,,november1 ,volume ,,xvi4 #aiae ,number #a4 ,the ,ohio ,journal of ,science 7,continuation of ,the ,ohio ,naturalist7 ,official ,organ of the ,,ohio ,,state ,,university ,,scientific ,,society and of the ,,ohio ,,academy ,,of ,,science ,,columbus1 ,,ohio ,annual ,subscription ,price1 #b4jj ,single ,number1 #cj ,cents ,entered at the ,post-,office at ,columbus1 ,ohio1 as ,second-,class ,matter4 ,,the ,,ohio ,,journal ,,of ,,science ,,published ,,by ,,the ,ohio ,state ,university ,scientific ,society ,issued ,monthly during the ,academic ,year1 from ,november to ,june 7eight numbers74 ,,official ,,organ ,,of ,,the ,,ohio ,,academy ,,of ,,science ,subscription ,price3 #b4jj per ,year1 payable in advance2 to ,foreign ,countries1 #b4ej4 ,single ,copies1 #cj ,cents4 ,editor1 ,,john ,h4 ,,schaffner ,associate ,editor1 ,,james ,s4 ,,hine ,associate ,editor1 ,,frederick ,w4 ,,ives ,,editorial ,,board ,j4 ,f4 ,,lyman ,agricultural ,chemistry ,f4 ,w4 ,,ives ,agricultural ,engineering ,a4 ,g4 ,,mccall ,agronomy ,f4 ,l4 ,,landacre ,anatomy ,j4 ,h4 ,,schaffner ,botany ,,carl ,b4 ,,harrop ,ceramic ,engineering ,,jas4 ,r4 ,,withrow ,chemistry ,f4 ,h4 ,,eno ,civil ,engineering ,n4 ,w4 ,,scherer ,forestry ,c4 ,s4 ,,prosser ,geology ,v4 ,h4 ,,davis ,horticulture ,w4 ,a4 ,,knight ,industrial ,arts ,c4 ,j4 ,,west ,mathematics ,,horace ,,judd ,mechanical ,engineering ,,jonathan ,,forman ,pathology ,f4 ,c4 ,,blake ,physics ,r4 ,j4 ,,seymour ,physiology 7,general7 ,,clayton ,,mcpeek ,physiology 7,medical7 ,e4 ,r4 ,,hayhurst ,public ,health ,sanitation ,j4 ,s4 ,,hine ,zoology and ,entomology ,the ,,ohio ,,journal ,,of ,,science is owned and controlled by the ,ohio ,state ,university ,scientific ,society4 ,by a special arrangement with the ,ohio ,academy of ,science1 the ,,ohio ,,journal ,,of ,,science is sent without additional expense to all members of the ,academy who are not in arrears for annual dues4 ,the first fifteen volumes of the old ,,ohio ,,naturalist may be obtained at #a4jj per volume4 ,remittances of all kinds should be made payable to the ,business ,manager1 ,j4 ,s4 ,,hine4 ,address ,the ,ohio ,journal of ,science ,ohio ,state ,university1 ,,columbus ,ohio ,academy of ,science ,publications4 ,first and ,second ,annual ,reports ,price #cj cts4 each ,third and ,fourth ,annual ,reports ,price #be cts4 each ,fifth to ,sixteenth ,annual ,reports ,price #bj cts4 each ,seventeenth ,annual ,report ,price #dj cts4 each ,,special ,,papers4 #a4 ,sandusky ,flora4 pp4 #ajg4 ,e4 ,l4 ,,moseley #fj cts4 #b4 ,the ,odonata of ,ohio4 pp4 #aaf4 ,,david ,s4 ,,kellicott #fj cts4 #c4 ,the ,preglacial ,drainage of ,ohio4 pp4 #ge4 ,w4 ,g4 ,,tight1 ,j4 ,a4 ,,bownocker1 ,j4 ,h4 ,,todd and ,,gerard ,,fowke #ej cts4 #d4 ,the ,fishes of ,ohio4 pp4 #aje4 ,,raymond ,c4 ,,osburn #fj cts4 #e4 ,tabanid of ,ohio4 pp4 #fc4 ,,james ,s4 ,,hine #ej cts4 #f4 ,the ,birds of ,ohio4 pp4 #bda4 ,,lynds ,,jones #ge cts4 #g4 ,ecological ,study of ,big ,spring ,prairie4 pp4 #if4 ,,thomas ,a4 ,,bonser #ej cts4 #h4 ,the ,coccid of ,ohio1 i4 pp4 #ff4 ,,james ,g4 ,,sanders #ej cts4 #i4 ,batrachians and ,reptiles of ,ohio4 pp4 #ed4 ,,max ,,morse #ej cts4 #aj4 ,ecological ,study of ,brush ,lake4 pp4 #bj4 ,j4 ,h4 ,,schaffner1 ,,otto ,e4 ,,jennings1 ,,fred ,j4 ,,tyler #ce cts4 #aa4 ,the ,willows of ,ohio4 pp4 #fj4 ,,robert ,f4 ,,griggs #ej cts4 #ab4 ,land and ,fresh-water ,mollusca of ,ohio4 pp4 #ce4 ,v4 ,,sterkj #ej cts4 #ac4 ,the ,protozoa of ,sandusky ,bay and ,vicinity4 ,f4 ,l4 ,,landacre #fj cts4 #ad4 ,discomycetes in the ,vicinity of ,oxford1 ,ohio4 pp4 #ed4 ,,freda ,m4 ,,bachman #ej cts4 #ae4 ,trees of ,ohio and ,surrounding ,territory4 pp4 #abb4 ,,john ,h4 ,,schaffner #ge cts4 #af4 ,the ,pteridophytes of ,ohio4 pp4 #da4 ,,john ,h4 ,,schaffner #ej cts4 #ag4 ,fauna of the ,maxville ,limestone4 pp4 #fe4 ,w4 ,c4 ,,morse #fj cts4 #ah4 ,the ,agaricace of ,ohio4 pp4 #aaf4 ,w4 ,g4 ,,stover #ge cts4 #ai4 ,an ,ecological ,study of ,buckeye ,lake4 pp4 #ach4 ,,frederica ,,detmers #ge cts4 ,address3 ,c4 ,w4 ,,reebe1 ,librarian1 ,ohio ,academy of ,science4 ,library1 ,ohio ,state ,university1 ,columbus1 ,ohio4 ,,the ,,ohio ,,journal ,,of ,,science ,,published ,,by ,,the ,,ohio ,,state ,,university ,,scientific ,,society ,,volume ,,xvi ,,november1 #aiae ,,no4 #a ,,table ,,of ,,contents ,,introductory #a ,,lord--,the ,making of a ,photographic ,objective #c ,,transeau--,notes on the ,zygnemales #ag ,organization of the ,ohio ,state ,university ,scientific ,society #cb ,,introductory4 ,fifteen years ago the ,biological ,club of the ,ohio ,state ,university began publishing ,,the ,,ohio ,,naturalist4 ,this ,journal has had a continuous existence and has been an important medium in advancing the knowledge of the natural history of the state4 ,a number of years ago the ,,naturalist became the official organ of the ,ohio ,academy of ,science and was thus sent to every member of the ,academy4 ,at that time the ,ohio ,academy was largely composed of ,biologists and ,geologists1 but has now widened its scope to include ,physicists1 ,mathematicians1 and others4 ,it was1 therefore1 thought desirable by many that the scope of the ,,naturalist should be enlarged so as to make it representative of all of the activities of the ,academy4 ,in accordance with this desire1 committees were appointed by the various departments interested and a plan for future publication was proposed which was finally adopted4 ,the ,ohio ,state ,university ,scientific ,society was thus organized at the ,ohio ,state ,university and will take over the control of the new publication4 ,this ,society is to have somewhat the same relationship to ,,the ,,ohio ,,journal ,,of ,,science as the ,biological ,club had to the ,ohio ,naturalist4 ,the management of the ,journal is under an ,editorial ,board made up of representatives of various scientific departments of the ,university4 ,this ,board elects annually the ,editor and two ,associate ,editors4 ,,editorial ,,board4 ,agricultural ,chemistry1 ,j4 ,f4 ,lyman2 ,agricultural ,engineering1 ,f4 ,w4 ,ives2 ,agronomy1 ,a4 ,g4 ,mc,call2 ,anatomy1 ,f4 ,l4 ,landacre2 ,botany1 ,j4 ,h4 ,schaffner2 ,ceramic ,engineering1 ,carl ,b4 ,harrop2 ,chemistry1 ,jas4 ,r4 ,withrow2 ,civil ,engineering1 ,f4 ,h4 ,eno2 ,forestry1 ,n4 ,w4 ,scherer2 ,geology1 ,c4 ,s4 ,prosser2 ,horticulture1 ,v4 ,h4 ,davis2 ,industrial ,arts1 ,w4 ,a4 ,knight2 ,mathematics1 ,c4 ,j4 ,west2 ,mechanical ,engineering1 ,horace ,judd2 ,pathology1 ,jonathan ,forman2 ,physics1 ,f4 ,c4 ,blake2 ,physiology 7,general7 ,r4 ,j4 ,seymour2 ,physiology 7,medical71 ,clayton ,mc,peek2 ,public ,health and ,sanitation1 ,e4 ,r4 ,hayhurst2 ,zoology and ,entomology1 ,j4 ,s4 ,hine4 ,,the ,,ohio ,,journal ,,of ,,science is to be considered as a continuation of ,,the ,,ohio ,,naturalist4 ,it is hoped that with the wider field covered1 it may interest a much larger number of the scientific people of the state1 and be