1 every part of a rabbit's body is irrigated and drained by the finest branches of a system of pipes through which blood is always flowing2 and it is in this blood-stream that the food is conveyed to the muscles and other organs which are to be repaired4 ,the food finds its way into the blood when that fluid is flowing through the small vessels which lie in the thickness of the wall of the digestive tube4 ,before food can gain access to the blood it must be in a condition in which it is capable of diffusing through the thin membrane which separates them4 ,digestion is the process which renders food soluble and diffusible1 and hence capable of passing into the blood4 ,the food of animals is of several different kinds4 ,a few of these are soluble and diffusible at the time they are eaten1 but most of them are neither1 and therefore require treating according to their nature4 ,this is why so many different fluids are poured into the rabbit's digestive canal4 ,saliva1 gastric juice1 bile1 and pancreatic juice are each capable of acting upon certain constituents of the food and rendering them soluble and diffusible4 ,it would be beyond the scope of this book to consider the work of these fluids in detail1 but the action of saliva is not only fairly typical1 but it can easily be imitated outside the body4 ,starch is a very common constituent of vegetable foods1 and its presence or absence is readily determined by the blue colour which it gives with a solution of iodine4 ,starch is quite insoluble in cold water1 but when treated with hot water it swells up and1 to a great extent1 dissolves4 ,but a mere solution of starch cannot get into the blood1 for it is incapable 7,expt4 #de1 #a7 of passing through a thin membrane4 ,on the other hand1 if starch is mixed with saliva1 and the mixture is kept at the temperature of the body1 it is found in a short time that the starch has been changed into sugar1 which is not only soluble1 but readily diffuses through a thin membrane4 ,in other words1 starch as such is useless to the rabbit as food2 only after it has been digested by conversion into sugar can it be used by the body4 ,something very similar often takes place in plants4 ,it was seen 7p4 #cc7 that the cotyledons of a pea become sweet during germination4 ,starch is a convenient form of food for storing in the cotyledons of a pea1 the endosperm of the maize seed1 the short stem of the crocus-corm1 and so on2 but before the plant can use it as food the starch must be made soluble and diffusible by being changed into sugar4 ,in plants the change is brought about1 not by saliva1 but by a substance known as diastase4 ,the pancreatic juice continues the change of starch into sugar which is commenced by the saliva1 but it also digests other food-stuffs as well4 ,similarly1 gastric juice and bile are each concerned with the digestion of certain foods4 ,the result of the action--separate and combined--of the digestive fluids is that1 when a rabbit eats no more food than it requires1 all the useful parts of the food are absorbed into the blood1 and then distributed to the tissues by the blood as it flows through them4 #df4 ,,the ,,circulation ,,of ,,the ,,blood4 #a4 ,evidence of the circulation4--7a7 ,the arterial pulse4--,feel your pulse at the wrist and count the number of beats per minute4 7b7 ,the beats of the heart4--,similarly count how many times your heart beats per minute4 ,put your ear over the heart of a friend1 and listen to the sounds of the heart4 ,how many different sounds can you distinguish8 7c7 ,the valves of the veins4--,press your thumb on your arm inside the elbow1 and then move it down the arm towards the wrist4 ,notice the small knots which rise under the skin between the point of pressure and the wrist4 #b4 ,the structure of a sheep's heart4#ab--,procure from the butcher a sheep's heart with1 if possible1 the lungs still attached4 ,if the thin transparent bag which naturally surrounds the heart has been left on1 carefully cut it away4 ,make out the main external features of the heart before cutting into it4 ,the shape is conical1 the apex of the cone being posterior1 the base 7where the blood-vessels are attached7 anterior4 ,the ventral face is rounded2 the dorsal face is flatter4 ,compare ,fig4 #afd4 ,the line of fat 7#c7 marks the line of division between two chambers1 the right 7,r4,v47 and left 7,l4,v47 ventricles4 ,feel that the right ventricle yields to pressure more readily than the left4 ,two more chambers1 the right and left auricles1 are situated at the basal 7thick7 end4 ,r4,a4 and ,l4,a4 are flaps of the right and left auricles respectively4 ,identify the great vessels ,,svc and ,,ivc which discharge into the right auricle4 ,cut them open to see the entrance4 ,then lay open the right auricle4 ,pass your finger down and notice that the right auricle communicates freely with the right ventricle4 ,observe that you can from the right ventricle pass your finger into the tube ,p4,a42 make out that this goes to the lungs4 ,lay open the left auricle1 and see that it receives vessels from the lungs4 ,pass your finger from the left auricle into the left ventricle1 and notice that this latter chamber leads into the ,aorta1 ,ao4 7,ao4 a branch of ,ao474 ,notice that the walls of the blood-vessels in connection with the two auricles are collapsed1 while those 7,p4,a4 and ,ao47 leading from the two ventricles are more elastic and remain open4 ,which of the two auricles has the thicker wall8 ,which of the two ventricles has the thicker wall8 ,can you pass your finger from one auricle to the other8 ,from one ventricle to the other8 ,cut away the auricles and pour water into the ventricles4 ,then squeeze the heart gently1 and notice the flaps which rise to close the openings into the ventricles4 ,could blood pass from the ventricles to the auricles8 ,why not8 ,lay open the bases of the vessels ,p4,a4 and ,ao4 leading from the right and left ventricles respectively1 and notice the pockets of thin membrane which are attached there4 ,open them out gently with the point of a pencil4 ,put the heart under the tap and let water trickle down the vessels towards the ventricles2 notice how the pockets stand out as they fill with water4 ,what would be the effect of blood trying to pass from ,p4,a4 or ,ao4 back into their respective ventricles8 ,the circulation of the blood4--,the blood of such an animal as the rabbit is contained in a system of closed tubes called blood-vessels1 through which the fluid is continually flowing4 ,the regular flow of the blood in one direction is maintained by the action of the heart1 a four-chambered organ which is situated in the chest1 between the lungs4 ,the heart is muscular1 and1 like other muscles 7p4 #bbe71 has the power of 8contracting0 in definite directions4 ,the contraction of the walls of the chambers of the heart lessens their capacity1 and therefore drives the blood out of them1 the direction of flow being determined by valves4 ,the vessels which carry blood to the heart are called veins2 those which transmit the blood which is pumped out of the heart are called arteries4 ,the arteries branch into smaller and smaller tubes which supply the various organs of the body1 and the small arterial branches divide again and again in the organs until their finest ramifications form a close-meshed network of vessels with excessively thin walls1 through which diffusion can readily take place between the tissues and the blood4 ,these finest blood-vessels are called capillaries4 ,they can be studied in the transparent web of the frog's foot with the aid of a low power of the microscope4 ,the blood can then be seen flowing1 at a speed which varies with the size of the vessel1 its course being rendered obvious by the tiny oval particles 7red corpuscles7 which are suspended in it4 ,the smallest capillaries are so thin-walled that they appear to be merely channels in the substance of the web1 and the corpuscles creep along in single file4 ,but these channels unite to form larger vessels with obvious walls1 and these unite again and again until a main vein is formed in which the blood1 with its suspended corpuscles1 rushes along in a swift torrent towards the heart4 ,the heart4--,the beginner will find the sheep's heart more convenient for examination than the rabbit's1 on account of its larger size2 but apart from some difference in the arrangement of the great blood-vessels opening into them1 the two hearts are broadly similar4 ,the heart 7,fig4 #afd7 consists of four chambers4 ,two of these1 the auricles1 are receiving-chambers1 and are placed at the thick1 anterior end of the heart4 ,into the right auricle open the great veins 7,,svc1 ,,ivc17 which bring blood from all parts of the body except the lungs2 the left auricle receives only blood from the lungs4 ,each auricle opens into a more posterior chamber called a ventricle1 the right auricle opening into the right ventricle and the left auricle into the left ventricle4 ,the ventricles pump blood into the arteries4 ,the blood from the right ventricle is sent into the artery 7,p4,a47 which supplies the capillaries of the lungs2 while the blood of the left ventricle is forced into the aorta 7,ao471 a great artery which branches and supplies with blood all parts of the body except the lungs4 ,the two auricles contract simultaneously1 forcing their contents into the flaccid ventricles4 ,then both the filled ventricles contract at once1 and pump blood into the great arteries1 flaps of membrane between the auricles and ventricles preventing a backward flow into the auricles4 ,similarly the bases of the great arteries are provided with membranous pockets which readily admit the blood from the ventricles when these contract1 but entirely prevent a return of blood to the ventricles4 ,the appearance of these four sets of valves1 as seen from above1 is shown in ,fig4 #afe4 ,after the contraction of the two ventricles there is a short rest1 then the auricles contract again and the whole process is repeated4 ,illustration3 ,,fig4 #afd4--;,heart of ,sheep1 in position between the lungs4 ,r4,a41 appendage of right auricle2 ,l4,a41 appendage of left auricle2 ,r4,v41 right ventricle2 ,l4,v41 left ventricle2 ,s4,v4,c41 ,i4,v4,c41 great veins from the system generally2 ,p4,a41 artery to lungs2 ,ao41 aorta2 ,ao41 branch of aorta2 ,l41 lung2 ,tr41 windpipe1 leading to lungs2 #b1 #c1 #d1 fat4 ,illustration3 ,,fig4 #afe4--,the orifices of the heart seen from above1 the auricles and great vessels being cut away4 ,,pa1 valves at base of artery to lungs2 ,ao1 valves at base of aorta2 ,r4,a4,v41 orifice between right auricle and ventricle1 with its valves l4v4 #a1 l4v4 #b1 and l4v4 #c2 ,l4,a4,v41 orifice between left auricle and ventricle1 with its valves m4v4 #a and m4v4 #b4 ,illustration3 ,,fig4 #aff4--;,diagrammatic sections of veins with valves4 ,in the upper figure the blood is supposed to be flowing in the direction of the arrow1 towards the heart2 in the lower1 back towards the capillaries4 ,illustration3 ,,fig4 #afg4--;,a vein laid open to show a pair of pouch-shaped valves4 ,the sounds which are heard when the ear is placed over another person's heart are often compared to the syllables lub-dup4 ,the 8lub0 is partly caused by the contraction of the ventricles2 the 8dup10 which immediately follows1 is caused by the sudden closure of the valves at the bases of the great arteries4 ,the throb of the heart1 which can be felt from the outside1 is really the thrust of the apex of the heart against the chest-wall at each beat4 ,the sudden forcing of blood into the already-full but elastic arteries causes a wave to travel along these vessels1 which can readily be felt1 or even seen1 at places where a fairly large artery lies just beneath the skin4 ,this arterial wave is called the pulse4 ,many of the veins are provided with pouch-shaped valves which permit the blood to flow freely towards the heart1 but which bar the passage of blood in the opposite direction4 ,their action will readily be understood from ,figs4 #aff and #afg4 ,the importance of the capillaries4--,the capillaries are the least conspicuous part of the circulatory system1 but they are by far the most important4 ,the heart1 arteries1 and veins exist merely to renew constantly the blood which flows through these minute channels4 ,the excessive thinness of the walls of the capillaries makes it possible for a ready exchange to take place between the living tissue and the blood1 and the vessels themselves form a network of such extremely close texture that it is practically impossible to prick any living part of the body with a fine needle without puncturing some of them and 8drawing blood40 ,the work of the blood in supplying the various organs of the body with food has already been referred to4 ,we have next to see how this all-important fluid is of service in supplying the organs with oxygen4 #dg4 ,,respiration4 #a4 ,carbon dioxide is formed when flesh burns4--,dry a piece of meat and attach it to the end of a wire4 ,then light it1 and when it is burning vigorously lower it into a clean glass jar4 ,when the flame goes out remove the charred flesh1 and at once pour a little clear lime-water into the jar and shake up4 ,the lime-water turns milky1 showing the presence of carbon dioxide gas in the jar4 ,examine what is left of the meat4 ,it is charred1 showing that meat contains carbon4 ,how was the carbon dioxide formed during the burning8 #b4 ,carbon dioxide is formed by the living body4--,breathe through a glass tube into clear lime-water1 so that the air you expel from your lungs bubbles through the liquid4 ,does the lime-water remain clear1 or turn milky8 ,does the air you breathe out contain a considerable quantity of carbon dioxide gas8 ,burning and life4--,when a piece of the flesh of any animal has been dried it may easily be set on fire4 ,the burning is caused by the union of the constituents of the flesh with some of the oxygen of the air to form various gases4 ,one of these gases is carbon dioxide1 formed by the combination of the carbon of the flesh with oxygen4 ,carbon is present in all the parts of animals and plants1 as is evident from the separation of charcoal 7an impure form of carbon7 in the first stages of burning2 the carbon dioxide gas which is formed may easily be recognised by the milkiness which it produces in clear lime-water4 ,the liberation of heat1 and the formation of carbon dioxide1 which always accompany the burning of animal and plant tissues1 are worthy of very careful attention4 ,illustration3 ,,fig4 #afh4--;,experiment to prove that expired air contains carbon dioxide4 ,it is well known that the body of a living animal such as a rabbit or a man is always warm2 and the experiment 7,fig4 #afh7 of passing through clear lime-water the air breathed out from the lungs shows1 by the milkiness produced1 that the animal is also constantly producing carbon dioxide during its life4 ,is life1 then1 always accompanied by a peculiar form of burning1 in which the living substance of the body is the combustible material8 ,it seems so1 and the experiments of physiologists tend to confirm this view4 ,the necessity for breathing4--,the energy which enables a muscle to contract is derived from the oxidation--the slow burning--of part of its substance1 just as the energy which enables a steam-engine to move is derived from the burning of fuel in the boiler fires4 ,the fires soon go out1 and the engine stops1 unless fresh fuel is added from time to time and a plentiful supply of air is available4 ,similarly1 a muscle loses its power of contracting1 a gland that of secreting1 the brain that of thinking1 unless the waste matters resulting from previous activities are cleared away and replaced by fresh food and fresh oxygen4 ,wherever vital action is taking place1 whether in a contracting muscle1 a secreting gland1 or a thinking brain1 there is continual consumption of oxygen and continual production of waste material1 chiefly carbon dioxide4 ,in the higher animals the renewal of oxygen and the removal of waste material are performed by the blood4 ,blood-vessels are to the body what rivers and canals are to a country3 they act as highways for the transport of material4 ,we may perhaps carry the analogy a little farther and find in the red corpuscles of the blood the rough equivalents of boats or canal-barges1 for they carry with them tiny loads of oxygen4 ,as the blood creeps along the narrow channels in an active tissue the red corpuscles relinquish their oxygen1 and the fluid portion of the blood takes up carbon dioxide4 ,the blood continues its course1 and sooner or later arrives at a place where it can obtain a fresh supply of oxygen and get rid of its surplus carbon dioxide4 ,in the rabbit this exchange takes place as the blood is passing through the capillaries of the lungs4 ,there the blood is separated from the air by a membrane so delicate that gases can readily pass through it2 and1 hence1 on leaving the lungs the blood has got rid of the waste carbon dioxide1 and its red corpuscles are laden with fresh oxygen4 ,this exchange of useless carbon dioxide for oxygen constitutes respiration or breathing4 ,the mechanism of respiration4--,in active animals the air inside the lungs soon becomes vitiated1 unless there is some means of changing it4 ,under ordinary conditions a man changes the air in his lungs from thirteen to fifteen times a minute4 ,he does this quite automatically1 and without thinking about it4 ,every four seconds or so a set of muscles contracts and pulls his ribs upwards and outwards2 another muscular contraction pulls down the floor of his chest at the same time4 ,as a consequence the cavity is much enlarged4 ,the lungs follow the movements of the walls of the chest1 and some thirty cubic inches of air are sucked in4 ,immediately the ribs fall back to their former position1 the chest-floor rises1 and air is driven out4 ,then after a short pause the process is repeated4 ,it should be noticed that only about thirty cubic inches of air are changed at each respiration1 although the capacity of the human lungs averages about #bcj cubic inches4 ,all mammals breathe in much the same way4 ,plants and animals4--,there are considerably more points of similarity than of difference between plants and animals4 ,in every case the vital activities are accompanied by an oxidation of living substance1 and from this fact arises the necessity for food and oxygen4 ,the breathing of plants is essentially like that of animals1 and consists in taking in oxygen and giving out carbon dioxide2 though the mechanism of respiration is--except in the lowest plants and animals--entirely different in the two cases4 ,it is in the sources from which they obtain their food that plants and animals are most unlike4 ,an animal must be supplied with food which has already been prepared by some other living thing2 and it is obvious that the food even of carnivorous animals can ultimately be traced back to plants1 for the flesh-eater preys upon the vegetarian4 ,animals are therefore entirely dependent upon plants for food4 ,in this sense the saying 8all flesh is grass0 is full of significance4 ,green plants 7,chapter ,,ii47 are quite independent of all other forms of life1 and can build up their substance from water1 mineral matter1 and the carbon dioxide of the air4 ,the taking in of carbon dioxide and giving out of oxygen by green plants has nothing whatever to do with respiration2 it is part of their process of feeding4 ,green plants breathe in the usual manner--by taking in oxygen and giving out carbon dioxide4 ,it should1 however1 be noticed that the peculiar method by which a green plant obtains its carbonaceous food is of the highest importance to animal life2 for by this process the amount of injurious carbon dioxide in the air is considerably lessened1 while the proportion of life-supporting oxygen in it is greatly increased4 ,fungi 7,chapter ,,xi47 seem to be intermediate1 as regards their method of feeding1 between green plants and animals4 ,they require their carbonaceous food in an organic form1 that is1 already prepared by other living things2 but they can obtain the other elements of their food from mineral salts and water4 ,the thoughtful student will be increasingly impressed by the extent to which the plant and animal kingdoms are dependent upon each other1 and by the manner in which each utilises the waste products of the other for carrying on its own life processes4 ,,exercises ,,on ,,chapter ,,xiii4 #a4 ,of what parts does the skull of a rabbit consist8 ,what is the use of each part8 #b4 ,describe one of the long bones of a rabbit's leg4 ,to what features does it owe its strength8 #c4 ,the bones of the skeleton are useful 7#a7 as affording points of attachment for the muscles2 7#b7 as affording protection for delicate tissues and organs4 ,give examples of each of these uses4 ,do not give the technical names for the various muscles4 7,king's ,schol41 #aijb7 #d4 ,draw and describe one of the middle joints of the backbone of a quadruped1 and explain the uses of the various parts4 7#ahih7 #e4 ,what is meant by 8digestion08 ,why must food be digested8 ,where does digestion take place8 #f4 ,give full practical instructions for demonstrating the chief properties of saliva1 and its action upon various kinds of food4 7#ahig7 #g4 ,prove that the action of human saliva upon starch is not due to living particles contained in it4 7#ahih7 #h4 ,what are the chief uses of the blood8 ,why is it necessary that it should be kept in motion8 7#aija7 #i4 ,where would you look for the ,aorta in a sheep's heart8 ,what valves are found in it8 ,how does it differ in appearance and feel from a large vein8 7#aija7 #aj4 ,what kinds of valves are found in a sheep's heart1 and where are they placed8 ,describe a valve of each kind4 7#ahih7 #aa4 ,how does air breathed out from the lungs differ from common air8 ,how can the differences be demonstrated8 7#ahih7 #ab4 ,describe the process by which a mammal renews the air in its lungs4 #ac4 ,what is meant by 8respiration08 ,why is respiration necessary8 #ad4 ,point out the most remarkable differences between the nutrition of a green plant and that of an animal4 7#ahig7 #ae4 ,name organisms which can derive nourishment from carbon dioxide1 from sugar1 and from the dead bodies of animals4 7#ahih7 #af4 ,what are the simplest functions which distinguish living animal matter from inanimate matter8 7,king's ,schol4 #aijc7 #ag4 ,explain as fully as you can how food taken into the stomach acts upon organs1 such as the brain1 which are not closely connected with the stomach4 7#aijd7 #ah4 ,the uses of bone are1 generally speaking1 to protect delicate structures1 to support weight and to gain leverage4 ,illustrate this statement by a simple description of one example of each type4 7,certificate1 #aijd7 #ai4 ,the flow of liquids through the body is regulated in certain localities by valves4 ,explain the action of a valve1 and indicate where they are to be found in the body4 7,certificate1 #aijd7 #bj4 ,in which kind of blood-vessel can the pulse be felt8 ,in which kinds can it not be felt8 ,explain the reason of the difference4 7,certificate1 #aije7 #ba4 ,how is oxygen conveyed from the lungs to the various parts of the body8 ,describe what could be observed if a drop of blood were spread out on a piece of glass and examined under a microscope4 7,king's ,schol4 #aije7 ,,footnotes3 #i ,see footnote1 p4 #bca4 #aj ,prepared by adding to a solution of copper sulphate first tartaric acid1 and then caustic soda until the blue mixture is clear4 ,it may be obtained from a chemist if the materials are not available4 #aa ,,note ,,to ,,teachers4--,a general dissection of a frog should be made and exhibited to the class4 ,detailed instructions for such a dissection will be found in ,marshall's ,the ,frog 7,smith1 ,elder ,co47 or in ,huxley and ,martin's ,elementary ,practical ,biology 7,macmillan74 ,the frog's heart continues to beat for some time after the death of the animal1 and may be shown as an illustration of the next section of this chapter4 ,teachers who are unskilled in dissection may obtain prepared dissections1 mounted skeletons1 etc41 from ,newmann ,co41 #hd ,newman ,street1 ,london1 ,w4 #ab ,more detailed instructions will be found in ,foster and ,shore's ,physiology for ,beginners 7,macmillan74 ,,chapter ,,xiv4 ,,some ,,other ,,mammals4 #dh4 ,,the ,,cat ,,and ,,dog4 #a4 ,the external characters of the cat4--,carefully and gently examine a cat1 and make notes of the following characters3 7a7 ,hair4--,what is the covering of the body like8 ,is the hair like that of a rabbit1 i4e4 fur 7p4 #baf78 ,are the whiskers very noticeable8 ,on what parts of the head do they grow8 ,are the fur and large whiskers in any way connected with the animal's habits8 7b7 ,eyes4--,look at a cat's eyes in a bright light4 ,is the pupil 7p4 #bab7 round or slit-like8 ,keep the cat in the dark for a few minutes and then look again at the pupil of the eye2 has it changed in form8 ,is the change of any advantage to the cat8 7c7 ,teeth4--,gently open the cat's mouth and examine the teeth4 ,notice the sharp1 pointed teeth behind the incisors 7p4 #bai72 they are called the canine teeth4 ,has a rabbit any canine teeth8 ,why does a cat1 and not a rabbit1 need such teeth8 ,feel the remaining teeth with your finger2 are they flat like those of a rabbit1 or sharp-edged8 ,how are the characters of the teeth associated with the kind of food8 ,watch a cat eating2 does it chew its food or swallow it 8in lumps08 7d7 ,tongue4--,pass your finger-end over the cat's tongue2 is it rough or smooth8 ,in which direction of motion of the finger does the tongue feel roughest8 ,would the roughness be of any help to the animal in licking meat from bones8 7e7 ,the limbs4--,measure the legs4 ,are the fore and hind limbs of equal length1 slightly unequal1 or very unequal8 ,how do they compare in this respect with the limbs of the rabbit8 ,make out the main bones by feeling through the skin1 and especially notice where the ankle-joint is4 ,examine the toes and notice how1 when you gently squeeze them just behind the ends1 the sharp claws protrude1 and go back into a kind of sheath when the pressure is removed4 ,can the animal put out its claws and draw them back at will8 #b4 ,the habits of the cat4--7a7 ,food4--,what kind of food does the cat prefer1 animal or vegetable8 ,does it bolt its food greedily1 or does it eat deliberately and daintily8 ,have you ever known cats to hunt other animals8 ,do they hunt singly1 or do several cats join together to hunt8 ,how do they approach the prey2 do they try to run it down by speed1 or do they creep up slyly and then spring8 ,what is the use of the claws8 ,how does a cat drink8 7b7 ,locomotion4--,watch a cat moving slowly2 does it walk or hop8 ,try to find out the order in which it puts its feet down4 ,how does it run8 ,is it nimble or clumsy8 ,does the cat walk with the whole sole of its foot on the ground1 or does it walk 8on its toes08 7c7 ,likes and dislikes4--,do you consider a cat sociable1 i4e4 fond1 in general1 of the society of other cats8 ,do cats1 as a rule1 show much appreciation of the difference between right and wrong8 ,are they as affectionate as dogs8 ,have you ever heard of any cat trying to remain in a house after the family had removed to another house8 ,are cats fonder of warm or of cool places in a house8 ,do they like getting wet8 ,do they pay much attention to personal cleanliness8 ,how do they wash themselves8 ,do you think the tongue is used as a comb8 ,how8 ,can you know whether a cat is pleased or angry 7i7 by the appearance and movements of the tail1 7ii7 by the sounds which it makes8 7d7 ,intelligence4--,write accounts of cases of great intelligence which you have known cats to show4 7e7 ,voice4--,how do you describe a cat's voice8 ,how does the voice vary according to the animal's mood8 7f7 ,play4--,how does a cat play8 #c4 ,kittens4--7a7 ,appearance4--,are kittens helpless or active when they are born8 ,is there any very marked difference between the proportions of the body and limbs and those of a full-grown cat8 ,at what age is a cat full-grown8 7b7 ,play4--,how does a kitten play8 ,how does it pretend to 8stalk0 a small object1 such as a ball of wool8 ,in the same way that a full-grown cat stalks a mouse8 ,why does the kitten adopt this method before it has any experience of hunting8 7c7 ,education4--,watch a cat with its kittens1 and describe any actions which seem like education4 ,have you ever seen a cat teach its kittens to fight8 ,have you ever seen it punish a kitten for disobeying a call8 #d4 ,the external characters of the dog4--,examine a dog in the same way1 and compare it point by point with the cat as regards the following characters3 7a7 ,hair4--,notice that the dog is covered1 not with fur1 but with rough hair1 and that the whiskers are not very large4 ,how are these differences associated with differences in habit8 7b7 ,eyes4--,notice that the pupil is always round1 although it is smaller in a strong light than in a weak one4 7c7 ,teeth4--,compare the teeth with those of the cat1 and notice that they are of similar form--with strong interlocking canines and a sharp-edged tooth on each side of the upper jaw which clips against a similar tooth in the lower jaw--but that the cat's teeth are more pointed4 7d7 ,tongue4--,notice that the dog's tongue is much smoother than the cat's4 7e7 ,limbs4--,examine and measure the limbs1 comparing them with those of the cat1 rabbit1 and man4 ,notice that the claws are blunter than the cat's1 and that they cannot be withdrawn into sheaths4 ,how many toes are there on the feet8 #e4 ,the habits of the dog4--7a7 ,food4--,does the dog prefer animal or vegetable food8 ,watch a dog gnawing a bone1 and observe the use of the clipping teeth4 ,does a dog eat greedily or deliberately8 ,does it chew its food or swallow it in lumps8 ,do dogs hunt singly or in packs8 ,do they stalk the prey stealthily1 as cats do1 or do they try to run it down by speed8 ,whenever possible watch a pack of hounds2 upon what sense--hearing1 sight1 or smell--do the hounds rely most8 ,how does a dog drink8 7b7 ,locomotion4--,does a slowly-moving dog hop or walk8 ,try to find out the order in which it puts its feet down4 ,how does it run8 ,does a dog walk flat-footed or on its toes8 7c7 ,likes and dislikes4--,do you consider dogs sociable or otherwise8 ,do they seem to know the difference between right and wrong8 ,are dogs affectionate8 ,are they more attached to the people or to the houses to which they are accustomed8 ,what can you learn of a dog's feelings1 by the movements of its tail8 ,write accounts of instances1 which you know to be true1 illustrating its likes and dislikes4 ,what expression of the human face seems to you most like the snarl of an angry dog8 ,what are the resemblances8 7d7 ,intelligence4--,write accounts of evidence of intelligence1 or reasoning power1 which you have observed in dogs4 7e7 ,voice4--,what is the ordinary voice of the dog8 ,what other sounds do dogs make1 and what do they mean8 7f7 ,play4--,how do dogs play8 ,do you think dogs have any sense of humour1 or are able to appreciate a joke for the joke's sake8 ,have you ever seen any expression resembling a smile on a dog's face8 #f4 ,puppies4--7a7 ,appearance4--,are puppies blind and helpless when they are born1 or are they active8 ,how soon can they see8 ,are the proportions of the body and limbs markedly different from those of the full-grown dog8 ,at what age is a dog full-grown8 7b7 ,play4--,does a puppy play in the same manner as a kitten8 ,what differences have you noticed8 ,have these differences any connection with the methods of catching the prey of the adult animals8 7c7 ,education4--,have you ever seen a puppy being taught to do anything by its mother8 ,write full accounts of such cases4 #g4 ,different breeds of dogs4--,make notes of your observations of as many different breeds of dogs as possible1 e4g4 collies1 terriers1 retriever1 fox-hound1 pointer1 spaniel1 etc41 and describe the resemblances and differences in size1 form1 habits1 intelligence1 etc4 ,illustration3 ,,fig4 #afi4--,the ,cat4 ,the external characters of the cat and dog4--,the cat and the dog are so commonly kept as pets that they are perhaps more easily examined than any other animals4 ,in addition1 they are so closely related and yet exhibit so many differences that they afford a valuable exercise in the methods of comparison and contrast which are at the foundation of all successful work in ,nature-,study4 ,several differences are at once apparent on even a casual inspection4 ,the body of the cat 7,fig4 #afi7 is covered with soft1 smooth fur1 and its head is provided with long1 sensitive whiskers4 ,in both of these respects it resembles the rabbit and other mammals which are in the habit of creeping along narrow and dark passages4 ,it is commonly said that cats can see in the dark4 ,although this is not altogether true--for no animal can see in total darkness--the cat's eyes have the power of adapting themselves remarkably to the intensity of the light4 ,in a dim light1 the curtain1 or iris1 which surrounds the pupil 7the dark1 central window through which light enters the eye7 is drawn back so as to admit as much light as possible2 whereas in a very bright light the curtain is so nearly closed that the pupil is merely a narrow1 vertical slit4 ,on the other hand1 the dog 7,fig4 #agj71 which is not fond of dark passages1 has its body clothed with rough hair1 instead of fur2 and its whiskers are not nearly so long as those of the cat4 ,again1 although the iris of a dog's eye alters in size to regulate the amount of light entering the eye1 the pupil is always round1 and the change of size is much less marked than in the cat4 ,another very noticeable difference is in the claws at the ends of the toes1 corresponding to the nails at the ends of our own fingers and toes4 ,in the cat these are sickle-shaped and extremely sharp1 and are kept drawn completely back into sheaths when they are not required4 ,the dog's claws are blunt1 and cannot be retracted4 ,both the dog and the cat rest the weight of the body upon the toes--not upon the sole of the foot--when walking or running4 ,illustration3 ,,fig4 #agj4--;,foxhound4 ,there is also a very marked difference in the tongues of the two animals4 ,the tongue of the cat is rough1 with small points directed backwards4 ,these points are of great help in licking the flesh from bones2 and they also serve as a comb when the cat--which is fastidious about the cleanliness of its fur--8washes0 itself4 ,the tongue of the dog is smooth and moist4 ,the inherited habits of the cat and dog4--,very obvious differences are also to be seen in the habits of the two animals1 and these would be somewhat difficult to explain if we confined our attention to the domesticated animals only1 which live under artificial conditions4 ,when1 however1 we consider the wild relatives of the cat and dog1 many of the differences become full of significance4 ,the wild animals of the cat family1 almost without exception1 are either solitary or live in pairs2 whereas the wild dogs 7wolves1 jackals1 etc47 live in packs4 ,the habits which these respective methods of life entailed have become so firmly implanted in the nature of the race that even now1 after thousands of generations of domestication1 they may be traced4 ,such inherited habits1 which are not dependent upon1 or may be at variance with1 present conditions of life1 are called instincts4 ,we will first see how the ancestral custom of living in organised packs has left its impress upon the instincts of the domesticated dog4 ,the first essential to the success of any community of animals--whether these are bees or rooks1 wolves or men--is that all the creatures composing it shall conform to certain rules1 which have for their object the good of the community and not merely that of the individual4 ,acts which promote the wellbeing of the society as a whole are good1 and are directly or indirectly rewarded4 ,acts which tend to injure the society as such are bad1 and inevitably bring punishment either to the individual offender or1 what is worse1 to his pack4 ,a distinction between right and wrong is thus established which would be impossible to any animal living so solitary a life that its acts affected only itself4 ,in this manner were aroused the social instinct1 the love of praise and the dread of shame1 the lifelong attachment to early friends1 and almost all the other qualities which have so endeared the dog to mankind2 because these qualities resulted naturally from the ancestral pack-life4 ,left to itself1 the dog loses its nerve1 for it is by nature unfitted for a solitary life4 ,what more woe-begone animal is ever seen than a lost dog8 ,contrast the cat in these respects4 ,it is at heart an outlaw1 like its wild ancestors3 recognising1 in general1 no motives but those of its own ease and gratification4 ,its social instinct is almost absent2 and though it sometimes displays affection to people who pet it1 the cat is1 as a rule1 more attached to places than to persons4 ,it retains1 too1 the independence and versatility which are developed by a solitary life4 ,a lost cat can usually take care of itself and find sufficient food2 and cases are not uncommon of cats leaving comfortable homes and choosing to live wild lives in the woods4 ,ancestral methods of hunting also account largely for certain differences in the domestic cat and dog4 ,the solitary ancestral cats1 like the lions and tigers of to-day1 sprang suddenly upon the prey at the end of silent1 stealthy stalking4 ,how firmly this method has become fixed in the character of the race may be seen still in the manner in which a cat stalks a mouse or a small bird1 or even1 in play1 a dead leaf4 ,at the final spring the sharp1 sickle-shaped claws are used to hold down the victim4 ,the solitary hunter is able to devour its capture at leisure1 and the domestic cat is still distinguished by its dainty and deliberate manner of feeding4 ,the wild dogs hunt in a quite different manner4 ,the whole pack joins in the chase1 the trail being followed by the sense of smell4 ,there is no attempt at concealment1 no stealthy stalking2 but an open reliance upon speed1 endurance1 and numbers1 rather than upon cunning4 ,if one dog loses the scent another picks it up and gives the signal4 ,mutual help is thus the secret of success in hunting4 ,but this is at an end when the prey is killed4 ,the victim is torn to pieces and devoured greedily1 each animal eating as rapidly as possible1 for in most cases there is not enough to satisfy them all4 ,and the well-fed domestic dog still betrays the ancestral necessity for hurried eating in the manner of bolting his food4 ,methods of expressing feeling4--,animals express their feelings in various ways--by the voice1 by the face1 by the tail1 and by the general attitude of the body4 ,perhaps no animal's feelings are more readily recognised by man than the dog's4 8,it is a remarkable fact10 says ,darwin1#ac 8that the dog1 since being domesticated1 has learnt to bark in at least four or five distinct tones4 ,although barking is a new art1 no doubt the wild parent-species of the dog expressed their feelings by cries of various kinds4 ,with the domesticated dog we have the bark of eagerness1 as in the chase2 that of anger1 as well as growling2 the yelp or howl of despair1 as when shut up2 the baying at night2 the bark of joy1 as when starting on a walk with his master2 and the very distinct one of demand or supplication1 as when wishing for a door or window to be opened40 ,the movements of the tail are also full of meaning1 and capable of expressing several different moods4 ,it seems likely that in a dog the movements of the tail were originally of use chiefly to signal to the rest of the pack4 ,the use of the movements of a cat's tail is not very clear1 although these also differ according to the animal's feelings4 ,carnivores4--,dogs and cats1 with several other mammals1 which are mostly flesh-eaters1 are called ,carnivores4 ,they have never fewer than four distinct toes on each foot1 and the claws 7nails7 are often capable of being withdrawn into sheaths4 ,the teeth 7,fig4 #aga7 are characterised by the large1 interlocking canines1 which are conical1 curved1 and pointed2 and by one of the cheek teeth on each side having a sharp1 