financially supported so that it may soon develop into a journal of high standard4 ,it is the intention of the present ,editors1 with the large field before them1 to publish results of research as well as articles of general interest in the advancement of ,science4 ,on the natural history side the aim at present will be to pay more especial attention to the biology1 geology and geography of ,ohio1 but articles dealing with any other region will be acceptable4 ,the ,editors for the present year are as follows3 ,john ,h4 ,schaffner--,editor4 ,james ,s4 ,hine--,associate ,editor 7,business74 ,frederick ,w4 ,ives--,associate ,editor 7,subscriptions74 ,,john ,h4 ,,schaffner4 ,,the ,,making ,,of ,a ,,photographic ,,objective4 ,being a ,description of a ,course in ,applied ,optics ,offered at the ,emerson ,mc,millin ,observatory of the ,ohio ,state ,university4 ,h4 ,c4 ,,lord4 ,photography1 in its more serious phase1 has taken an important place in almost every field of human activity while in its lighter mood1 through the development of the 8,kodak0 and the roll film1 is giving us one of our most delightful pastimes4 ,as a condition for the best work1 a high grade lens is a necessity and especially so for those extremely short exposures required in the photography of rapidly moving objects4 ,it often happens that some of the most perfect and at the same time most difficult specimens of optical design are found on cameras so small that they can be easily carried in one's coat pocket4 ,these so called anastigmats furnish to the optician a difficult and yet at the same time most fascinating problem for mathematical investigation4 ,thousands of photographic objectives are placed on the market every year1 yet though almost every branch of engineering is covered by our technical schools1 ,i know of no place outside of ,germany where a student can be instructed in the design and construction of a simple photographic objective4 ,professor ,silvanus ,p4 ,thompson in his inaugural address as ,president of the ,british ,optical ,convention held in ,london in #aiab1 states3 8,in the ,universities and ,colleges the only people who are learning ,optics are merely taking it as a part of ,physics for the sake of passing an examination for a degree1 and care nothing for the application of ,optics in the industries4 ,they are being taught ,optics by men who are not opticians1 who never ground a lens or calculated even an achromatic doublet1 who never worked an opthalmoscope or measured a cylindrical lens40 ,further on he speaks as follows3 8,what is wanted is an establishment where the whole atmosphere is one of optical interest2 where theory and practice go hand in hand2 where the mathematician will himself grind lenses and measure their performance on the test bench2 where braincraft will be married to handcraft2 where precision1 whether in computation or workmanship1 will be the dominating ambition40 ,some four years before the above quotations were written1 the author started to work up a course in ,optics which should aim1 not only to give to the student a knowledge of the fundamental theory of lenses1 but should also apply those principles to the methods of optical design and thus enable him to compute the curves of the component lenses of a photographic objective4 ,this has now been fairly well worked out and is given in the ,arts college under the official titles 8,astronomy1 #ajg1 #ajh1 #aji and #aaj40 ,the basis of this course is 8,a ,system of ,applied ,optics10 by ,h4 ,dennis ,taylor1 the inventor of the ,cooke lens4 ,this splendid volume develops1 from the standpoint of geometric optics1 a complete discussion of the formation of an image by a combination of any number of lenses1 but does not apply the methods and formulae there developed to the actual design of a photographic objective4 ,the writer of this paper was1 therefore1 compelled to work out this part of the theory for himself and1 as he had always felt that all mathematics should ultimately end in arithmetic and that all arithmetic should ultimately end in doing something1 he resolved at the outset that the course should end in laboratory work in the actual computation1 grinding and polishing of lenses4 ,as to how well this has succeeded1 ,i will let the illustrations which accompany this article speak for themselves4 ,suffice it to say that the half tone cuts were made from five by seven enlargements from negatives1 one and three quarters by two and one-eighth inches1 taken with a lens designed and built at this observatory and working at an aperture of ,f six4 ,a peculiar feature of this lens is that it is composed of four lenses all cut from the same piece of crown glass4 ,this lens beautifully illustrates the importance of adding to the theoretical side of the course1 the practical work in the laboratory in construction and testing as this lens1 though in the main satisfactory1 has one serious defect and a defect which is very instructive in that it shows that at a certain point in the design1 the theory was weak and needed to be extended and enlarged4 ,it should be stated that this theoretical investigation is now completed and ready to be put to the test of practice4 ,this ,observatory possesses a well equipped instrument shop1 which was used for the practical side of this work and it has seemed to me that a description of how we used the ordinary tools of a machine shop1 of what special appliances we were compelled to make1 and how we finally ground and polished our lenses would be of general interest4 ,these methods do not pretend to be the best1 nor those actually employed by the manufacturer1 but they do illustrate how a lens can be made and how a little ingenuity will enable one if he has the standard tools of a machine shop to carry out almost any kind of experimental work4 ,as a preliminary to this1 a brief outline of the problem before the lens designer may be of interest4 ,a simple lens consists of a piece of glass bounded by either plane or spherical surfaces as these1 except in large reflecting surfaces1 are the only kind that can be made with sufficient accuracy4 ,such a lens would have a great many defects or errors and would be unable to give a sharp image on the photographic plate unless stopped down to a very small aperture4 ,by changing the radii of the surfaces1 and the thickness of the lens1 the designer can vary these errors1 but after all is said and done he can do but little to improve the single lens4 ,he then combines lenses of different forms and of different kinds of glass into a single objective1 in this way making the positive errors of some of the lenses balance the negative errors of the others1 until he arrives at a combination which is more or less perfect according to his skill as a designer4 ,how this is accomplished is far beyond the limits of this paper1 so ,i will now proceed to the mechanical side of the problem4 ,the first consideration is the glass2 of course it must be what is known as optical glass and its selection is really part of the work of the designer4 ,optical glass is nothing more than a very perfect kind of glass which has been exquisitely annealed4 ,you are all familiar with the intense green of window glass when seen edgewise2 a piece of white paper will hardly be changed in color when seen through twelve inches of a good optical crown4 ,the best optical glass is not made in this country1 but must be purchased from either ,schott ,gen4 of ,jena or ,mantois of ,france4 ,the ,jena glass has become very celebrated and most of the lens makers state that their lenses are made out of it and as a consequence most people think that ,jena glass means a certain kind1 while1 as a matter of fact1 their catalogue for #aiji shows about seventy different varieties4 ,these differ in optical qualities and chemical composition1 and cost from about a dollar to five dollars a pound1 with a few special varieties costing as much as fifteen dollars4 ,this glass comes in slabs1 but will be cut by the makers with either a diamond saw or a sand saw1 the purchaser paying for the 8saw dust40 ,illustration3 ,,fig4 #a ,illustration3 ,,fig4 #b ,the slabs that were used here were #b #f and the first operation was to cut from these round disks a little larger than the finished lens4 ,this was accomplished in the following manner and is illustrated in ,fig4 #a4 ,in the chuck of a drill speeder on a ,barnes drill press was placed a steel rod which carried at its lower end a copper tube1 ,a1 which was steadied at the bottom by a steel washer1 bored to a loose fit to the tube1 and clamped to the glass as shown4 ,number #dj ,carborundum was used and lubricated with plenty of water4 ,the tube must be lifted frequently to allow the abrasive to flow to the cutting edge4 ,this is done so often that it seems almost a continuous motion of lifting and pressing down again1 the tool resting on the glass hardly more than two or three seconds at a time4 ,the cutting may be done at such a speed as to allow of a slight heating4 ,as soon as the tube has cut itself about a sixteenth of an inch into the glass1 the guiding washer may be removed and the glass will then act as its own guide4 ,a disk about one inch in diameter and a half of an inch thick could be cut out in a little over a half of an hour4 ,at ,b ,fig4 #a is shown one of the uncut slabs and at ,c and ,d two that are about used up4 ,though working rather slowly this proved quite satisfactory though wasteful of glass as it cut a rather wide scarf1 copper must be used2 brass was tried but the wear was so great as to render it almost useless while the copper shows almost none4 ,as these disks are cut out they are not only cone shaped but the edges are very rough so that the next operation was to grind these to smooth and true circular disks4 ,this was done on a ,wells tool grinder shown in ,fig4 #b1 which was slowed way down by placing a large pulley on the counter shaft4 ,the glass to be ground was held by cementing it with pitch onto a piece of brass rod which in turn was held in the drawing collet of the head ,a4 ,a special wheel ,b1 made by the ,norton people for grinding the rims of spectacle lenses1 was used and the machine slowed until the wheel would keep wet when running against a sponge1 ,c1 resting in water4 ,the glass disk was in this way kept dripping and heating entirely prevented4 ,the grinding was then carried out just as with any other material and the edge was made beautifully smooth and true in a few minutes4 ,the beauty of pitch as a cement for holding the glass is that a slight heating will soften it so that the disk can be shifted to any position and then a dash of cold water clamps it in place and at the same time the pitch will slowly yield to the slightest pressure so that in a few minutes the glass is entirely free from strain4 ,in manufacturing this sort of work is done with a diamond and is of course done much more quickly4 ,the disks were thick enough to make two lenses each so we sawed them into two as illustrated in ,fig4 #c4 ,a is an old polishing head upon which was mounted a pulley at one end and a copper disk1 ,b1 at the other1 the disk being held between large washers4 ,c is a cast iron box fastened to an arm1 ,d1 hinged at ,e and kept pressed against the copper disk by a cord passing over two pulleys on the ceiling4 ,this made a most excellent automatic feed4 ,the glass to be split was fastened to a block of pine with pitch and the wood held in the iron box1 ,c1 with wedges4 ,number #dj ,carborundum was used with plenty of water and the glass was cut through faster than a power hack saw would cut through steel4 ,the glass should be cut half way through and then reversed so that the final break will come in the middle and thus prevent the edges from spawling off4 ,the chief defect of this machine was the way it scattered emery4 ,illustration3 ,,fig4 #c ,the disks are now ready for the grinding which is done on the machine on the right of ,fig4 #c1 which consists simply of a vertical spindle run by a quarter twist belt from the counter shaft against the wall4 ,the end of this spindle is tapered at the upper end to receive the grinding tool or laps1 shown on the table in ,fig4 #e which also shows the spindle raised so that the grinding lap is seen above the tin box1 ,c1 which surrounds the spindle to catch the abrasive that is thrown off in grinding4 ,the glass is first smoothed down on a flat lap until it is of equal thickness at all points as measured by a micrometer when it is ready to be ground to the proper curves4 ,for this purpose the spherical laps1 shown in ,fig4 #e1 are turned in the special machine illustrated in ,fig4 #d4 ,the compound rest of an old ,seller's lathe was removed and in its place1 on the cross slide of the carriage1 was mounted the sphere turning rest4 ,this consists of a base1 ,a1 in which the slide1 ,b1 is so mounted that it can be rotated about the center1 ,c1 by turning the milled head1 ,d1 which carries a worm at the opposite end4 ,e is the tool post with the cutting tool ,t and ,l the lap to be turned4 ,a hole was drilled at ,c into which was fitted a round piece of steel the upper end being pointed and then half cut away like a center reamer4 ,this was used in finding the zero2 the rod1 pointed end up1 was placed in the hole at ,c and the cutting tool adjusted against the flattened side4 ,the zero position is then determined by measuring1 with an inside micrometer1 the distance from the tool post to a stop placed at the end of the slide ,b4 ,by adding to or subtracting from the zero reading of the micrometer the length of the radius of the grinding lap1 the tool post may be set to the proper position for either a convex or a concave surface4 ,this1 however1 is only approximate1 for these