cutting edge which bites against the similar tooth of the other jaw1 almost in the manner of the blades of scissors4 ,the seals and walruses1 however1 which are carnivores adapted to living in water1 have no such clipping teeth4 ,illustration3 ,,fig4 #aga4--,skull of ,wolf1 seen from left side4 #di4 ,,the ,,bat4 #a4 ,habits4--,at what time of the year have you seen bats flying about8 ,do they fly in broad daylight1 or only in the evening8 ,how can you distinguish a bat's flight from that of a bird8 ,have you ever heard a bat squeak8 ,upon what does it feed8 ,are flying insects plentiful in winter8 ,have you ever seen a bat drink8 ,how does it drink8 ,what does the bat do in winter8 ,try to find a sleeping bat in winter in a barn1 a hollow tree1 or a belfry4 ,what is its position8 #b4 ,appearance4--,examine a sleeping bat or a stuffed specimen4 ,what is its body covered with1 hair or feathers8 ,is it a bird or a mammal8 ,is the hair soft and furry8 ,how large are the ears8 ,are the whiskers large or small8 ,what are the wings like8 ,can you see any fingers8 ,how many fingers are there8 ,do any of the fingers bear claws8 ,do the fingers support the wings8 ,which are longer1 the fore limbs or the hind limbs8 ,do the toes of the hind limbs bear claws8 ,what is their use8 ,if possible1 put a live bat on the ground2 does it walk easily8 ,apart from the wings1 what animal does the bat seem most to resemble8 ,do you know of any other flying mammal8 ,the ,bat 7,figs4 #agb and #ahd;a74--,on summer evenings in most country districts of ,britain bats may be seen flitting about catching insects4 ,the flight is peculiar1 and somewhat suggestive of that of a butterfly1 so that even in the dusk the animal may be distinguished easily from a small bird4 8,bats drink on the wing like swallows1 by sipping the surface as they play over pools and streams4 ,they love to frequent waters1 not only for the sake of drinking1 but on account of insects1 which are found over them in the greatest plenty40#ad ,illustration3 ,,fig4 #agb4--,the ,bat4 7 47 ,the voice of the bat is a shrill squeak1 of so high a pitch that many people cannot hear it at all4 ,the animal is probably quite blind1 but it has keen powers of scent and hearing1 and in avoiding obstacles seems to be greatly aided by patches of specially sensitive skin on the face1 and by delicate whiskers4 ,during the day it lurks in dark corners of barns1 church-towers1 hollow trees1 etc41 hanging head downward by the hooked claws of its hind feet4 ,on close examination the body of the bat is seen to be covered with soft fur1 a character which at once proclaims the animal to be not a bird--as it has been incorrectly considered--but a mammal4 ,the fur is often of a bright chestnut colour4 ,the ears are large and practically devoid of hair1 and are so thin as to be almost transparent4 ,the wings are thin folds of skin1 which are attached in front to the long arms1 are supported by the greatly elongated fingers1 and reach to the hind limbs4 ,another membrane passes between the hind limbs1 and in common species is also supported by the tail4 ,the thumb is free1 and bears a claw which is of some assistance in climbing4 ,the hind limbs are small4 ,the structure of the bat is obviously but little adapted to walking1 and the animal moves about very awkwardly when on the ground1 although it can rise on the wing again without much difficulty4 ,the bat is rarely to be seen abroad after the middle of ,november1 for as the cold weather approaches and insects become scarce1 it suspends itself by its hind claws in some dark and sheltered corner1 and goes to sleep for the winter1 reappearing in early spring4 #ej4 ,,hoofed ,,mammals4 #a4 ,the external characters of the sheep4--7a7 ,wool4--,how does the covering of a sheep's body differ from the fur of a cat or rabbit1 and from the hair of the dog8 ,examine a lock of 8raw0 wool2 is it at all greasy8 ,dip it in water2 is it much wetted8 ,are the fibres easily entangled together8 ,why is woollen clothing so warm8 7b7 ,teeth4--,obtain a sheep's head from the butcher1 and examine the teeth4 ,notice the absence of incisors and canines in the upper jaw1 and of canines in the lower jaw4 ,observe the thickened pad on the surface of the upper jaw1 against which the lower incisors bite4 ,are the cheek teeth flat1 or sharp-edged like the cheek teeth of carnivores8 ,watch a sheep feeding1 and notice how it bites the grass4 ,how is the lower jaw moved during the chewing of the cud8 7c7 ,horns4--,which sheep have the largest horns1 the males 7rams7 or the females 7ewes78 ,if you can find a cast horn notice whether it is hollow or solid4 ,what is the use of horns8 7d7 ,limbs4--,is there any marked difference in the lengths of fore and hind limbs8 ,notice the hoofs which cover those parts of the feet touching the ground4 ,how many hoofs are there on each foot8 #b4 ,the habits of the sheep4--,are sheep solitary or do they live in flocks8 ,what kind of ground do they seem to prefer1 flat or hilly8 ,are sheep on a hillside easily seen from a distance8 ,why not8 ,are sheep nimble or clumsy8 ,can they run very fast8 ,would a flock of sheep be safer from1 say1 wolves on a rocky hillside or on an open plain8 ,in a grazing flock of sheep notice whether most of the animals have their heads turned in the same direction4 ,has the direction any relation to the direction of the wind8 ,can you explain this8 ,in a running flock of sheep does any one animal act as leader8 ,is the leader a ram or a ewe8 ,is it a lamb or an old animal8 ,do the rest of the flock imitate the actions of the leader1 and1 for example1 leap over a wall at the same place in single file8 ,have you ever noticed that if one animal jumps at a certain place1 all the following sheep jump at the same place8 ,have you ever seen sheep fighting8 ,were the combatants rams or ewes8 ,how did they fight8 ,what is the voice of a sheep like8 #c4 ,lambs4--7a7 ,appearance4--,at what time of the year are lambs born8 ,are they helpless or active8 ,have they long legs8 ,what advantage to the lamb is length of limb8 7b7 ,play4--,watch lambs playing4 ,do they show a preference for any eminence1 e4g4 a rock1 in the neighbourhood8 ,what is the meaning of this preference8 ,how do lambs fight8 ,have you ever seen a ewe stamp with her fore-feet when anyone approached her lamb8 ,at what age is a sheep full grown8 ,the sheep4--,the sheep 7,fig4 #agc7 differs in several important respects from any of the animals previously mentioned4 ,it is of course a mammal1 for it suckles its young1 and its body is covered by hair2 but the hair is of that warm fleecy kind which is called wool4 ,the fibres of wool are seen under the microscope to be rough and scaly4 ,for this reason they can be spun into loosely-textured threads which entangle a great deal of air2 woollen garments are thus very bad conductors of heat4 ,the wool upon the sheep's body is slightly greasy1 from a substance which is given off by the skin and protects the animal from rain4 ,the toes of the sheep are not armed with ordinary nails or claws1 but claws are represented by horny masses called hoofs1 which encase the ends of the toes1 and upon which the whole weight of the body is thrown4 ,the sheep1 especially the male 7ram71 is often provided with weapons in the form of hollow horns1 which grow upon its forehead4 ,illustration3 ,,fig4 #agc4--,sheep4 ,illustration3 ,,fig4 #agd4--,section of ,skull of ,sheep4 7,after ,flower47 ,illustration3 ,,fig4 #age4--,stomach of a ,ruminant opened to show the internal structure4 ,for description1 see text4 ,method of feeding4--,the sheep is a strict vegetarian1 living largely upon grass4 ,it grips the grass between its lower incisor teeth and a hard pad on the upper jaw2 there are no incisor teeth in the upper jaw4 ,neither upper nor lower jaw bears canine teeth2 and the cheek teeth1 which are used for chewing the food1 have their crowns ridged lengthwise4 ,the arrangement of the teeth of the sheep is shown in ,fig4 #agd4 ,during grazing1 however1 the food is not at once chewed1 but is simply mixed with a large quantity of saliva and swallowed1 the chewing-process being performed at a later period4 ,it is obviously a great advantage to an animal1 which in the wild state is liable at any moment to be attacked by enemies1 to be able to stow away its food quickly1 and afterwards masticate it at leisure4 ,this is rendered possible1 in oxen1 sheep1 goats1 deer1 and the few other animals which chew the cud1 by the peculiar form of stomach shown in ,fig4 #age4 ,the hastily swallowed food is passed into the large paunch b and into the compartment c4 ,when the animal finds an opportunity of 8ruminating0 or chewing the cud1 the food is returned to the mouth in small quantities at a time1 and is there finely divided by the cheek teeth4 ,in this condition it is again swallowed1 and makes its way at once into the compartment d1 where it is strained between leaf-like folds and then passed into the last chamber e1 and thence to the intestines1 to undergo the final processes of digestion4 ,ruminants4--,animals which1 like the sheep1 oxen1 goats1 deer1 etc41 ruminate or chew the cud in this manner1 are called ruminants4 ,in all ruminants the weight of the body is supported by the tips of the third and fourth toes of the feet1 the remaining toes either having completely disappeared or remaining very small 7,fig4 #agf74 ,the tips of the toes are encased in horny hoofs1 which represent greatly enlarged claws or nails4 ,the ruminants therefore belong to what may be called the even-toed hoofed mammals4 ,pigs are also even-toed hoofed mammals1 but they are not ruminants1 because1 having simple stomachs1 they do not chew the cud4 ,illustration3 ,,fig4 #agf4--;,bones of fore-foot of ,red ,deer4 7,after ,flower47 ,illustration3 ,,fig4 #agg4--;,bones of fore-foot of ,horse4 7,after ,flower47 ,other hoofed mammals4--,in the horse and donkey the reduction of the number of toes has gone still further2 for these animals have now only the third or middle toe of each foot left 7,fig4 #agg72 and because it has to carry the whole weight of the body1 it has become very large and stout2 its tip is encased in a hoof4 ,the hoofed mammals are therefore divided into two groups3 7#a7 the odd-toed1 including the horse and ass 7they have simple stomachs1 and therefore do not chew the cud72 and 7#b7 the even-toed1 including 7a7 ruminants like the sheep1 etc41 and 7b7 such non-ruminants as the pigs and their relatives4 ,the inherited habits of the sheep4--,as in the cases of the dog and cat1 so in the sheep1 the true explanation of several curious habits is to be found in the manner of life of the wild ancestors2 for it must be remembered that domestication1 however kindly an animal may take to it1 is an artificial condition of life4 ,wild sheep live in flocks1 as a rule in cold and mountainous districts2 and some organisation is necessary if they are not to be at the mercy of savage carnivores4 ,an old and experienced ram is generally in charge of the flock1 and in case of alarm he leads the way to a more inaccessible position4 ,the rest of the flock follow in single file1 closely imitating his every movement1 leaping without hesitation--and therefore saving valuable time--wherever he has leapt4 ,the survival of this instinct in domestic sheep may be observed whenever a flock is travelling along the road4 ,even young lambs still display a decided preference for rocks1 hillocks1 and other elevated positions4 ,wild sheep1 being so liable to sudden interruption when grazing1 are enabled by their compound stomachs to swallow food quickly and postpone the chewing process to a more favourable opportunity4 ,sentinels usually keep watch1 and warn the flock of approaching enemies by stamping their hoofs on the ground1 an action which may still be seen whenever a ewe fears danger to her lambs4 ,the play and education of the young4--,the young of mammals are usually under the care of the mother for education and protection until they are nearly adult2 and it is generally found that the longest infancy 7in proportion to the natural life of the animal7 occurs in the most intelligent races4 ,the importance of the play and education period is very great1 for it not only gives the young animal an opportunity of training its natural faculties in comparative safety1 by exercise of various kinds and by games with companions of its own age and strength2 but it allows the mother to impart1 by direct instruction1 some of the experience which she has personally gained during her life4 ,the extent of this maternal education is greater than has been generally supposed2 and every opportunity should be taken of observing and recording cases of it4#ae ,the play of young animals also in many cases gives important clues to lost ancestral habits1 which are not now to be seen in adult life4 ,the inherited tendency of animals to repeat1 during their own development1 the history of their race is very great2 some striking cases of this will be considered in later chapters4 ,,exercises ,,on ,,chapter ,,xiv4 #a4 ,make a list of cases which you have observed of protective colouration in mammals1 specifying 7a7 the colour of the animal1 7b7 the colour of its surroundings4 #b4 ,describe any cases which you have observed of mammals having differently-coloured coats in summer and winter4 ,of what use is the change in colour8 #c4 ,make a list of the mammals you know from observation to walk 7a7 flat-footed1 7b7 on their toes1 7c7 on the tips of their toes4 #d4 ,make a list of the mammals which habitually hop1 walk1 fly1 and swim respectively2 and find out1 by observation if possible1 how the structure is adapted to the method of life4 #e4 ,study the habits of the mole1 and try to discover by what modifications it is enabled to burrow so rapidly4 #f4 ,what is the difference in the ways in which cows and horses get up and lie down8 #g4 ,for what purposes do the following mammals use their tails--cows1 squirrels1 rabbits8 ,what mammals do you know which are without tails8 #h4 ,observe and describe the differences--apart from speed--between walking1 trotting1 and galloping1 in the case of the horse4 #i4 ,describe how you have tamed any wild animal4 ,why is it easier to tame a young animal than an old one8 #aj4 ,describe cases of mammals showing antipathy to certain colours4 ,how do you explain the dislike8 #aa4 ,which domestic mammals are 7a7 most shy1 7b7 most inquisitive1 7c7 most gentle1 7d7 most suspicious1 7e7 most intelligent8 #ab4 ,of what shape is the pupil of the eye in a dog1 a cat1 and a sheep8 ,does the shape of the pupil change from time to time in any of these animals8 7#ahih7 #ac4 ,describe the fore-foot of a cat1 a dog1 and a sheep4 ,the bones of the foot need not be described in detail4 ,draw a footprint of each animal 7fore-foot71 and show how each part of the print is produced4 7#ahih7 #ad4 ,give a short account of the life of a bat4 ,when and where does it seek its food8 ,how does it pass the winter8 7#ahih7 #ae4 ,give illustrations 7from your own experience if possible7 of the curiosity of dogs and cats4 ,show that their curiosity is necessary to their welfare4 7#aija7 #af4 ,mention animals which are nocturnal 7only coming forth at night71 animals which burrow in the ground1 animals which are solitary1 and animals which are social4 7#aija7 #ag4 ,how are young cats treated by their mother when they are helpless1 when they first run about freely1 and when they are able to get their own food8 7#aijc7 #ah4 ,mention some of the peculiarities which serve in most cases to distinguish the hind limb of a quadruped from the fore limb4 7#aije7 #ai4 ,the habits of an animal can be inferred from its teeth4 ,to what extent is this statement true of 7a7 the cat1 7b7 the rabbit8 7,king's ,scholarship1 #aije7 ,,footnotes3 #ac ,the ,descent of ,man4 ,cheap edition1 #as4 7,murray74 #ad ,gilbert ,white1 ,the ,natural ,history of ,selborne4 #ae ,see ,lloyd ,morgan's ,habit and ,instinct 7,arnold71 ,thompson-,seton's ,wild ,animals ,i have known 7,nutt71 and ,long's ,school of the ,woods 7,ginn74 ,,chapter ,,xv4 ,,the ,,pigeon3 ,a ,,typical ,,bird4 #ea4 ,,habits ,,and ,,structure ,,of ,,the ,,pigeon4 #a4 ,general observations upon the dovecote pigeon4--,watch a group of pigeons4 ,what is the shape of the body8 ,with what is the body covered8 ,what is the colour of the feathers8 ,does the bird walk or hop8 ,how many walking limbs has it8 ,has it any other means of moving from place to place1 in addition to walking8 ,how many wings has it8 ,are the wings anterior or posterior 7p4 #bag7 to the legs8 ,watch a pigeon preening its feathers2 why does it apply its bill so frequently to its tail8 ,can the bird bend its neck easily in all directions8 ,on what do pigeons feed8 ,how do they pick up their food8 ,do they chew the food8 ,what is the voice of the pigeon like8 ,at what time of the year do pigeons moult8 ,how many eggs does the hen-pigeon lay8 ,what is the colour of the eggs8 ,what are newly-hatched pigeons like8 ,how do the parent birds feed them8 ,try to find a wood-pigeon's nest4 ,what is its shape8 ,what is it made of8 ,is the top open or closed-in8 #b4 ,the external characters4--,closely examine a dead pigeon in respect of the following features3 7a7 ,feathers4--,in what direction do the free ends of the feathers point8 ,where are the longest feathers8 7b7 ,the head4--,what is the general shape of the head8 ,notice the horny bill2 is it blunt1 pointed1 or hooked8 ,does it bear teeth8 ,observe the cere1 a whitish patch of swollen skin at each side of the base of the upper beak1 and surrounding the nostril4 ,examine the large eyes1 and notice the upper and lower eyelids and the transparent third eyelid4 ,find the ear-opening1 a little below and behind the level of the eye1 and hidden by the small feathers of the neck4 ,open the mouth and see the pointed tongue4 7c7 ,the neck4--,in the feathered bird this appears short2 it will be better seen after the removal of the feathers 7contour feathers7 which cover it4 7d7 ,the trunk4--,what is the apparent shape of the trunk8 ,where is its heaviest part8 7e7 ,the wings4--,open out the wings fully and measure the distance from tip to tip2 compare it with the length of the trunk4 ,which surface1 upper or lower1 of the expanded wing is rounded 7convex7 and which is hollowed 7concave78 ,put up an umbrella and1 holding it by the handle1 move it quickly 7i7 away from you1 7ii7 towards you4 ,in which direction of motion does the air offer more resistance8 ,is it an advantage for the expanded wing to be convex above and concave below8 ,why8 ,feel the wing-bones through the skin1 and notice that the wing-skeleton consists of three parts corresponding to the bones of your upper-arm1 fore-arm1 and hand 7with the wrist7 respectively2 and that they are bent on each other in the form of a ,z when the wings are folded4 ,the large quill-feathers attached to the segment which corresponds to the hand and wrist are called primaries2 count them4 ,those attached to the fore-arm are called secondaries2 count them4 ,find the tuft of smaller feathers which spring1 at the front edge of the wing1 from the thumb2 this tuft is called the thumb-wing4 ,the primaries and secondaries collectively may be called the rowing feathers4 ,notice the smaller feathers which1 on both the upper and lower surface of the wing1 cover the quills of the primaries and secondaries2 these smaller feathers are called the wing-coverts4 7f7 ,the legs4--,feel the leg-bones through the skin1 and make out the various segments4 ,is the whole of the hind-limb feathered8 ,which part is devoid of feathers8 ,with what is this part covered8 ,how many toes are there8 ,do any point backwards8 ,stretch out the legs and notice that the toes open4 ,bend the ankle-joint and notice that the toes close automatically4 ,of what use is this in perching8 7g7 ,the tail4--,examine the tail and notice the large quill-feathers attached to it2 count them4 ,as they are largely used for steering during flight they are sometimes called the steering feathers4 #c4 ,the feathers4--,examine the arrangement of the feathers4 ,the short feathers which clothe the body generally are called contour feathers because they determine the contour of the unplucked bird2 remove one or two and place them aside4 ,the feathers which cover the bases of the large quills are called coverts--wing-coverts or tail-coverts according to their position4 ,remove one or two for future examination4 ,examine the arrangement of the quill-feathers of the wings1 and notice how the vane or web of one partially overlaps the next4 ,the vane is supported by a shaft4 ,are the two sides of the vane of equal width8 ,is the narrower side directed forwards or backwards8 ,pull out a quill-feather from each wing and compare them4 ,how could you recognise1 if you did not know1 whether any particular feather had come from the right or from the left wing8 ,pull out a quill-feather from the tail2 are the sides of the vane of equal width8 #d4 ,examination of various feathers4--,examine in detail a quill-feather from the wing4 ,make out3 7a7 ,the quill4--,is it hollow or solid8 ,try to bend it and notice its great strength4 ,observe the small hole at its base4 7b7 ,the shaft4--,this is the prolongation of the quill1 and carries the web or vane4 ,is the shaft hollow or solid8 ,notice the small tuft of down on the inner face of the feather1 at the junction of the quill and shaft4 7c7 ,the vane4--,hold up the feather to the light and examine the vane with a lens4 ,notice that the vane consists of a number of laths which spring from the shaft2 these are called barbs4 ,try to separate the barbs1 and observe that they offer considerable resistance to the pull1 as if they were somehow fastened together4 ,examine a barb with a strong lens and observe the finer branches1 called barbules1 which it bears4 ,the barbules on one side of the barb carry little hooks1 while those of the other side bear flanges1 on which fit the hooks of barbules carried by the next barb below4 ,the hooks and flanges cannot be seen without a microscope4 7d7 ,other feathers4--,compare the covert and contour feathers with the quill feathers4 ,observe1 in the contour feathers1 the less perfect interlocking of the barbs of those parts which are covered by other feathers4 ,pluck the pigeon1 and notice the hair-like structures left in the skin4 ,they are called filoplumes4 ,pull one out and examine it with a lens2 it bears a few barbs at its upper end1 but these do not interlock4 ,examine a nestling-pigeon1 and notice the down-feathers which clothe it temporarily4 ,each is at first covered at the base with a horny sheath4 ,the barbs do not interlock4 ,the down-feathers are pushed off by the growth of the permanent feathers4 #e4 ,the plucked pigeon4--,observe that feathers do not grow on all parts of the body1 but are confined to definite feather-tracts1 which can be recognised by the scars left by the quills4 ,notice especially the sockets of the large wing-and tail-quills4 ,make out the oil-gland1 a small knob just above the tip of the true tail4 ,it furnishes a lubricating fluid used in preening the feathers4 ,examine more closely the different regions of the body--the neck1 the joints of the limbs1 etc41 which were disguised by the feathers4 ,the filoplumes have already been seen4 ,feel the great muscles of the breast1 and the edge of the sternum or breast-bone in the middle line4 ,just in front of this feel the soft crop1 with the grain which is probably present in it4 ,before boiling the bird in order to separate and examine the bones1 open the crop and inspect its contents4 ,cut away the enormous muscles of the breast 7why are they so large87 and open the body-cavity behind and remove the internal organs1 being careful not to break any bones4 #f4 ,the skeleton4--,boil the bird until the flesh can be easily removed4 ,a small nail-brush will be found useful in cleaning the bones4 ,keep as many of these in contact as possible1 and make out and examine the following parts3 7a7 ,the skull1 with the rounded brain-case1 horny beak1 and large eye-sockets4 ,notice1 at the back of the skull1 the single knob1 which fits into a hollow on the first vertebra4 7b7 ,the backbone4--,notice the long neck1 the fusion of many of the vertebrae in the trunk-region1 and1 at the end of the tail1 the 8ploughshare bone40 ,this last supports the tail-quills4 7c7 ,the breast-bone1 or sternum1 produced ventrally into a thin plate called the keel 7to which were attached the great muscles of the breast71 and connected by ribs to the backbone4 7d7 ,the position of the shoulder joint1 and the socket for the bone of the upper-arm4 ,notice the ,v-shaped 8merrythought40 7e7 ,the bones of the fore-limb 7wing74--,make out the parts belonging to the upper-arm1 fore-arm1 and wrist and hand1 and notice that the bones of the wrist and hand are firmly fused together to give increased strength4 7f7 ,the large hip-bones4--,notice their forward extension and fusion with the joined vertebrae of this region1 and the resulting increased firmness of this part4 7g7 ,the bones of the hind-limbs4 #g4 ,pneumatic bones4--,examine the bone of the upper-arm of the pigeon and notice1 just below the head of the bone1 a small hole which leads into the interior4 ,break the bone across2 is it hollow or solid8 ,does the inside contain marrow8 ,how does it differ from the corresponding bone of a rabbit8 #h4 ,different breeds4--,examine various breeds of domestic pigeons1 and compare them with the common variety1 as regards colour1 shape1 method of flight1 extent of feathering of the hind-limbs1 etc4 ,birds4--,it is probable that no class of animals has been more studied than that of the birds2 and the reasons for this are not difficult to find4 ,the wonderful power of flight--rivalled only by the insects--and the perfect adaptation of structure to this power2 the habits1 always interesting and in many cases showing a curious parallelism to human institutions2 the beautiful voices of song birds2 the grace of movement2 the mysteries of migration2 and1 it may be added1 the remarkable story of the origin of birds which has been revealed by modern zoology1--form a combination of characters1 at once familiar and elusive1 which has greatly stimulated human sympathy and imagination4 ,it is well to begin the study of birds by first taking one familiar species and examining it somewhat closely1 and afterwards comparing and contrasting other members of the class4 ,such a convenient type for study is found in the dovecote pigeon4 ,illustration3 ,,fig4 #agh4--,pigeons4 ,the pigeon4--,the body of the common dovecote pigeon 7,fig4 #agh7 is ovoid in shape1 tapering gently at the neck and appearing1 in the living animal1 to pass insensibly into the head4 ,the fore-limbs are modified to form a pair of wings1 which are set on a little above and in front of the centre of gravity of the body4 ,except during flight the weight of the body is entirely supported by the hind-limbs or legs1 which are fixed almost exactly below the centre of gravity of the body1 i4e4 in the best imaginable position4 ,each foot bears four toes1 the first of which is directed backwards4 ,each toe is armed with a claw4 ,the body generally is clothed with feathers1 remarkable structures which are as characteristic of birds as hairs are 7p4 #bbj7 of mammals4 ,the great majority of the feathers are small1 overlapping and plate-like1 with their free ends pointing backwards2 and they form a light1 warm1 and smooth covering which is admirably adapted to the animal's needs4 ,certain large feathers1 carried by the wings and tail1 are used in flight4 ,the legs are feathered to the ankle-joint1 but the feet are covered only with scales4 ,the general colour of the dovecote pigeon is a slaty blue4 ,the head is rounded1 and terminates in front in a horny bill1 which does not bear teeth4 ,at the base of the upper beak there is1 on each side1 a whitish patch of swollen skin called the cere1 which surrounds the opening of the nostril4 ,the eyes are large and round2 in addition to upper and lower eyelids1 each is provided with a transparent third eyelid1 which can be flicked rapidly across the eyeball4 ,birds generally have very powerful sight and depend more upon this sense than upon any other4 ,there are no external ears1 but when the feathers are separated1 a little below and behind the eyes1 a pair of apertures leading to the internal ears may be seen4 ,habits4--,the pigeon lives upon grain1 which it picks up by means of its horny bill4 ,the length and flexibility of the neck are a great help in feeding4 ,the food is swallowed immediately and passed into a large bag called the crop1 which is really a dilatation of the lower part of the gullet4 ,here it is macerated for some time before it passes onward to the true stomach4 ,the hinder part of the stomach is called the gizzard2 it has very thick walls and a hard horny lining4 ,in the gizzard the food is ground up by the aid of small stones which the pigeon swallows for the purpose4 ,the stomach is followed by a much-coiled intestine1 in which the process of digestion is completed4 ,the pigeon differs from many birds in walking instead of hopping4 ,when perching1 it bends its legs at the ankles1 an action which automatically closes the toes in such a manner that the perch is grasped behind by the first toe and in front by the second1 third1 and fourth4 ,the weight of the body is sufficient to maintain a tight clasp upon the perch1 so that the bird is able to sleep comfortably in this position4 ,illustration3 ,,fig4 #agi4--;,a ,falcon4 ,the regions of a bird's body4 ,the hen-pigeon lays two white eggs1 which are sat upon by the parents for fourteen days and thereby kept at a temperature of about #dj degrees ,centigrade4 ,the young birds then break through the shell and are hatched4 ,as the chicks are at first quite helpless and unable to feed themselves1 the parents supply them with a milky fluid secreted by their crops4 ,this is sometimes called 8pigeon's milk40 ,newly hatched pigeons are covered with fine feathers called down1 which are pushed off by the development of the permanent feathers beneath them4 ,the nests of wood-pigeons 7,fig4 #ahj7 are usually built in trees2 they are somewhat rough structures1 composed of twigs1 and open at the top4 ,illustration3 ,,fig4 #ahj4--,wood-pigeon's nest4 ,the wings4--,a bird's wings are full of interest1 from whatever point of view they are considered4 ,even now1 the exact manner in which they and the tail are used to bring about the many different movements of flight is not fully understood2 but a general idea may be obtained by an examination of the bones and feathers and the careful observation of flying birds4 ,illustration3 ,,fig4 #aha4--,the skeleton of the limbs and tail of a flying-bird4 ,,oa1 bone of upper arm2 ,,os1 bone of upper leg2 ,rd1 ,ul1 bones of fore-arm2 ,t1 ,fi1 bones of leg2 ,,hw1 ,,mh1 bones of wrist2 ,f1 ,f1 ,f1 bones of fingers2 ,z1 ,z1 ,z1 ,,mp1 bones of foot2 ,scp1 shoulder blade2 ,cr1 keel on sternum 7,st72 ,pg1 ploughshare bone4 ,the bones of the fore-limb and the neighbouring regions show a remarkable modification of the primitive plan4 ,the bones of the upper arm ,,oa1 7,fig4 #aha7 and fore-arm 7,rd41 ,ul417 are arranged much like the corresponding bones of the rabbit2 but those of the wrist and hand are unlike anything we have yet examined4 ,the fourth and fifth fingers have entirely disappeared2 and the first 7thumb71 second1 and third1 though they can be still recognised 7,figs4 #aha1 ,f1 ,f1 ,f and #ahd;a71 have become consolidated with what remains of the wrist 7,,hw1 ,,mh7 to form a firm mass which is in no danger of 8giving0 during the powerful down-stroke of the wing4 ,the head of the bone of the upper arm fits into a socket 7gl4cv41 ,fig4 #ahb7 at the junction of the shoulder-blade 7scp47 and another and stouter bone 7cor47 which runs back and is attached to the breast-bone or sternum 7st474 ,the sternum in its turn is connected by means of ribs with the spinal column1 which is strengthened here by the fusion of some of its bones4 ,the ventral part of the sternum is produced into a large plate called the keel 7car41 ,fig4 #ahb71 which gives attachment to the great muscles of the breast1 used in the movements of the wings4 ,so great is the development of these muscles in flying birds that in the pigeon they have a weight equal to one-fifth the total weight of the body4 ,the three segments of the wing1 corresponding to the upper-arm1 fore-arm1 and wrist and hand respectively are1 in the position of rest1 bent upon each other like the letter ,z4 ,the large quill feathers of the wing1 fixed along the hinder border of the limb1 are in two series 7,fig4 #agi74 ,those attached to the fore-arm are called secondaries2 while those attached to the wrist and hand are known as primaries4 ,a smaller tuft of feathers borne by the thumb is called the bastard-wing or thumb-wing4 ,the smaller feathers covering the bases of the wing-quills are called wing-coverts4 ,illustration3 ,,fig4 #ahb4--,pigeon4 ,the bones of the trunk4 actb1 socket for bone of upper leg2 car1 keel of sternum2 cd4v1 vertebrae of tail2 cor1 coracoid2 fur1 merrythought2 gl4cv1 socket for bone of upper arm2 pyg4st1 ploughshare bone2 scp1 shoulder blade2 s4scr1 fused vertebrae of hip region2 st1 sternum2 st4r1 vr4r1 rib2 th4v4#a1 first1 and th4v4#e1 last thoracic vertebra4 7 47 ,the hind-limbs and tail4--,the hind-limbs1 or legs1 of birds are the sole support of the body except during flight1 and a relatively great weight is thus thrown upon them4 ,to provide for this1 the skeleton of the hip region is exceptionally strong4 ,not only are the bones of the spine here welded together into one solid mass1 but the hip-bones extend forward much further than is the case in quadrupeds1 and are firmly attached to the fused vertebrae4 ,each hip-bone possesses a socket 7actb41 ,fig4 #ahb7 into which fits the head of the bone of the upper leg4 ,another fusion of bones is to be noticed at the end of the tail1 resulting in the ploughshare-bone 7,fig4 #ahb1 pyg4 st47 which supports the large steering feathers of the tail4 ,the quills of these feathers are covered at their bases by the tail-coverts4 ,just above the end of the tail of a plucked pigeon is to be seen a small conical body1 the oil-gland1 from which the bird obtains a fluid which it applies to the feathers during the preening process4 ,the feathers4--,feathers do not grow upon all parts of a bird's body1 but are restricted to certain definite areas or 8feather tracts0 which1 however1 differ in arrangement in different species4 ,illustration3 ,,fig4 #ahc4--,pigeon4 ,a1 portion of a wing feather2 cal1 quill2 rch1 shaft2 ,b1 filoplume2 ,c1 nestling-down4 ,one of the large feathers of the wing of the pigeon is illustrated in ,fig4 #ahc1 ,a4 ,it consists of a hollow1 horny quill 7cal471 prolonged into a solid shaft 7rch47 which supports the web or vane4 ,the outer face of the feather is slightly convex and smooth2 while the inner surface is somewhat concave and rough1 and carries a little tuft of down at the junction of quill and shaft4 ,the growing feather is nourished by a conical projection of the deeper part of the skin1 which fits into a small hole 7inf4 umb47 at the base of the quill4 ,it is easily shown that the vane of the feather is composed1 on each side1 of a large number of parallel laths which spring from the shaft4 ,these laths are called barbs4 ,considerable resistance is felt when an attempt is made to pull the barbs apart1 but the manner of their connection cannot be clearly seen without the aid of the microscope4 ,a fairly low magnifying power1 however1 shows 7,fig4 #ahd7 that each barb bears extremely delicate threads--barbules--on each side1 arranged on the barb much as the barbs are arranged on the shaft4 ,the barbules on one side of each barb 7the side furthest from the quill7 are seen to carry tiny hooks2 while the barbules of the other side of the barb are furnished with flanges4 ,the hooked barbules of one barb cross the flanged barbules of the next and interlock with them2 so that relatively great force is required to pull the barbs apart and destroy the continuity of the web4 ,the quill-feathers of the tail1 and the coverts1 have webs of similar structure4 ,illustration3 ,,fig4 #ahd4--,structure of a ,feather4 ,a1 small portion of a feather with pieces of two barbs1 each having to the left three hooked barbules1 and to the right a number of flanged barbules2 ,b1 hooklet of one barbule interlocking with flange of another barbule2 ,c1 two adjacent flanged barbules2 ,d1 a hooked barbule4 7,after ,pycraft47 ,the contour-feathers are used for protection and warmth rather than for flight1 and hence have less-perfectly interlocking barbs4 ,the hair-like structures seen on the skin of the plucked bird are extremely simple feathers called filoplumes 7,fig4 #ahc1 ,b74 ,each consists of a long1 slender axis1 bearing at the end a few barbs which do not interlock4 ,the down-feathers 7,fig4 #ahc1 ,c71 which form the temporary covering of nestling pigeons1 also bear barbs which do not interlock4 ,at regular intervals1 either once or twice a year1 birds moult1 that is1 shed most or all of their feathers and grow new ones4 ,the moulting usually takes place gradually and symmetrically3 a flight feather from each wing1 for example1 being dropped at the same time4 ,flight4--,the outstretched wing of a pigeon has a relatively great area2 and is markedly convex on the upper surface and concave on the lower1 resembling in this respect an open umbrella4 ,the great difference in the resistance which the inside and outside of an open umbrella respectively oppose to the wind is familiar to everyone1 and illustrates the advantage of the dome-shape of the outstretched wing4 ,the force which the great breast-muscles put into the down-stroke of the wing is enormous in comparison with the weight of the body1 and is sufficient to push the bird upwards and forwards in the air4 ,the gently tapering shape and smooth surface of the feathered bird diminish the resistance of the air4 ,when the wing is raised again for the next stroke1 the quill-feathers are turned a little edgewise1 so that the air slips between them2 just as an oarsman 8feathers0 his oar to lessen the resistance to the blade in the return-stroke4 ,the direction of the wing-stroke can be altered in accordance with the direction of air currents1 and the fan of tail-feathers is capable of being opened or closed1 raised or lowered1 and turned at various angles to act as a rudder4 ,but the method of flight which perhaps most of all excites the observer's admiration is soaring1 in which the bird seems to remain almost passive1 with outstretched wings and spread tail1 and mounts automatically in a spiral course4 ,exactly how the soaring is performed1 only the birds themselves know2 but it must be similar in essence to the arrangement of the sails of a yacht so as to select that component of the force of the breeze which will drive the boat in the required direction1 even though this be almost 8in the teeth of the wind40 ,such spiral soaring may be seen to perfection1 among common ,british birds1 in the skylark 7p4 #caf74 ,a breeze is necessary for soaring4 ,in hovering1 the motion of the wings is extremely rapid1 and the bird remains poised in one place4 ,the kestrel 7p4 #ccj7 derives its common name of 8windhover0 from its habit of using this method of flight when looking for food4 ,the pigeon's air supply4--,we know that a man breathes more quickly when he is taking active exercise than at ordinary times2 and we might1 from this and similar observations1 expect to find the most perfect breathing organs in animals which lead the most active lives4 ,of all vertebrate animals1 birds probably perform the most work in proportion to their size2 and it is not surprising1 therefore1 to learn that they have special facilities for quickly replacing fouled air by fresh4 ,the lungs are comparatively small1 but they are not the only organs of respiration 7p4 #bdb72 for the windpipe opens also into several air-sacs1 which supply nearly all parts of the body with air1 and even communicate with the interior of certain bones4 ,the bone of the pigeon's upper-arm1 for example1 is hollow and contains air4 ,by means of the system of air-sacs1 the air in the lungs is completely renewed at each respiratory act1 and thus the waste carbon-dioxide in the blood can be exchanged for fresh oxygen much more completely than it is in mammals4 ,one result of this is that the blood of birds is much warmer than that of mammals4 ,the air-sacs are also an assistance to flight by rendering the body more buoyant4 ,different breeds of pigeons4--,the various breeds of domestic pigeons furnish one of the best examples of the changes in structure which breeders can bring about1 after several generations1 by careful crossing4 ,in spite of the great differences between1 say1 the tumbler1 with its habit of turning head-over-heels in the air2 the pouter1 with its exaggerated crop2 the ,jacobin1 with its neck-feathers reversed2 the fantail1 with its large number of erect tail-feathers2 and others1--there can be no doubt that all these varieties have been artificially produced from the rock-pigeon2 and it is curious to observe occasional reversions to the characters of the ancestral stock4 8,the rock-pigeon is of a slaty blue1 with white loins4444 ,the tail has a terminal dark bar1 with the outer feathers externally edged at the base with white4 ,the wings have two black bars4 ,some semi-domestic breeds1 and some truly wild breeds1 have1 besides the two black bars1 the wings chequered with black4 ,these several marks do not occur together in any other species of the whole family4 ,now1 in every one of the domestic breeds1 taking thoroughly well-bred birds1 all the above marks1 even to the white edging of the outer tail-feathers1 sometimes concur perfectly developed4 ,moreover1 when two birds belonging to two or more distinct breeds are crossed1 none of which are blue or have any of the above-specified marks1 the mongrel offspring are very apt suddenly to acquire these characters40#af ,this is a striking instance of the tendency exhibited by living things to revert to ancestral characters1 even though these latter may have lain dormant for hundreds of generations4 ,,exercises ,,on ,,chapter ,,xv4 #a4 ,why does a bird require a long neck1 and a keel upon the breast bone8 7#ahih7 #b4 ,draw the bones of a bird's wing1 and mark the places of insertion of the largest quills4 7#ahih7 #c4 ,what bones carry the primary and secondary quills of a bird's wing1 and the quills of the tail8 ,illustrate your answer by a drawing4 7#aija7 #d4 ,point out the chief differences between the skulls of a quadruped and a bird4 7#aija7 #e4 ,describe one of the large feathers of a bird's wing4 7#ahih7 #f4 ,draw general plans of the fore-limbs of a mammal and a bird4 ,letter the principal bones1 so as to show how they correspond in the two animals4 7#aija7 #g4 ,if the skull of a bird were placed before you1 what features would enable you to recognise it with certainty8 7#aija7 #h4 ,how does the fact that a bird stands on two legs affect the skeleton of the trunk8 7#ahig7 ,illustration3 ,,fig4 #ahd;a4--,comparison of ,bat and ,bird4 #i4 ,point out the chief differences between the wing of a bird and that of a bat4 #aj4 ,explain how the barbs of a quill feather are attached to one another4 ,describe a feather at the time when it is forcing its way through the skin4 7#aije7 #aa4 ,what peculiarities distinguish feathers which aid in flight from feathers which merely prevent loss of heat8 7#aijf7 #ab4 ,describe the wing of a bird1 both as to skeleton and as to external appearance4 ,compare the skeletal parts with those of the corresponding structures in a ,mammal4 7#aijh7 ,,footnote3 #af ,darwin1 ,the ,origin of ,species 7,murray74 ,cheap edition1 #as4 ,,chapter ,,xvi4 ,,the ,,development ,,and ,,education ,,of ,,the ,,chick4 #eb4 ,a ,,hen',s ,,egg4 ,obtain three or four hen's-eggs1 and make the following observations upon them3 #a4 ,external appearance4--,what is the colour of the egg8 ,what is its shape8 ,how does the shape differ from that of a cricket ball or other sphere8 ,the shape of an egg is said to be ovoid4 ,what is the difference between an ovoid and an oval8 ,measure1 with a tape1 the length and breadth of the egg1 and also its distance round1 7i7 in the direction of its greatest length1 7ii7 in the direction of its greatest width4 ,what advantages has this shape8 ,could a hen sit so comfortably upon her eggs if they had sharp corners8 ,put an egg upon the table and roll it gently4 ,does it roll in a straight line8 ,does it roll far before coming to rest8 ,compare the rolling of a cricket ball or other sphere4 ,is it an advantage that an egg is not likely to roll far1 or in a straight line8 ,why8 #b4 ,the strength of the shell4--,hold an egg with your thumb at one end and your first or second finger at the other1 and press exactly in the line of the length of the egg4 ,you cannot break the shell4 #c4 ,structure4--7a7 ,the shell4--,tap the egg gently at the middle of its broad end until the shell cracks4 ,then carefully remove small pieces of the shell and notice the shell-membrane1 a tough skin which is closely applied to the inside of the shell4 ,snip through the membrane in the middle of the broad end2 notice the air-chamber which lies beneath it4 ,observe the inner membrane which separates the air-chamber from the inside of the egg4 ,hold a piece of shell up to the light1 and notice the small1 almost transparent dots4 ,the shell is perforated by very small pores1 through which the air can pass4 7b7 ,the white of the egg4--,tap the shell so as to crack it all round at its widest part2 raise bits of shell carefully and see the membrane here4 ,tear through the membrane and notice that in this region there is no air-space1 but the white lies just beneath the shell-membrane4 ,separate the halves of the shell1 notice the position and shape of the yolk1 and then let the contents of the egg fall gently into a basin4 ,observe the appearance1 colour1 and transparency of the white1 and try to distinguish two tangled cords of firmer white--the balancers 7,fig4 #ahe7--;arising close to the yellow yolk4 7c7 ,the yolk4--,what is the shape of the yolk as it lies in the basin8 ,how does it differ from the shape of a yolk suspended naturally in the white8 ,what is the cause of the change of shape8 ,notice carefully a small paler patch in the middle of the upper surface4 ,this is the lightest part of the yolk1 so that the yolk always settles with this part uppermost after any turning of the egg1 and therefore the pale patch is always more directly exposed to the heat of the hen's body 7during incubation7 than is any other part of the yolk4 ,prick the yolk and notice that the yellow1 fluid contents flow out4 ,you have evidently pierced the thin bag which formerly preserved the shape4 7d7 ,a hard-boiled egg4--,boil an egg in water for five minutes1 and then chip round the shell in the direction of the length and1 with a sharp knife1 cut the whole egg into halves along this plane4 ,make a drawing of the section1 indicating the shell1 shell-membrane1 air-chamber1 white1 and yolk in position4 ,observe that the white is no longer transparent and fluid1 but an opaque1 white1 and elastic solid4 ,try to peel off the white in layers4 ,they will probably break off short1 but you may be able to see that the white is deposited in spiral sheets around the yolk4 ,the hen's egg4--,a hen's egg bears a somewhat similar relation to the adult bird that the maize or bean seed 7,chapter ,i47 bears to the adult plant2 for the egg contains 7#a7 a speck of living matter which little by little grows and becomes marked off1 by orderly arrangement1 to form the various regions and organs of the adult animal2 and 7#b7 a store of food1 which enables the young chick to develop in security1 without being hampered1 whilst still weak and helpless1 by the necessity of earning its own living4 ,the changes by which the speck of living matter becomes the perfect chick will be considered in the next section4 ,we must now examine the structure of the egg itself1 and see what provision it contains for the nourishment and safety of the developing bird4 ,the egg is ovoid in shape1 one end being distinctly broader than the other4 ,this shape has the advantage of preventing the egg from rolling very far when placed upon a slightly inclined surface1 and it is worthy of notice that the eggs of birds which lay on cliffs and other exposed situations are usually more elongated and pointed than others1 so that when stirred they do not roll away1 but simply describe a small circle and come to rest again4 ,in the case of eggs which are laid in cup-shaped nests 7,fig4 #aig7 the pear-shape lends itself to close packing1 and thus allows the eggs to be more easily kept warm by the parent bird4 ,the shell 7sh41 ,fig4 #ahe7 is composed of a chalky material1 and is perforated by small pores1 through which the developing chick obtains fresh oxygen from the air1 and gives off its surplus carbon dioxide 7p4 #bdb74 ,a small piece of shell easily snaps1 but the shape of the complete shell so distributes an outside pressure1 especially one in the direction of the long axis1 that relatively great force is required to break it4 ,the shell is lined by a thin1 parchment-like membrane 7sh4 m474 ,at the broad end of the egg this membrane is double1 and the two layers enclose an air-chamber 7a74 ,inside the shell-membrane are the white or albumin1 and the yolk4 ,the white 7alb47 is a viscous1 transparent fluid4 ,its innermost part 7alb471 which immediately surrounds the yolk1 is of thicker consistency than the rest1 and is prolonged into two twisted cords called the balancers 7ch471 which suspend the yolk in position4 ,illustration3 ,,fig4 #ahe4--,semi-diagrammatic view of a fowl's egg at the time of laying4 a1 air-space2 alb1 dense layer of albumin2 alb1 more fluid albumin2 bl1 germinal disc2 ch1 balancers2 sh1 shell2 sh4m1 shell-membrane2 sh4m #a1 sh4m #b1 its two layers separated to enclose air-space2 yk1 yolk4 7,after ,marshall47 7 #a47 ,the yolk is a golden-yellow fluid enclosed in a thin1 elastic membrane and hence preserving a spherical shape4 ,on its upper surface 7but under the membrane7 is a small circular patch 7bl47 of paler colour4 ,this patch1 called the germinal disc1 is about 0 in diameter2 it contains the living matter from which the chick will be formed2 the rest of the yolk1 and the white1 are simply a store of inert food which is used up by the growing chick4 ,the work of the balancers4--,in order that the small living patch of pale yolk1 the germinal disc1 may grow and develop into the chick it must be kept warm4 ,when eggs are hatched in the natural manner1 the heat is supplied by the body of the sitting hen1 and the upper part of the egg is consequently kept warmer than the rest4 ,it is important that the living part of the egg shall always lie nearest the hen's body and thus be kept warm1 and this is secured by an arrangement as effective as it is simple4 ,the yolk is lightest in the neighbourhood of the germinal disc1 and therefore always lies with this part uppermost4 ,if the egg is slowly turned over1 the yolk remains 8right side up40 ,if it is turned over quickly1 the yolk soon swings round into its original position4 ,the twisted cords of white1 the balancers1 not only sling up the yolk and guard it from being thrown to one side by a sudden movement1 but they also prevent it from rotating too quickly--and so possibly injuring the delicate body of the young chick--when it rights itself after the egg has been turned over4 ,the balancers are rendered necessary by the hen's habit of turning her eggs two or three times a day4 ,it is often supposed that the eggs are turned in order to keep them equally warm on all sides1 but this is unnecessary4 ,most probably the egg is turned in order to alter slightly the young chick's position from time to time1 and allow its parts to grow naturally1 unimpeded by the other contents of the egg4 #ec4 ,,the ,,development ,,of ,,the ,,chick4 #a4 ,a simple incubator4--,eggs are best incubated in the natural manner1 that is1 by the warmth of the hen's body2 but if a sitting hen cannot be obtained1 an ordinary water-oven1 such as is used in chemical laboratories1 may be made to answer4 ,it should be heated by a self-regulating burner1 and kept at a temperature of about #dj ,c4 ,the eggs should be turned two or three times a day1 and the air of the oven should be kept moist by sprinkling water upon pieces of cloth1 blotting paper1 or hay1 kept with the eggs4 ,spring is the most favourable time of the year for making the observations1 as eggs laid at other seasons are not always in a condition to produce chicks4 #b4 ,how to mark the eggs4--,the most instructive changes take place during the first five days of incubation4 ,if all the stages of the first five days are to form the subject of one lesson1 an egg should be marked 8#e0 with pencil1 and then put into the incubator or under the hen five days before the lesson2 a day later1 an egg numbered 8#d0 should be put in1 and so on4 ,the numbers will then indicate the length of incubation at the time of the lesson1 and the eggs should be examined in order1 from #a to #e4 ,if one egg is to be examined each day1 five should be put in the incubator at the same time2 no numbering will then be required4 #c4 ,how to examine the eggs4--,have ready a basin of water1 heated slightly above the temperature of the hand 7i4e4 to about #dj ,c471 and dissolve table-salt in it in the proportion of a level teaspoonful of salt to a pint of water4 ,the young chicks will keep alive longer in this solution than in ordinary water4 ,tap the shell in the middle of its broad end1 and open the air-chamber 7a1 ,fig4 #ahe7 completely4 ,then crack the shell in the middle of the length and1 keeping the length of the egg horizontal1 cut transversely round the middle of the shell with scissors in a vertical plane1 until the halves are on the point of coming apart4 ,then lower the egg into the warm saline solution1 pull the halves of the shell apart1 and float out the contents4 ,examine the embryo carefully1 making out as much as possible1 and then snip round it with a pair of fine scissors to remove it from the yolk2 float it into a watch-glass and cover it with weak alcohol 7equal parts of water and spirits of wine74 ,examine it with a lens4 ,after it has remained for a day in weak alcohol1 put the embryo into strong alcohol in a small bottle 7writing the age on a label71 and preserve it4 ,notice the gradual absorption of the white of the egg as development proceeds4 #d4 ,chick after one day's incubation4--,notice that the embryo is now to be distinguished as a streak crossing the germinal disc in a direction at right angles to the long axis of the egg4 ,notice a rounded swelling at one end of the embryo2 this is the head4 ,place the egg before you with the broad end to your left1 and observe that the head of the embryo points away from you4 #e4 ,chick after two days' incubation4--,observe the increase in size of the embryo2 make a note of its length4 ,the head and neck of the embryo are now almost covered by a very thin transparent bag which has grown over it from the sides4 ,this bag is called the amnion2 it is filled with fluid1 and protects the embryo from jars4 ,remove the amnion and notice the large head2 it is now twisted so that its left side lies against the yolk1 while the rest of the embryo still lies 8face-down40 ,observe the large eye on the right side of the head2 the left eye cannot be seen without turning the head over4 ,notice the heart1 a small red dot which by help of a lens can be seen to beat rapidly4 ,surrounding the embryo is a circular network of blood-vessels which bring food from the yolk to the heart1 to be distributed to the various parts of the body4 ,how large is the circular area of blood-vessels8 #f4 ,chick after three days' incubation4--,the white of the egg is distinctly shrunken1 and the network of blood-vessels is much larger than before4 ,remove the amnion and notice the marked increase in size of the embryo1 especially of the head4 ,the right side of the head and neck are still turned towards the shell4 ,they are now quite free from the yolk1 but the body of the embryo communicates with the yolk by a short1 wide tube1 the yolk-stalk4 ,try to see a small pit1 a little above and behind the large eye4 ,this is the beginning of the right ear4 ,measure the embryo and the width of the surrounding network of blood-vessels4 ,watch1 through a lens1 the beating of the heart4 #g4 ,chick after four days' incubation4--,carefully cut open the amnion to see the embryo better4 ,observe that the young chick is still more completely folded off from the yolk1 and that the yolk-stalk is consequently narrower than before4 ,the head is so strongly bent upon itself that the snout almost touches the tail4 ,the body also has now turned over so as to lie with its left side on the yolk4 ,observe the two pairs of small buds which are the rudiments of the limbs4 #h4 ,chick after five days' incubation4--,cut open the amnion1 and notice the great increase in size of the embryo1 and especially the enormous development of the head4 ,the limbs now show signs of division into segments4 ,observe1 under the hinder end of the body1 a small1 bladder-like outgrowth1 the allantois1 which in the later stages grows rapidly and spreads all round the inside of the shell4 ,it is the breathing organ of the chick4 #i4 ,effect of varnishing an egg4--,varnish an egg1 and leave it under the hen with unvarnished eggs for the whole period of incubation 7#ba days74 ,the varnished egg does not develop1 because the varnish closes the pores of the shell and prevents the embryo from breathing4 ,illustration3 ,,fig4 #ahf4--;,hen's ,egg after #a day's incubation4 a1 air-chamber2 hd1 head of embryo2 v4a41 area in which yolk blood-vessels will appear later2 yk1 yolk4 7 #a47 ,the early development of the chick4--,when the hen's egg is exposed to a temperature of about #dj;,c41 the germinal disc--the circular patch of living matter which lies1 somewhat like a small inverted watch-glass1 upon the upper surface of the yolk--grows larger1 and its parts are gradually modified to form the various regions of the chick's body4 ,the white and yolk of the egg are used up during the process1 and by the time they are absorbed1 the young bird is in a condition to break the shell and take up the activities of an independent life4 ,to watch the orderly appearance and gradual development of the different systems of organs is most fascinating1 and fortunately the observation of the main features presents no great difficulty if the foregoing instructions are followed4 ,the first signs of the chick are to be seen 7,fig4 #ahf71 towards the end of the first day of incubation1 in a streak which crosses the germinal disc in a direction at right angles to the long axis of the egg4 ,one end of the streak is distinctly rounded1 and this is the head end 7hd474 ,in almost all cases1 if the egg be placed so that its broad end is to the observer's left1 the head of the embryo will be directed away from him4 ,a day later1 the embryo is markedly larger1 and is partly covered by a double membrane called the amnion4#ag ,surrounding the embryo is now 7,fig4 #ahh7 a network of fine blood-vessels which ramify over the yolk and carry small particles of yolk to feed the growing organs4 ,at the end of the second day the network could be about covered by a sixpenny piece4 ,on each side1 its veins join to form a single small tube running to the heart 7ht471 a tiny red dot which is situated behind the head and can be seen1 by the help of a lens1 to be beating rapidly4 ,the head has grown more than the rest of the embryo1 owing to the rapid development of the primitive brain1 and is bent forwards4 ,the head has turned over a little1 so that its right side is directed towards the egg-shell2 the rest of the embryo still lies 8face-down40 ,the right eye 7e47 can easily be seen as a dark spot on the side of the head4 ,illustration3 ,,fig4 #ahh4--;,hen's ,egg after #b days' incubation4 ,the amnion has been removed4 a1 air-chamber2 au1 beginning of right ear2 e1 right eye2 ht1 heart2 v4a41 network of yolk blood-vessels2 yk1 yolk4 7 #a47 ,by the end of the third day 7,fig4 #ahi7 the head and neck are raised distinctly above the yolk1 and the tail is also more plainly marked off1 so that the body is connected with the yolk only by a short wide tube1 the yolk-stalk 7yk4st41 ,fig4 #ahg1 ,b74 ,the neck as well as the head has now turned so as to lie with the right side directed towards the shell4 ,the commencement of the ear is to be seen on each side as a small pit 7au47 a little above and behind the large eye4 ,illustration3 ,,fig4 #ahi4--;,hen's ,egg after #c days' incubation4 ,the amnion has been removed4 ,references as in ,fig4 #ahh4 7 #a47 ,illustration3 ,,fig4 #aij4--;,chick ,embryo after #d days' incubation4 ,the amnion has been removed4 all1 allantois2 am1 cut edge of amnion2 f4l41 fore-limb2 h4l41 hind-limb2 ht1 heart2 t1 tail4 7,after ,duval47 7 #b47 ,on the fourth day the embryo turns to lie entirely on its left side4 ,it becomes more completely folded off from the yolk1 and the connecting yolk-stalk is a narrower tube than before4 ,the previously formed organs increase in size and complexity4 ,the disproportionate size of the head1 owing to the great development of the brain1 is still more marked than before1 and the head is so strongly bent upon itself that the snout almost touches the tail4 ,one of the most noteworthy features of the fourth day is the appearance of the limbs4 ,as yet these are merely a pair of small buds 7fl41 hl41 ,fig4 #aij71 and no joints can be detected in them4 ,illustration3 ,,fig4 #aia4--;,hen's ,egg after #e days' incubation4 a1 air-chamber2 all1 allantois2 am1 amnion2 ar4 vasc41 area of yolk blood-vessels2 emb1 embryo2 yk1 yolk4 7,after ,duval47 7 #a47 ,illustration3 ,,fig4 #aib4--;,diagrams illustrating the method of development of the allantois4 al1 allantois2 am1 amnion fold2 am4c41 amniotic cavity2 em1 embryo2 yk1 yolk4 7,after ,foster and ,balfour47 ,by the end of the fifth day 7,fig4 #aia7 the head is enormous1 and the limbs now show signs of being divided into definite segments4 ,a thin bladder-like structure--the allantois 7all471 which appeared on the fourth day--has grown out from the lower part of the body1 behind the yolk-stalk4 ,its mode of origin is well shown in ,fig4 #aib4 ,it rapidly increases in size1 and soon extends over the embryo 7,figs4 #aib ,b1 and #aia7 and becomes closely applied to the shell-membrane4 ,air passes through the pores of the shell1 and its oxygen is taken up by the blood which circulates in the vessels of the allantois4 ,at the same time1 waste carbon dioxide is able to escape from the blood to the outer air4 ,the allantois is therefore the breathing organ of the developing chick4 ,if the egg is varnished and the shell thus rendered air-tight1 the embryo dies of suffocation at an early stage4 ,illustration3 ,,fig4 #aic4--;,chick after #i days' incubation4 7,after ,duval47 7 #a47 ,the chief organs of the bird are now established1 and the later development may be sketched more briefly4 ,by the end of the ninth day 7,fig4 #aic7 the white of the egg is almost used up2 the yolk1 however1 is still large1 and is connected with the chick's body by the narrow yolk-stalk4 ,it thus appears that the white is not directly absorbed by the chick1 but is first taken up by the yolk and afterwards passed on by the yolk blood-vessels which run to the heart4 ,by this time1 too1 the allantois has spread at least halfway round the inside of the shell1 that a supply of oxygen adequate to the increased needs of the animal may be obtained from the air4 ,the chick has now a characteristic bird-like appearance2 the beak has appeared2 feathers have begun to sprout2 the neck is long and slender2 and the segments of the limbs1 including the fingers and toes1 are well defined4 ,about the fourteenth day the chick turns so as to lie lengthwise in the shell1 with its head near the broad end4 ,the yolk-sac dwindles in size1 and at last1 about the twentieth day1 it is drawn into the interior of the body4 ,now the chick becomes restless1 and--usually on the twenty-first day--thrusts its beak through the inner shell-membrane into the air-chamber at the broad end of the egg4 ,for the first time it draws refreshing air into its lungs1 and is stimulated to break the shell by a knob on its beak1 and to creep out into the world4 #ed4 ,,the ,,education ,,and ,,later ,,growth ,,of ,,the ,,chick4#ah #a4 ,hatching4--,on the #bjth or #bast day of incubation remove three or four eggs from the clutch under the hen1 and keep them in a warm cosy place so that you may watch the process of hatching4 ,can you hear the chick tapping the inside of the shell8 ,could it have been taught to tap8 ,which part of the shell cracks first8 ,when the shell has cracked1 can you hear the chick chirping8 ,could it have been taught to chirp8 ,imitate the chirp and listen for a response4 ,keep the newly-hatched chicks in a warm1 soft place4 ,how soon do they recover from the exhaustion of hatching8 ,do the chicks show a liking for warm corners8 ,are they afraid of being touched gently8 #b4 ,locomotion4--,how soon do the chicks begin to run about8 ,do they stumble upon obstacles1 or do they avoid or leap over them8 ,do they use their wings in running1 or in jumping down a small step8 ,put a chick into a basket1 and lower the basket quickly through the air1 being careful not to let the chick fall out4 ,does it move its wings8 ,how8 #c4 ,feeding and drinking4--,lay a few grains of soaked wheat upon the ground before a chick which has not yet been fed4 ,does it peck at them instinctively8 ,tap a grain with the point of a pencil2 does the chick now peck at it8 ,does it hit the grain at the first try8 ,does it ever strike at a grain which is out of reach8 ,watch a hen with her chicks2 does she teach them to peck at food8 ,how8 ,do the chicks know instinctively the difference between food and grains of sand1 or have they to learn8 ,try if a chick can distinguish between a small worm and a bit of red worsted4 ,are young chicks afraid of large insects8 ,take a chick1 which has not yet drunk1 to a small pool 7a few drops7 of water4 ,does it seem to know the use of the water8 ,induce it to peck at the water2 does it now drink8 ,how8 #d4 ,the crouching-instinct4--,clap your hands suddenly and loudly near young chicks4 ,how do the chicks behave8 ,does this behaviour render them less conspicuous8 #e4 ,non-recognition of hen4--,having made the above observations on chicks hatched apart from the hen1 put the chicks among their brothers and sisters with the parent hen4 ,do the new-comers respond1 as readily as the others1 to the clucking1 etc41 of the hen8 #f4 ,maternal training and protection4--,how many different meanings can you recognise in the different sounds of the hen's voice8 ,how does she call and protect the chicks when any danger threatens them8 #g4 ,the voice of the chick4--,notice the different sounds by which a chick expresses pleasure1 alarm1 distress1 etc4 #h4 ,preening and scratching4--,at what age do chickens begin to preen their feathers1 and to scratch the ground8 ,try to discover if these are instinctive activities1 or whether they have to be learnt from the hen4 #i4 ,change in plumage4--,at what age are the down feathers replaced by the true plumage8 ,at what age is it possible to distinguish the young cocks from the young hens8 #aj4 ,external characters1 etc41 of adults4--,notice the flowing tail-feathers1 hackles 7the long feathers on the neck and loins71 comb1 and spurs of the cock-birds1 and their absence or small size in the hens4 ,what differences are there as regards voice8 ,how does the hen announce that she has laid an egg8 ,which sex is the more pugnacious8 ,the recently hatched chick4--,the newly-hatched chick is clothed with fine down-feathers 7pp4 #bgc and #bgg74 ,it is generally exhausted by its struggles to escape from the shell1 but it soon recovers1 and is able to run about freely on the second day after hatching4 ,young birds which1 like the chick1 are active immediately after hatching1 are said to be precocious4 ,instinct and education4--,from the first1 the chick performs certain movements which are obviously instinctive1 that is1 which have not been acquired by any process of imitation or instruction4 ,even in the egg1 it may be heard chirping soon after it has taken its first breath of air2 and the complex activities of walking1 running1 jumping over obstacles1 and1 later1 preening the feathers and scratching the ground--each of which involves the nicest adjustment of several muscles--are also instinctive4 ,certain other powers have to be learnt2 the hen1 for example1 lifts and drops before the chick a particle of food which she wishes it to seize1 and it soon learns to peck4 ,at first its pecks generally fall a little short of the objects1 but presently it becomes very adroit at catching food4 8,a chick a day or so old will catch a running fly at from the seventh to the twelfth shot40#ai ,there does not appear to be much instinctive recognition of the difference between objects which are valuable as food and those which are the reverse4 ,such discrimination comes only by experience1 and to a very young chick a piece of red worsted and a small worm are equally attractive before being seized4 ,in the same way1 the nature of water has to be learnt4 ,chicks peck at drops of water1 but do not seem to know the use of water until their beaks are wetted1 when they drink instinctively in the usual manner4 ,the use of the wings is also a matter of instinct1 but it is acquired somewhat late1 and is assisted by parental encouragement and example even in birds which are noted for their powers of flight4 ,fowls do not fly much1 but chicks may be observed to use their wings as an aid in running or jumping4 ,prof4 ,lloyd ,morgan#bj quotes an interesting experiment which shows well how deeply the reliance on flight is stamped in bird-nature4 8,if a chick a day or two old be placed in a basket1 held firmly in the hand1 and then lowered rapidly through the air1 the fledgling will stretch out his little immature wings in such an attitude as would make them break the fall were they fully developed2 or will1 if he be a little older1 flap them with flight-like action1 in either case showing an instinctive response40 ,hens and chickens4--,chickens which have been hatched in the natural manner are1 from the first1 under the control of the hen 7,fig4 #aid71 and her anxious care for their welfare has always been considered one of the most beautiful examples of the maternal instinct4 ,in their defence her courage is unbounded2 should she discover a succulent worm or other dainty morsel1 her ordinary complacent cluck changes to a note of invitation1 to which the brood at once responds2 and at her danger-signal the chickens run to take refuge under her wings1 or crouch motionless against the ground4 ,the chirp of a chick also is capable of expressing several states of feeling1 such as contentment1 pleasure1 alarm1 and distress4 ,these different notes are not only perfectly intelligible to the hen1 but are familiar to anyone who has had experience of poultry4 ,illustration3 ,,fig4 #aid4--;,hen and ,chickens4 ,in the face of these well-known instances of the perfect understanding between the hen and her chickens1 it is somewhat surprising to find that chickens1 hatched apart from the hen and then placed with the rest of the brood after a few days1 at first pay very little attention to the hen1 except for their instinctive tendency to nestle into warm places1 and do not seem to understand her clucks4 ,adult fowls4--,the down-feathers are soon shed and replaced by the true plumage1 and the chicken gradually takes on the appearance of the adult4 ,a marked difference is generally to be seen between the cocks and hens 7,fig4 #aie7 of any breed of poultry4 ,the cock is usually provided with flowing tail-feathers1 hackles 7elongated feathers on the neck and loins71 a prominent comb1 and 8spurs0--features which are either absent or much less perfectly developed in the hens4 ,as great differences exist between the voices of the two sexes1 the crow by which the pugnacious male challenges his rivals1 and the cackle of the hen when she has laid an egg1 being familiar examples4 ,illustration3 ,,fig4 #aie4--;,cock and ,hens4 ,,exercises ,,on ,,chapter ,,xvi4 #a4 ,point out the differences in appearance and position between the white and yolk of a fowl's egg4 ,what becomes of each during the development of the egg8 #b4 ,when does the heart of a chick begin to beat8 ,describe its appearance at this time1 and explain what must be done to expose it to view4 #c4 ,explain exactly where the chick is to be found in a fertile egg which has been incubated for three days4 ,how big is a chick of that age8 ,of what colour is it8 ,does it give any signs of life8 7#ahih7 #d4 ,what is the amnion8 ,where1 in a developing chick1 is it to be found1 what is its appearance1 when and how is it formed1 and what is its use8 #e4 ,explain the nature and use of the 8balancers0 of an egg4 #f4 ,explain how a developing chick breathes4 #g4 ,what new organs are first seen distinctly on the fourth and fifth days respectively of incubation of a hen's egg8 ,explain exactly how you would expose them to view1 and describe their appearance4 #h4 ,what is the period of incubation of a duck's egg8 ,observe and describe exactly how the hatching duckling breaks open the shell and escapes from it4 #i4 ,observe and describe a duckling's first attempt to swim4 ,is the action instinctive or not8 #aj4 ,make other observations upon ducklings1 comparing them in as many respects as possible with chicks1 and write careful accounts of the results you obtain4 #aa4 ,how does a fowl's egg which has been hatched for four days differ from a fresh-laid egg8 ,describe the new structures which have formed in it1 so far as they can be made out by the unaided eye4 7#aijd7 #ab4 ,where does the chick begin to form in the egg8 ,explain the arrangement which brings it as near as possible to the body of the sitting hen4 7#aije7 #ac4 ,what is the use of the cloudy masses attached to opposite sides of the yolk of a fowl's egg8 7#aijf7 ,,footnotes3 #ag ,the amnion originates1 early in the second day1 as a double fold of the yolk-surface in front of the embryo4 ,similar folds arise round the sides and tail1 forming a low wall 7,fig4 #ahg1 ,a72 the folds gradually grow over the embryo 7,fig4 #ahg1 ,b7 until1 during the fourth day1 they meet 7,fig4 #ahg1 ,c7 and enclose it in a protective transparent bag1 containing a watery fluid4 ,illustration3 ,,fig4 #ahg4--;,diagrams to illustrate the method of development of the amnion4 ,the embryo and the rest of the yolk are supposed to be seen in median longitudinal section2 the head end is to the right4 ,for convenience1 the yolk-membrane 7yk4m47 is represented at some distance from its contents4 am1 folds of amnion2 am4c41 amniotic cavity2 em1 embryo2 yk1 yolk2 yk4st41 yolk-stalk4 7,after ,foster and ,balfour47 #ah ,i desire to acknowledge my indebtedness1 in drawing up this section1 to ,prof4 ,lloyd ,morgan's ,habit and ,instinct 7,arnold74 #ai ,lloyd ,morgan's ,habit and ,instinct 7,edward ,arnold74 #bj ,lloyd ,morgan's ,habit and ,instinct 7,edward ,arnold74 ,,chapter ,,xvii4 ,,some ,,familiar ,,british ,,birds4 #ee4 ,,the ,,thrush ,,family4 #a4 ,the song-thrush1 mavis1 or throstle4--,throstles are to be seen throughout the year4 ,take every opportunity of observing their habits1 and make careful notes of these at the time4 ,especially attend to the following characters3 7a7 ,general appearance4--,what is the average size of the bird8 ,what is the length of the tail8 ,at what angle is the tail held8 ,does the bird move it in any special manner8 ,what is the prevailing colour of the body8 ,notice the light-coloured and spotted breast4 ,compare the male and female as regards size1 colouration1 etc4 7b7 ,habits4--,what situations do throstles chiefly inhabit8 ,do they keep near the edge of the wood1 or have you often seen them inside thick woods8 ,does the bird hop1 or walk1 when on the ground8 ,upon what does it feed8 ,have you ever seen it cracking the shell of a snail8 ,if you find a heap of snail-shells near a stone1 watch1 at a little distance1 for the throstle coming to crack snail-shells on the stone4 ,does it also eat worms1 or fruit8 ,describe a throstle's beak4 ,how would you describe the flight--as high or low1 swift or slow1 straight1 in wide curves1 or undulating8 ,does the bird perch on trees8 ,how does it use its toes in perching8 7c7 ,song4--,in what months does the throstle sing8 ,does it sing late at night and early in the morning8 ,how does it compare with other birds in this respect8 ,in what positions have you seen the bird singing--when flying1 perching1 or on the ground8 ,try to write down the syllables which seem to you most like the throstle's song1 and notice how the phrases are repeated4 ,notice that throstles sing less during ,august than in autumn4 ,listen1 in ,september or ,october1 for young thrushes learning to sing1 and contrast their efforts with the song of the adult birds4 7d7 ,the nest4--,at what time of the year do throstles pair and build their nests8 ,in what situations have you found the nests8 ,write a description of the shape1 size1 and materials of the first throstle's nest you find4 ,visit it frequently1 try not to disturb the birds1 and note the dates of laying of the eggs4 ,how many eggs are laid8 ,what are their size and colour8 ,how are they arranged in the nest8 ,do the broad or the narrow ends point inwards8 ,what are the advantages of this arrangement 7i7 for purposes of packing1 7ii7 when the eggs hatch8 ,do both birds sit on the eggs8 ,if only one1 which8 ,what is the time of incubation8 7e7 ,the young4--,are the young birds naked and helpless1 or feathered1 at hatching8 ,how do the parent-birds feed them8 ,what is the appearance of the fledglings8 ,in what respect do they 7i7 resemble1 7ii7 differ from1 the parents8 ,how long do the birds remain in the nest after hatching8 ,write an account of any education you have observed them to receive from the parents4 ,make similar observations and notes on other birds1 in addition to the special observations mentioned below1 and learn to recognise their appearance1 flight1 song1 nest1 and eggs4 ,a field-glass will be found of great assistance4 #b4 ,the missel-thrush1 or storm-cock4--,compare the missel-thrush with the song-thrush4 ,notice its larger size1 the brighter colour of its spotted breast1 and its somewhat less musical song4 ,listen for its song during1 or immediately after1 a storm1 even in winter4 ,in the nesting season observe the marked courage and pugnacity of the bird4 #c4 ,the blackbird4--,compare the blackbird with the thrushes in respect of appearance1 food1 habits1 and song4 ,notice the difference in the colouration of the male and female blackbird4 ,observe that the young bird has a spotted breast like that of a thrush1 but that old blackbirds are not spotted4 ,have you noticed a blackbird show a preference for singing in any particular place8 ,what observations would lead you to suppose that the blackbird is a near relative of the thrushes8 #d4 ,fieldfares4--,distinguish these birds from thrushes4 ,notice that they arrive about ,october1 and frequent fields in large parties4 ,the thrush family4--,for many reasons the thrush family forms a convenient starting point in the study of the habits of common ,british birds4 ,it includes some of our very finest songsters and therefore most popular birds2 many of its members are abundant in most parts of the country1 so that nearly every student has the opportunity of observing them at first hand2 the birds are not specially shy2 and1 lastly1 the family affords excellent material for the method of comparison and contrast1 which1 be it repeated1 is the essence of all sound work in nature-study4 ,the song-thrush1 which is also known as the throstle and mavis1 is a shapely bird1 easily recognisable by its grey1 spotted breast 7,fig4 #aif71 which may be seen all the year round in wooded parts of the country4 ,the male and female are very similar in appearance1 and of almost equal size1 measuring #h or #i inches from head to tail4 ,the thrush generally feeds on the ground1 hopping along on a pair of sturdy legs and feet1 seizing and pulling out worms which incautiously show themselves