laps must be made with the highest possible accuracy4 ,after sufficient cuts have been taken to give a spherical surface1 the radius is carefully measured with a special spherometer and the error in the radius corrected by changing the position of the cutting tool by an amount calculated from the readings of the spherometer4 ,this spherometer we were compelled to build as we could find none of sufficient accuracy on the market and it is described in a note at the end of this article4 ,illustration3 ,,fig4 #d ,illustration3 ,,fig4 #e ,in ,fig4 #d1 ,r is simply a steady rest made with the large overhang to allow the slide ,b to swing under it in turning a convex surface4 ,two master laps1 male and female1 must be made and carefully ground together4 ,every effort should be taken to make these as accurate as possible since upon these depends the goodness of our lens4 ,this special tool is easy to make and leaves nothing to be desired in its operation4 ,detail drawings and directions for making it are given in a note at the end4 ,we now come to the grinding or lapping of the lenses themselves4 ,this is done in a lap turned as above and carefully fitted to the master laps and which must be trued from time to time as the work progresses4 ,this lapping of glass is entirely different from the lapping of metals in that1 while in metals the lap is to be kept almost free from the abrasive1 in glass the lap must be freely supplied with emery and water or deep scratches will result4 ,the best way to apply the emery is with a paint brush2 the brush1 saturated with emery1 being held in front of the lens as it is ground4 ,the lens may be held in the hand or cemented to a disk of brass having a center hole drilled in the back in which is placed a pointed piece of steel held in the hand1 the lens being free to rotate about the pointed steel holder4 ,of course where the lens has to be ground to a definite thickness it must be held by hand4 ,flour of emery was used to rough grind though coarser grades would have worked faster4 ,the final smooth grinding was done with a special fine emery made for this purpose by ,bausch and ,lomb4 ,great care must be taken in the grinding to keep the lens as nearly centered as possible4 ,a lens is said to be centered when the line which joins the centers of curvature of the surfaces passes through the center of figure4 ,obviously if a double convex lens could be ground to a knife edge it would be centered but if this were done the edge would be almost certain to crumble in the final polishing and deep scratches result4 ,the centering of a convex lens can be watched by keeping the edge as nearly uniform of thickness as possible with a concave lens1 if the original blank is made larger than necessary and care is taken to make the sides parallel1 the centering can be watched by keeping a flat edge of equal width around the concave portion1 the lens being placed back on the flat tool1 from time to time1 as the work progresses4 ,if care is used the lens need be made but little larger than the finished size to allow for the final accurate centering to be described later4 ,after being smooth ground the lens is beautifully smooth and velvety to the touch but is just as much ground glass as ever1 that is1 it is absolutely opaque4 ,we now come to the polishing4 ,this is done with specially prepared rouge and only an excessively small amount of glass is taken off4 ,lord ,rayleigh in a paper on 8,polishing of ,glass ,surfaces0 read before the ,british ,optical ,convention held in #aije1 states3 8,i started with a finely ground surface1 rather more finely ground ,i think than is used in practice1 and ,i found that in order to obtain a pretty good polish it was necessary to remove a weight of glass1 corresponding to a depth of about #f wavelengths4 ,i do not pretend that such a polish would satisfy the requirements of commerce2 probably the #f would have to be raised to #aj or #ab in order to get to the bottom of the deepest pits40 ,when it is remembered that a wave length is about the fifty thousandth part of an inch we realize how very delicate such lapping must be4 ,for this work the lap is covered with pitch which has been brought to the proper degree of hardness either by boiling1 to harden it or by adding asfalt varnish to soften it4 ,the proper degree of hardness is very important and must be adjusted to the temperature of the room4 ,obviously if the pitch is too soft it will not hold its shape and it will be impossible to hold the polishing tool to the proper radius4 ,i have put three different curves on a lens about an inch in diameter in a few minutes and it had to go back on the grinding machine before it could be finished4 ,the polishing tool is prepared as follows3 ,a disk of pitch1 about thick1 is cast by pouring it in a mold made by a strip of brass bent to a circle1 the ends clamped with a tool maker's clamp1 and rested on a piece of cold cast iron which has been planed smooth4 ,this should be of such size that when bent to the proper shape it can be molded over a tool similar to the grinding tool but with a radius changed by about the thickness of the pitch4 ,this tool is then heated and painted with a stick of pitch1 the disk is warmed1 and the two pressed together1 when cooled the pitch will stick tight to the iron but will be far from a smooth surface4 ,this and the master tool of the opposite curvature are placed in warm water and pressed together and at the same time one slowly rotated1 one about the other4 ,when a good fit is secured they are cooled and a number of small holes1 about #a-h in diameter1 are drilled all over the pitch to distribute the abrasive1 which of course spoils the surface and the tool must be again pressed4 ,this pressing to shape must be done repeatedly and requires great care and some practice in order to have the pitch come to the exact opposite of the pressing tool4 ,the most important thing is to do the pressing slowly and in fact in the whole process of this work one must never get in a hurry4 ,ritchey1 in his memoir on the construction of the great #fj at ,mt4 ,wilson1 recommends covering the pitch with beeswax1 and for quicker and poorer work a cloth polisher may be used1 the cloth being a special felt and cemented to the cast iron tool with a thin layer of pitch4 ,the abrasive is rouge or red oxide of iron and its preparation is fully described in the above mentioned work by ,ritchey4 ,we purchased the anhydrous red oxide of iron from ,merck ,co4 ,this was mixed with plenty of water in the jars shown at ,e1 ,fig4 #e4 ,the rouge will rapidly precipitate1 the coarse particles falling to the bottom1 and leaving clear water above the precipitated rouge4 ,the upper two-thirds of the rouge will be almost perfect and will give a beautiful polish when carefully siphoned off4 ,this should be kept in tightly corked bottles1 one of the best things is a horse radish jar as this has a place for the handle of the brush in the glass stopper1 and all dust and grit can be easily washed off before the jar is opened4 ,for polishing1 the lens is cemented to a handle at whose end is a piece of brass turned to fit the lens in the sphere turning machine already described4 ,even in a small lens the polishing tool must be run slowly1 the speeds of our machines run from #agj to #cjj revolutions per minute and the fastest can seldom be used4 ,the reason of this is that the lens fits the polisher so perfectly that almost a perfect vacuum is formed and the lens hugs the polished so closely that it is impossible to hold it in small sizes by hand alone and in the case of a convex surface1 if the cavity is carried clear out to the edge of the glass disk1 this may be broken simply by the friction due to this grip of the glass and pitch4 ,fig4 #e shows a horizontal polishing head at ,b and a vertical one at ,c4 ,there is little choice except that for convex surfaces ,b seems the best1 as it can be run faster1 while for concave ,c seems better4 ,the lenses are now ready to be centered1 that is1 the circumference so turned that the line which joins the centers of curvature of the two spherical surfaces shall pass through the center of figure4 ,in order to accomplish this1 the lens is first cleaned from the pitch used to cement it to the handle used in holding the lens for polishing4 ,for a long time ,i could find no way of doing this satisfactorily when pitch was the cement2 finally1 ,i laid my troubles before ,dr4 ,a4 ,m4 ,bleile1 ,head of the ,department of ,physiology1 and he suggested to first soak the lens in lard and then wash it in benzol 7,c#f;,h#f74 ,this worked like magic though the first time ,i tried it ,i used some lard that had been heated with some pitch in it which made the lard very soft in fact almost as soft as it could be and yet not be an oil1 and this same lard was used over and over again4 ,the action is rather peculiar2 the lard does not apparently effect the pitch at all but after a few minutes in the benzene it all flakes off and leaves the lens perfectly clean4 ,the actual centering is then carried out on the grinding machine shown in ,fig4 #b2 ,a holder1 ,d1 whose front face has been turned in the spherical turning machine to fit one of the surfaces of the lens1 is held in the head ,a4 ,if the lens be cemented to this with a thin coat of pitch1 it is obvious that the surface of the lens next to the holder will have its center of curvature coincide with the axis of rotation of the spindle of the head1 ,a1 but the center of curvature of the other lens surface will probably fall outside of this axis4 ,a lamp1 ,l1 has a tin chimney with a pin hole in it turned towards the lens1 this pin hole forming a brilliant point of light1 an image of which is formed by each surface and reflected by the total reflecting prism1 ,p1 into the telescope1 ,t1 where it is seen through the eyepiece4 ,if the centers of curvature of both surfaces do not accurately coincide with the axis of rotation of the head1 ,a1 the images of the pin hole will describe circles as this axis is rotated4 ,the back surface will of course be centered if the layer of the pitch used as cement is of uniform thickness which will generally be the case if the work has been carefully done2 but in any case the image formed by it should be examined4 ,if the front surface is out of center1 as it generally will be1 the holder should be warmed and the lens shifted1 care being used to keep it tight against the surface of the holder as it is being shifted4 ,as soon as both images remain stationary as the head1 ,a1 is rotated1 the lens is fed against the wheel1 ,b1 and ground true and to size4 ,this worked beautifully and the tests were wonderfully sensitive4 ,as soon as the component lenses of the objective have all been thus centered1 they are ready to be assembled in the cell or shutter in which they are to be used2 but as this is simply a matter of careful machine work1 ,i need not describe it further4 ,i know of no literature on the grinding of small lenses though the following memoirs on the making of large reflecting telescopes should be in the hands of any one interested in this work3 ,on the ,construction of a ,five-foot ,equatorial ,reflecting ,telescope4 ,by ,a4 ,a4 ,common1 ,,ll4 ,d41 ,f4 ,r4 ,s4 ,memoirs of the ,royal ,astronomical ,society1 ,vol4 ,l41 #ahij-ia4 ,on the ,construction of a ,silvered ,glass ,telescope1 ,fifteen and a ,half ,inches in ,aperture1 and its ,use in ,celestial ,photography4 ,by ,henry ,draper1 ,m4 ,d41 ,smithsonian ,contributions to ,knowledge1 ,vol4 #cd4 ,on the ,modern ,reflecting ,telescope and the ,making and ,testing of ,optical ,mirrors4 ,by ,george ,w4 ,ritchey4 ,smithsonian ,contributions to ,knowledge1 ,vol4 #cd4 ,,note #a--;,a ,,spherometer ,,for ,,short ,,radii4 ,illustration3 ,,fig4 #f ,in ,fig4 #f1 ,a is a regular ,brown ,sharpe ,micrometer ,head with the measuring point ground to an angle of #fj and slightly rounded2 ,b is a round steel base all machined at one setting in which the micrometer head is clamped by a set screw not shown4 ,let r be the radius of the spherical surface1 ,,mno1 and we will have at once r 7a#b d#b7 _/ #b;d4 ,the advantage of this form of spherometer is that it is very easy to make the point of the micrometer exactly central with the base and the value of #b;a can be accurately determined by means of an ordinary micrometer calliper4 ,for a convex surface1 #b;a should obviously be the inside diameter of the base1 ,b4 ,in using the instrument1 two tables1 one for concave and one for convex surfaces1 should be prepared2 these tables to give the power in dioptres for each one thousandth of an inch in the value of d4 ,using the ,american ,optical ,co4's ,standard ,index1 namely1 equal to #a4ejjj and one dioptre as being the power of a lens of #dj inches focus1 we have1 for a plano lens1 p #d_/;f #dj;d_/7a#b d#b7 since f r_/7-#a74 ,the advantage of forming the table in dioptres in place of radii directly is that the tabular differences are small at all parts of the table so that interpolation can be readily done and this is not the case in tables which give the radii directly4 ,if upon measuring the radius of the tool or lap being turned in the sphere turning machine1 ,fig4 #d1 with this spherometer1 the tool is found to be in error by an amount p this may be corrected by changing the position of the cutting tool by an amount #bj 7p _/ p#b74 ,,note #b--;,,cross ,,section ,,of ,,the ,,sphere ,,turning ,,rest4 ,illustration3 ,,fig4 #g ,in ,fig4 #g is shown a cross section of the sphere turning rest further illustrated in ,fig4 #d4 ,in machining this the following suggestions should be followed4 ,the piece ,m should be cast with a lug projecting from the face ,,pq to chuck it by and all the turning done at one