at the mouths of their burrows1 and catching insects and snails4 ,a thrush usually has a favourite stone on which it cracks the shells of snails1 and it is not uncommon to find1 near the stone1 a little heap of broken snail-shells--the remains of many a feast4 ,in winter1 when the summer diet can no longer be obtained1 the thrush subsists largely upon the fruit of hawthorn1 mistletoe1 etc4 ,its beak1 as is usual with birds1 is distinctly adapted to the capture of its food1 being1 in this case1 narrow1 round1 and fairly long4 ,the thrush is a strong and rather rapid flier4 ,illustration3 ,,fig4 #aif4--,song-,thrush4 7 74 ,thrushes begin to sing at the first signs of spring1 pairing and commencing the work of nest-building in ,february or early ,march4 ,the throstle's song is surpassed by very few birds2 and many people consider it equal1 if not superior1 to the nightingale's4 ,the song begins before sunrise1 and may be heard when almost all other birds have retired to rest4 ,the thrush has a curious habit of repeating each strain two or three times1 8lest10 as ,browning says1 8you should think he never could recapture the first fine careless rapture40 ,many attempts have been made to imitate the song by words2 ,mr4 ,r4 ,kearton#ba quotes with approval the following rendering by the famous ,scottish naturalist ,macgillivray3 8,qui qui qui kweeu quip1 ,tiurru tiurru chipiwi1 ,too-tee1 too-tee1 chiu choo1 ,chirri chirri chooee ,quiu qui qui40 ,but1 as ,mr4 ,kearton remarks1 8no human words can ever represent1 especially in cold type1 the passionate vehemence1 the sprightliness1 or the tender pleading of a thrush's song40 ,illustration3 ,,fig4 #aig4--,nest of ,song-,thrush4 7 74 ,the nest of the thrush 7,fig4 #aig7 is a massive structure1 deep and cup-shaped1 and open at the top4 ,it is built of small twigs and grass1 and is plastered with mud or cow-dung until the inside is smooth and hard4 ,it is usually placed in an evergreen bush or tree1 but may also be found in cavities in tree-trunks or in holes in walls1 or even in sheltered places on the ground4 ,the eggs number from #d to #f2 they are about an inch long1 are sky-blue in colour1 and marked with black spots1 which are most numerous near the thick end4 ,the eggs are arranged with their pointed ends inwards2 this method not only allows them to be packed more closely together and therefore to be more easily covered by the sitting bird1 but is also of convenience at the time of hatching1 as the young birds usually emerge 7p4 #bid7 at the thick end4 ,the eggs hatch after a fortnight's incubation4 ,the young thrushes are at first blind1 almost naked1 and are quite helpless4 ,they make rapid progress1 however1 and are sufficiently fledged to leave the nest in about a fortnight after hatching4 ,the fledgling throstle 7,fig4 #aih7 is lighter in colour than the adult1 and much more distinctly spotted4 ,in ,october the young birds may be heard learning to sing2 their first efforts are hesitating and uncertain1 but by tireless practice and careful imitation of the old birds they presently come into full possession of their delightful powers4 ,illustration3 ,,fig4 #aih4--,young ,song-,thrushes in ,nest4 ,the missel1 or mistletoe1 thrush 7,fig4 #aii7 much resembles the song-thrush in appearance and manner of life1 but is distinctly larger1 measuring about #aj inches from head to tail4 ,it has a very pleasing song1 which may be heard1 even in the depth of winter1 when all other song-birds are mute4 ,the missel thrush's habit of singing vigorously during storms has led to its alternative name of 8storm-cock40 ,the bird is noted for its pugnacity in the breeding season1 and for the courage with which it defends its nest and young2 any other birds approaching the nest are promptly attacked and driven to a distance4 ,the nest is generally built in a tree1 where a branch springs from the trunk4 ,it is made of dried grass1 moss1 and wool1 and the hen lays from #d to #f pale-green eggs1 which are speckled with brown4 ,illustration3 ,,fig4 #aii4--,mistletoe-,thrush4 7 47 ,illustration3 ,,fig4 #bjj4--;,blackbird 7,hen74 7 47 ,the blackbird 7,fig4 #bjj7 may easily be distinguished from the thrush by its colour--the male being black1 with a yellow beak1 and the female blackish brown1 slightly mottled below4 ,the blackbird is slightly larger than the thrush1 but in shape and habits the two birds are very similar2 they haunt the same woods1 live upon similar food 7i4e4 worms1 insects1 snails and1 in winter1 fruit7 and build their nests in similar situations4 ,the blackbird's song is1 however1 quite distinctive1 and consists of mellow1 flute like notes1 without the repetition which is so characteristic of the throstle and missel-thrush4 ,the blackbird is fond of perching1 when singing1 upon a bare branch which commands a good view of the surroundings4 ,the nest 7,fig4 #bja7 is much like that of the song thrush1 but the inside has a soft lining of fine grass instead of being hardened with mud4 ,the #d1 #e1 or occasionally #f eggs are bluish-green in colour1 and are marked with blurred brown spots4 ,illustration3 ,,fig4 #bja4--;,blackbird's ,nest4 ,curiously enough1 young blackbirds1 like young thrushes1 are very distinctly spotted4 ,there can be no doubt that blackbirds and thrushes are descended from the same stock1 and that their ancestors had spotted breasts4 ,for some reason1 the blackbird has lost its family colours1 although1 as is so often the case among animals1 it is still compelled to bear the marks of its ancestry during its infancy4 ,young blackbirds also receive a musical education from their parents1 and may often be heard practising their song in ,september or ,october4 ,the fieldfare1 another near relative of the thrush1 arrives in this country about the beginning of ,october1 and stays with us for the winter1 returning in spring to its nesting places among the pines and firs of ,norway4 ,the general colour of the bird is grey1 with reddish-brown on the wings1 and its breast is speckled in the thrush-manner4 ,fieldfares frequent fields in large parties1 especially in the evenings1 but are readily alarmed4 ,other birds of the thrush family4--,the redwing1 wheat-ear1 whin-chat1 stone-chat1 redstart1 robin1 nightingale1 and hedge-sparrow are other members of the thrush family which can here be only referred to4 ,they have many points of resemblance1 one of the most interesting of which is that the young birds are invariably spotted4 ,the bill is usually rather long1 stout1 and straight1 the staple food being insects1 worms1 etc41 though fruit is also eaten1 especially in winter4 ,the nests are typically cup-shaped1 and the eggs greenish or blue1 with or without spots4 ,the young birds are quite helpless and almost naked when hatched1 and can only open their mouths to be fed by the parents4 ,even after they have left the nest they need careful and continuous teaching by the parents before they can be made to understand that in future they will have to obtain their own food4 ,birds of this family1 on account of the variable character of their food1 are not so markedly migratory as many others1 although they generally move further southward in winter1 as the supply of insects becomes scarce--their place being taken by birds which have spent the summer in more northerly regions4 ,this habit is very obvious in the case of the fieldfare and redwing1 which visit us for the winter and return to ,norway and ,sweden for the summer4 ,the nightingale1 on the other hand1 arrives here from the south in ,april to build its nest and rear its young4 #ef4 ,,the ,,swallow ,,family1 ,,the ,,skylark1 ,,and ,,crows4 #a4 ,the swallow4--7a7 ,general appearance4--,notice1 first of all1 the bird's colouration1 as this readily distinguishes the swallow from the martins4 ,the whole of the upper surface is steel-blue2 the only white is on the ventral surface4 ,a black band stretches across the breast2 the throat and forehead are pink4 ,observe the long1 deeply forked tail1 and the broad1 short bill4 7b7 ,habits4--,what are the earliest and latest dates on which you have seen swallows8 ,do the birds seem to prefer the neighbourhood of water8 ,have you ever seen them 7i7 perching on trees1 7ii7 on the ground8 ,why do swallows occasionally alight on the ground8 ,do they seem comfortable on the ground8 ,observe the small and weak feet2 are these adapted to a terrestrial life8 ,do swallows feed on the ground8 ,what do they eat8 ,how are the insects caught8 ,what is the advantage of the very wide gape8 ,how would you describe the flight of the swallow8 7c7 ,voice4--,does the swallow sing8 ,describe its voice4 ,have you heard it when the bird was on the wing1 or only when it was at rest8 ,what kind of sound is uttered by the swallow when it is alarmed or angry8 7d7 ,nest4--,in what situations have you found swallows' nests8 7,do not confuse the nest with that of the house-martin1 which lays white1 unspotted eggs47 ,how soon after their arrival do the birds begin to build8 ,what is the shape of the nest8 ,of what materials is it composed8 ,how many eggs does it contain8 ,what is their colour8 7e7 ,young4--,look for the newly-hatched young about the last week in ,june1 and describe their appearance4 ,how soon after hatching do they leave the nest8 ,do they at once feed themselves1 or are they fed by the parents8 ,keep the nest under observation after the young birds have left it1 and notice whether the old birds rear another brood the same summer4 ,in ,september look for the annual congregation of swallows which precedes their departure for ,africa4 #b4 ,the house-martin4--,distinguish the house-martin from the swallow by the patch of white on the upper tail-coverts 7,fig4 #agi71 and by the feathered toes4 ,make notes of the dates of arrival and departure of the birds4 ,do house-martins occupy old nests or build fresh ones8 ,what are the position1 material1 shape1 and size of the nest8 ,how does it differ from the swallow's nest8 ,is the martin of sociable or solitary habits8 ,watch the birds building new nests or repairing old ones1 and describe the process4 ,examine and count the pure-white eggs4 ,what are the newly-hatched young like8 ,how many broods have you known one pair of martins to rear in one season8 ,have you ever known martins to be turned out of their nests by sparrows8 ,watch for the autumn congregation4 #c4 ,the sand-martin4--,notice the small size of the bird1 the mouse-colour of the upper parts1 and the black feathers of the wings and tail4 ,note the dates of arrival and departure4 ,is the bird often seen near houses8 ,look for the nesting-holes in cliffs1 banks1 etc4 ,examine the holes1 and notice that they lead into tunnels which slope slightly upwards4 ,what is the use of the slope8 ,if possible examine the nest at the end of the tunnel1 and compare it and the eggs with those of the swallow and house-martin4 ,observe the peculiar jerky flight4 ,does the bird sing8 ,describe its voice4 #d4 ,the skylark4--,does the skylark frequent woods or open ground8 ,describe the appearance1 size1 and colouration of the bird1 and try to see the long toes4 ,especially notice the long claw of the hind-toe4 ,have you ever seen the bird perching on trees or bushes8 ,are the feet well adapted for perching8 ,does the skylark run or hop8 ,in what month does it begin to sing8 ,in ,march look for larks' nests in hollows and ruts of fields4 ,what are the materials of the nest8 ,describe the number and appearance of the eggs4 ,listen to the song1 and try to say in what respects it differs from that of other birds4 ,does the bird sing only when flying1 or also when on the ground8 ,describe the skylark's flight1 and study its method of soaring 7p4 #bgh74 ,observe that the birds collect into flocks in autumn4 ,do they leave the country for the winter8 ,how do they spend the winter8 ,do they sing in winter8 ,if possible examine the beak2 for what kind of food do you think it best adapted8 #e4 ,the rook4--,notice the size1 shape1 and colouration of the bird4 ,do rooks live merely in pairs or in large communities8 ,do they build on the ground or in trees8 ,are the trees high or low8 ,what is the largest number of rooks' nests you have seen in one tree8 ,watch the birds repairing and building nests in ,february and ,march4 ,of what are the nests composed8 ,have you ever seen rooks stealing sticks from other rooks' nests8 ,are the birds quarrelsome8 ,where do they feed8 ,do they hop or walk8 ,do they keep together when feeding8 ,do all the birds of one rookery feed at the same time1 or do some remain in the trees8 ,why8 ,what is the shape of the beak8 ,how is this associated with the food of the bird8 ,do the farmers in your neighbourhood consider rooks useful or the reverse8 ,why8 ,what is the voice of the rook like8 ,how does it vary to express warning1 anger1 etc4 ,describe any observations which lead you to suppose that a colony of rooks has a code of laws4 ,describe the flight of the rook2 what other birds fly in a somewhat similar manner8 ,in spring1 look beneath the trees for the broken shells of eggs which may have fallen from the nests4 ,what is their colour8 ,describe the appearance and habits of the young birds4 ,where do rooks spend the winter8 ,have you ever seen them visiting and inspecting their nests in winter8 #f4 ,other birds of the crow family4--,with the rook compare and contrast the crow1 raven1 jackdaw1 magpie1 and jay4 ,the swallow family4--,swallows and martins are popular with all lovers of birds1 for many reasons4 ,their arrival is welcomed as visible evidence of the approach of summer2 their graceful and rapid flight delights the eye2 their obvious liking for the neighbourhood of human dwellings wins our sympathy2 and1 lastly1 they claim our gratitude by their incalculable services in keeping down insect pests4 ,the swallow 7,fig4 #bjb7 may readily be distinguished from the martins by the absence of white from its upper parts1 which are glossy and of a steel-blue colour4 ,the forehead1 chin1 and throat are of a pink or chestnut colour2 the ventral surface is white1 with a black band crossing the neck4 ,the tail is long1 and very deeply forked4 ,the bill is short and broad1 and the gape stretches nearly to the eyes--a great advantage to a bird living on insects which are caught flying4 ,the feet are very small and weak1 but as the swallow spends most of its time in the air1 and rarely alights on the ground except to collect materials for its nest1 it does not need very sturdy hind-limbs1 and the feet are chiefly used for perching4 ,illustration3 ,,fig4 #bjb4--,the ,swallow4 7 47 ,swallows arrive in this country about the middle of ,april1 and about a month later proceed to build their nests in the chimneys of houses and on the rafters of barns and outhouses4 ,the nest is basin-shaped and open at the top2 it is chiefly composed of mud1 which the birds collect on the ground1 place in position1 and allow to dry4 ,short straws are used to bind the mud together1 and the nest is lined with soft grass and feathers4 ,the hen lays from #d to #g eggs1 which are a translucent white1 with reddish-brown or grey markings4 ,the first brood of young is usually hatched about the end of ,june1 but a second or even a third brood may be raised before the parents depart for the south4 ,gilbert ,white#bb gives the following charming account of the training of young swallows3 8,for a day or two they are fed on the chimney-top1 and then are conducted to the dead1 leafless bough of some tree1 where1 sitting in a row1 they are attended with great assiduity1 and may then be called perchers4 ,in a day or two more they become flyers1 but are still unable to take their own food2 therefore they play about near the place where the dams are hawking for flies2 and1 when a mouthful is collected1 at a certain signal given1 the dam and the nestling advance1 rising towards each other1 and meeting at an angle2 the young one all the while uttering such a little quick note of gratitude and complacency1 that a person must have paid very little regard to the wonders of ,nature that has not often remarked this feat40 ,when the young bird has learnt to feed itself 8it at once associates with the first brood of house-martins2 and with them congregates1 clustering on sunny roofs1 towers1 and trees4444 ,all the summer long is the swallow a most instructive pattern of unwearied industry and affection2 for from morning to night1 while there is a family to be supported1 she spends the whole day in skimming close to the ground1 and executing the most sudden turns and quick evolutions4444 ,when a fly is taken a smart snap from her bill is heard1 resembling the noise at the shutting of a watch case2 but the motion of the mandibles is too quick for the eye40 ,the swallow drinks whilst flying1 sipping the water from the surface of pools4 ,its song is a delicate and pleasing warble1 which is uttered both at rest and during flight4 ,the voice becomes a squeak when the bird is alarmed or angry4 ,just before the autumn migration1 swallows perch in crowds on roofs1 hedges1 and the branches of trees4 ,they leave for ,africa about the beginning of ,october4 ,the house-martin may be distinguished from the swallow by the patch of white upon the upper tail-coverts1 and by its feathered toes4 ,like the swallow1 it arrives in this country about the middle of ,april4 ,the birds soon begin to repair their old nests and to construct new ones under the eaves of houses4 ,the nest is largely composed of clay or mud1 which the birds collect from damp places in the road1 etc41 place in position against the wall1 and allowed to harden4 ,the completed nest is somewhat bag-shaped1 having only a small hole at the top2 it is lined with soft grass4 ,the eggs are white1 without spots4 ,it is worthy of notice when a wild bird lays white eggs1 they are hidden from sight by the shape or position of the nest1 as in the case of the martins1 or the nest is built in an inaccessible place4 ,exposed eggs are usually made more or less inconspicuous by being coloured or spotted4 ,house-sparrows 7,fig4 #bjh7 have often been known to expel the defenceless martins from their nests1 and to lay their own eggs therein4 ,the eggs of the sparrow may be recognised by their grey colour1 and by the brown blotches with which they are marked4 ,the structure of the martin1 like that of the swallow1 is admirably adapted to a life in the air1 and to a diet of flying insects--the bird having powerful wings1 small and weak feet1 and a soft and short but widely-opening beak4 ,house-martins leave us about the beginning of ,october4 ,the sand-martin is distinctly smaller than either the swallow or house-martin1 and it may be further distinguished from them by the 8mouse-colour0 of its upper parts4 ,it usually arrives in this country about a fortnight in advance of its two relatives1 and also departs before them1 leaving in ,august or ,september4 ,these birds live in colonies in tunnels which they excavate in banks or friable cliffs 7,fig4 #bjc7--;generally in the near vicinity of water4 ,the excavation may be three feet in length2 it slopes slightly upwards to the nest 7which is placed at the end of the tunnel71 in order that rain water may not collect in it4 ,the eggs are pure white1 and five or six in number4 ,the birds are exclusively insectivorous2 they do not sing1 but utter a little twitter4 ,the flight is very characteristic1 consisting of 8odd jerks and vacillations1 not unlike the motions of a butterfly40 ,illustration3 ,,fig4 #bjc4--,sand ,martins' ,nesting ,holes4 ,illustration3 ,,fig4 #bjd4--,the ,skylark4 7 47 ,the skylark4--,at the first glance1 it is obvious that the skylark 7,fig4 #bjd7 is adapted for a life spent largely upon the ground4 ,the large toes lie flat on the earth1 and the long claw of the hind toe is plainly not very suitable for grasping the twigs of trees in the act of perching4 ,in fact1 the skylark only occasionally perches1 on low bushes4 ,walking or running on the ground1 it lives upon grubs1 caterpillars1 flies1 worms1 etc41 and also upon seeds1 which its strong beak enables it to extract from the husks4 ,the body is brown1 the wings being streaked with black1 and the dull-white throat and breast being marked with brown spots--a colouration which is a considerable protection4 ,the nest is built in ,march1 in a hollow or rut on the ground2 it is lined with dry grass4 ,the four or five eggs are greenish-grey1 and spotted with brown4 ,whilst the hen sits upon her eggs 7,fig4 #bje7 the cock-bird either hunts for food or sings his delightful song as he soars in the air4 ,the wonderful powers of soaring of this bird have already 7p4 #bgh7 been referred to4 ,when the lark drops to the ground he alights at a little distance from the nest1 and then runs up to it through the grass4 ,by this device he avoids revealing the position of his mate and young4 ,illustration3 ,,fig4 #bje4--,skylark at ,home4 ,skylarks rarely sing in the depth of winter2 in autumn they form large flocks which patrol the fields until spring in search for food--rendering incalculable services to mankind by the destruction of insect-larvae4 ,during the coldest weather of winter the birds crouch under banks and hedges4 ,the rook4--,the rook 7,fig4 #bjf7--often called the crow--is a rather large bird1 measuring about #ag inches from head to tail4 ,its plumage is black1 but as it becomes adult the feathers covering the face and nostrils are shed1 leaving the skin of these parts bare4 ,the bird has long and pointed wings1 and is a strong flier4 ,the bill is stout and almost straight4 ,rooks are no songsters1 their harsh 8caw0 being destitute of musical qualities4 ,when heard at a distance1 however1 the cry 8becomes a confused noise or chiding2 or rather a pleasing murmur1 very engaging to the imagination1 and not unlike the cry of a pack of hounds in hollow1 echoing woods1 or the rushing of the wind in tall trees1 or the tumbling of the tide upon a pebbly shore40#bc ,illustration3 ,,fig4 #bjf4--,the ,rook4 7 _/47 ,one of the most interesting features of rook-ways is the habit of living in organised communities4#bd ,it is true that a primitive form of social life is found among swallows1 martins1 and 7in winter7 larks1 reminding us of the gregarious habits of the rabbit 7,chapter ,,xii47 among mammals2 but a rook-society is rather to be compared with the pack-life of the wild dogs 7p4 #beb71 which depends for its integrity upon the observance of certain rules of conduct by its members4 ,naturalists have long known that such a code of laws is in force in every rookery1 but what these laws are we do not fully understand4 ,here is a profitable and interesting field of observation for the student4 ,it has sometimes been observed that certain birds are prevented by the rest from building until the nests already commenced are finished1 and cases have been known of birds being expelled from the rookery1 or even put to death1 after a consultation or 8trial10 presumably for some breach of law4 ,on the other hand1 it must be admitted that rooks are generally arrant thieves1 not scrupling to rob their neighbours' nests of building-materials to save themselves trouble4 ,they are also very quarrelsome4 ,illustration3 ,,fig4 #bjg4--,rooks' ,nests in ,trees4 ,the nests are built on high trees 7,fig4 #bjg72 they are composed of sticks and turf1 and are lined with moss and soft grass4 ,as each of several adjacent trees often contains a large number of nests1 a sort of rook-town called a 8rookery0 is formed4 ,this is added to from year to year1 as the number of the birds increases4 ,during the summer the rookery forms the headquarters of the community1 but about ,august or ,september1 before the leaves are shed1 the birds leave their nests1 to spend the winter in thicker or evergreen woods1 often at some distance4 ,at intervals during the winter they revisit their spring nests4 ,they come back to the rookery in ,february or ,march1 and at once set about repairing old nests or building new ones4 ,the male bird begins to feed the female even before the bluish-green eggs are laid1 and is a pattern of domestic virtue throughout the period of incubation4 ,for some time after hatching1 the young birds are fed by the parents4 ,rooks feed on the ground in flocks1 a few birds remaining behind in the trees as sentinels to give the alarm when danger threatens4 ,the food consists very largely of the larvae of injurious insects1 especially the grubs of the cockchafer beetle1 and although the birds undoubtedly eat corn and other young crops1 they do far more good than harm4 ,other birds of the crow family4--,the crow1 raven1 jackdaw1 magpie1 and jay are so similar in many respects to the rook and to each other that naturalists include them all in one group1 which they call the crow family4 ,the passerine order4--,the families of the birds hitherto considered in this chapter1 with the flycatchers1 wrens1 chats1 tits1 finches1 linnets1 starlings1 etc41 are further grouped together to form what is called an order4 ,the order which consists of these families derives its name passerine from the sparrow#be 7,fig4 #bjh71 perhaps the commonest of the birds included in it4 ,it is probably in this order that bird structure attains its most perfect development4 ,again1 the birds of the crow family are generally considered to stand at the head of the order2 if this view is correct1 rooks must be regarded as occupying1 among birds1 a position which roughly corresponds to man's place in the class of mammals4 ,passerine birds are nearly all singers1 and their toes are generally adapted for perching4 ,they feed upon insects1 seeds 7especially the seeds of grasses71 and soft fruit4 ,their beaks vary in form according to the nature of the food upon which they most depend1 as is well shown by the soft1 widely opening bills of the swallows1 the strong but slender beaks of the thrushes1 larks1 and crows1 and the short1 hard beaks of such seed-eaters as the canary1 sparrow1 and other finches4 ,birds which are exclusively1 or almost exclusively1 insectivorous are compelled to migrate to warmer countries to obtain food during the winter4 ,the eggs of passerine birds are usually coloured or spotted1 and the young birds are hatched in a helpless and almost naked condition1 being carefully tended and fed by both parents until they are able to fend for themselves4 ,a few familiar birds of other orders will now be briefly considered4 ,illustration3 ,,fig4 #bjh4--;,house ,sparrows4 7 47 ,illustration3 ,,fig4 #bji4--,the ,swift4 7 47 #eg4 ,,the ,,swift ,,and ,,the ,,cuckoo4 #a4 ,the swift4--,distinguish the swift from the swallow by its larger size1 its sooty black colour 7except for the dull white of the throat71 and its long1 bowed wings4 ,in what respect does the swift resemble the swallow8 ,watch for the appearance of swifts about the end of ,april4 ,do the birds arrive singly1 in pairs1 or in flocks8 ,notice the rapid turns and twists of the flying bird4 ,does it as a rule fly near the ground1 or at somewhat great heights8 ,have you ever noticed the bird perching1 or settling on the ground8 ,have you seen it clinging to walls with its feet8 ,were these the walls of houses or barns1 or of high towers8 ,what actions would lead you to suppose that the nests are built in high towers8 ,are more swifts to be seen in the evening1 or during the day8 ,can you explain this8 ,watch during the first half of ,august1 and make a note of the day on which swifts were last seen4 #b4 ,the cuckoo4--,what is the earliest date on which you have heard the cuckoo8 ,imitate the cry by putting your hollowed hands together and blowing between the thumbs4 ,with practice you will be able to deceive the bird into thinking that another cuckoo is present1 and it will approach near enough to be seen distinctly4 ,estimate the size of the bird1 and write down a careful description of its form1 colouration1 and method of flight4 ,try to see that two of its toes point forwards and two backwards4 ,have you ever seen cuckoos mobbed by small birds8 ,carefully examine as many nests of small birds as possible1 and try to find one containing an egg slightly larger than the rest and perhaps differently coloured4 ,this will probably be a cuckoo's egg4 ,visit the nest at frequent intervals1 both before and after the hatching of the eggs1 and write descriptions of the eggs1 the appearance and size of the young birds1 what becomes of each1 and the behaviour of the old birds4 ,what is the latest date on which you have heard the cuckoo8 ,the swift4--,though the swift bears a strong general resemblance to the swallow1 the two birds are not at all closely related1 but belong to different orders4 ,the swallow1 like all other passerine birds 7p4 #cbj71 has #ab tail-feathers1 and its first toe is separately movable and directed backwards4 ,the swift1 on the other hand1 has only #aj tail-quills1 and all its toes point forwards4 ,there are1 however1 more obvious differences1 which readily enable one bird to be distinguished from the other1 even at a distance4 ,the swift is1 with the exception of a dull-white patch on the throat1 of a sooty black hue over all the body1 and in flight its long and powerful wings take the form of a bent bow 7,fig4 #bji74 ,the swallow flies in bold1 sweeping curves1 while the more rapid swift turns sharply in the air1 in pursuit of the flying insects upon which it feeds1 in a manner suggestive of the flight of a bat4 ,while1 again1 the swallow flies much near the ground1 the swift is usually seen at greater heights4 ,the harsh scream of the swift is1 moreover1 in marked contrast with the swallow's pleasing song4 ,swifts do not willingly alight on the ground1 even to collect materials for their nests1 nor do they perch on trees or roofs1 the arrangement of their toes being quite unsuitable for either action1 and the length of the wings being such that1 even with toes of the normal type1 walking would be almost impossible4 ,the nest1 a somewhat rude structure of grass and feathers1 is generally built in high towers or other tall buildings4 ,the eggs are two in number2 they are more conical in shape than those of the swallow1 and1 as the position of the nest renders them independent of protective colouration1 are white4 ,the hen-bird sits on them during the day1 but generally leaves the nest and flies abroad in the evening to hunt for insects4 ,only one brood is reared1 and the birds take their departure early in ,august1 to spend the winter in ,south ,africa or ,madagascar4 ,the cuckoo4--,the cuckoo is placed by naturalists1 not among the passerine birds1 but in the order to which the swift belongs4 ,the reasons for this cannot be fully considered here1 but it may be mentioned that the cuckoo has only #aj tail-feathers1 and that it differs from all passerine birds in having its fourth toe1 as well as the first1 directed backwards1 the second and third pointing forwards 7,fig4 #baj74 ,the cuckoo has a total length of about #ad inches4 ,the upper surface of the body1 and the throat1 are grey2 the rest of the lower surface is white1 crossed with black bars4 ,the wings are large and powerful1 and the thighs are covered with long feathers4 ,in general appearance1 as well as in manner of flight1 the cuckoo bears a great resemblance to a hawk1 which may perhaps be the reason why small birds so often join forces and attack it4 ,a keen-eyed observer will1 however1 at once distinguish the birds by the head and the bill1 both of which are markedly longer in the cuckoo than in the hawk4 ,cuckoos arrive here in ,april1 the males usually appearing first4 ,the well-known call1 to which the bird owes its name1 is uttered by the male only2 the voice of the female is quite different1 and is often compared to the sound of bubbling water4 ,the cuckoo feeds entirely upon insects2 it is believed to be the only bird which eats the hairy caterpillar of the tiger-moth 7p4 #cfi74 ,illustration3 ,,fig4 #baj4--,the ,cuckoo1 7 _/47 ,of all bird-habits1 probably none has excited more interest than the manner of life of the young cuckoo4 ,its parents build no nest1 but depend entirely upon other birds for rearing their offspring4 ,the female cuckoo lays her egg upon the ground and then carries it in her bill to a nest which contains similarly coloured eggs1 if such a nest is to be found4 ,if not1 another convenient nest is selected4 ,it is said that the male sometimes renders assistance by distracting the attention of the rightful owners in the meantime4 ,in most cases the owners of the nest1 apparently unaware of the trick1 sit upon the strange egg with the rest1 and in due course the young birds are hatched4 ,the young cuckoo1 whilst still blind and naked1 wriggles itself under its foster brothers and hoists them over the edge of the nest4 ,far from resenting the crime1 the duped parents now devote their energies to feeding the murderer1 and continue their attentions until after it is fully fledged 7about a fortnight after hatching7 and perhaps several times their combined size4 ,illustration3 ,,fig4 #baa4--;,cuckoo's ,egg in ,greenfinch's ,nest 7,cuckoo's ,egg on the right74 ,the small size of the cuckoo's egg--about one-fourth of what might be expected from so large a bird--and its general similarity in colour to their own eggs1 both aid in deceiving the victimised birds in the first instance1 and the disproportionate size of their supposed offspring shortly after hatching apparently does not arouse their suspicions4 ,it is believed that any particular female cuckoo lays only eggs of one type and deposits them1 as far as possible1 in nests of the mimicked species--the species1 probably1 by which she herself was reared4 ,during the summer1 therefore1 she visits one such nest after another1 until she has disposed of all her eggs4 ,further1 it is supposed that her offspring inherit her tendency to lay eggs of the particular colour1 and therefore to prey in their turn upon the species of their foster-parents4 ,in this country1 the meadow pipit1 pied wagtail1 robin1 and reed-warbler are perhaps the most usual victims of the cuckoo's parasitism1 but the nests of other species 7,fig4 #baa7 are not uncommonly selected4 ,the old cuckoos depart about the end of ,july1 apparently leaving the young ones to find their way south alone4 #eh4 ,,the ,,duck4 #a4 ,tame ducks4--,closely observe ducks1 both on land and when they are swimming4 ,where is the heaviest part of the body8 ,are the legs attached in front of1 directly below1 or behind the centre of gravity8 ,is the position of the legs an advantage or a disadvantage 7i7 in walking1 7ii7 in swimming8 ,how does the foot differ from the feet of the birds previously mentioned8 ,between which toes is the web stretched8 ,how are the toes held when the bird lifts its foot in walking8 ,does it walk gracefully8 ,how does it swim8 ,are the legs moved together or alternately in swimming8 ,notice how the web folds up when the foot is moved forwards1 and spreads out for the back-stroke4 ,what does the duck eat8 ,how is the food obtained8 ,why are a duck's feathers so little wetted by the water8 ,watch1 and describe exactly1 how the bird preens its feathers4 ,how can you distinguish the male 7drake7 from the female duck1 7i7 by appearance1 7ii7 by the voice8 ,do the colours of the drake's plumage differ at different periods of the year8 ,what relation have the changes of plumage to the moulting-season8 ,what differences can you observe in the methods of moulting of ducks and fowls8 ,is there any time of the year when 7i7 ducks1 7ii7 fowls are unable to fly8 ,why8 ,when and where do ducks lay their eggs8 ,describe the appearance of the eggs4 ,are young ducks helpless or precocious 7p4 #bif71 naked or clothed1 at hatching8 ,can they feed themselves8 ,can they swim8 ,examine a dead duck4 ,notice the thick covering of down-feathers next the skin4 ,what is its use8 ,examine and draw a foot1 and see how the web folds between the toes4 ,observe the soft1 sensitive skin on the outside of the beak2 what do you suppose is its use8 ,notice the shape of the beak4 ,open it to see the horny plates fringing its inner edge1 and notice how these1 with other plates on the thick1 fleshy tongue1 form a strainer4 ,the duck4--,the birds of the duck order--which includes also the geese and swans--differ in many important respects from all our previous types1 and it is interesting to observe how perfectly these differences are adapted to the manner of life4 ,on land1 the ungainly waddle1 which is entailed by the insertion of the hind limbs so far back on the body 7,fig4 #bab71 shows that the duck is not in an entirely congenial element2 in the water the bird is a model of graceful movement1 perfectly balanced1 progressing smoothly by alternate strokes of its webbed feet1 and altering its course to any desired direction with the utmost ease4 ,the duck feeds largely upon the small animals which abound in the water of ponds1 and in the mud of the sides1 and the beak is beautifully fitted for the duties it has to perform4 ,it is covered on the outside by a soft and highly sensitive skin1 which enables the bird to detect with certainty the presence of its prey in the mud2 the inner edge of the beak is provided with horny plates which1 with similar plates situated on the edge of the thick1 fleshy tongue1 form a very efficient strainer1 by means of which the useless water and thin mud can be forced out at the sides of the mouth and separated from the worms1 etc41 which were taken into the mouth at the same time4 ,a thick coat of down-feathers1 which lies next the skin and contains a great deal of entangled air1 forms a non-conducting layer which prevents the undue escape of the heat of the body1 and saves the bird from becoming chilled when in the water4 ,ducks are1 moreover1 careful to keep their feathers well oiled1 and may often be seen preening themselves--applying the bill alternately to the oil-gland on the tail and to the feathers4 ,the completeness with which water flows off a duck's back is proverbial4 ,illustration3 ,,fig4 #bab4--;,ducks4 ,during the greater part of the year the brilliant plumage of the drake forms a striking contrast to the sober brown and grey feathers of the female4 ,another point of difference is that in the male the four middle tail-feathers are curled upwards4 ,from ,july to ,october1 however1 before the moult takes place1 the two sexes are very similar in appearance4 ,birds of the duck order moult in a somewhat different manner from most other birds1 in that all the quill-feathers are shed at once1 instead of in pairs4 ,until the new feathers develop1 flight is of course out of the question1 and the birds remain as secluded as possible in the meantime4 ,the eggs are white and greasy-looking2 they are laid in a rough1 open-topped nest1 lined with down1 which is placed on the ground4 ,the wild duck covers up the eggs when she leaves the nest4 ,the young are active immediately after hatching4 ,it has been noticed that the eggs of precocious birds are generally larger1 in proportion to the size of the parent1 than those of birds which are naked and helpless at hatching--the larger store of egg-food allowing a more complete development of the young bird in the shell4 ,further1 the nests of precocious birds are1 as a rule1 less elaborately constructed4 #ei4 ,,two ,,common ,,hawks4 #a4 ,the sparrow-hawk4--,watch for sparrow-hawks near farms4 ,notice the general resemblance of the bird to the cuckoo1 but distinguish them by the short head and beak of the hawk4 ,observe the bluish-grey colouration of the upper parts4 ,describe the flight of the hawk and1 if possible1 its method of catching its prey4 #b4 ,the kestrel or windhover4--,distinguish the kestrel from the sparrow-hawk 7i7 by the reddish colour of its upper parts1 and 7ii7 by its habit of hovering in mid-air4 ,have you ever known the kestrel to prey upon small birds8 ,upon what does it feed8 ,the sparrow hawk and kestrel4--,these two birds are the only ,british hawks which the average nature-student is likely to see during a country walk2 and as one of them is given to preying on young game-birds1 chickens1 etc41 while the other as generally confines itself to animals which are universally regarded as vermin1 it is important to be able to distinguish them at sight4 ,illustration3 ,,fig4 #bac4--,the ,nest of the ,sparrow ,hawk4 ,the sparrow-hawk 7,fig4 #bac7 attains a length of #ac inches2 the female is slightly