chucking4 ,it should be made a close fit to ,r and bolted tight against ,,dg and ,,ed with the bolts ,s#c and ,s#d1 clearance being given along the line ,,hf4 ,to compensate for ware the face ,,dg and ,,ed can be releaved from time to time with a file4 ,the base ,n1 should be planed along ,,ab1 where it fastens to the cross slide of the carriage1 then bolted to a face plate of the lathe and finished1 care being used to leave the setting of the compound rest unchanged between machining the faces ,,cd and ,c,d of the pieces ,m and ,n4 ,the dove tail on ,r should be first planed and then this bolted to a face plate and the boss ,,ghfe and the faces ,,kg and ,,el turned at one setting4 ,if these directions are followed almost no hand work will be needed4 ,w is a brass worm wheel held by screws not shown and ,j is the sliding tool post clamped at ,x with the tool at ,k4 ,,notes ,,on ,,the ,,zygnemales4,a ,,edgar ,,nelson ,,transeau4 ,the following notes principally concerning ,north ,american ,zygnemales are based on a study of the specimens accumulated in the course of eight years collecting in central ,illinois2 a collection made by ,mr4 ,charles ,bullard1 of ,cambridge1 ,mass41 in ,massachusetts and ,new ,hampshire2 the specimens distributed in the ,phycotheca ,boreali-,americana by ,collins1 ,holden and ,setchell2 the specimens distributed in ,american ,algae1 by ,miss ,josephine ,e4 ,tilden2 the specimens in the ,u4 ,s4 ,national ,herbarium2 and small collections sent me by ,professor ,farlow1 ,miss ,tilden1 ,professor ,a4 ,b4 ,klugh1 ,professor ,d4 ,s4 ,johnson and ,miss ,grace ,stone4 ,they have been compared with the species distributed by ,wittrock and ,nordstedt in their 8,algae ,aquae dulcis exsiccatae10 and other valuable ,european and ,south ,american specimens sent me by ,professors ,o4 ,borge and ,o4 ,nordstedt4 ,in determining almost any species of the ,zygnemales it is absolutely essential that the specimens show both the vegetative cells and the mature spores4 ,with the exception of a few species of ,mougeotia the spores are colored either yellow1 brown1 or blue when they are mature4 ,the characteristic markings of the median spore wall do not develop usually until this color appears4 ,consequently it is useless to attach names to vegetative specimens based on dimensions and number of chromatophores4 ,keys based on such characters are not only useless1 but misleading4 ,judging from my experience in ,illinois it is highly probable that the list of ,north ,american forms will be considerably augmented1 when intensive studies have been made at localities in the ,southern ,united ,states4 ,the most satisfactory method of collecting these forms is to take samples from the various ponds and streams at regular intervals of ten days1 or two weeks1 throughout the growing season4 ,many of the species show local variations and considerable experience is needed before many of the forms can be satisfactorily classified4 ,the writer has in course of preparation an illustrated key to the group1 in which figures for all of the species will be published4 ,,debarya ,wittrock4 ,this genus is in many respects the most generalized of all the ,zygnemales4 ,it is distinguished by three important characteristics3 7#a7 the entire contents of the gametangia enter into the making of the zygospore2 7#b7 the zygospore is formed in the conjugating tube and is not cut off from the other parts of the gametangia by partition walls2 7#c7 as the gametes move toward the tube during conjugation1 their place is taken by a secretion of cellulose1 which renders the gametangia solid and highly refractive4 ,this secretion also occurs when a vegetative cell forms an aplanospore4 ,debarya glyptosperma ,wittrock4 ,this species has been recorded for ,america4 ,it is not uncommon in ,massachusetts and has also been found in ,minnesota and ,florida4 ,in ,p4 ,b4-,a4 ,no4 #hjh from ,boswell1 ,california is a somewhat smaller variety with blue spores associated with ,zygnema peliosporum ,wittr4 ,the spores are common in the material and the vegetative cells and filaments occasional4 ,following is a diagnosis for this variety3 ,var4 formosa nov4 var4 ,cellulis vegetativis #g4e-i latis2 zygosporis #bd-cj #cj-db1 caeruleis2 ceterum ut in typo4 ,vegetative cells #g4e-i in diameter1 zygospores #bd-cj #cj-db steel blue1 otherwise like the type4 ,debarya americana nov4 sp4 ,cellulis vegetativis #i-ab #bg-abj1 ad dissepimenta constrictis2 chromatophoris cum pyrenoidibus #b2 cellulis fructiferis1 #aj-ad #ge-ahj2 zygosporis ovoideis vel quadrato-ovoideis1 #bj-dj #cj-dj1 angulis rotundatis1 productis1 vel retusis2 parthenosporis #ae-bj #bj-cj1 oblique ellipticis1 cum polis retusis2 mesosporio subtiliter et irregulariter verrucoso1 maturitate luteo-brunneo4 ,vegetative cells #i-ab #bg-abj constricted at the end walls1 chromatophore with two pyrenoids2 fertile cells #aj-ad #ge-ahj2 zygospores ovoid or quadrately ovoid1 #bj-dj #cj-dj1 with angles rounded1 produced1 or retuse2 parthenospores #ae-bj- #bj-cj unilaterally ellipsoid with retuse ends2 median spore wall minutely and irregularly verrucose1 yellow-brown at maturity4 ,this species was collected by ,professor ,a4 ,b4 ,klugh1 ,kingston1 ,ontario4 ,it is the material upon which the ,ontario record for ,mougeotia calcarea 7,cleve7 ,wittr4 is based4 ,of special interest is the chromatophore with two pyrenoids1 which although an axile plate is distinctly two-lobed and forms an easy transition to the next species1 in which the chromatophore resembles ,zygnema4 ,type in herb4 ,e4 ,n4 ,t4 ,collection ,no4 #biej4 ,debarya decussata nov4 sp4 ,cellulis vegetativis #af-bj #be-ej cylindraceis2 chromatophoris asteroidiis duobus1 singulis cum pyrenoidibus 7ut in ,zygnemate72 zygosporis vel ovoideis1 vel irregularibus1 #bd-cj #cj-dh cum angulis vel rotundatis1 vel retusis1 vel productis2 aplanosporis uno latere ovoideis1 #ag-be #bj-dj2 parthenosporis #ae-bj #bj-cj2 membrana media sporarum scrobiculata1 luteo-brunnea2 akinetis ad dissepimenta constrictis1 membrana subcrassa et glabra1 #ah-bj #bj-cf4 ,vegetative cells #af-bj #be-ej cylindrical2 chromatophores two1 stellate1 each with a pyrenoid 7as in ,zygnema72 zygospores ovoid1 quadrate-ovoid1 or irregular1 #bd-cj #cj-dh1 with rounded1 retuse1 or produced angles2 aplanospores unilaterally ovoid1 #ag-be #bj-dj2 parthenospores #ae-bj #bj-cj2 median spore walls scrobiculate1 yellow-brown2 akinetes with smooth heavy walls1 #ah-bj #bj-cj4 ,type in herb1 ,e4 ,n4 ,t4 ,collections ,no4 #aagg1 #aici1 #aidi1 #bfhf and #biah4 ,i have specimens from several localities in central ,illinois2 ,williamsport1 ,pa42 ,minnesota2 ,mackinaw1 ,mich4 and ,kingston1 ,ontario4 ,this form is of great interest because of its resemblance1 in the vegetative condition1 to ,zygnema decussatum 7,vauch47 ,transeau4 ,also because it shows not only the zygospores1 but aplanospores