larger than the male4 ,the upper parts of the body are bluish-grey in colour2 the lower parts are buffish white1 and crossed with brown bars4 ,the head is short and round2 the bill is hooked and sharp1 as in birds of prey generally1 and the toes are armed with sharp claws4 ,the bird is often to be seen near farms1 lurking behind hedges and waiting for an opportunity of dashing upon chickens or other small birds and carrying them off4 ,the kestrel1 which in size and shape much resembles the sparrow-hawk1 is really a species of falcon 7,fig4 #agi74 ,it is unrivalled among common ,british birds in its power of remaining poised in one position in mid-air by that rapid motion of the wings which is called hovering1 a power which has earned for it the name of 8windhover40 ,the kestrel1 though in reality one of the farmer's best friends1 from its wholesale destruction of field-mice1 voles1 and many injurious insects1 is often ignorantly confused with the sparrow-hawk4 ,the reddish hue of the plumage of the kestrel's upper parts1 together with the hovering habit1 ought to render such a mistake impossible to observant eyes1 and to secure the bird from a persecution which may reasonably be directed against the sparrow-hawk4 ,,exercises ,,on ,,chapter ,,xvii4 #a4 ,extend the foregoing methods of study to the following passerine birds3--,starling1 finches1 wagtails1 pipits1 nuthatch1 tits1 warblers1 wrens1 and flycatchers1 and make notes of the observations4 #b4 ,try to discover reasons for grouping 7a7 woodpeckers1 nightjars1 and kingfishers with swifts and cuckoos2 7b7 pheasants and grouse with fowls4 #c4 ,compare geese and swans with ducks1 and make notes of as many points of resemblance and difference as possible4 #d4 ,compare and contrast owls with hawks4 #e4 ,arrange the above birds in lists according to 7a7 food1 and the characters of the beak2 7b7 characters of feet and arrangement of toes2 7c7 nests 7open-topped1 covered1 built in holes or tunnels72 7d7 colour and number of eggs2 7e7 condition of young at time of hatching4 #f4 ,how many birds do you know which 7a7 spend only the summer1 7b7 spend only the winter1 7c7 stay all the year1 in this country8 ,state1 in each instance1 upon what food the bird most depends4 ,,footnotes3 #ba ,our ,bird ,friends 7,cassell74 #bb ,the ,natural ,history of ,selborne4 #bc ,the ,natural ,history of ,selborne4 #bd ,a delightful account is given in the story of 8,silverspot0 7,thompson-,seton's ,wild ,animals ,i ,have ,known74 #be ,latin1 passer1 a sparrow4 ,,chapter ,,xviii4 ,,frogs ,,and ,,tadpoles4 #fj4 ,,the ,,life ,,of ,,the ,,frog4 #a4 ,manner of life4--,where have you found frogs8 ,are they commonest in dry or in damp situations8 ,at what time of the year have you seen them actually in water8 ,how do frogs move about8 ,do they walk or hop8 ,chase a frog1 and notice that its hops become shorter as it is pursued4 ,upon what does the frog feed8 ,have you ever seen frogs abroad in the depth of winter8 ,are insects common in winter8 ,how do you suppose frogs spend the winter8 ,what are the principal enemies of frogs8 #b4 ,external characters4--,catch a frog2 is its body dry or moist8 ,does it feel cold or warm8 ,how does it behave when caught8 ,does it soon become tame if well treated8 ,put a frog under an inverted pickle-bottle and observe it carefully4 ,what is its size8 ,what was the size of the smallest frog you have seen8 ,at what time of the year can the smallest frogs be seen8 ,what is the colour of the frog8 ,put one frog with dark-coloured leaves and soil1 and another with light-coloured leaves1 and try to find out if the skin of the first becomes lighter and that of the second darker in colour4 ,is it an advantage to the frog to be able to change slightly in colour8 ,why8 ,what is the position of the frog when at rest8 ,notice the shortness of the body1 the hump on the back1 the relative lengths of the limbs1 the #d unwebbed fingers1 the #e webbed toes1 and the absence of a tail4 ,what is the advantage of the long hind-limbs8 ,mention other leaping animals whose hind-limbs are longer than the fore-limbs4 ,is a short-bodied animal 7i4e4 one with its four limbs pretty close together7 less likely to be injured by the fall1 after a leap1 than a long-bodied animal8 ,why8 ,put the frog into water1 and watch it swim4 ,what is the use of the webs between the toes8 ,examine the head4 ,notice the very wide stretch of the mouth1 the small openings of the nostrils1 the large prominent eyes1 and the ear-drum--a dark-coloured disc on each side1 a little below and behind the eye4 #c4 ,breathing4--,watch the up-and-down movements of the floor of the mouth1 by which the animal pumps air1 through its nostrils1 in and out of its mouth-cavity4 #d4 ,method of feeding4--,put live insects1 small worms1 etc41 under the upturned bottle enclosing the frog1 and watch the animal's method of feeding4 ,try to see how it uses its tongue4 ,what is the advantage of the wide gape of the mouth8 ,can you get the frog to accept dead insects8 #e4 ,the inside of the mouth4--,to kill a frog painlessly1 soak about a teaspoonful of chloroform on cotton wool1 and put it with the frog under a bottle or tumbler4 ,after #ae or #bj minutes the frog will be quite dead4 7a74--,open the jaws widely1 and examine the inside of the mouth4 ,notice how the rounded eyeballs project into the mouth-cavity when they are pressed from the outside4 ,pass your finger-end round the margins of the jaws1 and feel the row of fine teeth borne by the upper jaw2 the lower jaw is destitute of teeth4 ,feel also1 in the roof of the mouth1 two small patches of teeth 7,vo41 ,fig4 #baf72 these are carried by small bones called the vomers1 and are therefore called the vomerine teeth4 ,just to the outside of the vomerine teeth and in front of the eyeball1 notice on each side the internal opening of the nostril 7,ch41 ,fig4 #baf72 pass into one nostril a stiff bristle1 and observe that it emerges at the external nostril4 ,pull forward the tongue 7,t1 ,fig4 #baf7 and observe that it is attached at its front end2 feel how sticky the tongue is4 ,behind the eyes1 and at the angles of the jaws1 notice the openings of the ,eustachian tubes 7,e1 ,fig4 #baf72 push a stiff bristle into one and observe1 from the outside1 that the end of the bristle presses the inner surface of the ear-drum4 7b74--,if the roof of the mouth has dried1 moisten it with water1 and place a very small cork-shaving or a tiny snip of paper on it1 far back between the eyeballs4 ,notice that the shaving travels slowly down the throat4 ,this experiment ought to be made soon after the frog has been killed4 #f4 ,the bones4--,feel1 through the body-wall1 the various parts of the skeleton1 making out the skull1 backbone1 limb-bones and their manner of attachment1 and breast-bone 7protecting the heart74 ,observe the absence of ribs4 #g4 ,the skin4--,examine the skin of the dead frog1 and notice that it is damp or even somewhat slimy1 and that it differs from the skin of a mammal or bird in being naked1 bearing neither hairs1 feathers1 nor scales4 ,pinch up the skin1 and notice how very loosely it is attached to the underlying body-wall4 ,snip through the thin skin1 turn it back from the body-wall1 and see the network of blood-vessels upon its inner surface4 ,the habits of the frog4--,the common grass frog 7,fig4 #bad7 is to be found in abundance1 from early spring to ,october1 in ditches1 marshy land1 and other damp places4 ,as winter approaches1 frogs generally bury themselves in the mud at the bottom of ponds1 etc41 and remain there in a state of torpor until the spring1 when they emerge and the females lay their eggs4 ,frogs are said to be 8cold-blooded0 because their temperature never varies much from that of their surroundings4 ,birds and mammals1 on the other hand1 maintain an almost constant temperature1--a healthy man's blood1 for example1 being just as warm in the depth of winter as it is on a hot summer day4 ,so long as they are not actually frozen hard1 therefore1 frogs can endure the winter cold without much inconvenience4 ,although the frog is essentially a land animal1 it is quite at home in the water1 and swims gracefully and easily by the help of the webs which connect the long toes of its hind feet4 ,on land1 it progresses by long leaps1 its limbs and body being well adapted to this habit4 ,as is usual in leaping animals1 the hind legs and feet are markedly longer than the fore limbs2 and the shortness of the body enables the two pairs of limbs to be brought together to break the shock of the fall4 ,illustration3 ,,fig4 #bad4--,the ,frog4 7 #a47 ,food4--,the frog's method of catching its prey is very interesting1 and is graphically described by ,dr4 ,hans ,gadow#bf as follows3--8,the food1 which consists chiefly of insects1 snails1 and worms1 must be moving to excite interest2 then the frog1 whose favourite position is half squatting1 half supported by the arms1 erects itself and1 facing the insect1 turns round upon its haunches1 adjusts its position anew by a shifting of the legs1 and betrays its mental agitation by a few rapid movements of the throat4 ,all this time the prey is watched intently until it moves2 then there follows a jump1 a flap of the tongue1 and the insect is seen no more40 ,this flap of the tongue is well illustrated in ,fig4 #bae4 ,the frog's tongue is free behind1 but is attached1 by its anterior end1 close to the middle of the lower jaw1--an arrangement which enables it to be flicked out to its full length4 ,further1 it is covered by a glutinous secretion1 which sticks tenaciously to the prey4 ,illustration3 ,,fig4 #bae4--,three ,stages of the ,movement of the ,tongue of a ,frog4 7 #a47 ,the frog is fortunate also in the extremely wide gape of its mouth1 which stretches1 almost literally1 from ear to ear4 ,once in the mouth1 the captive is prevented from escaping by the teeth4 ,of these there are two sets2 a row of fine teeth is present along the greater part of the margin of the upper jaw1 and1 in addition1 two small patches of teeth--the vomerine teeth 7,vo41 ,fig4 #baf7--occur on the roof of the mouth4 ,fairly large insects are promptly gulped down into the stomach2 those which1 owing to their minute size1 escape being swallowed in the ordinary manner1 are slowly but surely forced down the throat by the incessant lashing of thousands of tiny threads--too small to be seen except by high powers of the microscope--which are carried by the skin of the roof of the mouth4 ,the action of these invisible threads may easily be seen if a frog's mouth be opened widely and a small cork-shaving be placed near the top of the throat 7,expt4 #fj1 #e1 b74 ,the shaving steadily travels backwards and is soon lost to sight4 ,it should be clearly understood that frogs and toads are of incalculable value in keeping down insect pests1 and deserve systematic protection for this if for no other reason4 ,how a frog breathes4--,when a resting frog is watched1 the floor of the mouth is seen to be raised and lowered alternately4 ,it is a common belief among children that these movements are a sign that the animal is 8getting ready to spit40 ,frogs do not spit1 however1 and the action is simply a part of the breathing process1 which is performed in the following manner4 ,the mouth being closed1 the nostrils are opened1 and1 by alternate up-and-down movements of the floor of the mouth1 the air present in the mouth-cavity is completely replaced by fresh air4 ,the nostrils are then closed1 and the slit-like glottis 7gl41 ,fig4 #afc7 which leads to the lungs 7l4 lng41 r4 lng47 is opened4 ,the foul air is forced out of the lungs and mixed with the pure air in the mouth-cavity4 ,then1 immediately1 the floor of the mouth is raised--pumping the mixed air into the lungs--and the glottis is closed4 ,in the lungs an exchange takes place between the oxygen of the refreshed air1 and the surplus carbon dioxide in the blood which is circulating in the capillaries 7p4 #bdb7 of the walls of the lungs4 ,in the meantime the nostrils have again been opened1 and the first stages of the process are already being repeated4 ,illustration3 ,,fig4 #baf4--;,inside of mouth of ,edible ,frog4 ,ch1 internal opening of nostril2 ,e1 opening of ,eustachian tube2 ,s1 opening leading into vocal sac2 ,t1 tongue2 ,vo1 vomerine teeth4 7 #a47 ,a considerable part of a frog's breathing is carried on1 in these first stages1 through the thin membrane forming the roof of the mouth-cavity4 ,this is richly supplied with blood capillaries1 and is therefore admirably adapted for the exchange of gases which constitutes respiration4 ,moreover1 the skin covering the general surface of the body has also a very abundant blood-supply1 and forms yet a third respiratory organ2 so that it is practically impossible to drown a frog in ordinary water--in water1 that is1 which contains dissolved air4 ,this power of breathing through the skin is of great importance to a frog during the winter sleep at the bottom of a pond4 ,the frog's skin4--,the frog's skin is kept moist by a slimy fluid which is continually being discharged from small glands in its substance4 ,the moisture not only facilitates skin-breathing as described above1 but its evaporation keeps the body cool even in hot weather--a matter of vital importance to an animal to which a temperature of #dj ,c4 or so is fatal4 ,a third most interesting property of the frog's skin is its power of changing somewhat in colour to match the colour of its surroundings4 ,the change depends upon an alteration in form and size of certain small brown specks imbedded in the thickness of the skin4 ,when the animal finds itself in dark-coloured surroundings these specks enlarge1 and the skin as a whole takes on a darker hue4 ,on a light background the reverse change takes place4 ,a case of evolution4--,the advantage which accrues to a frog from being thus rendered less conspicuous to enemies and prey alike is obvious1 and there is no difficulty in picturing to ourselves the probable manner in which the advantage was developed4 ,widely different races of animals have colour-specks in the skin1 and we may assume that frogs and their ancestors have possessed such spots for countless generations4 ,now suppose that1 ages ago1 a frog happened to be born with the power of altering very slightly the size of his colour-specks4 ,if this power rendered him less conspicuous1 in however slight a degree1 than his neighbour frogs he would1 other things being equal1 be more likely than they to escape from enemies1 grow to maturity1 and in due course have sons and daughters4 ,all his offspring1 and they might number thousands1 would tend to inherit1 to varying extents1 the power of changing colour4 ,in some--perhaps in most--the power would be practically absent2 in others it might be equal to that of the parent2 while in a few instances it would probably be greater4 ,in any case1 those frogs of the second generation which had the greatest power of changing their colour would be the most likely to survive the keen struggle for existence and therefore to leave offspring4 ,the survival of the 8fittest0 frogs of each generation1 and the transmission to the next generation1 in ever-increasing intensity1 of their favouring accomplishment1 would naturally result at last in the production of a race of animals in which1 as in the frogs of to-day1 the power of changing colour is universal4 ,illustration3 ,,fig4 #bag4--;,head of ,male ,edible ,frog1 seen from the left side1 showing inflated vocal sacs4 7 #a47 ,the laying of the eggs4--,about the end of ,march the frogs resort in great numbers to shallow ponds and ditches1 pair with much croaking1 and the females lay their eggs or 8spawn40 ,both sexes croak1 and the male of the edible frog1 though not of the common grass frog1 is able to make more noise in virtue of a pair of vocal sacs 7,fig4 #bag71 which he can inflate with air from the mouth 7,fig4 #baf71 and which act as resonators4 ,after spawning1 the frogs leave the water1 abandoning the eggs to their fate1 and resume their ordinary terrestrial life1 until approaching winter prompts them to hide in the mud and go to sleep4 #fa4 ,,the ,,development ,,of ,,the ,,frog4 #a4 ,a simple aquarium4--,a simple aquarium1 in which the development of the frog from the egg may be watched1 is easily made4 ,obtain a fairly large basin1 and cover the bottom with sand1 mud1 and stones from a pond4 ,arrange these so that the bottom shall shelve from the surface of the water at one side to a depth of #c0 or #d0 at the other4 ,put in some stones covered with green slime1 which will almost certainly be found in the pond1 plant a few water-weeds1 and allow the water to clear4 #b4 ,frog spawn4--,having prepared the aquarium1 obtain1 towards the end of ,march 7or earlier in a mild spring7 a handful of frog spawn from a pond or ditch4 ,it forms a mass of jelly in which the true eggs--small balls about _/0 in diameter--are imbedded4 ,put this in the aquarium and examine it carefully every day1 making the observations described below4 ,if possible1 obtain a pair of spawning frogs1 and place them in a bucket with a little water1 so that the earliest stages also may be studied4 #c4 ,the eggs before hatching4--,observe the globe of jelly which surrounds each egg4 ,try to pick it up between your finger and thumb4 ,do you think it is of any use in protecting the eggs from being eaten by fishes1 birds1 etc48 ,remove the jelly as completely as possible from one egg1 put the egg in a watch-glass with a little water1 and examine it carefully with a strong lens4 ,to which of the stages shown in ,fig4 #bah does it correspond8 ,if possible1 treat a newly-laid egg in the same manner and examine it every hour or so through the day4 ,make notes of the time elapsing between the various stages shown in ,fig4 #bah4 #d4 ,hatching4--,notice that the developing eggs change from the spherical to the ovoid form4 ,what is the shape when the embryo begins to move8 ,notice the appearance of a neck and a tail4 ,at this stage the embryo makes its way out of the jelly1 or hatches4 ,the jelly may now be thrown away1 as it is of no further use4 ,how does the embryo behave immediately after hatching8 ,put one in a watch-glass and with a lens try to see the sucker by which it attaches itself to water-weeds1 etc4 #e4 ,tadpolehood4--,examine the tadpoles at frequent intervals by the help of a lens1 and write careful accounts of the changes which take place in them4 ,notice particularly the fine threads--the external gills--which grow out from the sides of the neck4 ,how many are there8 ,after a time they shrivel up and are replaced by other gills which cannot be seen4 ,write a description of a tadpole at the time when it begins to feed4 ,how large is it8 ,count the tadpoles in the aquarium at intervals of a few days1 carefully removing all dead ones4 ,supply fresh green slime from the pond from time to time4 ,have you any reason to suppose that tadpoles are cannibals8 ,how soon do the tadpoles come to the surface to breathe air8 ,describe the appearance of one when it begins to do this4 ,has it any legs8 ,how many can you see8 ,in what order do the legs grow out8 ,notice now the dwindling of the tail4 7,it does not drop off1 as is so often stated47 ,the tadpole has become a frog4 ,what percentage of the original eggs have developed into frogs8 ,illustration3 ,,fig4 #bah4--,the early development of the ,frog4 mi1 small black cells2 mg1 large white yolk-cells2 ect1 black cells overspreading yolk-cells2 yk4pl1 yolk-plug2 md4gr1 groove of commencing nervous system2 md4f1 right margin of groove2 br4cl1 depressions marking position of future gill-slits2 stdm1 pit which will become mouth2 t1 tail2 br4#a1 br4#b1 external gills2 e1 eye2 sk1 sucker4 7 #e47 ,the early development of the frog's egg4--,a frog's egg is a little spherical mass about one-tenth of an inch in diameter4 ,when laid1 it is covered by a thin gelatinous layer which soon swells up in the water to form a transparent globe of about half-an-inch diameter1 in the centre of which the true egg can be seen4 ,this jelly is extremely slippery and difficult to grasp1 and is consequently an efficient protection against the attacks of birds1 fishes1 insect-larvae1 etc41 and even of parasitic fungi and other small organisms4 ,the jelly also acts as a float4 ,at the time of laying1 each egg consists of a black and a white portion4 ,in the lower1 or white1 part there is a store of food1 on which the little embryo subsists until it acquires a mouth and begins to fend for itself4 ,the development begins in the upper1 or black1 part of the egg1 and may easily be watched with a lens4 ,and to be appreciated properly1 the changes should be watched1 and not merely read about4 ,the student should get1 if possible1 some freshly-laid frog's eggs1 and remove the gelatinous investment from one or two4 ,it will require care to do this without injuring the eggs4 ,they should now be put1 with a little fresh water1 into a watch-glass1 and carefully examined at intervals of half an hour or so4 ,soon a little pit makes its appearance in the middle of the black half1 and gradually extends until it becomes a groove1 which little by little reaches quite round the egg 7,fig4 #bah1 ,a74 ,in the meantime another groove begins to form at right angles to the first1 and1 in its turn1 grows down round the egg 7,b74 ,if we compare the whole egg to the earth1 and the middle of the black half to the ,north ,pole1 these two grooves may be said to be along meridians at right angles to each other4 ,the third groove 7,c7 may be considered as along a parallel of latitude1 but it is somewhat to the north of the ,equator4 ,these first three grooves deepen until the whole egg is cut up into eight separate pieces4 ,the sight of the apparently lifeless speck dividing itself up in this regular and orderly manner1 8while you wait10 is an intellectual treat which should not be missed4 ,the cleavage of the egg goes on rapidly1 but in a less regular manner now1 until the whole is cut up into a hollow sphere of segments 7,f71 black and small 7mi7 in the northern hemisphere1 whitish and larger 7mg7 in the south4 ,it is worth while to pause here to consider how these early changes are assisted by the peculiar condition of the egg at the time of laying4 ,the southern hemisphere of the egg is laden with a store of food4 ,the food is dead1 and acts as a mechanical hindrance to the activity of the living matter4 ,in the northern half of the egg but little food is present to impede its activity1 and it is plainly important that this half shall receive as much warmth as possible from the uncertain sunshine of early spring4 ,two circumstances ensure this4 ,in the first place1 the food-laden region is the heaviest part of the egg1 so that the latter--buoyed up as it is by the jelly--tends to float with its most 8alive0 part upwards4 ,secondly1 this upper part is coloured black1--a great advantage1 since black objects absorb heat readily4 ,both these peculiarities therefore favour the more rapid development of the 8northern0 hemisphere4 ,hence the third cleft is to the north of the egg's equator1 instead of being halfway between the upper and lower poles1 and hence1 too1 at the close of segmentation the northern segments are smaller and more numerous than the southern4 ,in the case of the hen's egg 7,chapter ,,xvi471 the amount of stored food contained in the egg 7the yolk7 is so enormous that segmentation is confined entirely to a small patch on the upper surface4 ,another result of the relatively small amount of stored food in the frog's egg is that the tadpole is compelled to turn out and earn its own living at a stage when the chick's inherited fortune is still considerable4 ,the tadpole4--,the spherical mass soon becomes ovoid1 and is divided into head and trunk by a neck-constriction 7,j74 ,an occasional wriggle shows that the creature is alive4 ,shortly afterwards a tail grows out from the hinder end of the trunk1 giving the animal something of the appearance of a fish 7,l74 ,in this stage the tadpole makes its way out of the jelly1 and thus hatches1 about a fortnight after the laying of the eggs4 ,the little creature is quite helpless2 it has no mouth 7the egg food is not yet exhausted1 however71 and its attempts at swimming are still feeble and uncertain4 ,in this defenceless condition 7,fig4 #bai1 #a7 it will be seen to attach itself to the water-weed of the aquarium by means of a sucker 7,fig4 #bah1 ,l1 sk7 on the underside of its head4 ,it is in a very favourable position for examination1 and by help of a lens1 two--soon there are three--pairs of fine1 thread-like outgrowths can be distinguished on the sides of the neck 7,fig4 #bai1 #b and #b;a74 ,these are the external gills4 ,in a few days the mouth breaks through1 and the animal begins to nibble at the vegetation with little horny jaws1 and soon swims about the aquarium with confidence4 ,illustration3 ,,fig4 #bai4--,the ,frog4 ,stages in the life-history1 from the newly-hatched ,tadpoles 7#a7 to the young ,frog 7#h74 7 #a47 #b;a is a magnified view of #b4 ,the gills are the organs by which the young tadpole breathes1 and each little gill-thread is seen1 when viewed with a low power of the microscope1 to contain tiny loops of blood-vessels4 ,every time the tadpole uses his jaws1 wags his tail1 or1 in short1 does anything at all1 he uses up some oxygen and produces some carbon dioxide4 ,the water of the aquarium contains dissolved oxygen--green water-weeds are kept in aquaria for the express purpose of liberating oxygen 7p4 #ea7--;and this oxygen makes its way through the excessively thin membrane which divides the blood of the gills from the water1 to be swept away by the current of the blood to the various parts of the body4 ,the carbon dioxide produced is brought to the gills by the blood stream1 and passes through the membrane into the water1 where it is utilised by the water-weed as food 7p4 #ea74 ,animal and plant are thus mutually serviceable4 ,a series of slits soon opens through the sides of the neck1 and along their margins are formed folds which are usually called the internal gills4 ,the external gills dwindle and shrivel up as the internal gills are being formed1 and at the same time a flap of skin grows backwards from each side of the head and covers over the slits so that they cannot be seen4 ,presently the two flaps fuse at their edges--except at one point on the left side1 where a spout is left--and so enclose a chamber4 ,the water which enters the tadpole's mouth pours through the gill-slits1 into the chamber1 and out through the spout4 ,as it swills over the folds of the internal gills there is an exchange of carbon dioxide for oxygen in the manner just described4 ,the tadpole in the meantime is growing strong and active1 and the tail has grown out to form a powerful organ1 the sinuous motion of which propels the animal with relatively great speed through the water4 ,from the point of view of the biologist1 perhaps the most interesting feature of this stage of tadpolehood is the almost entire correspondence of the structure with that of a fish1 although the adult frog is not in any sense a fish4 ,this curious state of things is explained by supposing that frogs have descended from fish-like ancestors1 and that every frog1 in the course of its development1 is under the necessity of repeating1 in a more or less modified manner1 the chief stages of its ancestral history4 ,as ,marshall happily expressed it1#bg a frog during its development climbs up its own genealogical tree4 ,the metamorphosis4--,just as the external gills are replaced by internal gills1 so these1 in their turn1 are replaced by lungs1 and advanced tadpoles frequently come to the surface of the water to breathe air4 ,limbs have now grown out from the sides of the body1 and the webbed hind feet considerably assist the tail in swimming4 ,changes take place in nearly all the internal organs1 fitting the animal for its life on land2 and these changes are so extensive that there is necessarily a short period when the creature is neither tadpole nor frog1 and is incapable of feeding4 ,the tail1 however1 which would be useless to the terrestrial1 leaping frog1 is gradually absorbed1 and forms a store of nutriment during the transformation4 ,the gills shrivel up1 and the slits close2 the outer layer of the skin 7including the horny jaws7 is thrown off1 the hind limbs lengthen1 and the animal leaves the water--a frog4 ,,exercises ,,on ,,chapter ,,xviii4 #a4 ,make observations upon toads4 ,in what respects do they differ in appearance from frogs8 ,how do they move about8 #b4 ,are the skins of toads dry or moist8 ,in what situations have you found toads8 ,how do they protect themselves from the heat of the summer sun8 #c4 ,at what time of the year1 and in what places1 do toads lay their eggs8 ,compare the voice with that of a frog4 ,do toads inflate any part of the body when they sing8 ,compare the vocal sacs with those of frogs4 #d4 ,look for toad-spawn in the spring4 ,it forms long1 gelatinous ropes in which the eggs are embedded4 ,how large are the eggs8 ,in what respects do they differ from frogs' eggs8 #e4 ,keep toads' eggs in an aquarium1 and carefully compare all the stages of development with those of the frog4 #f4 ,count how many caterpillars you can persuade a toad to eat 8at one sitting40 ,what would be one result of the extermination of toads and frogs8 #g4 ,describe carefully what happens when a frog leaps4 ,point out the special arrangements which enable a frog to leap safely4 7#ahig7 #h4 ,describe the ordinary process of feeding of a frog1 and show how it is assisted by the peculiar structure of the frog's mouth and tongue4 7#ahie7 #i4 ,explain the special use of the wide gape of the frog4 ,where are the teeth of the frog situated8 7#ahih7 #aj4 ,mention some remarkable features of the mouth of a frog1 and try to show that they are adapted to meet special needs4 7#aija7 #aa4 ,describe the process of filling the lungs with air1 as observed in the frog and the rabbit4 7#ahif7 #ab4 ,what changes take place in a tadpole during the first week after hatching8 ,illustrate your answer by drawings4 7#ahih7 #ac4 ,describe the appearance of one of the gills of a very young tadpole as seen by a low magnifying glass4 7#aija7 #ad4 ,describe the appearance1 size1 and mode of life of a tadpole about a fortnight after hatching4 ,on what does it feed8 ,describe its mouth carefully4 7#ahig7 #ae4 ,compare a fresh-hatched tadpole with one in which the hind limbs have recently appeared4 7#ahih7 #af4 ,trace the history of a tadpole from hatching to the time when the tail begins to grow less4 ,what does it feed upon during this time8 7#ahih7 #ag4 ,relate the life-history of the frog1 from the time of hatching to the end of the first summer4 7#ahig7 #ah4 ,give some account of the habits of a young tadpole a few days after hatching1 especially with respect to locomotion and feeding4 ,make a drawing of such a tadpole in side view1 three times the natural length4 7#aijd7 #ai4 ,describe the hind leg of a frog1 and explain the ways in which it is used4 7#aije7 #bj4 ,show how a full-grown frog is enabled to live either in air or in water4 7#aijf7 ,,footnotes3 #bf ,the ,cambridge ,natural ,history1 ,vol4 ,,viii4 7,macmillan47 #bg ,marshall's ,the ,frog 7,smith1 ,elder ,co474 ,,chapter ,,xix4 ,,the ,,habits ,,and ,,life-,,histories ,,of ,,common ,,insects4 #fb4 ,,the ,,cockroach3 ,a ,,typical ,,insect4 #a4 ,habits4--,in what places have you seen cockroaches8 ,are they often to be seen during the day1 or do they1 in general1 come forth only at night8 ,what is the colour of the body8 ,put a live cockroach under a tumbler1 and watch its movements4 ,in what position is the head held8 ,notice the long feelers2 how are they used8 ,look at the lower part of the head1 and try to see the palps1 which resemble small feelers4 ,how many legs has the cockroach8 ,watch the rhythmical movement of the hinder part of the body4 ,soak a small piece of bread in milk or water1 and put it under the tumbler2 watch the cockroach feed4 ,how does it use the palps8 ,notice that the jaws move from side to side4 ,how does the insect clean itself8 #b4 ,external characters4--,put a cockroach into a test-tube1 and dip the tube into boiling water2 this kills the insect instantly4 ,notice the thin 8shell0 which covers the outside of the animal4 ,make out that the body consists of 7a7 head1 carrying the eyes1 feelers1 and jaws2 7b7 thorax1 carrying the wings and legs2 and 7c7 abdomen4 ,examine them in turn4 7a7 ,the head4--,notice the vertical position1 the black1 kidney-shaped eyes1 the feelers1 the 8upper0 lip 7labrum71 and the small1 blackish mandibles at the sides of the labrum4 ,pass your knife-point close behind the labrum and into the mouth1 and see the 8lower0 lip 7labium71 which lies behind the knife1 i4e4 behind the mouth4 ,cut off the head and carefully strip off the labium4 ,put it on a sheet of paper and examine it with a lens1 comparing it with ,fig4 #bbb 7,mx4 #b74 ,examine the same head from behind with a lens and see the pair of first maxillae4 ,notice how they are attached to the head1 and then remove one and compare it with ,fig4 #bbb 7,mx4 #a74 ,work one of the mandibles backwards and forwards with the point of a pin1 and then remove it and examine it with a lens to see the toothed inner margin4 7b7 ,the thorax4--,notice the overlapping fore-wings 7wing-covers74 ,pull them aside with forceps2 notice that they are narrow and rather stiff1 make out their points of attachment at the corners of the second segment of the thorax1 and then cut them off with scissors4 ,pull out the delicate hind-wings in the same way1 carefully noticing their fanlike method of folding1 and their points of attachment to the corners of the third segment of the thorax4 ,stretch one out1 cover it with a piece of glass to flatten it1 and then draw it1 marking the lines of folding4 7,notice that some cockroaches of the common species found in kitchens are destitute of wings1 and have only very small wing-covers4 ,these are females47 ,after removal of the wing-covers and wings1 the three segments of the thorax are very distinct4 ,notice that each segment bears a pair of legs4 ,take off one of the legs and draw it4 ,how many joints has it8 ,what is the use of its bristles8 7c7 ,the abdomen4--,observe the line which runs along the dorsal middle line of the abdomen2 this marks the position of the heart4 ,examine the method of telescoping of the segments of the abdomen1 and the soft membrane which connects the dorsal and ventral plates of each segment4 ,notice that the abdomen bears neither wings nor legs4 ,observe the pair of short palp-like bodies 7cer41 ,fig4 #bbc7 at the end of the abdomen1 and between them1 in the male1 a pair of more slender styles4 ,in the female observe the boat-shaped 8brood-chamber0 7,fig4 #bbc1 st4 #g71 on the ventral surface4 7d7 ,the spiracles4--,in the thin membrane between the dorsal and ventral plates1 at the junction of two abdominal segments1 look for a small hole 7spiracle7 leading into the interior of the body4 ,how many abdominal spiracles can you find on each side8 ,observe the two larger spiracles on each side of the thorax1 between the first and second1 and the second and third legs4 ,what is an insect4--,the word insect is so commonly applied to animals having no claim whatever to the title1 that it is advisable to point out at once some of the features which distinguish insects from other animals with which they are often confused4 ,insects1 spiders1 crustaceans1 centipedes1 and their near relatives1 all have jointed bodies and legs1 which are covered by a continuous suit of armour of a substance called chitin4 ,in some cases1 as in lobsters and crabs1 this is for the most part hardened by mineral matter to form a stout shell1 being soft and flexible only at the joints where ease of movement is required4 ,in other cases the layer of chitin may remain thin and delicate1 and all gradations between the two extremes may be found4 ,though soft where movement of one part on another takes place1 the chitin is always firm enough1 elsewhere1 not only to form a protection for internal organs1 but also to afford attachment to the muscles which move the body and limbs4 ,it is therefore a skeleton1 but as it is on the outside of the body it is called an exoskeleton1 to distinguish it from the internal skeleton 7p4 #bbd7 of the vertebrata4 ,animals such as insects1 spiders1 centipedes1 and crustaceans1 which have jointed bodies and legs1 and are covered by a chitinous exoskeleton1 are called arthropods4 ,insects may be at once distinguished from all other arthropods by the single pair of feelers and the six legs4 ,many of them1 but not all1 possess wings--structures which are found in no other arthropods4 ,insects are always air-breathers when adult4 ,the cockroach4--,the cockroach is not a general favourite1 but it displays so well the essential features of insect structure that it affords an excellent introduction to the study of the more popular members of the class1 which in many respects are highly specialised4 ,it is also easily obtained1 and of fairly large size4 ,the body of the cockroach 7,fig4 #bbj7 is very distinctly divided into three regions3 7#a7 the head 7,fig4 #bba7 which carries the feelers1 the eyes 7ey47 and the jaws 7man41 max41 and max472 7#b7 the thorax1 separated from the head by the slender neck1 and bearing the legs and the wings2 and 7#c7 the abdomen1 which bears neither jaws nor limbs4 ,illustration3 ,,fig4 #bbj4--;,cockroach1 male1 seen from above4 7 #a47 ,the head 7,fig4 #bba7 hangs nearly vertically from the neck4 ,the large1 compound eyes 7ey47 are somewhat kidney-shaped2 the long1 jointed feelers are set in sockets just below the eyes4 ,the front of the head is smooth and rounded2 hinged on its lower edge is a flap which hangs down in front of the mouth1 and is called the labrum or upper lip4 ,just behind the labrum1 and attached to the side and front plates of the head1 is the first pair of jaws1 the mandibles 7man41 ,fig4 #bba2 ,mn41 ,fig4 #bbb72 they work from side to side1 and their inner edges1 which bite against each other1 are strongly toothed4 ,the second pair of jaws1 called the first pair of maxillae 7max41 ,fig4 #bba2 ,mx4 #a1 ,fig4 #bbb7 is situated behind the mandibles4 ,each first maxilla consists of a two-jointed base and two branches2 the inner branch bites against the inner branch of the first maxilla of the other side1 while the outer and longer branch forms the maxillary palp1 which acts as a small feeler4 ,the two second maxillae 7the third pair of jaws7 are broadly like the first maxillae1 but are partially fused to form the labium or lower lip 7,fig4 #bbb1 ,mx4 #b71 which hangs down behind the mouth4 ,the outer branches of the second maxillae are called the labial palps 7,lab4 ,pa474 ,it is well to acquire clear notions of the arrangement of the jaws in the cockroach1 in order to understand the great modification which the mouth-parts of many other insects have undergone4 ,it is important to notice that the jaws of all arthropods work from side to side1 not vertically as do the jaws of vertebrates4 ,illustration3 ,,fig4 #bba4--;,cockroach4 ,the head and its appendages seen from the left side4 cerv41 one of the neck-plates2 ey41 eye2 gen41 side plate of head2 man41 mandible2 max41 first pair of maxillae2 max41 second pair of maxillae 7labium74 7 #e47 ,the thorax consists of three segments1 each of which bears a pair of legs1 upon which the weight of the resting or walking insect is supported4 ,it has been found1 by instantaneous photography1 that in a walking insect the weight is carried at any instant by the first and third legs of one side and the second leg of the other side4 ,at the next step the body is carried by the remaining three legs4 ,in the ,american 7,fig4 #bbj7 and ,german cockroaches both sexes possess two pairs of wings1 which are fixed at the front angles of the second and third segments of the thorax4 ,the hind-wings1 which alone are used in flight1 are folded up fanwise when not in use1 and are covered by the smaller fore-wings1 which are generally called the wing-covers4 ,in the common cockroach of this country1 only the male has well developed wing-covers and wings4 ,in the female the wing-covers remain small1 while the wings themselves have disappeared4 ,illustration3 ,,fig4 #bbb4--;,jaws of the ,cockroach4 ,mn41 mandibles2 ,mx4 #a1 first pair of maxillae2 ,mx4 ,pa41 maxillary palp 7outer branch72 ,la41 ,ga41 inner branch2 ,mx4 #b1 second pair of maxillae 7labium72 ,lab4 ,pa41 labial palp 7outer branch72 ,la41 ,ga41 inner branch4 7 #h47 ,the abdomen consists of ten segments1 although only eight can be clearly seen without dissection4 ,the 8telescopic0 arrangement of the segments is well shown in ,fig4 #bbc4 ,where one segment joins the next1 the chitin remains thin and flexible4 ,in each segment the chitin forms a dorsal 7p4 #bag7 and a ventral plate1 which are joined together at the sides by a flexible membrane4 ,the chitinous covering of the upper surface of the abdomen is so transparent that the heart1 a median tube1 may be seen through it4 ,how an insect breathes4--,if the sides of the abdominal segments be carefully examined1 a small aperture will be seen perforating the thin layer of chitin between the dorsal and ventral plates1 at the point where each segment joins the next2 and1 in the thorax1 larger but similar openings will be found on each side between the first and second and the second and third legs4 ,these holes are called spiracles 7,fig4 #bbc1 spir472 they lead into a complex system of air-tubes which ramify throughout the whole system and supply the organs with oxygen4 ,the tubes are prevented from collapsing by a spiral lining thread of chitin4 ,this peculiar method of respiration1 which is characteristic of insects1 should be carefully contrasted with the manner of breathing in a rabbit or a man 7p4 #bdb7 and in a tadpole 7p4 #cdd74 ,it ought to be borne in mind1 however1 that the essence of respiration is the same in all living things1 and consists in a replacement of excess carbon dioxide by fresh oxygen 7p4 #bdb72 the difference lies merely in the manner of effecting the exchange4 ,in the rabbit1 the blood1 carrying the excess of carbon dioxide1 is brought to the air 7in the lungs72 in the tadpole it is exposed1 in the gills1 to the dissolved air of the surrounding water2 while in the cockroach the air is carried directly to the tissues needing fresh oxygen4 ,the air of the tubes is renewed by a rhythmic action of the abdomen1 which can readily be observed in the living insect4 ,the internal organs4--,figs4 #afc and #bbc1 which represent a general dissection of a frog and of a cockroach respectively1 exhibit in the most striking manner the essential differences in the structure of vertebrates and arthropods4 ,the fact that the skeleton of the frog is wholly internal and that of the cockroach wholly external1 has already been mentioned4 ,it will be seen1 further1 that while in the frog the central nervous system 7the brain and spinal cord7 lies entirely dorsal to the digestive canal1 in the cockroach the great nerve chain 7,fig4 #bbc1 n1 n17 is mainly ventral--the only dorsal part of the central nervous system being the so called brain 7brn471 which is connected with the ventral chain by a ring surrounding the gullet 7gul474 ,the heart of the frog is ventral to the digestive canal2 that of the cockroach is the most dorsally placed organ of the body4 ,illustration3 ,,fig4 #bbc4--;,cockroach2 general dissection of female from the left side4 abd4 #a1 first1 and abd4 #e1 fifth abdominal segments2 brn41 8brain02 cer41 cercus2 c4gl41 glands which form the egg-case2 cr41 crop2 f41 feeler2 giz41 gizzard2 gul41 gullet2 int41 intestine2 lab4 pa41 labial palp2 mx4 pa41 maxillary palp2 n1 n1 nerve chain2 r4 ov41 right1 and l4 ov41 left ovary2 sal4 du41 salivary duct2 sal4 gl41 salivary gland2 spir41 spiracles2 st4 #g1 brood-chamber2 th4 #a1 first1 th4 #b1 second1 and th4 #c1 third thoracic segments4 7 #b47 ,habits and life-history4--,cockroaches infest kitchens and pantries2 they are of social habits1 and hide together in crevices during the day1 but come forth at night to feed4 ,they are not at all fastidious as to diet1 but are especially fond of starchy foods1 which they are able to digest 7p4 #bcd7 by means of the fluid formed in their large salivary glands 7,fig4 #bbc1 sal4 gl474 ,the eggs are laid sixteen at a time in a little oblong case1 which the female carries about in a boat-shaped receptacle 7st4 #g1 ,fig4 #bbc7 at the end of her abdomen1 until she finds a suitable place in which to deposit it4 ,when the little cockroaches hatch1 they are quite white1 but except for the absence of wings they closely resemble the parents in form1 and run about and feed freely from the first4 ,the chitinous exoskeleton is shed from time to time as the animal increases in size1 a new coat1 at first soft and wrinkled1 but rapidly stretching and hardening1 having previously formed beneath the old one4 ,shortly before the last moult1 the wing-covers and wings begin to grow out from the angles of the second and third thoracic segments4 ,in this manner the young animal gradually takes on the form and dimensions of the adult4 ,the position of the cockroach in the insect class4--,the cockroach is familiarly known as the 8black-beetle10 but the name is a very misleading one1 because the true beetles differ from cockroaches not only in structure1 but also in life history4 ,cockroaches are grouped with earwigs1 grasshoppers1 crickets1 and locusts in the order ,orthoptera1#bh a term alluding to the fanlike folding of the hind-wings4 #fc4 ,a ,,water ,,beetle4#bi #a4 ,the habits of ,dytiscus4--,search a pond for water beetles4 ,put them in a wide-mouthed bottle with some of the weeds to be found in the pond1 and take them home and observe their habits4 ,among the larger beetles--especially from ponds with a clear surface 7not covered with duckweed1 etc47--will probably be seen some with a yellow band round the edge of the upper surface4 ,these are ,dytisci4 ,notice the ovoid1 smooth body1 the breadth of the hind legs1 and--in the male--the cup on each fore leg4 ,try to see how the legs of each pair are used4 ,on what does the animal feed8 ,take a small piece of meat in a pair of forceps and hold it near the beetle's head4 ,if the animal does not notice it1 stroke one of the feelers with the meat2 how does the beetle behave8 ,what is the use of the feelers8 ,notice how the beetle rises to the surface immediately it stops paddling4 ,which end of the body sticks out of the water8 ,why does the beetle need to come to the surface8 ,in ,april look for larvae 7,fig4 #bbd1 ,a71 and describe their appearance and habits4 #b4 ,external characters4--,kill a ,dytiscus by dropping it for a moment into boiling water4 ,examine it first from the dorsal surface1 noting the almost unbroken oval outline1 and the firmness of the armour4 ,notice that the inner edges of the two wing-covers fit closely together in the middle line4 ,how does the beetle compare in this respect with the cockroach8 ,observe the small triangular plate between the anterior ends of the wing-covers2 open out the covers and wings to find of which segment of the thorax it is a part4 ,examine the wing-covers and wings closely2 notice that the wings are folded transversely as well as longitudinally4 ,spread and pin out one wing-cover and wing of one side1 and draw a dorsal view of the animal4 ,dissect out the jaws and compare them with the jaws of the cockroach 7,fig4 #bbb74 ,examine and draw one leg of each pair4 ,the bordered little diver4--,in nearly every ,english pond there at times occurs a beetle--an inch or more in length--which is known to naturalists as ,dytiscus marginalis4 ,the name is somewhat cumbrous1 but it would be difficult to find a more appropriate one2 for 8bordered little diver0--the plain ,english of the scientific term--indicates at once the peculiarities which soonest strike the observer3 the creature's skill in diving1 and the yellow band which runs round the edge of the olive-green body4 ,the outline of the beetle is an almost unbroken oval1 and it is worth noticing that either such a boat-shape 7,fig4 #bbd1 ,b71 or the cigar-shape of the torpedo is adopted by almost all actively swimming aquatic animals4 ,the resistance of the water is further lessened by the smoothness of the beetle's armour1 which forms a hard shell enclosing the body4 ,as in all insects1 the body is divided into head1 thorax1 and abdomen4 ,the eyes are large1 and are so arranged that the animal can at the same time see objects both above and below--a great advantage to a creature living so active a life4 ,the feelers are very sensitive organs of touch1 and possibly of smell also4 ,the jaws consist of one pair of mandibles and two pairs of maxillae1 and are shaped much like those of the cockroach2 they are powerful1 and render ,dytiscus a very formidable enemy to the more peaceable inhabitants of the pond4 ,illustration3 ,,fig4 #bbd4--;,a beetle of the ,dytiscus family4 ,a1 larva2 ,b1 adult insect 7male74 ,the thorax consists of the usual three segments1 but only the first and a small triangular area of the second are to be seen until the wing-covers are pulled aside4 ,these last differ from the wing-covers of the cockroach not only in being much harder and stronger1 but also in their inner edges meeting accurately along the middle line of the body4 ,the delicate1 filmy wings1 which alone are of use in flight1 are folded transversely as well as longitudinally4 ,on the lower side of the thorax are three pairs of legs2 they are very interesting and are worth examining in some detail4 ,in the male1 the first leg on each side is furnished with little circular areas which were at one time believed to be suckers4 ,it is now known1 however1 that they give off a sticky substance which adheres firmly to any object clasped by the legs4 ,the middle pair of legs seems to be used chiefly for steering4 ,in both sexes the third or last pair of legs is modified to form a pair of sculls4 ,ordinary land-beetles can move their legs in a vertical direction1 as well as in a horizontal one2 but the hind legs of water-beetles are jointed to the thorax in such a manner that they can only move backwards and forwards1 not up and down4 ,the resemblance of the hind leg to an oar does not stop here1 however4 ,on one side there is a fringe of stiff hairs1 forming the blade of the oar4 ,the joint carrying the hairs is so arranged that the beetle can 8feather0 its oar--by turning the edge of the blade to the water--at each stroke4 ,occasionally1 usually after sunset1 the beetle quits his watery home1 and 8wheels his droning flight0 in search of pastures new4 ,his flights are1 however1 only temporary and merely from one pond to another4 ,although ,dytiscus thus normally lives in water1 very cursory observation only is needed to see that he cannot exist without a regular supply of fresh air4 ,he no sooner stops paddling than his body rises naturally to the surface1 and as the tail is lighter than the head1 it rises out of the water4 ,the wing-covers are now raised a little1 so that the space between them and the wings is put into communication with the outside air4 ,the impure gas contained in this space is soon replaced by a bubble of fresh pure air1 the wing-cases are lowered1 and the 8little diver0 plunges once more into the depths4 ,the water is prevented by hairs from getting into the air-space below the wing-cases1 and the true wings are thus kept always dry4 ,the spiracles 7p4 #cee7 are in communication with the air-space1 so that the animal is enabled to remain below the surface for a relatively long time4 ,the life-history of ,dytiscus4--,in ,march or ,april the female ,dytiscus lays her eggs in slits which she cuts in the submerged stems of pond-weeds1 and the eggs hatch in about three weeks4 ,the creature which emerges from the egg is of active habits1 but is not at all like the parent in appearance4 ,a young animal which leads an independent and self-supporting life1 and differs markedly in structure from the adult1 is called a larva4 ,thus a tadpole is a larval frog1 and a caterpillar is the larva of a butterfly or moth4 ,the larva of ,dytiscus when of full size is about #b inches in length4 ,like other larvae of its family 7,fig4 #bbd1 ,a71 it has six slender legs1 which serve both for swimming and for crawling over the bottom of the pond1 and its head is provided with a pair of sickle-shaped mandibles1 with which it seizes its prey4 ,each mandible is grooved on its inner side1 the groove being converted into a tube by a membrane which covers it in4 ,the savage larva sucks the blood of its victim until literally nothing is left but the shrivelled husk4 ,at the end of the ,dytiscus larva's tail are two appendages which are fringed with hair4 ,when the creature wishes to breathe it comes to the surface1 and the tip of its tail protrudes out of the water4 ,as each of the appendages just mentioned is pierced with a hole which leads into one of the two main air-tubes of the body1 an interchange of vitiated for pure air readily takes place4 ,when the larva is about six weeks old1 it leaves the pond and buries itself in the soil on the banks4 ,its exoskeleton is shed1 and a thin1 transparent layer of chitin--the 8pupa-skin0--takes its place4 ,in this condition the animal sinks into a state of torpor1 and apparently becomes as motionless as a mummy4 ,in this resting stage it is called a pupa4 ,the pupal stage is necessary for the completion of the great changes--commenced some time previously--which must take place before the larva can acquire the structure of the adult4 ,the pupal stage lasts two or three weeks1 and when at last the creature emerges from its cell it is a beetle like its parents4 ,in consisting of three well-marked stages1 the life-history of a beetle thus differs essentially from that of a cockroach4 ,all beetles agree with ,dytiscus in this respect1 though in manner of life almost every conceivable variation is found4 ,the beetle-order of insects receives its scientific name--,coleoptera#cj--;from the sheathing character of the strong and closely-fitting wing-covers4 ,the wings themselves are large1 and folded in a somewhat complex manner4 ,the mouth parts greatly resemble those of the cockroach4 #fd4 ,,butterflies ,,and ,,moths4#ca #a4 ,cabbage-white butterflies4--7a7 ,the eggs4--,in ,may or ,september1 search the leaves of cabbages1 turnips1 and other crucifers 7p4 #ie7 for the tiny eggs of cabbage-white butterflies4 ,do the eggs occur singly or in clusters8 ,are they found on the upper or the lower surface of the leaf8 ,cut off a piece of leaf which carries eggs1 put it under a tumbler1 and examine it every day until the larvae 7caterpillars7 emerge from the eggs4 7b7 ,the larva4--,have ready a 8breeding-cage10 i4e4 a box measuring1 say1 #ah0 #h0 #f01 one large face of which is of perforated zinc or fine wire gauze1 and the other of glass2 the box should be without bottom1 so that it can be placed over a food-plant4 ,put the larvae1 with leaves of the plant on which they were found1 under the box1 and observe them carefully4 ,replace all rotted or soiled leaves by fresh ones4 ,it is best to keep the food-plant in a bottle of wet sand inside the case2 the leaves then remain fresh for several days4 ,describe the appearance of the caterpillar2 notice its general worm-like form and absence of wings4 ,in the head1 observe the small feelers1 and watch the action of the mandibles in feeding4 ,behind the head come the three segments of the thorax2 notice that each bears a pair of short1 jointed legs4 ,how many segments can you see in the abdomen8 ,which of the abdominal segments bear legs or feet8 ,how do these differ from the thoracic legs8 ,look for the spiracles 7p4 #cee7 at the sides of the body4 ,which segments have spiracles8 ,kill a full-fed caterpillar by immersing it in methylated spirit1 or by putting it into a small box with a few drops of ether 7a most inflammable liquid7 or chloroform4 ,when it is dead1 examine it more closely4 ,try to make out the mouth-parts clearly2 they are best seen from the back of the head4 ,the labium 7p4 #cec7 is here represented by a conical body called the spinneret1 out of which come the silken threads used to protect the pupa4 7c7 ,the pupa4--,when the larva is full-fed1 it seeks out a sheltered place1 and fixes itself in position by means of silk threads which issue from the spinneret2 the larval skin is shed and replaced by a pupal skin1 and the animal remains quiescent until the change from larva to butterfly is complete4 ,examine the manner of attachment of the pupa to its support4 ,kill a pupa by immersion in methylated spirit1 or by dipping it for a moment in boiling water2 carefully strip off the skin1 and make a drawing of the animal4 ,especially notice the arrangement of the wings and legs4 7d7 ,the imago or winged insect4--,when the internal organs of the butterfly are completed1 the pupal skin splits1 and the perfect insect comes out4 ,look for pupae between ,september and ,march1 or in ,july1 and try to see the transformation4 ,notice the method of flight of the butterfly1 and the position in which the wings are held when it settles4 ,at what time of the day1 and in what kind of weather1 have you seen cabbage-whites flying8 ,kill a butterfly by putting it into a bottle containing crushed laurel leaves1 or a few lumps of potassium cyanide 7a deadly poison7 wrapped in blotting paper1 and examine it closely4 7i7 ,the head4--,notice the large1 compound eyes1 the knobbed feelers1 the long and coiled proboscis1 and the labial palps 7which look like tusks74 7ii7 ,the thorax4--,the true form of the thorax and abdomen is concealed by the hairs which clothe the body4 ,wet the body with methylated spirit to make the hairs lie down4 ,notice that the first and third segments of the thorax are very small1 while the middle segment1 which carries the fore-wings1 is large4 ,observe that the fore-wings are not modified into wing-covers1 but are1 generally speaking1 much like the hind-wings4 ,determine the sex of the specimen by means of ,fig4 #bbe4 ,notice that1 when you touch a wing1 a little white dust comes off on your finger2 the dust consists of very small scales4 ,do both surfaces of the wings bear scales8 ,with a rather stiff camel-hair brush1 brush the scales from the wings of one side4 ,what markings have been removed1 and what new markings have been made clear1 by the removal of the scales8 ,how many legs has the butterfly8 7iii7 ,the abdomen4--,count the segments4 #b4 ,the tiger moth4--,in early summer examine lettuce1 strawberry1 and nettle leaves for 8woolly bears0--the hairy caterpillars of the tiger moth4 ,keep these in the breeding-cage with the food-plants1 and observe and describe their appearance and habits4 ,how do they behave when alarmed8 ,watch them spin their cocoons 7pupa cases7 about the end of ,june1 and describe the process4 ,examine the pupa1 and state in what respects it differs from the caterpillar4 ,about the end of ,july watch for the emergence of the perfect moth4 ,notice the position of the wings of a resting moth4 ,are they held like those of a butterfly8 ,kill and examine the moth1 and compare it further with a butterfly4 ,especially notice 7a7 ,that the feelers of the tiger moth are not knobbed at the ends1 but are either thread-like 7in the female7 or comb-like 7in the male72 and 7b7 ,that a bristle at the base of the hind-wing hooks on a catch in the fore-wing of the same side4 #c4 ,the vapourer moth4--,about the end of ,june examine rose trees1 fruit trees1 willows1 oaks1 etc41 for caterpillars of the vapourer moth4 ,they may be recognised 7,fig4 #bbh7 by the reddish warts and the tufts of hair which stand out from various parts of the body4 ,notice that the caterpillars fall into two groups according to size1 being1 when full-grown1 about #b in4 and #a in4 long respectively4 ,keep the larvae in a breeding-cage until they pupate and change into moths2 notice that the moths 7the females7 which come from the large caterpillars have no wings2 while the male moths1 which are derived from the small caterpillars1 have well-developed wings4 ,a typical butterfly4--,the great beauty of butterflies and moths1 and the ease with which the stages of their wonderful life-history can be followed1 have made these insects favourite objects of study among naturalists of all ages4 ,among the commonest of butterflies are the well-known cabbage-whites1 the caterpillars of which work so much havoc upon crops of cruciferous plants 7p4 #ie74 ,the eggs are laid in ,may and ,september upon the leaves1 and soon hatch out into small larvae called caterpillars1 which feed voraciously and grow rapidly4 ,the larval skin is shed from time to time as it becomes too small4 ,the caterpillar 7,fig4 #bbe1 ,a7 is somewhat worm-like in appearance1 but insect characters may easily be recognised in it4 ,the head is small and shiny4 ,it carries six eye-spots1 but the large compound eyes of the adult are not yet visible4 ,a pair of short feelers is present2 and the mouth-parts are obviously comparable with those of the cockroach1 although the labium 7p4 #cec7 has become converted into a spinneret1 which gives out the silk threads used for the protection of the pupa4 ,the mandibles1 which are used in gnawing leaves1 are stout and toothed2 the first maxillae are rather small4 ,behind the head come the three segments of the thorax1 each of which bears a pair of short jointed legs2 wings have not1 as yet1 developed4 ,the abdomen really consists of ten segments1 although only nine can be seen without dissection4 ,segments #c to #f of the abdomen bear short1 unjointed legs called pro-legs or cushion feet1 and the last segment bears a pair of appendages called the anal feet4 ,spiracles are to be seen on the first eight abdominal segments4 ,in the larva of the green-veined cabbage-white1 each spiracle is reddish and surrounded by a yellow border4 ,illustration3 ,,fig4 #bbe4--;,cabbage ,white ,butterfly4 ,a1 larva2 ,b1 pupa2 ,c1 perfect insect4 7,all 47 7,b and ,c from photographs by ,mr4 ,a4 ,flatters7 ,when the caterpillar has attained its full size1 it stops feeding and seeks out a sheltered place--often a chink in a wall4 ,silken threads are given off by the spinnerets until a little heap of silk is formed into which the hooked end of the abdomen is fixed4 ,then a girdle of silk is made1 passed round the thicker fore-part of the body1 and so attached to the wall that the animal is supported in an upright position4 ,the larval skin now splits and is peeled off1 and the pupa1 or chrysalis1 stage 7,fig4 #bbe1 ,b7 is entered upon4 ,all the external parts of the butterfly are complete at the time of pupation1 but profound changes are still necessary in the internal organs2 it is to allow these changes to take place in tranquillity that the resting1 or pupal1 stage is interposed between larval and adult life4 ,at last the new organs are ready for their work1 the pupal skin cracks1 and the perfect insect 7,fig4 #bbe1 ,c7 emerges4 ,the head now carries a pair of large compound eyes1 and two slender feelers with knobbed ends4 ,the jaws also have been remodelled in accordance with the completely different manner of life upon which the insect is now entering4 ,the mandibles are now only doubtfully recognisable2 the first pair of maxillae are elongated and grooved1 and are closely applied to each other to form a long tube called the proboscis 7,fig4 #bbf1 ,mx4 #a71 which1 when not in use for sucking up the sweet juices of flowers1 is kept coiled up beneath the head2 the palps of the labium 7,lab4 ,pa47 project like tusks on the sides of the head4 ,the thorax is provided with two pairs of broad wings1 which are covered with minute overlapping scales--forming a delicate 8bloom0 which is readily detached by rough handling4 ,in many butterflies and moths the scales are gorgeously coloured and arranged in symmetrical patterns4 ,the name ,lepidoptera1#cb which is applied to this order of insects1 was suggested by the scaly covering of the wings4 ,when the butterfly is at rest the wings are either fully expanded horizontally1 or are held vertically over the back1 the upper surfaces of the fore wings being in contact4 ,the first segment of the thorax1 which bears the first of the three pairs of legs1 is greatly reduced2 the third segment also is but small4 ,illustration3 ,,fig4 #bbf4--;,a1 ,head of a ,lepidopterous insect2 ,b1 the labium2 ,ant41 feeler2 ,e1 eye2 ,lab4 ,pa41 labial palp2 ,mx4 #a1 proboscis2 ,mx4 ,pa41 maxillary palp 7magnified74 ,in short1 the whole organisation of a butterfly is definitely adapted to the special duties which belong to this period of its life4 ,the growing stage is over2 the sole object of life is now to seek a mate and--in the case of the female--to lay the eggs in a place where the future larvae may find plenty of food4 ,ease of locomotion and conspicuousness are secured by the broad and brilliantly-coloured wings2 the peculiar manner of flight is considerable protection against the attacks of birds2 large eyes aid in the recognition of the mate2 and a concentrated and easily-digested food is supplied by the nectar of flowers1 and made accessible by the long1 sucking proboscis--the service of cross-pollination 7p4 #ib7 often being unconsciously rendered in return for the sweet draught4 ,the common species of cabbage-white butterflies spend the winter as pupae2 the perfect insects emerge in ,april1 lay their eggs1 and then die4 ,the caterpillars pupate and a second generation of butterflies appears1 their offspring reaching the pupa stage about the end of autumn4 ,moths4--,moths pass through a life-history which is identical1 in its broad features1 with that of butterflies4 ,the larva which hatches from the egg is a caterpillar1 whose life is spent in feeding and growing4 ,at the same time the external features of the adult are gradually taking form under the skin4 ,when at last the full larval size is attained1 and a resting stage is necessary for the perfection of the internal organs1 the caterpillar's skin splits1 and is shed1 and the animal becomes a pupa or chrysalis4 ,a moth-pupa is generally somewhat egg-shaped 7,fig4 #bbg71 whereas the pupa of a butterfly is usually conical1 though there are many exceptions4 ,the winged moth1 which at length emerges from the pupal skin1 differs from a butterfly in certain obvious respects4 ,its body is usually broad and thick2 its feelers are either comb-like or thread like1 not knobbed at the ends2 the two wings of one side are in most cases secured together at the base by one or more bristles on the hind-wing hooking over a catch on the fore-wing2 in rest1 the wings usually slope and are not fully extended4 ,whereas butterflies usually fly only in the sunshine1 moths often fly by night1 and the flowers which night-flying moths frequent for nectar are as a rule white and strongly-scented1 and close during the day4 ,in finding their mates1 moths seem to depend largely upon the sense of smell1 which is probably lodged in the feelers4 ,illustration3 ,,fig4 #bbg4--,stages of ,tiger ,moth4 ,a1 ,caterpillar1 from left side2 ,b1 pupa 7removed from cocoon71 ventral view2 ,c1 perfect insect 7female74 7,from a photograph by ,mr4 ,a4 ,flatters47 7 _/47 ,the life-history of a typical moth is well exemplified by the ,tiger ,moth 7,fig4 #bbg71 which is easily reared in captivity4 ,the larva--often called the 8woolly bear10 from its thick covering of hair--may be found in early summer on the leaves of lettuce1 strawberry1 nettle1 and other plants4 ,it pupates about the end of ,june1 working its hair1 together with silk spun by the spinneret1 into a cocoon1 in which the resting stage is passed4 ,about a month later the perfect moth emerges2 its fore-wings are beautifully mottled with cream colour and chocolate brown2 the hind-wings are red1 with metallic violet spots4 ,the feelers of the male are comb-like1 and are probably very sensitive organs of smell1 by means of which he seeks out his mate4 ,the female's feelers are thread-like4 ,in the ,vapourer ,moth 7,fig4 #bbh71 whose 8looping0 flight may often be observed even in the streets of towns during the day1 the two sexes are remarkably different from each other4 ,the male 7,c7 alone can fly2 the female 7,d7 is wingless1 and is confined for the whole of her short adult life to the place where she emerged from the cocoon4 ,here she lays her eggs and then dies4 ,neither she nor her mate is capable of feeding4 ,illustration3 ,,fig4 #bbh4--,stages of ,vapourer ,moth4 ,a1 ,larva 7male72 ,b1 male pupa2 ,c1 male moth2 ,d1 female moth4 7,from a photograph by ,mr4 ,a4 ,flatters47 7 47 ,it would be difficult to find a more striking example of the fact that the one duty of the adult moth is reproduction4 ,the female vapourer is even debarred from the privilege of choosing favourable places for her eggs2 but a compensation for this disadvantage lies in the agility of the larvae 7,a71 which are able to migrate without difficulty to another plant whenever food becomes scarce4 ,as ,prof4 ,miall remarks3#cc 8,whatever the larva can do for itself1 the female can safely leave undone2 but what the larva cannot do1 by reason of sluggishness or restricted diet1 the parent must provide for4 ,hence activity and intelligence in the one lead to degeneration in the other4444 ,wings are to insects what spores are to ferns1 plumed seeds to dandelions1 and hooked seeds to burrs--a ready means of dispersal40 ,other insects4--,space does not permit of more than a reference to other insects1 and the work of this chapter is to be regarded as the merest introduction to the study of this fascinating class of animals4 ,the chief remaining orders are the ,neuroptera1 including ,may flies1 dragon flies1 and caddis flies2 the ,hemiptera1 among which are included the various 8bugs10 water boatmen1 plant lice1 etc42 the ,diptera 7two-winged flies71 such as the house-fly1 gnat1 harlequin fly1 daddy-long-legs1 etc42 and the ,hymenoptera1 including bees1 wasps1 ants1 gall flies 7p4 #adf71 and ichneumons4 ,many of these insects have aquatic larvae which may be found in ponds2 and their life-histories should be studied in aquaria and careful notes made of the transformations4#cd ,,exercises ,,on ,,chapter ,,xix4 #a4 ,examine the following animals1 and find out 7a7 which are arthropods1 7b7 which are insects3 tortoise1 spider1 grasshopper1 lobster1 earwig1 centipede4 ,give reasons for your conclusions4 #b4 ,keep a grasshopper under a tumbler with a small sod of grass4 ,observe its habits1 and find out how it 8chirps40 ,compare its structure with that of the cockroach4 #c4 ,compare a cockchafer with a water-beetle4 ,in what order of insects would you place the cockchafer1 and why8 #d4 ,compare other water-beetles with ,dytiscus1 and try to trace their life-history4 #e4 ,observe the habits and examine the structure of the water-boatman4 ,what reasons can you find for excluding it from the beetle-order8 #f4 ,examine a daddy-long-legs1 and try to find the two stumps which are all that remain of the hind-wings4 #g4 ,look for 8blood worms0 7larvae of the harlequin fly7 in horse-troughs and sluggish streams in summer2 keep them in a saucer of water with a few dead leaves4 ,observe their habits and describe the appearance of the pupa4 ,what kind of insect emerges from the pupa8 #h4 ,keep caddis-worms in an aquarium and describe their habits4 #i4 ,examine the leaves of stinging nettles for caterpillars in ,june1 and try to rear butterflies from them4 ,carefully notice from which kind of caterpillar each butterfly is derived4 #aj4 ,look for caterpillars of the ,privet ,hawk ,moth on privets and lilacs on ,august and ,september evenings4 ,keep some1 with earth and twigs of the food plant1 in a covered flower-pot1 and observe their method of pupation4 #aa4 ,compare the colouration of the wings of butterflies and moths with that of the plants they most frequent1 and describe any cases of protective colouration which you find4 ,,footnotes3 #bh ,greek3 orthos1 straight2 pteron1 a wing4 #bi ,see ,footnote1 p4 #cgb4 #cj ,greek3 koleos1 a sheath2 pteron1 a wing4 #ca ,living eggs1 larvae1 and pupae of ,lepidoptera may be obtained from ,mr4 ,h4 ,w4 ,head1 ,burniston1 near ,scarborough1 and other dealers4 #cb ,greek3 lepis1 a scale2 pteron1 a wing4 #cc ,injurious and ,useful ,insects 7,bell74 #cd ,miall's ,injurious and ,useful ,insects 7,bell71 and ,natural ,history of ,aquatic ,insects 7,macmillan71 are strongly recommended as guides to further work4 ,,chapter ,,xx4 ,,some ,,crustaceans1 ,,molluscs1 ,,and ,,worms4 #fe4 ,,some ,,common ,,crustaceans4 #a4 ,the crayfish and lobster4--7a7 ,habits4--,readers in limestone districts will probably be able to find crayfishes in the streams1 and the habits of the animals in their natural surroundings should be observed and described4 ,other readers will be able to obtain live specimens from dealers4#ce ,place the animal on the table or desk4 ,notice that the body consists of an anterior1 unsegmented portion1 the cephalothorax 7corresponding to the head plus the thorax of an insect71 and a posterior1 jointed abdomen4 ,watch the movements of the stalked eyes1 the feelers and legs2 allow the claws of the largest pair of legs 7the 8pincers07 to grasp a pencil4 ,put the crayfish in a white dish1 with an inch or two of water1 and by means of a pipette discharge a few drops of water containing some suspended colouring matter1 such as carmine or indigo1 near the point of attachment of the last walking leg4 ,describe the movements of the coloured water4 ,when the animal is startled1 notice the sudden vertical flexure of the abdomen1 by means of which the body is pulled backward in the water4 ,feed the crayfish with meat or worms1 and try to see the action of the jaws4 7b7 ,external characters4--,kill the crayfish instantaneously by dropping it into boiling water4 ,compare the animal with a cockroach 7p4 #cdi74 ,examine more closely the stalked eyes1 the two pairs of feelers1 the four pairs of walking legs and the single pair of large pincers1 and the fusion of the head and thorax to form the cephalothorax4 ,count the segments of the abdomen4 7c7 ,the appendages4--,examine the ventral surface of the abdomen1 and notice that each segment1 except the last1 bears a pair of small jointed organs2 these are called swimmerets4 ,remove one of the pair carried by the last segment but two1 examine and draw it2 make out that it consists of a stalk and two branches4 ,notice that the branches of the swimmerets of the last segment but one are expanded1 and form1 with the last segment1 the tail fin4 ,study the appendages of the cephalothorax from behind forwards4 ,they consist of 7i7 four pairs of legs used for walking1 and a larger pair of pincers2 7ii7 three pairs of foot-jaws or maxillipedes2 7iii7 two pairs of maxillae2 7iv7 one pair of mandibles2 7v7 two pairs of feelers4 7d7 ,the gills4--,with strong scissors cut off the side part of the exoskeleton of the cephalothorax1 and notice the plume-like gills in the gill-chamber thus laid open4 ,move the adjoining legs1 and see that some of the gills also move4 #b4 ,the crab4--,obtain a crab and compare it1 point by point1 with the crayfish1 or lobster4 ,notice the great width of the shell of the cephalothorax2 much of this width is due to the gill-covers1 which stand out from the sides of the true body4 ,look for the opening of the gill-chamber at the base of the pincers4 ,make out the stalked eyes 7in sockets71 the two pairs of feelers1 and the five pairs of legs4 ,notice how the animal runs2 in what respects does the method differ from the gait of the crayfish8 ,examine the ventral surface of a dead specimen1 and notice that the abdomen is tucked under the cephalothorax4 ,stretch out the abdomen2 compare it with that of the crayfish1 and count the segments4 ,notice the absence of the tail fin2 it is not required1 as the crab does not swim4 ,extend the abdomen1 and make drawings of the animal 7i7 from above1 and 7ii7 from below1 and label the parts4 ,carefully remove the foot-jaws and the true jaws1 and compare them with the corresponding appendages of the crayfish4 ,with strong scissors cut off one of the gill-covers1 and examine the gills4 ,observe that in the crab the gills are not in any case attached to appendages2 they all spring from the sides of the body-wall4 ,tabulate the respects in which you have found the crayfish and crab 7i7 to agree with1 7ii7 to differ from1 insects4 ,illustration3 ,,fig4 #bbi4--;,crayfish1 seen from the right side4 ,the appendages are numbered in ,arabic and the abdominal segments in ,roman numerals4 ant4 #a1 first1 and ant4 #b1 second1 feelers of the right side2 c4th41 cephalothorax2 ,e1 eye2 g4c41 gill-cover4 7 47 ,the student who has worked through ,chapter ,,xix4 will at once recognise in a crayfish1 or a lobster1 an animal possessing many features in common with the insects1 and will find it interesting to try to discover for himself why it is not called an insect1 but is placed by naturalists in a different class4 ,the crayfish4--,the crayfish 7,fig4 #bbi71 or the lobster 7which agrees closely in structure with the crayfish71 is obviously an arthropod 7p4 #cea71 for it is covered by an exoskeleton of chitin1 and has hollow jointed limbs and a segmented body4 ,in these respects it agrees with the insects4 ,on the other hand1 it plainly possesses at least five pairs of legs1 and has two pairs of feelers 7ant4 #a and ant4 #b1 ,fig4 #bbi71 whereas no insect has more than three pairs of legs 7when adult71 or more than one pair of feelers4 ,illustration3 ,,fig4 #bcj4--;,crayfish2 the right gill-chamber and gills as seen after removal of the right gill-cover4 a1 a1 feelers2 #f-ac1 sixth to thirteenth appendages2 xiv1 xv1 first and second abdominal segments2 ,e1 eye2 ep4 #e1 scoop on second maxilla2 g4ch41 gill-chamber2 pdb4 #g1 gill attached to seventh appendage2 pdb4 #ab1 gill attached to twelfth appendage2 plb4 #ac1 gill on body-wall above thirteenth appendage4 7,slightly reduced47 ,these differences are apparent at the first glance1 and closer examination reveals even greater contrasts4 ,the three primary divisions of the body into head1 thorax1 and abdomen1 which are so characteristic of insects1 are not obvious in the crayfish2 for the head and thorax are here fused into one mass1 the cephalothorax#cf 7,fig4 #bbi1 c4th471 which is covered by a shield called the carapace4 ,moreover1 in the crayfish every segment except the last bears a pair of appendages1 which vary in form in different regions of the body according to their duties1 but which can all be shown1 by careful comparison1 to be modifications of one primitive form1 which is ,y-shaped and consists of a basal stalk and two branches4 ,this form of appendage is well seen in the swimmerets 7#ag1 ,fig4 #bbi7 of the abdominal region2 further forwards the appendages become walking legs 7#i-ac1 ,fig4 #bbi72 next come three pairs which combine the characters of legs and jaws1 and are called maxillipedes 7#h1 ,fig4 #bbi72 then are the true jaws--two pairs of maxillae1 and one pair of biting and crushing mandibles2 and lastly1 in front of the jaws1 two pairs of feelers 7ant4 #b and ant4 #a74 ,it is believed that the first pair of feelers corresponds to the single pair of feelers of the cockroach2 that the jaws correspond to the jaws2 that the maxillipedes of the crayfish are the equivalents of the walking legs of the cockroach2 while the remaining appendages of the crayfish have no representatives in the insect4 ,lastly1 the crayfish differs essentially from the insect in its method of respiration 7p4 #cee71 for it is an aquatic animal and breathes dissolved oxygen4 ,it therefore possesses neither lungs nor spiracles but gills 7,fig4 #bcj74 ,these are situated at the sides of the true body-wall1 in gill-chambers formed by the downgrowth of the sides of the carapace4 ,the gills are delicate plumes1 containing fine blood-vessels1 so that an exchange of gases readily takes place between the blood and the surrounding water4 ,on each side1 a scoop 7,fig4 #bcj1 ep4 #e7 on the second maxilla is continually baling water out of the front of the gill-chamber1 fresh water flowing in from behind to take its place4 ,certain of the gills are attached to the legs1 so that the motion of the legs also is some assistance to respiration4 ,illustration3 ,,fig4 #bca4--;,crab2 ,a1 from above1 ,b1 from below1 ant4 #a1 first1 and ant4 #b1 second feelers2 abd4 #c1 third1 and abd4 #g1 seventh abdominal segments2 ,e1 eye2 l4 #a1 pincers2 l4 #e1 last walking leg2 mxp1 third maxillipede4 7 47 ,the crab 7,fig4 #bca7 is markedly different in shape