and parthenospores4 ,in all cases the secretion of cellulose accompanies the process of spore formation4 ,the unilaterally placed aplanospores are strikingly different from those formed by the ,zygnemas4 ,in some of the ,illinois ponds it regularly produces only zygospores1 in other ponds from which ,i have collections covering a period of several years it fruited only asexually1 producing aplanospores and akinetes4 ,but several of the collections show all the forms of reproduction in different cells of the same filament4 ,the characteristics of this species suggest that the peculiar ,zygnema reticulatum1 which was described by ,hallas in #ahie;,b1 is in reality a ,debarya4 ,the fact that the reproductive cells become filled with cellulose1 that the aplanospores are very irregular in form and that the vegetative cells contain as high as seven chromatophores1 are all in harmony with this idea4 ,on this basis it is also easy to understand the most notable peculiarity of the species--that spores derived from cells with several chromatophores produce two or three sporelings4 ,with the addition of the two new ,american species and this ,danish species ,debarya reticulata 7,hallas7 nov4 comb4 the description of the genus needs to be modified as follows3 ,vegetative cells cylindrical or constricted at the ends1 varying from #a-af diameters in length2 chromatophore varying from an axile plate with two or more pyrenoids to stellate chromatophores1 each with a central pyrenoid4 ,reproduction by zygospores formed of the complete contents of the gametangia2 not cut off from the gametangia by partition walls2 but in the process of conjugation1 as the gametes pass into the conjugating tube1 their place is taken by a secretion of cellulose4 ,aplanospores occupying only part of the sporogenous cell1 the remainder being filled with cellulose4 ,all spores variable in form4 ,parthenospores and akinetes occur not infrequently in some of the species4 ,the walls of the aplanospores and parthenospores resemble the zygospores of the same species in their markings4 ,there are now eleven described species belonging to this genus4 ,d4 immersa ,w4 ,west and ,d4 africana ,g4 ,s4 ,west bear a close resemblance to ,mongeotia sphaerocarpa ,wolle4 ,d4 ,hardyi ,g4 ,s4 ,west has much the same appearance as ,mongeotia viridis 7,kutz7 ,wittrock4 ,d4 desmidiodes ,w4 ,g4 ,s4 ,west1 ,d4 calospora 7,palla7 ,w4 ,g4 ,s4 ,west1 ,d4 reticulata1 ,d4 americana1 and ,d4 decussata have characters in common with the ,zygnemas4 ,d4 glyptosperma has the vegetative characters common to several of the species1 but its spores are quite unique among the ,zygnemales4 ,,zygnema ,agardh4 ,z4 pectinatum 7,vauch47 ,agardh4 ,this is probably common in the eastern half of the ,united ,states at least4 ,in ,illinois along with the type occurs the variety conspicuum 7,hass47 ,kirchner1 and a variety with large spores4 ,this latter variety in fact is more common than the type4 var4 crassum nov4 var4 ,cellulis vegetativis #cj-dj #bj-hj2 zygosporis #dj-ee #ej-fj1 ceterum ut in typo4 ,vegetative cells #cj-dj #bj-hj2 zygospores #dj-ee #ej-fj1 otherwise like the type4 ,type in herb4 ,e4 ,n4 ,t4 ,collections ,no4 #bcej1 #bcib1 #bffj1 #bfhe4 ,z4 ericetorum 7,ktz7 ,hansgirg4 ,professor ,g4 ,s4 ,west has studied the reproduction of this species and finds that it is a true ,zygnema and that the description and figure by ,de ,bary1 which shows the cutting off of two special gametangia before the union of the gametes is at fault1 consequently there is no longer any need of maintaining the genus ,zygogonium ,ktzing4 ,z4 peliosporum ,wittrock4 ,specimens of this species have been distributed under the name of ,z4 chalybeospernum ,hansgirg1 in ,p4 ,b4-,a4 ,no4 #hjh from ,boswell1 ,calif4 7,n4 ,l4 ,gardner72 ,amer4 ,alg4 ,no4 #aef from ,ft4 ,collins1 ,colo4 7,j4 ,h4 ,cowan72 and ,amer4 ,alg4 ,no4 #cib from ,vancouver1 ,b4 ,c4 7,j4 ,e4 ,tilden74 ,z4 chalybeospermum has the median wall smooth1 but the spores of all of the above specimens have distinctly scrobiculate median walls4 ,in size the specimens show a somewhat greater variation in dimensions than has been recorded for ,european localities4 ,z4 cruciatum 7,vauch7 ,agardh4 ,specimens of this species have been found at ,fath ,pond1 north of ,coffeen1 ,ill41 in which both zygospores and aplanospores occurred in abundance4 ,the aplanospores fill or slightly enlarge the vegetative cells as in ,z4 ,collinsianum ,transeau1,c but the ends of the spores are usually more nearly truncate1 #cd-ej #cj-hj4 ,at ,casey1 ,ill41 a variety with the same dimensions but steel blue spores occurs in the old ,ice ,plant ,pond4 var4 caeruleum nov4 var4 ,cellulis vegetativis et sporis ut in typo1 sed membrana media sporarum caerulea4 ,vegetative cells and spores as in the type1 except that the median spore wall is steel blue4 ,type in ,collection ,e4 ,n4 ,t4 ,no4 #die4 ,zygnema stellinum 7,mller7 ,agardh4 ,the specimen distributed under the name ,z4 insigne 7,hass47 ,ktz4 in the ,p4 ,b4-,a4 ,no4 #deg1 from ,chestnut ,hill1 ,mass4 7,g4 ,f4 ,moore71 belongs to this species as shown by the scattered mature spores4 ,this species is common everywhere in central ,illinois4 ,in the ,u4 ,s4 ,natl4 ,herb1 is a specimen from ,baltimore ,co41 ,md41 7,j4 ,d4 ,smith74 ,in ,amer4 ,alg4 ,no4 #aeg1 a specimen from ,st4 ,paul1 ,minn41 7,j4 ,e4 ,tilden7 shows both zygospores and aplanospores4 ,the aplanospores are cylindric ovoid in form1 occupying the entire cell #cj-cc #dj-hh1 median wall scrobiculate4 ,zygnema cylindricum nov4 sp4 ,cellulis vegetativis #bh-cc #bh-ff2 zygosporis incognitis2 aplanosporis cylindricis vel tumido-cylindricis1 #cj-cc #bd-eh1 sporangia complentibus2 membrana media brunnea scrobiculata4 ,vegetative cells #bh-cc #bh-ff2 zygospores unknown2 aplanospores cylindric or tumid-cylindric1 #cj-cc #bd-eh1 filling the sporangia1 median wall brown1 scrobiculate4 ,type in ,herb4 ,e4 ,n4 ,t4 ,no4 #aafd1 #aagg4 ,this species is not uncommon in ponds1 and pools throughout central ,illinois4 ,it was at first classified as aplanosporic material of ,z4 stellinum 7,mller7 ,agardh4 ,on going over the specimens in all my collections1 however1 it was found that in no case were the filaments containing the aplanospores connected with the filaments containing zygospores4 ,this must be the final test of the identity of the species1 as it occurs in some collections alone1 sometimes associated only with fruiting ,zygnema pectinatum1 and sometimes with ,z4 stellinum4 ,zygnema rhynchonema ,hansg4 ,in a collection of algae made at the ,minnesota ,seaside ,station1 ,vancouver ,island1 ,b4 ,c41 in #aija1 by ,professor ,tilden1 is a form which perhaps belongs here4 ,the vegetative cells are from #bb-bh in diameter1 and #cb-eb in length1 while the ,european specimens are described as #af-bj in diameter and #b-f diameters long4 ,the ,vancouver specimens are