from the crayfish or lobster1 but is nevertheless easily seen to be built on essentially the same lines of structure4 ,it also consists of twenty segments1 of which the first thirteen are fused to form a cephalothorax2 and the appendages of this region are quite comparable with those of the crayfish4 ,the great width of the shell is largely due to the gill-covers1 which stand out from the sides of the body much further than do those of the crayfish4 ,as a result the crab finds it easy to run side-first4 ,the crab is essentially a walking1 not a swimming1 animal1 and the abdomen--upon which the crayfish and lobster so much depend in swimming--is in the crab reduced in size and kept tucked under the cephalothorax4 ,illustration3 ,,fig4 #bcb4--,the ,wood-louse4 7 #a47 ,crustaceans4--,these facts are sufficient to show that the title 8insect0 cannot with any propriety be given to either the crayfish or the crab1 unless1 indeed1 the term is to be applied to all arthropods indiscriminately4 ,the crayfish1 lobsters1 shrimps1 prawns1 crabs1 barnacles1 and many less-familiar animals1 are placed in the crustacean class of arthropods4 ,crustaceans have usually a distinct head1 thorax1 and abdomen2 but some of the thoracic segments may be fused with the head to form a cephalothorax 7p4 #cge74 ,like other arthropods1 the animals are covered with an armour of chitin1 and in many cases this is so hardened1 except at the joints1 by mineral matter that it becomes a rigid shell or crust4 ,the head bears two pairs of feelers in addition to the jaws2 and the segments of the thorax and abdomen are provided with appendages which are variously modified as jaw-feet1 legs1 swimmerets1 etc4 ,typically1 the animals breathe by gills and are aquatic1 but forms are known which are able to live comfortably on land if the gills are kept moist4 ,one of the most interesting examples of this is found in the common wood-louse 7,fig4 #bcb71 which lurks under stones and logs in damp and dark situations1 and breathes by plate-like gills on the abdominal segments4 ,other arthropods4--,other familiar arthropods1 which are neither insects nor crustaceans1 are spiders and centipedes4 ,the spiders belong to the arachnid class1 and the centipedes to the myriapod class of arthropods4 #ff4 ,,some ,,common ,,molluscs4#cg #a4 ,the fresh-water mussel4--7a7 ,habits4--,study the habits of the living animal 7,fig4 #bcc7 in the aquarium4 ,notice the muscular foot which is protruded between the halves 7valves7 of the shell1 and by means of which the mussel slowly makes its way along the sandy bottom4 ,with a pipette1 discharge some water1 coloured with carmine or indigo1 close to the more pointed end of the shell4 ,where is the coloured water taken in1 and where is it expelled8 ,notice that the shell closes when the animal is handled4 7b7 ,the regions of the shell4--,the rounded end is anterior1 the more pointed end posterior1 the straight hinge-line dorsal1 and the gape ventral4 ,notice the knob-like umbo on each side near the anterior end of the hinge2 it is the oldest part of the valve4 ,make out the concentric lines of growth1 showing the successive positions of the margin4 ,draw the shell from the right side and from above4 7c7 ,general structure4--,kill the mussel by putting it for a few minutes into hot1 but not boiling1 water4 ,notice that the valves of the shell now gape apart somewhat4 ,hold up the animal and see1 lining the shell1 a thin soft membrane1 the mantle4 ,carefully separate the mantle from one valve and notice1 near each end1 a thick white pillar which passes from one valve to the other4 ,these pillars are the closing muscles4 ,pass the blade of a knife between the mantle and valve1 and cut through each closing muscle quite near to the valve4 ,turn the valve back and remove it from the other valve by cutting through the elastic ligament 7at the hinge7 with strong scissors4 ,clean the inside of the separated valve and examine it2 notice 7i7 the line of attachment of the mantle2 7ii7 the impressions of the closing muscles2 7iii7 the lines of shifting of the closing muscles--triangular depressions stretching from the umbo to the muscles4 ,examine the animal as it lies in the other valve4 ,make out3 7i7 ,the right and left lobes of the mantle which line the valves and 7in the natural position of the mussel7 hang down from the sides of the body2 7ii7 the two plate-like gills on each side1 lying between the mantle and the foot2 7iii7 the median foot2 7iv7 the reddish1 triangular palps surrounding the mouth--an aperture at the anterior end of the foot4 ,push a stout pin into the mouth and upwards into the gullet4 ,make a drawing showing the relative positions of the parts4 #b4 ,the garden snail4--7a7 ,habits4--,where have you seen snails8 ,at what time of the year are they most active8 ,upon what do they feed8 ,place a snail upon a lettuce leaf and carefully watch its method of eating4 ,how does it move about8 ,put a live snail upon a sheet of glass1 and look through the glass to see the wave-like action of the flat sole--the foot--by means of which it moves4 ,have you ever found snails in winter8 ,how much of the animal was visible8 ,how is the mouth of the shell closed in winter8 7b7 ,general appearance4--,make a drawing of the animal from the left side and another from the right side1 and notice the differences between the two4 ,is the shell placed over the middle of the animal1 or does it lie to one side8 ,how many turns has the spiral of the shell8 ,in a fully expanded snail observe the fleshy 8collar0 round the margin of the shell2 it is the edge of the mantle4 ,notice the rounded head1 the two pairs of tentacles1 the eye-spot at the tip of each of the larger and upper tentacles1 the mouth1 and1 near the base of the shell on the right side1 the respiratory pore1 which opens into the lung4 ,touch various parts of the body in turn to see if they are irritable2 how are the tentacles retracted8 ,can the animal close and open its respiratory pore at will8 #c4 ,an air-breathing pond-snail4--,obtain several fresh-water snails and study their habits in glass aquaria4 ,the commonest fresh-water snails are species of ,limnaea2 identify some of these by comparison with ,fig4 #bcd1 ,a1 and try to make out the parts already seen in the garden snail4 ,watch the action of the mouth as the animal feeds on the green scum which often collects on the sides of aquaria4 ,notice how it creeps over the glass or along the surface-film of the water4 ,when the snail comes to the surface it replaces the air of its lung by fresh air1 and a bubble may often be seen escaping from the respiratory opening under the lip of the shell4 ,look for the spawn 7egg-masses7 of this snail on leaves or on the sides of the aquarium1 and examine the eggs frequently with a hand lens4 ,illustration3 ,,fig4 #bcc4--;,fresh-water ,mussel4 ,a1 from left side2 ,b1 from behind4 ft1 foot2 in4 sph41 inhalant siphon2 ex4 sph41 exhalant siphon2 lg1 ligament2 m1 mantle2 um1 umbo4 7 47 7,after ,howes47 ,molluscs4--,molluscs are soft-bodied animals1 in most cases protected by a hard1 external shell1 but they differ essentially from crustaceans and all other arthropods in not being segmented1 and in not possessing jointed limbs4 ,familiar and instructive examples of two classes of the group are found in the fresh-water mussel and the garden snail4 ,the fresh-water mussel 7,fig4 #bcc7 is to be found in streams1 along the bed of which it ploughs its way by means of a muscular foot 7ft474 ,the body is enclosed in a brown shell1 which consists of halves called valves1 hinged together along the straight1 dorsal edge by an elastic ligament 7lg474 ,the action of the ligament is to separate the valves slightly unless they are forcibly held together by the contraction of closing muscles which run from one valve to the other4 ,hence the shell of a dead mussel always gapes open4 ,the rounded end of the shell is anterior1 the more pointed end posterior4 ,the oldest part of each valve is the umbo 7um41 ,fig4 #bcc71 a knob just in front of the ligament2 and concentric lines surrounding the umbo mark successive positions of the margin of the valve as the animal increased in size4 ,the valves are formed by the activity of the mantle lobes 7m47--a pair of delicate membranes which hang down from the sides of the body4 ,the foot is a median prolongation of the body itself1 and on each side a pair of plate-like gills lies between the foot and the mantle lobe of that side4 8,thus the whole animal has been compared to a book1 the back being represented by the hinge1 the covers by the valves1 the fly-leaves by the mantle lobes1 the first two and the last two pages by the gills1 and the remainder of the leaves by the foot40#ch ,when the living mussel is undisturbed1 the mantle folds project slightly at the hinder end of the shell1 their edges being so placed in contact that they form two short tubes4 ,a current of water flows in at the lower of these 7in4 sph41 ,fig4 #bcc71 carrying to the mouth a supply of food-particles1 and to the gills and mantle a store of dissolved oxygen2 while an outgoing current leaves by the upper tube 7ex4 sph474 ,the garden snail 7,fig4 #bcd1 ,b7 seems at first sight to have but little resemblance to a mussel2 but it also is a mollusc--consisting of a soft1 unsegmented body1 which is produced ventrally into a foot1 and is protected by a shell formed by the activity of a mantle fold of the body4 ,in this case1 however1 the shell is one piece1 and is spirally coiled4 ,the snail has also a distinct head1 which bears two pairs of tentacles2 at the tip of each of the longer and upper tentacles 7t7 is an eye 7e74 ,the animal crawls about by wave-like contractions of the muscular foot2 it feeds upon vegetation1 which it rasps into small particles by means of a toothed tongue1 and then swallows4 ,the snail is entirely adapted to a terrestrial life1 and breathes air--the mantle fold under the shell enclosing a lung chamber with blood-vessels in its walls1 which opens to the exterior by a respiratory pore 7p4o41 ,fig4 #bcd7 on the right side4 ,the snail spends the winter1 in a state of torpor1 under logs or stones1 the body being entirely retracted into the shell1 the mouth of which is closed by a plate of hardened slime4 ,illustration3 ,,fig4 #bcd4--;,a1 ,a ,fresh-water ,snail 7,limnaea72 ,b1 ,garden ,snail4 e1 e1 eyes2 p4o41 respiratory pore2 t1 t1 tentacles1 7 #a47 ,illustration3 ,,fig4 #bce4--,slug1 p4a41 respiratory pore4 7 #a47 ,slugs 7,fig4 #bce7 are of very similar structure1 but in them the shell has almost disappeared1 even the trace which remains being concealed by the mantle fold4 ,among the commonest of fresh-water snails are various species of ,limnaea 7,fig4 #bcd1 ,a74 ,they may be found abundantly in ponds1 and are often kept in aquaria1 where they perform a useful service by devouring the minute plants which are apt to accumulate to an undesirable extent and form green scum on the sides4 ,these snails1 like the garden snail1 breathe air1 and often come to the surface to take a fresh supply into their lung chambers4 ,some other water snails1 however1 breathe dissolved oxygen by means of gills beneath the shell4 #fg4 ,,earthworms4 #a4 ,external characters4--,dig up several earthworms from the soil and examine them4 ,what is the length of the largest and of the smallest specimens8 ,what is the thickness of the body8 ,watch the worms crawling about1 and describe the method of locomotion4 ,has the animal any legs8 ,do the length and thickness of any one worm vary during its movements8 ,is the variation connected with locomotion8 ,how8 ,can you distinguish between the fore 7anterior7 and hind 7posterior7 ends1 and between the upper 7dorsal7 and lower 7ventral7 surfaces8 ,how do they differ8 ,kill a large worm by immersion in methylated spirit and examine it more closely4 ,notice the segmented character of the body1 and estimate the number of segments4 ,which part of the body has the largest segments8 ,observe the swollen appearance of segments #cb to #cg2 this region is called the clitellum4 ,notice the mouth 7overhung by a short lobe7 in the first segment1 and the vent in the last segment4 ,on the ventral surface of segment #ad try to see a pair of small pores2 these pores are the openings through which the eggs are discharged from the body4 ,pull the worm gently between your fingers1 and notice the bristly feel2 in which direction of motion is this most apparent8 ,examine the ventral surface with a strong lens in a good light1 and try to see four double rows of very small bristles4 #b4 ,habits4--,examine the surface of the ground of a garden or lawn at night by help of a lantern or lamp1 being careful to tread lightly1 and observe the actions of any worms you see4 ,are more worms to be seen at night than during the day8 ,do the worms seem disturbed by the light of the lantern8 ,try to grasp one2 is it easily caught8 ,why not8 ,where does the worm retreat8 ,if you can grasp a worm before it has time to withdraw completely into its burrow1 observe the difficulty of drawing it out without tearing it4 ,try if the worms are disturbed by a loud shout 7be careful not to blow upon them when shouting71 or by a heavy stamp of your foot4 ,carefully lay open several burrows and notice3 7a7 ,whether the mouths of the burrows are plugged in any way1 and1 if leaves are used for this purpose1 whether the leaves have been dragged into the hole 7i7 by the broad ends1 7ii7 by the narrow ends1 or 7iii7 by the sides2 do you find any signs of intelligence in the method adopted8 7b7 ,the length and width of the burrow and the character of its lining4 7c7 ,the end of the burrow2 is it enlarged8 ,examine worm castings4 ,mark out a square yard of surface and collect1 dry1 and weigh all the castings found on this area in a certain time1 say a month4 ,such observations should be made at different periods of the year1 and over different kinds of soil1 and comparisons made4 ,estimate the weight brought up per acre by worms during a year4 ,are the particles composing the castings very fine1 fine1 or coarse8 ,place worms in glass-covered flower-pots with earth of different degrees of firmness1 and observe the methods of burrowing in loose and in firmly compacted earth respectively4 ,place pieces of leaf of carrot1 onion1 and cabbage on the surface1 and at night observe how the worms grasp the pieces and drag them into the burrows4 ,earthworms4--,few people except naturalists have any idea of the vast number of earthworms living in the surface soil of this and most other countries1 or of the importance of the work which they do4 ,the common earthworm 7,fig4 #bcf7 is much simpler in structure than any of the animals previously considered in this book4 ,it is roughly cylindrical in shape1 though somewhat flattened on the ventral surface4 ,it is divided into about #aej segments1 which are marked on the exterior by grooves running round the body4 ,the mouth is an opening in the first segment 7,fig4 #bcf1 #a7 and is overhung by a short fleshy lobe4 ,the worm crawls along by alternate elongation and shortening of its body1 being aided by short bristles which are directed backwards and act as pivots2 limbs are entirely absent4 ,the animal is very sensitive to touch1 even to the vibrations of the ground2 but it is stone-deaf1 only just capable of distinguishing between light and darkness1 and has very little sense of smell4 ,illustration3 ,,fig4 #bcf4--;,earthworm1 seen from right side4 #a1 #ae1 #cc1 first1 fifteenth1 and thirty-third segments4 7 47 ,during the day1 the earthworm generally remains in its burrow in the soil1 with its head just inside the entrance4 ,its method of forming the burrow depends upon the texture of the ground4 ,in loose soil the earth is simply pushed aside1 but where the material is too compact for this1 the animal actually eats its way through4 ,the burrow is lined with soft earth or little stones1 and is plugged at the mouth with leaves or other convenient objects4 ,the animal was found by ,darwin to display distinct intelligence in its manner of drawing leaves into the mouth of its burrow1 seizing them in most cases by their narrow ends1 so that they could be pulled in with as little difficulty as possible4 ,objects are generally grasped between the lobe1 which overhangs the mouth1 and the lower part of the first segment1 the hold being maintained by a sucking action4 ,the inner end of the burrow is enlarged to allow the worm room to turn round4 ,at night1 the fore part of the body is protruded in search of food1 the tail being generally retained in the burrow1 ready for instantaneous retreat in case of alarm4 ,the earthworm feeds upon leaves--which are first softened by a fluid discharged over them1 and then sucked into pieces small enough to be swallowed1 for the animal has no jaws--and upon the half-decayed organic matter which is always present in ordinary soil4 ,the soil itself is swallowed in large quantities2 the nutritious portion is extracted1 and the undigested matter deposited upon the surface of the ground1 near the mouth of the burrow1 in the form of castings4 ,as a result of numerous experiments1 ,darwin estimated the weight of castings thus thrown up by earthworms on an acre of land as #ae tons annually4 ,the following passage is worthy of very careful attention3 8,when we behold a wide1 turf-covered expanse1 we should remember that its smoothness1 on which so much of its beauty depends1 is mainly due to all the inequalities having been slowly levelled by worms4 ,it is a marvellous reflection that the whole of the superficial mould over any such expanse has passed1 and will again pass1 every few years through the bodies of worms4 ,the plough is one of the most ancient and most valuable of man's inventions2 but long before he existed the land was in fact regularly ploughed1 and still continues to be thus ploughed by earthworms4 ,it may be doubted whether there are many other animals which have played so important a part in the history of the world as have these lowly organised creatures40#ci ,the earthworm lays its eggs in a small cocoon formed by the hardening of a viscid material which is discharged by a swollen part of the body called the clitellum1 extending from the #cbnd to the #cgth segments4 ,after the formation of the cocoon the worm moves backwards1 and the eggs leave the body by small pores on the ventral surface of segment #ad1 as this region passes the cocoon4 ,a small amount of food-material is also enclosed in the cocoon1 and forms a store of nutriment for the young worms during their early development4 ,,exercises ,,on ,,chapter ,,xx4 #a4 ,compare the legs of a cockroach with those of a crayfish and a vertebrate4 7#aijj7 #b4 ,describe the respiratory organs of the crayfish4 ,how are they continually supplied with fresh water8 7#ahih7 #c4 ,examine a spider4 ,how many legs has it8 ,of what divisions does its body consist8 ,why do you consider that a spider is not an insect8 #d4 ,make observations1 and write descriptions1 of the habits of spiders1 paying special attention to the methods of construction of the webs1 the manner of catching prey in different cases1 and the care of the young by the parents4 #e4 ,compare a centipede with an insect1 pointing out the features of resemblance and difference4 7#ahig7 #f4 ,how does a pond-mussel open and close its shell8 7#aijj7 #g4 ,compare an oyster with a fresh-water mussel1 and try to find points of resemblance and difference1 making careful notes and sketches of these4 ,how many closing muscles has the oyster8 ,are its gills plate-like8 ,why do you consider the oyster a mollusc8 #h4 ,where is the lung of a snail situated8 ,how do we know that it is really a lung8 7#ahig7 #i4 ,how does an earthworm resemble and differ from a caterpillar8 7#aijj7 #aj4 ,explain the action of an earthworm in the formation of vegetable mould4 7#ahig7 #aa4 ,classify the animal described below3 ,a land animal with a long narrow soft body and no legs2 two pairs of tentacles on the head2 a breathing hole on one side8 7#aijd7 #ab4 ,give the characters by which insects can be distinguished from crustaceans4 7#aije7 ,,footnotes3 #ce ,living specimens may be obtained from ,mr4 ,t4 ,bolton1 #be ,balsall ,heath ,road1 ,birmingham4 #cf ,greek1 kephalon1 a head4 #cg ,see footnote1 p4 #cgb4 #ch ,parker and ,haswell's ,text-book of ,zoology 7,macmillan74 #ci ,darwin's ,vegetable ,mould and ,earthworms 7,murray74 ,,chapter ,,xxi4 ,,field-,,work4 ,an animal or a plant must be studied from several points of view before its manner of life can be understood in any real sense4 ,it must1 for example1 be regarded1 first1 as a complicated piece of machinery1 every part of which is beautifully fitted for the performance of a special duty2 it must also be considered as an individual1 having likes or dislikes--or at least tendencies--which are to some extent peculiar to itself2 finally1 it must be considered in its relation to other animals and plants1 and to its surroundings4 ,field-work is especially concerned with the last of these methods of study--the observation of living things under natural conditions1--and this ought constantly to be borne in mind4 ,to make nature-study a pretext for uprooting locally-rare plants and robbing birds' nests is indefensible4 ,the commonest plants are usually the most instructive1 and afford ample material for the beginner's experimental work2 while the pleasure of finding and describing 7perhaps photographing7 a bird's nest1 and of keeping the eggs and young under observation1 is something unknown to the mere collector of eggs4 ,the life of both plant and animal is sacred in the eyes of every nature-student worthy of the name4 ,at the same time1 no sentimentality ought to prevent the destruction of undoubtedly noxious insects and weeds4 ,in general1 however1 specimens should be killed only for the purpose of a leisurely examination of structure1 which would otherwise be impossible1 or to make needed additions to the teaching-collection of a school museum4 ,generally speaking1 collecting is of very doubtful value1 except to experts4 ,insects and common plants may1 however1 be collected without scruple by the beginner1 though it is worth remembering that the most perfect specimens of butterflies and moths are those reared in captivity from the eggs1 larvae1 or pupae4 ,the student is strongly recommended to make a sketch map of some small area to which he has easy access1 and to record upon this the positions of features of special interest4 ,such a map may1 in the first instance1 be copied on an enlarged scale from an ordnance map of the neighbourhood1 which may be obtained at the local free library4 ,it will be advisable to duplicate the drawing by means of one of the many appliances for such work1 and to keep one copy each for trees1 flowering plants1 birds' nests1 etc4--the position of each object1 or of a well-defined group1 being carefully marked by a small number 7,fig4 #bcg71 and the reference1 with the date1 being filled in on the margin4 ,the varying character of the ground--sandy1 marshy1 clayey1 etc4--should be indicated by diagrammatic shading or colouring4 ,by following this method the student will more clearly realise that different plants are dependent upon different conditions of soil1 drainage1 etc42 and that1 e4g41 plants at home on a bleak moor1 in a hedge1 in marshy land or in water respectively1 are characteristically modified so that they can make the best of their special conditions of life4 ,in this manner he will1 almost unconsciously1 gain wider views of the relationships which exist between the facts learned from his more detailed observations4 ,it would be a distinct gain to biological science if field clubs also would adopt some such plan1 each member undertaking to fill in upon his map information of the animal and plant life of the area allotted to him4 ,the co-operation of various clubs1 and the systematic arrangement of information thus obtained1 would result in a store of knowledge of the highest value4 ,many animals are so shy that they can only be approached with difficulty4 ,in such cases it is especially necessary for the observer to move quietly and silently1 and1 when a favourable position is reached1 to remain as motionless as possible1 preferably with his back to the sun4 ,if a field-glass can be obtained it will be of great assistance1 but some practice will probably be required before it can be used easily4 ,it is well to start each ramble with some definite object of study in view--either trees1 grasses1 flowers1 fruits1 birds1 caterpillars1 or pond life1 for example1 and to be provided with pill-boxes1 bottles1 etc41 according to circumstances4 ,a notebook1 pencil1 pocket knife1 and hand lens should1 however1 always be carried1 and observations should be recorded on the spot4 ,pond life4--,practically the only method of gaining a real knowledge of aquatic organisms is by the help of the aquarium4 ,specimens may be obtained by means of a net1 or of a small wide-mouthed bottle tied to a stick4 ,a pickle bottle is convenient for carrying home the material collected4 ,the conditions of a natural pond should be imitated as closely as possible in the aquarium4 ,at first1 some little difficulty will probably be found in obtaining the necessary balance between the animals and plants of the aquarium4 ,when this has been reached1 it will only rarely be necessary to change the water1 provided that dead or sickly specimens are promptly removed4 ,,the ,,school ,,journey4 ,in the organisation of school journeys so much depends upon local conditions of various kinds1 so much must of necessity be left to the initiative of the teacher1 that it is manifestly impossible here to do more than enunciate certain general principles4 ,in the first place1 it should be borne in mind constantly that the primary object of the school journey is the cultivation of habits of thoughtful observation2 and that the chief danger to be guarded against is that out-of-focus condition into which the mind1 like the eye1 inevitably falls when it is concerned with too many things at once4 ,to obviate this danger the teacher should go over the route in advance1 noting carefully the features1 physical and otherwise1 which afford material for observation and investigation by the class4 ,the order in which these features may be best studied should be decided upon1 and a scheme of several visits1 each to be concerned with one special subject of study1 can then be drawn up4 ,such a preliminary survey should suggest a plan by which every member of the class may be allotted a definite task--to find something or do something1 or to solve some problem on the spot4 ,these principles may be best illustrated by a special example1 but it will be obvious that the same ideas1 with modifications in detail1 may be applied in any district4 ,the sketch-map 7,fig4 #bcg7 illustrates a walk through ,healey ,dell1 near ,rochdale1 ,lancashire4 ,the rocks which are exposed at various places along the route belong to the ,carboniferous formation1 and are composed of shale1 coal1 or millstone grit4 ,the object of the first journey will be in most cases to familiarise the class with the 8lie of the land0 and the most obvious features of the scenery4 ,as a preparation1 lessons should be given on the points of the compass and the various methods of finding the direction of the north4 ,the simplest of these is by the use of the compass3 it being remembered that the needle points about #af to the west of true north4 ,a second method depends on the fact that at noon the sun is in the south and that therefore 7because the hour hand of a watch makes two revolutions in the twenty-four hours7 the north and south line approximately bisects the angle between twelve and the hour hand1 if the latter is pointed to the sun when the watch is horizontal4 ,incidentally1 the method of finding the pole-star might be also explained to the class4 ,further1 each pupil should be encouraged to find out how many steps he takes1 on the average1 in pacing a given measured distance4 ,if the general direction of the walk is north and south1 as in the example1 it will be found best to begin the first journey at the south end 7in this case from ,shawclough ,station71 since to most children it is easier to conceive of a journey northward than in any other specified direction4 ,throughout the ramble constant reference should be made to the direction of the route and the relative positions of well-marked features of the landscape4 ,the distances between certain points should be estimated1 and1 whenever possible1 measured 7by pacing71 and notes made by the class4 ,for example1 from ,shawclough to ,ending the distances and directions are roughly3 -mile ,w4,n4,w41 -mile ,n4,n4,w41 -mile ,e4,n4,e4 ,in the first journey also the class should be made to notice where the ground slopes most and where least 7the direction and angle of slope should be estimated in a few cases71 and the names of neighbouring woods1 farms1 etc41 should be learnt4 ,the direction of flow of the river and the various bends in its course should also be noted1 and reference made to the route by which1 after joining those of other rivers1 its waters ultimately reach the sea4 ,afterwards1 the pupils should write an account of the journey and1 in the higher classes1 should be encouraged to draw a sketch-map1 however crude1 from memory4 ,illustration3 ,,fig4 #bcg4--,sketch-map of ,healey ,dell1 ,rochdale4 #a1 birches2 #b1 willows2 #c1 beech2 #d1 potholes2 #e1 two waterfalls2 #f1 shallows1 and vertical concave bank2 #g1 8,fairies' ,chapel02 #h1 stratification of rocks2 #i1 mud deposits2 #aj1 waterfall2 #aa1 docks2 #ab1 sloping trees2 #ag1 weir2 #ad1 railway viaduct2 #ae1 horse chestnut2 #af1 aqueduct2 #ag1 sycamore2 #ah1 elm2 #ai1 elm2 #bj1 beech2 #ba1 pond life2 #bb1 well2 #bc1 shale2 #bd1 sycamore2 #be1 oak1 bearing leaves in winter2 #bf1 flagstones2 #bg1 beeches1 with wood-pigeons' and magpies' nests2 #bh1 hawthorn hedge2 #bi1 solitary oak2 #cj1 gutter1 with ,pellia2 #ca1 blackberry bush2 #cb1 stunted oak4 ,illustration3 ,g4 ,a4 ,close1 photographer1 ,rochdale4 ,,fig4 #bch4--,waterfall1 ,healey ,dell1 ,rochdale 7marked 8#aj0 in ,fig4 #bcg74 ,before the second journey each pupil should be provided with a blank sketch-map of the route4 ,this may1 in the first instance1 be copied or traced from the six-inch ,ordnance ,map1 and then duplicated in large numbers4 ,only the route and river1 and a few of the more conspicuous landmarks1 should be indicated on the maps as given to the class3 details should be filled in1 on the spot1 by the pupils4 ,the object of the second journey may conveniently be the study of the river and its work1 and for this purpose it will be advisable to follow the stream in the direction of its flow4 ,variations in the speed of the current1 and in the width of the stream and the hardness of the rocks or banks between which the water flows1 should be noted1 and the relations between cause and effect elicited by questioning4 ,the hardness of the rocks at #d has prevented the channel from being widened to a greater extent by the water1 and accounts for the rapidity of the flow4 ,a glass of water collected here is found to contain much suspended gravel4 ,the considerable loss of weight of bodies in water is noteworthy1 as explaining the great size of the stones which may be transported by rivers4 ,the scouring action of such stones is shown in the fine 8potholes0 at #d and below the waterfall 7,fig4 #bch7 at #aj1 and has resulted also in the quaint stone portico of the 8,fairies' ,chapel0 under the right 7west7 bank of the river at #g4 ,again1 the difference in the rates of erosion of hard and soft rocks has had much to do with forming the waterfalls at #e and #aj4 ,where the stream is wider and the flow slower 7as at #f and #i1 and below #aj71 may be noticed sand and mud deposits2 and where the stream makes a bend it is found that the slowest flow and the maximum deposit are on the convex bank2 while the concave bank is worn almost vertical 7as at #f and other places7 by the swifter rush of the water1 and may be undercut to such an extent as to cause the bank to give way4 ,in this manner a river is constantly changing its course4 ,the weir at #ac1 and the old water-wheel still to be seen in the ruined mill below1 suggest remarks on the motive power of water1 and on the circumstances which may cause the old industries of a district to be superseded by new ones4 ,along the rest of the route the bed of the river is less steep and its banks exhibit less variation1 but they still afford plenty of material for study4 ,the railway viaduct at #ad and an aqueduct at #af suggest at least a casual reference to the derivation of the terms4 ,before the pupils are asked to write a 8composition0 on the ramble1 a revision lesson on the features noticed should be given1 and the accuracy of the entries on the sketch-maps checked by comparison with an enlarged map drawn by the teacher1 or with a large 8parish plan0 of the ,ordnance ,survey1 on the scale of #be4c inches to the mile4 ,it will be well to devote two or more journeys to the study of the trees along the route4 ,one journey should be taken in the spring1 before the leaves are out1 and another in the summer1 when the foliage is well developed4 ,it is far better to study three kinds of trees in some detail than to risk confusion at the beginning by attending to a dozen4 ,in ,healey ,dell the commonest trees are beech1 oak1 and sycamore1 and these serve admirably as an introduction to tree lore4 ,if the first tree-journey be taken in the summer1 the leaves of some three abundant species should be compared and contrasted1 and each pupil should secure good specimens1 to be drawn and preserved afterwards4 ,the presence of a little bud in the 8axil0 7the upper angle between leaf and twig7 of most of the leaves should be pointed out by the teacher2 and since the arrangement of the buds 7and therefore of the subsequent branches of the twig7 thus depends on the positions of the leaves1 this last point is of considerable interest4 ,in the sycamore1 the leaves are in pairs at right angles to each other2 in the beech and oak they are single and alternate1 but much more crowded together in the oak than in the beech4 ,the bark of the three trees is equally distinctive1 and with the method of branching 7obscured when the foliage is thick7 serves to identify the trees from a distance in the winter4 ,in winter and spring the interest of a tree is centred in its buds1 and there are few things which more richly repay study4 ,in spring1 attention should also be given to the flowers--generally arranged in catkins--of common trees4 ,separate sketch-maps should be used as records of the positions of the more notable trees or plantations along the route4 ,any tendency to vandalism on the part of the pupils by tearing off branches should1 of course1 be sternly repressed2 especially interesting twigs should1 on occasion1 be cut off by the teacher only1 for later study4 ,there is much diversity of opinion as to the way in which flowers may be best studied in a limited number of school journeys4 ,in most cases it will perhaps be impracticable to attempt more than teaching the names and calling attention to the habitat of the commonest4 ,this1 though a necessary introduction to the subject1 tends to degenerate into a mere exercise of the memory1 and in itself possesses little educational value4 ,it should be supplemented by a detailed examination of a typical flower--say a buttercup--and by the explanation of the work of each part4 ,once the pupil has understood that the single duty of a flower is the production of healthy seeds1 and has been led to notice how1 by the aid of ingenious devices1 the up-to-date plants have learnt to call in the aid of insects1 while the more conservative families still rely on the aid of the wind1 he will be eager to discover for himself 8how the thing works40 ,with young children it is folly to attempt any but the very broadest principles of classification of flowers2 but quite young children can appreciate the advance from flowers without petals1 through flowers with separate petals1 to those with petals united to form a tube 7thus restricting the nectar more and more to 8useful0 insects72 and so understand the advantage which a primrose has over a buttercup1 and a buttercup over an oak flower4 ,at least one journey should be given1 in the autumn1 to the study of the dispersion of fruits and seeds4 ,the pupils should provide themselves with empty match-boxes or chip pill-boxes4 ,in this ramble the class may with advantage be divided into four groups4 ,group ,a will collect examples of fruits and seeds which are dispersed by the wind2 ,group ,b1 of fruits which by means of hooks or otherwise become attached to the hides of grazing animals1 and are carried far from the place where they grow2 ,group ,c will collect fruits which tempt animals to eat them for the sake of sweet pulp 7in these cases the pupils should find out a how the fruit is made conspicuous1 b how the seeds themselves are protected from being injured by the animals72 while ,group ,d will search for specimens of plants which sow their own seeds4 ,there still remains abundant material for study in this walk1 and mention only can be made of the sticklebacks1 frog-spawn1 snails1 caddis-worms1 dragon fly larvae1 blood-worms--of the 8things creeping innumerable1 both small and great beasts0--which have been found in the river1 ponds1 and wells along our route1 and have been used to stock the aquarium2 of the rabbits and birds2 of the nests of ants and wild bees and wasps2 of a certain blackberry bush 7#ca7 rich in interesting leaves2 and of a thousand and one other things which1 under the guidance of a judicious leader1 may well be the means of teaching children to see what they look at and to think about what they see4 ,for this is the first and last object of the school journey4 ,,monthly ,,nature ,,calendar4#dj ,,january4 ,,plant ,,life4 ,general4--,as in ,december 7p4 #dbb74 ,plants usually in flower4--,shepherd's purse1 daisy1 snowdrop1 and a few others4 ,,animal ,,life4 ,general4--,as in ,december 7p4 #dbb74 ,mammals4--,bats 7p4 #bee7 reappear at the end of the month4 ,birds4--,missel thrush 7p4 #cjf7 sings4 ,insects4--,winter pupae of butterflies and moths 7,chap4 ,,xix47 may be found4 ,,february4 ,,plant ,,life4 ,general4--,as in ,december4 ,plants usually in flower4--,shepherd's purse1 daisy1 snowdrop1 hazel1 and a few others4 ,hedges are now clipped2 study the effect which this treatment has upon subsequent growth4 ,corn4-- ,barley and oats are sown4 ,liverworts4--,spore-cases of ,pellia 7p4 #bjj7 become visible4 ,,animal ,,life4 ,general4--,as in ,december4 ,mammals4--,bats reappear4 ,birds4--,thrushes and blackbirds pair and begin to build2 study differences in song 7pp4 #cjd and #cjh74 ,rooks repair and build nests 7p4 #cah74 ,frogs4 7p4 #ccb7 reappear4 ,insects4--,pupae of cabbage-white butterflies and other ,lepidoptera may be found4 ,,march4 ,,plant ,,life4 ,general ,work for ,spring ,months4--,study the germination of seeds and the early stages of growth of the new plants 7,chap4 ,i472 the structure and methods of unfolding of buds 7,chaps4 ,,iv4 and ,,viii472 the movements of young twining stems2 8bleeding0 of stems1 and paths of food-currents 7,chap4 ,v472 and examine and collect spring flowers 7,chaps4 ,,vi41 ,,vii41 and ,,viii474 ,plants usually in flower--,shepherd's purse1 marsh marigold1 wild plum1 daisy1 dandelion1 daffodil1 snowdrop1 hazel1 alder1 willow1 poplar1 elm1 and others4 ,horsetail4--,fertile haulms 7p4 #aie7 appear4 ,corn4--,barley and oat sowing continued4 ,,animal ,,life4 ,general ,work for ,spring ,months4--,study the development of frogs and toads 7,chap4 ,,xviii47 and insects 7,chap4 ,,xix472 the development and education of the chick 7,chap4 ,,xvi472 the nesting-habits of birds 7,chap4 ,,xvii472 the education and play of lambs and other young mammals 7,chap4 ,,xiv472 the habits of molluscs 7,chap4 ,,xx472 and the work of earthworms 7,chap4 ,,xx474 ,stock aquaria4 ,mammals4--,lambs are born4 ,birds4--,thrushes1 blackbirds1 skylarks1 rooks1 and other birds lay eggs4 ,fieldfares and redwings begin to depart4 ,frogs and ,toads lay their eggs4 ,insects4--,dytiscus 7p4 #cfa7 lays eggs4 ,pupae of cabbage-white butterflies and other ,lepidoptera may be found4 ,,april4 ,,plant ,,life4 ,plants usually in flower4--,wallflower1 shepherd's purse1 buttercup1 anemone1 marsh marigold1 common vetch1 plum1 pear1 strawberry1 primrose1 cowslip1 daisy1 dandelion1 speedwell1 red deadnettle1 daffodil1 wild hyacinth1 wild tulip1 rushes1 arum1 annual meadow grass1 oak1 birch1 alder1 willow1 poplar1 elm1 ash1 and others4 ,trees which unfold their leaf-buds4--,larch1 horse chestnut1 beech1 elm1 sycamore4 ,elm fruits 7p4 #aed7 are abundant2 study the method of dispersal 7p4 #agc74 ,corn4--,barley and oat sowing continued4 ,,animal ,,life4 ,birds4--,sand-martins1 cuckoos1 swallows1 house-martins1 nightingales1 swifts1 and other birds arrive4 ,kestrels and sparrow-hawks nest4 ,fieldfares and redwings depart4 ,frogs and ,toads4--,tadpoles hatch4 ,insects4--,cabbage-white butterflies 7p4 #cfb7 and other ,lepidoptera emerge from pupae4 ,caterpillars are plentiful4 ,moths may be taken on willow flowers at beginning of month4 ,larvae of ,dytiscus 7p4 #cfa7 and other aquatic insects may be found in ponds4 ,molluscs4--,garden snails 7p4 #cgi7 reappear4 ,,may4 ,,plant ,,life4 ,plants usually in flower4--,wallflower1 shepherd's purse1 buttercup1 anemone1 marsh marigold1 laburnum1 common vetch1 red clover1 white clover1 broom1 cherry1 apple1 pear1 strawberry1 hawthorn1 primrose1 cowslip1 daisy1 dandelion1 speedwell1 red deadnettle1 white deadnettle1 lily of the valley1 wild hyacinth1 star of ,bethlehem1 wild tulip1 rushes1 sedges1 arum1 sweet-scented vernal grass1 slender foxtail1 meadow foxtail1 annual meadow grass1 perennial rye grass1 oak1 beech1 birch1 willow1 elm1 horse-chestnut1 ash1 sycamore1 and others4 ,most forest trees are now in leaf4 ,liverworts4--,spore-cases of ,pellia 7p4 #bjj7 open4 ,,animal ,,life4 ,birds4--,swallows build nests4 ,most birds are incubating eggs 7,chap4 ,,xvi474 ,frogs and ,toads4--,tadpoles may be found in ponds4 ,insects4--,moths and butterflies are common4 ,cabbage-whites lay eggs4 ,caterpillars of tiger-moth 7p4 #cfd7 and other ,lepidoptera may be found4 ,aquatic insect-larvae in ponds4 ,,june4 ,,plant ,,life4 ,general ,work for ,summer ,months4--,study the forms and duties of leaves 7,chap4 ,,iii472 and the thickening of stems 7,chap4 ,v474 ,examine1 identify1 and collect grasses 7,chap4 ,,vii47 and summer flowers 7,chap4 ,,vi471 and make observations upon cross-pollination of flowers by insects 7,chap4 ,,vi474 ,study the development and structure of fruits 7,chap4 ,,ix472 and the life-history of ferns 7,chap4 ,x474 ,compare and contrast mushrooms and toadstools 7,chap4 ,,xi474 ,plants usually in flower4--,wallflower1 shepherd's purse1 buttercup1 anemone1 meadow vetchling1 common vetch1 red clover1 white clover1 broom1 wild rose1 hawthorn1 poison hemlock1 cow parsnip1 carrot1 daisy1 dandelion1 speedwell1 mullein1 snapdragon1 thyme1 sage1 red deadnettle1 white deadnettle1 lily of the valley1 wild hyacinth1 star of ,bethlehem1 rushes1 sedges1 sweet-scented vernal grass1 slender foxtail1 meadow foxtail1 ,timothy grass1 ,yorkshire fog1 wild oat1 annual meadow grass1 smooth-stalked meadow grass1 rough-stalked meadow grass1 meadow fescue1 sheep's fescue1 perennial rye grass1 couch grass1 lime1 sycamore1 and others4 ,lime leaves unfold4 ,fruits of strawberry1 willow1 and other plants are ripe4 ,haymaking begins4 ,,animal ,,life4 ,mammals4--,examine young wild rabbits 7,chap4 ,,xii474 ,birds4--,most birds are hatching eggs4 ,first brood of swallows hatched at end of month4 ,drake's plumage becomes similar to duck's 7p4 #cbi74 ,frogs and ,toads4--,tadpoles reach full size4 ,insects4--,all stages of ,lepidoptera very abundant4 ,caterpillars of tiger-moth 7p4 #cfd7 pupate at end of month4 ,vapourer caterpillars 7p4 #cfd7 may be found at end of month4 ,larvae of aquatic insects in ponds2 pupae of ,dytiscus 7p4 #cfa7 in soil on banks4 ,,july4 ,,plant ,,life4 ,plants in flower4--,shepherd's purse1 candytuft1 buttercup1 meadow vetchling1 red clover1 white clover1 wild rose1 blackberry1 poison hemlock1 water hemlock1 cow parsnip1 carrot1 hedge parsley1 fool's parsley1 water dropwort1 daisy1 dandelion1 thistle1 foxglove1 speedwell1 snapdragon1 mullein1 musk1 mint1 thyme1 sage1 red deadnettle1 white deadnettle1 rushes1 slender foxtail1 ,timothy grass1 ,yorkshire fog1 wild oat1 annual meadow grass1 smooth-stalked meadow grass1 rough-stalked meadow grass1 meadow fescue1 sheep's fescue1 couch grass1 ,spanish chestnut1 lime1 and others4 ,fruits of gooseberry1 cherry1 raspberry1 strawberry1 and other plants are ripe4 ,ferns4--,spores of male-fern1 bracken1 and hart's tongue are ripe 7,chap4 ,x474 ,fungi4--,mushrooms 7p4 #bjc7 and toadstools may be found4 ,,animal ,,life4 ,mammals4--,lambs are weaned4 ,birds4--,many birds are hatching second broods4 ,old cuckoos begin to depart at end of month4 ,poultry moult4 ,young wild ducks may be seen in water meadows4 ,frogs and ,toads4--,young animals leave ponds4 ,insects4--,cabbage-white caterpillars pupate4 ,tiger moths 7p4 #cfi7 emerge from pupae at end of month4 ,caterpillars of vapourer moth 7p4 #cfd7 may be found4 ,,august4 ,,plant ,,life4 ,plants in flower4--,shepherd's purse1 candytuft1 buttercup1 meadow vetchling1 red clover1 white clover1 wild rose1 blackberry1 water hemlock1 cow parsnip1 carrot1 hedge parsley1 fool's parsley1 water dropwort1 daisy1 dandelion1 thistle1 foxglove1 speedwell1 snapdragon1 mullein1 musk1 mint1 thyme1 sage1 red deadnettle1 white deadnettle1 rushes1 slender foxtail1 ,timothy grass1 ,yorkshire fog1 wild oat1 annual meadow grass1 couch grass1 and others4 ,leaves of horse chestnut begin to fall4 ,fruits of cherry1 plum1 raspberry1 and other plants are ripe4 ,corn4--,wheat1 oats1 and barley harvests begin4 ,ferns4--,spores of male-fern1 bracken1 and hart's tongue are ripe4 ,fungi4--,mushrooms and toadstools may be found4 ,,animal ,,life4 ,birds4--,swifts and old cuckoos depart4 ,many rooks go into winter quarters4 ,nightingales begin to depart4 ,sand-martins congregate4 ,song-birds are comparatively silent4 ,insects4--,all stages of vapourer moth may be found4 ,,september4 ,,plant ,,life4 ,general ,work for ,autumn ,months4--,study the storage of food in twigs1 underground stems1 bulbs1 etc4 7,chaps4 ,,iv4 and ,v472 collect good specimens of leaves showing autumn colours1 observe the phenomena of leaf-fall and the formation of vegetable mould1 and notice the order in which forest trees become leafless 7,chaps4 ,,iv4 and ,,viii474 ,study the development and structure of fruits1 and the methods of dispersal of seeds 7,chap4 ,,ix474 ,make collections of dry fruits 7,chap4 ,,ix471 and of the 8seed0 of useful and injurious grasses 7,chap4 ,,vii474 ,plants usually in flower4--,shepherd's purse1 buttercup1 meadow vetchling1 red clover1 white clover1 blackberry1 hedge parsley1 water dropwort1 daisy1 dandelion1 thistle1 foxglove1 speedwell1 snapdragon1 musk1 mint1 red deadnettle1 white deadnettle1 slender foxtail1 annual meadow grass1 and others4 ,ash and horse chestnut leaves fall4 ,fruits of apple1 pear1 plum1 blackberry1 and other plants are ripe4 ,corn4--,wheat-sowing begins4 ,fungi4-- ,mushrooms and toadstools may be found4 ,,animal ,,life4 ,general ,work for ,autumn ,months4--,study the various methods by which animals prepare for the winter3 e4g4 migration of birds1 hibernation of bats1 frogs1 insects1 etc42 change of colour or thickness of coat1 storage of food1 etc4 ,birds4--,swallows and house-martins congregate4 ,sand-martins and nightingales depart4 ,rooks go into winter quarters4 ,young song-birds may be heard learning to sing4 ,insects4--,moths may be taken on ivy blossoms1 etc4 ,eggs of cabbage-white butterflies may be found4 ,caterpillars are mostly full-fed and ready to pupate4 ,pupae of vapourer moth may be found4 ,,october4 ,,plant ,,life4 ,plants usually in flower4--,shepherd's purse1 white clover1 daisy1 dandelion1 snapdragon1 red deadnettle1 white deadnettle1 slender foxtail1 and others4 ,most forest-trees shed their leaves4 ,fruits of apple1 pear1 plum1 and other plants are ripe4 ,corn4--,wheat-sowing continued4 ,,animal ,,life4 ,birds4--,young song-birds may be heard learning to sing4 ,fieldfares and redwings arrive4 ,swallows and house-martins depart4 ,drakes reassume their distinctive plumage4 ,frogs hibernate 7p4 #ccd74 ,insects4--,october is the best month for pupa hunting4 ,,november4 ,,plant ,,life4 ,plants usually in flower4--,shepherd's purse1 daisy1 white deadnettle1 and others4 ,most forest-trees are now leafless4 ,fruits of hawthorn1 rose1 holly1 mistletoe1 etc41 are ripe4 ,corn4--,wheat-sowing continued4 ,,animal ,,life4 ,mammals4--,bats hibernate 7p4 #beg74 ,birds4--,larks patrol fields in flocks 7p4 #cah74 ,insects4--,pupae may be found4 ,,december4 ,,plant ,,life4 ,general ,work for ,winter ,months4--,arrange collections of flowers1 grasses1 leaves1 etc4 ,study the methods of branching1 and the bark1 of trees1 and make drawings of typical examples 7,chap4 ,,viii474 ,examine bulbs and corms1 7,chap4 ,v47 and grow them in water-glasses4 ,trace the water-conducting strands in the flower-stalks of snowdrop1 narcissus1 etc4 7,chap4 ,v474 ,flowers of daisy1 white deadnettle1 and a few others may be found4 ,fruits of mistletoe1 holly1 etc41 are ripe4 ,,animal ,,life4 ,general ,work for ,winter ,months4--,prepare skeletons1 etc41 and study the structure and manner of life of rabbits1 poultry1 and pigeons 7,chaps4 ,,xii41 ,,xiii41 and ,,xv474 ,in snowy weather1 examine and draw the footprints of domestic and other animals 7,chap4 ,,xiv474 ,place grain1 crumbs1 suet1 and other food for birds1 and identify those which come to feed 7,chap4 ,,xvii474 ,birds4--,missel-thrush sings4 ,sparrow-hawks may be seen near farms4 ,insects4--,pupae may be found4 ,,footnote3 #dj ,no attempt has been made to compile a complete calendar1 the events noticed being those only which are considered in this book4 ,,typical ,,examination ,,papers4 ,the ,national ,froebel ,union4 ,,elementary ,,certificate4 ,,nature ,,knowledge4-- ,paper ,i4 7,questions #a and #b and ,,any ,,two others to be answered47 #a4 ,describe the flower provided1 and draw it in longitudinal section4 ,explain how cross-pollination is ensured in this flower2 give drawings to illustrate4 #b4 ,give and plan out the subject-matter for one or more ,lessons1 to be given to children of seven or eight years of age1 on the ,dispersal of ,fruits and ,seeds by ,animals4 #c4 ,describe the structure of an ,acorn and of a ,wheat grain1 and contrast these two seeds4 ,give enlarged drawings of each4 #d4 ,what is the work of the root of a plant1 and how is this work carried out8 ,what different forms of roots are to be found8 ,give examples and make a rough sketch of each4 #e4 ,describe the bud in winter1 and its method of unfolding in spring1 of any two of the following trees3--,oak1 ,beech1 ,sycamore4 ,make sketches to illustrate4 #f4 ,make as complete a list as you can of ,flowering ,plants which grow in ponds2 state how these plants have adapted themselves to their habitat1 and say at what time of the year each of them flowers4 ,what plants would you expect to find growing round the margin of the pond8 ,paper ,,ii4 7,questions #a and #b ,,must be answered1 and ,,any ,,three others47 #a4 ,draw up ,notes of ,lessons on one of the following subjects3--8,a ,mole10 8,domestic ,fowls10 8,a ,cat40 ,state the age of the children1 and the method you would pursue4 #b4 ,what is a ruminant8 ,give as many groups of ruminating animals as you can and the habits of one4 #c4 ,give the life-history of one of the following1 with illustrations3--a ,bee1 a ,caddis-fly1 a ,spider1 a ,butterfly4 #d4 ,give the life and habits of the ,squirrel4 #e4 ,how does a ,starling differ from other ,birds8 #f4 ,draw a common ,snail and a ,slug4 ,give a short account of their life-histories4 #g4 ,give instances of protective colouring amongst 7#a7 ,insects1 7#b7 ,birds1 7#c7 ,mammals1 in this country4 ,board of ,education4 ,,teachers' ,,certificate ,,examination4 ,,general ,,elementary ,,science4 ,,part ,,ii4 #aa4 ,give an example in each case of a plant with--7a7 ,plumed fruits or seeds4 7b7 ,winged fruits or seeds4 7c7 ,climbing stem covered with hooks4 7d7 ,flowers which come out before the leaves4 7e7 ,flowers in which the stamens are united to form a tube4 #ab4 ,show in the case of any two ,british wild plants the special means they possess for survival in the struggle for existence4 #ac4 ,name five of the earliest flowering wild plants in your neighbourhood1 in the order in which they flower1 and mention the chief characteristics of the flower in each case4 #ad4 ,describe the life-history of a fern so far as it can be observed by the naked eye and with the aid of a pocket lens4 #ae4 ,describe1 with the help of drawings1 the work of a bee in its mode both of collecting pollen and honey and of fertilising flowers4 #af4 ,give a short account of the structure of a bird's wing4 ,how are the wings made use of during flight8 #ag4 ,give an account of some simple experiments you would employ to demonstrate the phenomena of respiration in animals and plants4 ,board of ,education4 ,,preliminary ,,examination ,,for ,,the ,,certificate4 ,,part ,,ii4 ,,elementary ,,science4--,,syllabus ,,no4 ,,ii4 7,you should answer ,,six questions47 #a4 ,describe with the aid of a drawing the various structures seen by means of a pocket lens in a section across the middle region of a grain of wheat4 #b4 ,how would you measure the rate of transpiration of water from a small plant or a leafy stem8 #c4 ,how can it be shown that the root responds to external influences of moisture1 light and gravity8 #d4 ,give a brief account of the function of the green leaf in the nutrition of plants4 #e4 ,compare by drawings the leaves of broad bean and garden pea4 ,then discuss the means by which the two plants obtain mechanical support4 #f4 ,when the bulb of a thermometer is placed in a jar of soaked and germinating seeds1 what temperature change is observed8 ,explain the cause of this4 #g4 ,describe experiments which show in what respects the air is affected in composition by passing through the lungs4 #h4 ,describe with the help of drawings the structure of the flowers of the hazel or willow and show how they are adapted for cross-pollination4 #i4 ,what is meant by root pressure1 and how would you demonstrate it8 ,illustrate your answer by drawings4 #aj4 ,what are the conditions of the soil which make it a suitable medium for healthy root-action and vigorous plant growth8 ,conversely under what conditions of soil would the plant fail to thrive or die8 ,board of ,education 7,south ,kensington74 ,,general ,,biology4 ,,section ,i4 ,,of ,,stage ,i4 7,you are permitted to answer only ,,eight questions47 #a4 ,write what you can of the habits of the common ,house ,fly and of the common ,clothes ,moth2 draw figures of their appearance at different stages of the life-history4 #b4 ,where and when do you find ,frog's eggs8 ,of what use is the jelly with which they are surrounded8 #c4 ,how does the ,tadpole swim1 and how does the ,frog swim8 ,how does the ,frog jump1 and how does it catch a fly8 #d4 ,contrast the characters of the mouth 7including teeth if present7 in the ,frog1 ,bird1 ,cat1 ,rabbit and ,sheep4 #e4 ,describe the characteristic modes of locomotion in the ,bird1 ,dog1 ,rabbit and ,bat1 and point out any peculiarities of the skeleton which are related to these habits4 #f4 ,describe the heart of the ,sheep1 and account so far as you can for any differences you can point out between the various chambers4 #g4 ,in what way are bees useful to flowers8 ,explain in any one example you choose what happens when a bee visits the flower4 #h4 ,describe the roots of a pea or bean4 ,what importance do you attach to the different parts you mention8 #i4 ,what is starch8 ,how would you show whether or not it was present in a leaf8 ,what conditions are necessary in order that the leaf may produce it8 #aj4 ,describe the fruit of either the ,sycamore or the ,poppy1 and explain the uses of the different parts in dispersing the seed4 #aa4 ,describe how you would proceed in arranging an experiment to enable you to study the germination of a seed4 ,give a brief account of the process of germination of any seed you may select4 #ab4 ,describe and sketch the specimen provided1 and explain1 as far as you can1 the use of the different parts4 ,,index4 ,acorn1 #ada1 #add1 #adf1 #age1 #agg ,air1 carbon dioxide in1 #ca1 #cc ,air-chamber of hen's egg1 #bhc1 #bhe ,air sacs of birds1 #bgi ,albumin1 #bhe ,alder1 #adb1 #adi ,allantois1 #bhi1 #bic ,alternation of generations1 #ahi1 #aif ,amnion1 #bhh1 #bij ,anemone1 #ig1 #ih ,animals and plants1 resemblances and differences1 #bdc ,annual1 meadow grass1 #ace2 rings1 #gc ,anterior1 #bag ,anther of stamen1 #ia ,aorta1 #bcf1 #bch ,appendages of crayfish and lobster1 #cgc1 #cge ,apple1 #ajd1 #ajf2 fruit of1 #agf1 #agi ,apricot1 #ajf ,aquarium1 a simple1 #cdj ,arachnids1 #cgh ,arteries1 #bcg1 #bch ,arteries1 pulse in1 #bce1 #bci ,arthropods1 #cea ,arum1 #abb ,ash1 #aec1 #aef2 fruit of1 #aga1 #agc2 mountain1 #aeg ,aspen1 #aeb ,auricles of heart1 #bce1 #bcg ,awn1 #abi1 #acj1 #aca ,axil of leaf1 #de1 #dg ,backbone1 of pigeon1 #bfi2 of rabbit1 #bag1 #bbb1 #bbg ,bacteria1 #bji ,balancers of hen's egg1 #bhc1 #bhe ,bark1 #gd ,bast1 #ga1 #gb ,bat1 #bee1 #bef ,bean seed1 #a1 #b1 #e2 germination of1 #i1 #ac2 starch in1 #b ,beech1 #adb1 #ade1 #adg2 fruit of1 #age1 #agh ,beetle1 a water1 #ceg ,beetles1 #cfb ,berries1 #age1 #agi ,biennials1 #ca1 #if ,bile1 #bcb1 #bcd ,birch1 #adb1 #adg1 #adh ,birds1 #bfi ,bird's foot trefoil1 #ajb ,black bent1 #ace ,blackberry1 #ajc1 #aje2 fruit of1 #age1 #agi2 leaves1 #ch1 #da1 #aje ,blackbird1 #cjb1 #cjg ,bleeding of stems1 #fg1 #gj ,blood1 #bcc1 #bce1 #bdb2 circulation of1 #bce2 red corpuscles of1 #bcg1 #bdb ,blue mould1 #bjg1 #bjh ,bone1 structure of a long1 #bbc1 #bbh ,bones1 of birds1 #bfi2 of pigeon1 #bgd2 of rabbit1 #bbb ,box leaves1 #dd1 #de ,bracken fern1 #ahd1 #ahi ,bracts of anemone1 #ig1 #ii2 of daisy1 #aaa2 of dandelion1 #aac2 of lime1 #aeb1 #aed1 #aee1 #agd ,branches1 position of1 #de1 #dg ,breast bone1 of pigeon1 #bfi2 of rabbit1 #bag1 #bbc1 #bbg ,breathing1 definition of1 #bdb2 necessity for1 #bda2 of cockroach1 #cee2 of crustaceans1 #cgf1 #cgg2 of fresh-water mussel1 #cha2 of frog1 #ccc1 #ccg2 of mammals1 #bdb1 #bdc2 of snails1 #chb1 #chc2 of tadpole1 #cdd ,breathing organ of chick-embryo1 #bhi1 #bid ,broad bean seed1 #a1 #b1 #e ,broccoli1 #if ,broom1 #aja ,brussels sprouts1 #if ,bud1 a typical1 #ee1 #eh ,buds1 #ee1 #fi2 bursting of1 #ef1 #fa1 #fd2 of ash1 #aec1 #aef2 of horse chestnut1 #eg1 #fc2 of sycamore1 #ef1 #fj2 position of1 #de1 #ej ,bulb1 #ha1 #hd ,burrows of earthworms1 #chd1 #che ,buttercup1 #if1 #ig2 family1 #if1 #ig ,butterflies1 cabbage-white1 #cfb1 #cfe ,calamites1 #aif ,calceolaria1 #aaf ,calyx1 #ij ,cambium1 #gb ,candytuft1 #id ,canine teeth1 #bdf1 #bdh1 #bee ,capillaries1 #bcg1 #bdj ,capsule1 #afh ,carbon1 contained in plants1 #ca1 #cc2 contained in starch1 #cb ,carbon dioxide1 formed by living body1 #bdj1 #bda2 formed when flesh burns1 #bdj1 #bda2 formed when wood burns1 #ca2 in air1 #ca1 #cc ,carnivores1 #bed ,carpel1 #if1 #ih ,carrot1 #if1 #ajh ,castings of earthworms1 #chd1 #chf ,cat1 #bdf1 #bej1 #beb1 #bed ,catkin1 #adf ,catkins1 of alder1 #adb1 #adi2 of beech1 #adb1 #adh2 of birch1 #adb1 #adh2 of hazel1 #adb1 #adi2 of oak1 #ada1 #add1 #ade2 of poplar1 #aea2 of willow1 #aej1 #aea ,caterpillar1 of cabbage-white butterfly1 #cfb1 #cfe2 of tiger-moth1 #cfd1 #cfi2 of vapourer-moth1 #cfd1 #cgj ,cauliflower1 #if ,celery1 #ajh ,centipedes1 #cgh ,cephalothorax of crab1 #cgc1 #cgf2 of crayfish and lobster1 #cgc1 #cge ,cherry1 #ajc1 #aje1 #ajf2 fruit of1 #age1 #agi ,chestnut1 horse1 #ch1 #db1 #dg1 #eg1 #fc1 #fe1 #aeg1 #aei2 ,spanish or sweet1 #adh ,chick1 development of1 #bhf1 #bhi2 education of1 #bie1 #bif2 embryo of1 #bhg1 #bhi2 hatching of1 #bid1 #bie ,chitin1 #bea ,chrysalis1 #cff ,claws of cat1 #bdg1 #bea ,cleavers1 #age1 #agg ,climbing stems1 #ge ,clitellum of earthworm1 #chc1 #chf 8,clock0 of dandelion1 #aab1 #aga1 #agb ,clover1 #aja1 #ajb ,cockroach1 #cdi1 #cea2 habits of1 #cef2 life-history of1 #cef2 position of in insect class1 #ceg2 structure of1 #cee ,cocoon of earthworm1 #chf2 of tiger-moth1 #cfd1 #cfi ,coleoptera1 #cfb ,collar of mushroom1 #bjc1 #bje2 of garden snail1 #cgi ,collecting1 #chi1 #cij ,colour1 of flowers1 #ic2 of fruits1 #ahb ,compositae1 #aad ,cone-bearing trees1 #afj1 #afa ,cones of alder1 #adi2 of horsetail1 #aia1 #aib1 #aid1 #aie2 of larch1 #afa1 #afc2 of ,scotch pine1 #afj1 #afb1 #aga1 #agd2 of spruce fir1 #afc1 #aga1 #agd ,convolvulus1 #gf1 #gh1 #gi ,cork1 #ge ,corm1 #ha1 #he ,corolla1 #ia ,corona1 #abj1 #abb ,cotyledons1 #ac1 #af1 #bb1 #bc2 of bean1 #b1 #f ,cowslip1 #aji1 #aaj ,crayfish1 #cgb1 #cgd ,creeping stems1 #hj1 #hb ,cress1 #id1 #if ,crocus corm1 #ha1 #he ,crop of pigeon1 #bga ,cross fertilisation1 #ib1 #ajb1 #aaj1 #aah1 #abb1 #aea ,crow1 #cab1 #cah1 #cbj2 family1 #cab1 #cbj ,crucifers1 #ie ,crustaceans1 #cgb1 #cgg ,cuckoo1 #cbb1 #cbd2 cuckoo-pint1 #abb ,currants1 #agf1 #agi ,cushion-feet of caterpillar1 #cfe ,daffodil1 #hd1 #he1 #abj1 #abb ,daisy1 #aaa1 #aab ,dandelion1 #aab1 #aac2 fruit of1 #aga1 #agb ,deadnettle1 #aag ,deer1 #bfa ,dentine1 #bai ,development of chick1 #bhf1 #bhi2 of frog1 #cdj ,diaphragm1 #bah ,diastase1 #bcd ,dicotyledons1 #bc1 #dj1 #gb ,digestion1 #bca1 #bcc2 definition of1 #bcc ,digestive canal of frog1 #bca2 of rabbit1 #bcb ,diptera1 #cgj ,dispersal of insects1 #cgj2 of seeds1 #afe ,dissection1 #bad ,dog1 #bdh1 #bea1 #beb1 #bed ,donkey1 #bfa ,dorsal1 #bag ,down feathers1 #bgc1 #bgg ,dropwort1 water1 #ajh ,duck1 #cbf1 #cbg ,dytiscus1 habits and structure of1 #ceg1 #ceh2 life-history of1 #cfa ,ear1 of grass1 #acj ,ears1 of rabbit1 #bah ,earthworms1 #chc1 #chd ,education of young animals1 #bdh1 #bdi1 #bfb ,eggs1 of cabbage-white butterfly1 #cfb2 of cockroach1 #ceg2 of ,dytiscus1 #cfa2 of earthworm1 #chf2 of frog1 #cci1 #cdj1 #cda2 of hen1 #bhb1 #bhd2 of ,limnaea1 #chj ,elm1 #aeb1 #aec2 fruit of1 #aga1 #agc ,embryo1 #ab2 of chick1 #bhg1 #bhi2 of fern1 #ahh1 #aia2 of horsetail1 #aie ,enamel1 #bai ,endosperm1 #bb ,evolution1 a case of1 #cch ,extinct horsetails1 #aif ,eyes1 of butterfly1 #cfc1 #cfg1 #cfh2 of cat1 #bdf1 #bej2 of cockroach1 #cdh1 #ceb2 of crab1 #cgc2 of crayfish and lobster1 #cgb2 of dog1 #bdh1 #bea2 of pigeon1 #bga2 of rabbit1 #bah2 of snail1 #cgi1 #chb ,falcon1 #bgb1 #ccj ,fantail pigeon1 #bhj ,feathers of pigeon1 #bfe1 #bff1 #bfg1 #bgj1 #bge1 #bgf ,feelers1 of butterfly1 #cfc1 #cfg2 of cockroach1 #cdi1 #ceb2 of crayfish and lobster1 #cgb1 #cgc1 #cgd1 #cge2 of ,dytiscus1 #ceh1 #cei2 of moth1 #cfd1 #cfh1 #cfi ,fehling's solution1 #bcj ,ferns1 #ahc2 bracken1 #ahd1 #ahi2 hart's tongue1 #ahe1 #aij1 #aia2 male fern1 #ahc1 #ahe ,fertilisation1 #ib2 of ferns1 #ahh2 of forest trees1 #adf2 of 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germination of1 #ba ,whiskers1 of bat1 #bef2 of cat1 #bdf1 #bej2 of rabbit1 #bag ,white1 mould1 #bjg1 #bjh2 of egg1 #bhc1 #bhe ,wild oat1 #acc1 #acf ,willow1 #aej2 fruit of1 #aga1 #agc ,windhover1 #cbi1 #cca ,wind-sown seed1 #agb ,wing-covers1 of cockroach1 #cej1 #ced2 of beetles1 #ceh1 #cei1 #cfb ,winged seeds1 #agd ,wings1 of bat1 #beg2 of cockroach1 #cej1 #cec2 of pea flower1 #ajj1 #ajb2 of pigeon1 #bff1 #bgj1 #bgc ,wood #gj1 #ga1 #gb2 avens1 fruit of1 #agd1 #agg2 louse1 #cgg ,wool1 #beg1 #beh 8,woolly bear10 #cfd1 #cfi ,worm castings1 #chd1 #chf ,worms1 #chc ,yellowoat ,grass1 #acg ,yolk of hen's egg1 #bhc1 #bhe ,yorkshire fog1 #abe1 #acb1 #acf ,,glasgow3 ,,printed ,,at ,,the ,,university ,,press ,,by ,,robert ,,maclehose ,,and ,,co4 ,,ltd4 ,a ,,health ,,reader ,,by ,c4 ,e4 ,,shelly1 ,m4,a41 ,m4,d41 ,m4,r4,c4,p4 ,,consulting ,,medical ,,officer1 ,,haileybury ,,college ,,and ,e4 ,,stenhouse1 ,b4,sc4 ,,associate ,,of ,,the ,,royal ,,college ,,of ,,science1 ,,london ,globe #hvo4 ,,book ,i4 ,for children of #i to #aj years of age4 #afj pp4 #as4 ,,book ,,ii4 ,for children of #aj to #ab years of age4 #bjd pp4 #as4 #d;d4 ,,book ,,iii4 ,for children of #ab to #ad years of age4 ,in the ,press4 ,,some ,,press ,,opinions4 ,,book ,i4 ,schoolmaster4--8,all the facts are presented in the same lucid and simple style1 so that very young readers can understand them4 ,the book will carry health and happiness with it1 so that we hope it will find its way into many a school for boys as well as for girls40 ,head ,teacher4--8,full of good advice that should be within reach of all40 ,lancet4--8,the book is divided into #cj lessons3 the subject matter of each is well arranged and simply expressed4444 ,can only do good to those who read it40 ,educational ,news4--8,it is appropriately simple in diction1 carefully arranged1 and quite sufficiently full of information for the young people whom it is meant to serve as a ,class ,reader4444 ,a special word of praise is due to the photographic illustrations40 ,teacher4--8,we have looked carefully through the pages of this little book1 and believe it will be exceedingly helpful to teachers4 ,it is simply written4 ,each lesson is practical1 concise1 and interesting40 ,teachers' ,aid4--8,the physiology necessary to a proper appreciation of the laws of health is delightful in the simplicity of its treatment1 while the simple way of pressing home the truths of hygiene in a language suited to the capacity of young children is considerably enhanced by the novel and original illustrations which consist of photographs specially taken for the purpose4 ,to teachers taking the subject in school we can most cordially recommend this reader40 ,child ,life4--8,from the scientific point of view the matter is very valuable1 and such as every boy and girl should know before they leave school40 ,,book ,,ii4 ,schoolmaster4--8,this is a capital little book1 attractively written and well illustrated40 ,child ,life4--8,the book is an accurate and easy reader1 provided with suitable illustrations40 ,bookseller4--8,illustrations are provided in profusion1 and the book should certainly prove most useful and attractive for all those who have to teach or study the important matters with which it deals40 ,head ,teacher4--8,is clearly and well written by practical men who understand the capacities of children40 ,lancet4--8,their book will be of real service to those teachers who are empowered to impart such instruction4 ,the pictures are well planned to catch a child's attention40 ,,macmillan ,,and ,,co41 ,,ltd41 ,,london4 ,,macmillan ,,and ,,co4',s ,books for ,elementary ,schools4 ,,macmillan',s 8,,official0 ,,copy ,,books4 ,nos4 ,i4-,,xiii4 #b;d4 each4 ,,macmillan',s 8,,official0 ,,writing ,,charts4 ,size1 #cb by #ba in41 on ,cloth1 ,rollers1 and ,varnished4 ,no4 ,i4--,small ,letters4 ,no4 ,,ii4--,small ,letters1 ,difficult ,joinings4 ,no4 ,,iii4--,capital ,letters4 ,no4 ,,iv4--,capitals and ,joinings4 ,price #bs4 #f;d4 each4 ,,macmillan',s ,,spelling ,,for ,,promotion4 ,,by ,r4 ,f4 ,,macdonald4 ,junior 7,parts ,i4 and ,,ii47 #b;d4 each4 ,intermediate4 #d;d4 ,senior4 #d;d4 ,,macmillan',s ,,story ,,readers4 ,,by ,,evelyn ,,sharp4 ,introductory--,for ,infant ,classes4 ,with ,coloured illustrations4 #h;d4 ,book ,i4 for ,stage ,i4 #aj;d4 ,book ,,ii4 for ,stage ,,ii4 #as4 ,,the ,,boys' ,,book ,,of ,,poetry4 ,part ,i4 ,junior 7,stages ,i4 and ,,ii474 ,part ,,ii4 ,intermediate 7,stages ,,iii4 and ,,iv474 ,part ,,iii4 ,senior 7,stages ,v4 and upwards74 ,limp ,cloth1 #e;d4 each4 ,sewed1 #d;d4 each4 ,,the ,,girls' ,,book ,,of ,,poetry4 ,part ,i41 ,junior 7,stages ,i4 and ,,ii474 ,part ,,ii41 ,intermediate 7,stages ,,iii4 and ,,iv474 ,part ,,iii41 ,senior 7,stages ,v4 and upwards74 ,limp ,cloth1 #e;d4 each4 ,paper ,covers1 #d;d4 each4 ,,the 8,,globe0 ,,poetry ,,books4 ,junior 7,stages ,i4 and ,,ii474 ,intermediate 7,stages ,,iii4 and ,,iv474 ,senior 7,stages ,v4 and upwards74 ,paper ,covers4 #f;d4 each4 ,cloth4 #h;d4 each4 ,,the 8,,globe0 ,,poetry ,,reader4 ,for ,advanced ,classes4 #as4 #d;d4 ,,macmillan',s ,,departmental ,,poetry ,,books4 ,edited by ,s4 ,c4 ,b4 ,,edgar1 ,m4,a4 ,paper ,covers4 ,infants1 #b;d4 ,junior ,i41 #d;d4 ,junior ,,ii41 #e;d4 ,senior ,i41 #e;d4 ,senior ,,ii41 #e;d4 ,,macmillan',s ,,new ,,globe ,,readers4 ,primer ,i41 #d;d4 ,primer ,,ii41 #e;d4 ,infant ,reader ,i41 #f;d4 ,infant ,reader ,,ii41 #h;d4 ,book ,i41 #aj;d4 ,book ,,ii41 #as4 ,book ,,iii41 #as4 #b;d4 ,book ,,iv41 #as4 #d;d4 ,book ,v41 #as4 #f;d4 ,book ,,vi41 #as4 #h;d4 ,,macmillan',s ,,new ,,literary ,,readers4 ,reading ,sheets 7#ag sheets on ,manilla4 ,size1 #cgbh7 #abs4 ,primer ,i4 #d;d4 ,primer ,,ii4 #e;d4 ,infant ,reader #f;d4 ,introductory #h;d4 ,book ,i4 #i;d4 ,book ,,ii4 #aj;d4 ,book ,,iii4 #as4 ,book ,,iv4 #as4 #d;d4 ,book ,v4 #as4 #f;d4 ,book ,,vi4 #as4 #f;d4 ,,macmillan',s ,,history ,,readers4 ,book ,i4 ,simple ,stories #i;d4 ,book ,,ii4 ,simple ,stories #aj;d4 ,book ,,iii4 ,stories and ,tales #as4 ,book ,,iv4 #ajff to #adhe #as4 #d;d4 ,book ,v4 ,the ,tudor ,period #as4 #f;d4 ,book ,,vi4 ,the ,stuart ,period #as4 #h;d4 ,book ,,vii4 ,the ,hanoverian ,period #as4 #i;d4 ,,macmillan',s ,,new ,,history ,,readers ,,on ,,the ,,concentric ,,plan4 ,primary4 #as4 ,junior4 #as4 #f;d4 ,intermediate4 #as4 #f;d4 ,senior4 #bs4 ,summaries3 ,junior and ,intermediate4 #c;d4 each4 ,senior4 #d;d4 ,scottish ,edition4 ,primary4 #as4 ,junior4 #as4 #f;d4 ,intermediate4 #as4 #f;d4 ,senior4 #bs4 ,summaries3 ,junior and ,intermediate4 #c;d4 each4 ,senior4 #d;d4 ,,macmillan',s ,,geography ,,readers4 ,book ,i4 #aj;d4 ,book ,,ii4 #as4 ,book ,,iii4 ,england #as4 #d;d4 ,book ,,iv4 ,the ,british ,empire #as4 #d;d4 ,book ,v4 ,europe #as4 #f;d4 ,book ,,vi4 ,the ,british ,colonies1 etc4 #as4 #f;d4 ,book ,,vii4 ,the ,united ,states1 etc4 #as4 #i;d4 ,,macmillan',s ,,new ,,geography ,,readers4 ,asia4 #as4 #f;d4 ,america4 #as4 #f;d4 ,africa and ,australasia4 #as4 #f;d4 ,,macmillan',s ,,short ,,geography ,,of ,,the ,,world4 ,,by ,,george ,f4 ,,bosworth1 ,f4,r4,g4,s4 #as4 #f;d4 ,a ,,summary ,,of ,,geography4 ,by ,,george ,f4 ,,bosworth1 ,f4,r4,g4,s4 ,with ,maps4 ,in ,three ,parts4 ,sewed1 #d;d4 each ,part ,i4--,the ,british ,isles and ,europe4 ,part ,,ii4--,asia and ,africa4 ,part ,,iii4--,america1 ,australia1 and ,islands of the ,pacific4 ,,macmillan ,,co41 ,,ltd41 ,,st4 ,,martin',s ,,street1 ,,london1 ,w4,c4 ,,macmillan ,,and ,,co4',s ,,publications4 ,,macmillan',s ,,orographical ,,map ,,of ,,europe4 ,designed by ,b4 ,b4 ,,dickinson1 ,m4,a41 and ,a4 ,w4 ,,andrews1 ,m4,a4 ,cloth1 mounted on ,rollers1 and ,varnished4 #aes4 ,unmounted4 #aas4 ,mounted on ,weekes' ,rollers with cords1 unvarnished4 #bas4 ,notes to same4 #as4 ,,macmillan',s ,,globe ,,geography ,,readers4 ,by ,v4 ,t4 ,,murch4 ,introductory4 #as4 ,junior4 #as4 #f;d4 ,intermediate 7,england74 #as4 #i;d4 ,intermediate 7,our ,island ,home74 #bs4 ,senior4 #bs4 #f;d4 ,,murch',s ,,object ,,lessons ,,for ,,infants4 ,two ,vols4 #bs4 #f;d4 each4 ,,murch',s ,,object ,,lessons ,,in ,,elementary ,,science4 ,vol4 ,,ii4--,stages ,,iii41 ,,iv4 #cs4 ,,murch',s ,,object ,,lessons ,,in ,,elementary ,,science4 ,new ,edition4 ,stage ,i4 #bs4 ,stage ,,ii4 #bs4 ,stage ,,iii4 #bs4 ,stage ,,iv4 #bs4 ,stage ,v4 #bs4 ,stage ,,vi4 #bs4 ,stage ,,vii4 #bs4 ,,murch',s ,,science ,,readers4 ,book ,i4 #as4 ,book ,,ii4 #as4 ,book ,,iii4 #as4 #d;d4 ,book ,,iv4 #as4 #d;d4 ,book ,v4 #as4 #f;d4 ,book ,,vi4 #as4 #f;d4 ,book ,,vii4 #as4 #i;d4 ,,murch',s ,,teachers' ,,manual ,,of ,,object ,,lessons ,,in ,,domestic ,,economy4 ,vol4 ,i4--,stages ,i41 ,,ii4 #bs4 #f;d4 ,vol4 ,,ii4--,stages ,,iii41 ,,iv4 #cs4 ,,murch',s ,,domestic ,,science ,,readers4 ,book ,i4 #as4 ,book ,,ii4 #as4 ,book ,,iii4 #as4 #d;d4 ,book ,,iv4 #as4 #d;d4 ,book ,v4 #as4 #f;d4 ,book ,,vi4 #as4 #f;d4 ,book ,,vii4 #as4 #i;d4 ,,murch',s ,,teachers' ,,manual ,,of ,,object ,,lessons ,,in ,,geography4 #cs4 #f;d4 ,,murch',s ,,teachers' ,,manual ,,of ,,object ,,lessons ,,in ,,elementary ,,science ,,and ,,geography4 ,a ,complete ,scheme4 ,vol4 ,i4--,stage ,i4 #as4 #f;d4 ,vol4 ,,ii4--,stage ,,ii4 #as4 #f;d4 ,vol4 ,,iii4--,stage ,,iii4 #as4 #f;d4 ,,murch',s ,,readers ,,in ,,elementary ,,science ,,and ,,geography4 ,book ,i4 #as4 ,book ,,ii4 #as4 ,book ,,iii4 #as4 #d;d4 ,a ,,health ,,reader4 ,by ,c4 ,e4 ,,shelly1 ,m4,a41 ,m4,d41 and ,e4 ,,stenhouse1 ,b4,sc4 ,book ,i4 #as4 ,book ,,ii4 #as4 #d;d4 ,book ,,iii4 ,in preparation4 ,,murch',s ,,object ,,lessons ,,in ,,nature ,,knowledge4 ,junior4 #as4 #f;d4 ,intermediate4 #bs4 ,senior4 #bs4 #f;d4 ,,murch',s ,,nature ,,knowledge ,,readers 7,,rural ,,readers74 ,junior4 #as4 ,intermediate4 #as4 #c;d4 ,senior4 #as4 #i;d4 ,,buchanan ,,and ,,gregory',s ,,junior ,,country ,,readers4 ,book ,i4 ,true ,animal ,stories4 #as4 ,book ,,ii4 ,more ,true ,animal ,stories4 #as4 #b;d4 ,book ,,iii4 ,talks on ,country ,life4 #as4 #d;d4 ,,buchanan',s ,,senior ,,country ,,readers4 ,book ,i41 #as4 #f;d42 ,book ,,ii41 #as4 #f;d42 ,book ,,iii41 #bs4 ,,buchanan ,,and ,,gregory',s ,,lessons ,,on ,,country ,,life4 #cs4 #f;d4 ,,macmillan',s ,,wall ,,pictures ,,of ,,farm ,,animals4 ,unmounted1 varnished or unvarnished1 #cs4 each2 mounted on cards1 bound edges1 and hanger1 varnished1 #cs4 #f;d4 each2 in oak frame1 varnished1 #es4 each4 #a1 ,thoroughbred ,horse4 #b1 ,shire ,horse4 #c1 ,shorthorn ,cow4 #d1 ,ayrshire ,cow4 #e1 ,lincoln and ,southdown ,sheep4 #f1 ,large ,white and ,berkshire ,pigs4 ,,macmillan',s ,,mental ,,arithmetic4 ,with ,answers4 ,stages ,i41 ,,ii4 #f;d4 ,stages ,,iii41 ,,iv4 #f;d4 ,stages ,v41 ,,vi4 #f;d4 ,stages ,i4 to ,,vi4 separately4 ,without ,answers4 #b;d4 each4 ,,the ,,rational ,,arithmetic4 ,by ,george ,ricks1 ,b4,sc4 ,teachers' ,books for ,first1 ,second1 ,third1 ,fourth1 ,fifth1 ,sixth1 and ,seventh ,years' ,courses4 #h;d4 each4 ,scholars' ,books for ,first1 ,second1 ,third1 ,fourth1 ,fifth1 ,sixth1 and ,seventh ,years' ,courses4 #c;d4 each4 ,,macmillan',s ,,rational ,,test ,,cards ,,in ,,arithmetic4 ,third1 ,fourth1 ,fifth1 ,sixth1 and ,seventh ,years4 #fd ,cards in each4 #as4 net per packet4 ,,macmillan',s ,,picture ,,arithmetic4 ,book ,i4 #c;d4 ,book ,,ii4 #c;d4 ,book ,,iii4 #c;d4 ,answers ,i4-,,iii4 #d;d4 ,,macmillan',s ,,arithmetic ,,for ,,irish ,,elementary ,,schools4 ,,by ,w4 ,h4 ,,adair4 ,parts ,i4 and ,,ii4 #a;d4 each4 ,,iii4 and ,,iv4 #b;d4 each4 ,v41 ,,vi4 and ,,vii4 #c;d4 each4 ,,metric ,,arithmetic4 ,with ,copious ,examples and ,answers4 ,by ,,richard ,,wilson1 ,b4,a4 7,lond474 ,globe #hvo4 ,sewed4 #f;d4 ,,arithmetic ,,for ,,the ,,standards4 ,scheme ,a4 ,by ,rev4 ,j4 ,b4 ,,lock1 ,m4,a41 and ,,geo4 ,,collar1 ,b4,a4 ,b4,sc4 ,part ,i4 #b;d4 ,part ,,ii4 #b;d4 ,part ,,iii4 #b;d4 ,part ,,iv4 #b;d4 ,part ,v4 #c;d4 ,part ,,vi4 #d;d4 ,part ,,vii4 #f;d4 ,answers to ,parts ,i41 ,,ii41 ,,iii41 ,,iv41 #c;d4 each2 ,parts ,v41 ,,vi41 ,,vii41 #d;d4 each4 ,,arithmetical ,,test ,,cards4 ,scheme ,a4 ,stage ,,ii41 #fj ,cards and #b sets of ,answers1 #as4 #f;d4 per packet4 ,stage ,,vi41 #dh ,cards1 #as4 #f;d4 per packet4 ,stage ,,vii41 #dj ,cards1 #as4 #f;d4 per packet4 ,,arithmetic ,,for ,,promotion4 ,scheme ,b4 ,by ,rev4 ,j4 ,b4 ,,lock1 ,m4,a41 and ,r4 ,f4 ,,macdonald4 ,part ,i4 #c;d4 ,part ,,ii4 #c;d4 ,part ,,iii4 #c;d4 ,part ,,iv4 #c;d4 ,part ,v4 #c;d4 ,part ,,vi4 #d;d4 ,part ,,vii4 #f;d4 ,answers to ,parts ,i41 ,,ii41 ,,iii41 ,,iv41 #c;d4 each2 ,parts ,v41 ,,vi41 ,,vii41 #d;d4 each4 ,,arithmetical ,,test ,,cards ,,for ,,arithmetic ,,for ,,promotion4 ,scheme ,b4 ,by ,r4 ,f4 ,,macdonald4 ,stages ,,iii4 to ,,vii41 #as4 #f;d4 each4 ,,macmillan',s ,,monthly ,,test ,,books ,,in ,,arithmetic4 ,scheme ,b4 ,by ,r4 ,f4 ,,macdonald4 ,part ,i4 #c;d4 ,part ,,ii4 #c;d4 ,part ,,iii4 #c;d4 ,part ,,iv4 #c;d4 ,part ,v4 #c;d4 ,part ,,vi4 #c;d4 ,part ,,vii4 #c;d4 ,answers1 #d;d4 each4 ,,algebra ,,for ,,elementary ,,schools4 ,by ,h4 ,s4 ,,hall and ,r4 ,j4 ,,wood4 ,parts ,i41 ,,ii41 and ,,iii41 #f;d4 each2 ,cloth1 #h;d4 each4 ,answers1 #d;d4 each4 ,,mensuration ,,for ,,beginners4 ,with the ,rudiments of ,geometrical ,drawing4 ,by ,f4 ,h4 ,,stevens1 ,m4,a4 #as4 #f;d4 ,,english ,,grammar ,,for ,,elementary ,,schools4 ,,by ,j4 ,c4 ,,nesfield1 ,m4,a4 ,book ,i4 #c;d4 ,book ,,ii4 #d;d4 ,book ,,iii4 #e;d4 ,book ,,iv4 #f;d4 ,,word-,,building ,,and ,,composition4 ,by ,,robert ,s4 ,,wood4 ,book ,i4 #b;d4 ,book ,,ii4 #b;d4 ,book ,,iii4 #c;d4 ,book ,,iv4 #c;d4 ,complete in #a ,vol4 ,cloth #as4 ,book ,v4 #f;d4 ,book ,,vi4 #f;d4 ,book ,,vii4 #as4 ,complete in #a ,vol4 ,cloth #bs4 ,,the ,,teachers' ,,manual ,,of ,,composition4 ,by ,,robert ,s4 ,,wood4 ,vol4 ,i4 ,junior4--,for ,infants and ,stages ,i4 and ,,ii4 #as4 #f;d4 ,,six ,,large ,,charts ,,in ,,colours ,,for ,,the ,,class ,,teaching ,,of ,,composition4 7#a7 ,sentence ,structure and ,anatomy 7,diagram7--,synoptic and ,analytic4 7#b7 ,a ,writer's ,guide and ,danger ,signal ,code in marking ,exercises4 7#c7 ,common ,faults in ,composition--,their effectual ,criticism and ,prevention4 7#d7 ,how to orally ,describe ,common ,objects for ,juniors4 7#e7 ,letter-,writing ,guide--,general and ,commercial ,correspondence4 7#f7 ,use of ,capitals1 ,stops1 and ,marks in ,writing4 ,price #cs4 each1 ,mounted and ,varnished4 ,the ,six on ,roller to turn over1 #acs4 7,e4 ,j4 ,,arnold ,,and ,,son1 ,,publishers1 ,,leeds47 ,a ,,text-,,book ,,of ,,needlework1 ,,knitting1 ,,and ,,cutting ,,out1 ,,with ,,methods ,,of ,,teaching4 ,by ,,elizabeth ,,rosevear1 ,training ,college1 ,stockwell4 ,with ,illustrations4 ,crown #hvo4 #ds4 #f;d4 ,,needlework1 ,,knitting1 ,,and ,,cutting ,,out ,,for ,,older ,,girls4 ,by ,,elizabeth ,,rosevear4 ,globe #hvo4 ,stage ,v4 #h;d4 ,stages ,,vi41 ,,vii41 and ,ex-,,vii4 #as4 ,,varied ,,occupations ,,in ,,weaving1 ,,and ,,cane ,,and ,,straw ,,work4 ,by ,,louisa ,,walker4 ,with ,illustrations4 ,globe #hvo4 #cs4 #f;d4 ,,varied ,,occupations ,,in ,,string ,,work4 ,comprising ,knotting1 ,netting1 ,looping1 ,plaiting1 and ,macrame4 ,by ,,louisa ,,walker4 ,illustrated4 ,globe #hvo4 #cs4 #f;d4 ,,the ,,teachers' ,,work ,,book2 ,syllabus of ,instruction and ,examination2 ,progress and ,mark ,book2 and ,head ,teachers' ,report ,book4 ,arranged by ,a4 ,,flavell and ,g4 ,h4 ,,robinson4 ,fcap4 folio4 #as4 #f;d4 ,,the ,,infant ,,school ,,teachers' ,,work ,,book3 ,syllabus of ,instruction and ,examination2 ,progress and ,mark ,book2 and ,head ,teachers' ,report ,book4 ,arranged by ,a4 ,,flavell and ,g4 ,h4 ,,robinson4 ,fcap4 folio4 #as4 #f;d4 ,,macmillan',s ,,attendance ,,register4 ,for the ,latest ,requirements of the ,code4 #as4 #f;d4 ,,macmillan',s ,,register ,,of ,,admission1 ,,progress1 ,,and ,,withdrawal4 #hs4 #f;d4 ,,summary ,,of ,,attendances ,,for ,,five ,,years4 ,arranged for a ,mixed or an ,infants' ,department4 #cs4 #f;d4 ,arranged for a ,boys' or ,girls' ,department4 #cs4 #f;d4 ,arranged for an ,infants' ,department4 #cs4 #f;d4 ,,macmillan',s 8,,three ,,term0 ,,class ,,record ,,book4 #dto4 #as4 ,,macmillan',s ,,class ,,time ,,table4 ,arranged by ,a4 ,,flavell and ,g4 ,h4 ,,robinson4 #f;d4 ,,macmillan',s ,,school ,,time ,,table4 ,arranged by ,a4 ,,flavell and ,g4 ,h4 ,,robinson4 ,mounted1 #bs4 ,paper1 #as4 ,,the ,,class ,,teachers' ,,journal4 ,arranged by ,g4 ,h4 ,,robinson and ,h4 ,m4 ,,cohen4 ,fcap4 folio4 #as4 #i;d4 ,,macmillan',s 8,,official0 ,,drawing ,,books4 ,no4 ,i4-,,xx4 ,price #c;d4 each4 ,,blackboard ,,drawing4 ,by ,m4 ,,swannell4 ,royal #dto4 #ds4 #f;d4 ,,the ,,first ,,elements ,,of ,,science4 ,arranged as ,observation ,lessons1 and correlated with ,drawing4 ,by ,,george ,,ricks1 ,b4,sc4 ,illustrated by ,,arthur ,,wilkinson4 ,in #c parts4 ,med4 #dto4 #as4 #f;d4 each4 ,,macmillan',s ,,art ,,studies ,,of ,,animals1 ,,plants1 ,,common ,,objects ,,and ,,conventional ,,forms4 #hvo4 ,sewed4 #f;d4 ,a ,,graduated ,,course ,,of ,,drawing ,,for ,,infants4 ,by ,,constance ,h4 ,,fowler4 ,royal #dto4 #ds4 #f;d4 ,,macmillan',s ,,brushwork ,,copy-,,books4 ,a ,graduated ,scheme of ,lessons ,designed and ,arranged by ,a4 ,r4 ,,cartwright and ,f4 ,c4 ,,proctor4 ,nos4 #a to #d4 #d;d4 each4 ,nos4 #e and #f4 #e;d4 each4 ,,macmillan',s ,,brushwork ,,cards4 ,being advanced ,drawing ,copies of ,animals and ,birds illustrating expression of ,mass and ,form with the ,brush4 ,selected and arranged by ,f4 ,c4 ,,proctor4 ,series ,a43 ,animals4 ,series ,b43 ,birds4 #bs4 each4 ,,macmillan',s ,,free ,,brush ,,design ,,drawing ,,cards4 ,,by ,,francis ,w4 ,,wallis4 ,in ,three ,sets4 ,junior #bs4 ,intermediate #bs4 ,senior #bs4 ,,nature ,,study ,,drawing ,,cards4 ,by ,,isaac ,j4 ,,williams4 #h ,subjects 7#bj alike in each box7 #dhs41 or separately1 #fs4 each4 ,packets containing #h assorted ,cards4 #bs4 #f;d4 ,,macmillan ,,co41 ,,ltd41 ,st4 ,martin's ,street1 ,,london1 ,w4,c4