producing both aplanospores 7globose1 #bd-bf in diam471 and zygospores 7ovoid #bd-bh #cf-dd7 by the union of gametes through the partition wall separating the two gametangia4 ,the specimens show some evidences of being in an abnormal condition4 ,,spirogyra ,link4 ,s4 ,juergensii ,ktzing4 ,the specimen in ,p4 ,b4-,a4 ,no4 #eaj from ,knightsville1 ,r4 ,i41 distributed under the name of ,s4 longata 7,vauch7 ,ktz4 with cell diameter #bg-cj1 and ellipsoid spores #cj-cc in diameter1 fertile cells enlarged1 evidently belongs to this species4 ,the spores of ,s4 longata are distinctly ovoid with rounded ends4 ,in the ,illinois specimens the spores of ,s4 ,juergensii frequently occur with diameters up to #cc4 ,s4 varians 7,hass47 ,ktz4 ,the varieties scrobiculata ,stockman and minor ,teodoresco have not been reported from ,america4 ,they both occur rarely in ,illinois4 ,the latter ,i have also seen in material collected by ,mr4 ,charles ,bullard1 at ,lynnfield1 ,mass4 ,the former is characterized by its scrobiculate spores1 the latter by its smaller dimensions throughout4 ,in my herbarium ,s4 varians scrobiculata is represented in ,collections ,no4 #agii1 and #ahha2 and ,s4 varians minor in ,collection ,no4 #biea4 ,s4 ,borgeana nov4 sp4 ,cellulis vegetativis #cj-ce #ej-bjj1 dissepimentis planis1 chromatophoris singulis anfractibus arctis #a4e-e2 cellulis fractiferis altero latere inflatis1 altero latere 7in quo conjugatio sequitur7 rectis2 zygosporis ellipticis1 #cc-dj #ed-gj1 membrana media flava1 glabra4 ,vegetative cells #cj-ce #ej-bjj1 end walls plane1 #a chromatophore making #a4e-e turns2 fertile cells inflated on the outer side1 straight on the conjugating side2 zygospores ellipsoid #cc-dj #ed-gj1 median wall yellow1 smooth4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #ahhc1 #ahij4 ,charleston1 ,illinois4 ,this species bears some resemblance to a form of ,s4 varians figured by ,professor ,borge4,d ,it differs from his figure in that the conjugating side of the fertile cells is not at all swollen1 and the dimensions are somewhat larger4 ,if this form had been found but once it would have been passed over as a variation intermediate between ,s4 ,juergensii and ,s4 varians4 ,but it has been found several successive years in a small stream south1 and at a small pond west of ,charleston1 ,illinois4 ,s4 lutetiana ,petit4 ,so far as ,i am aware no specimens of this species have been found in ,america4 ,the ,illinois record in my list,e is an error4 ,the ,p4 ,b4-,a4 specimen labelled ,s4 lutetiana is ,s4 fallax 7,hansg47 ,wille1 as shown by its often replicate cell walls1 verrucose spores and the number of chromotophores4 ,s4 velata ,nordstedt var4 occidentalis ,transeau4 ,specimens of this variety have been distributed in the ,p4 ,b4-,a4 ,no4 #if1 under the name of ,s4 dubia ,ktz4 var4 longiarticulata ,ktz4 from ,oak ,bay1 ,victoria1 ,british ,columbia 7,n4 ,l4 ,gardner74 ,the spores are for the most part not mature but they show the characteristic scrobiculate markings of the median wall4 ,s4 ,lagerheimii ,wittrock4 ,this species is not uncommon in central ,illinois4 ,the specimen labelled ,s4 communis in ,p4 ,b4-,a4 ,no4 #adaf1 from ,winchester1 ,mass41 has a cell diameter over #cj1 and the spores are ellipsoid instead of ovoid4 ,the median spore wall in the mature spores is punctate4 ,here also belongs the ,p4 ,b4-,a4 specimen ,no4 #cfe1 ,falmouth1 ,mass4 ,both the vegetative cells and the spores are considerably below the lower dimensions for ,s4 porticalis4 ,the ,p4 ,b4-,a4 specimen ,no4 #affh1 ,s4 porticalis var4 tenuispira ,collins establishes this name as a synonym of ,s4 ,lagerheimii4 ,professor ,farlow has recently sent me a specimen of this species from ,chocorua1 ,n4 ,h4 ,s4 daedalea ,lagerheim4 ,this species has recently been found in a pond south of ,coffeen1 ,ill4 ,the spores show the characteristic markings and the dimensions are near those of the original collection4 ,the spores are slightly more rhomboidal than in the type material1 which ,i have seen4 ,in herb4 ,e4 ,n4 ,t4 ,collection ,no4 #biab1 #bhej4 ,s4 ,goetzei ,schmidle4 ,this species previously known only from the tropics has been found in the collection of ,mr4 ,charles ,bullard1 from ,wellfleet1 ,mass4 ,in herb4 ,e4 ,n4 ,t4 ,collection ,no4 #bied4 ,s4 submarina 7,collins7 nov4 comb4 ,this species was described by ,collins as a variety of ,s4 decimina 7,mller7 ,ktz1 which it somewhat resembles in the form of the vegetative cells4 ,the spores1 however1 are distinctly ellipsoid1 while those of ,s4 decimina are ovoid4 ,the dimensions are much smaller than those of ,s4 decimina4 ,it seems better therefore to recognize this as a distinct species4 ,it has been collected in ,massachusetts1 ,connecticut and ,bermuda4 ,e4 ellipsospora ,transeau4 ,described originally from ,illinois1 ,i have seen specimens during the past year from ,maine1 ,massachusetts and ,minnesota4 ,professor ,g4 ,s4 ,west,f described about the same time a species from ,columbia1 ,south ,america1 which appears to be a form of this same species4 ,the vegetative cells are considerably larger1 the chromatophores are six 7or five7 in number1 and the spores are at the upper limit of size of the ,north ,american form4 ,as our specimens all show1 a wider range of dimensions and number of chromatophores1 the ,south ,american form is best classified as a variety under the name ,s4 ellipsospora var4 splendida 7,g4 ,s4 ,west7 nov4 comb4 ,s4 propria nov4 sp4 ,cellulis vegetativis #fj-fh #hj-aej1 dissepimentis planis2 chromatophoris #c1 anfractibus arctis 4#e-a2 cellulis fructiferis cylindricis2 zygosporis ellipticis #db-fj #hj-abj2 membrana media sporarum scrobiculis irregularis ornata1 luteo-brunnea4 ,vegetative cells #fj-fh #hj-aej1 end walls plane2 #c chromatophores making 4#e-a turn in the cell2 fertile cells cylindrical2 zygospores ellipsoid1 #db-fj #hj-abj1 median wall irregularly pitted1 yellow-brown4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #bfff4 ,coffeen1 ,illinois4 ,this species is very distinct in the form of its spores and their position in the fertile cells4 ,lateral conjugation only has been observed4 ,it is possible that the number of chromatophores is more variable1 but in all the vegetative cells in which they could be counted there were three4 ,spirogyra braziliensis 7,nordstedt7 nov4 comb4 ,owing to the indefinite and imperfect description of ,s4 lineata ,suring41 the variety ,braziliensis ,nordstedt1 of which we have a perfect description and specimens 7,w4 ,n4 ,alg4 aq4 dulc4 exsicc4 ,no4 #cfj71 should be given specific rank4 ,its connection with ,s4 lineata is very problematical4 ,s4 fluviatilis ,hilse4 ,in all the published descriptions of this species the spores are described as smooth1 and the number of chromatophores is given as four4 ,i have seen many specimens from ,illinois1 and collections from the upper peninsula of ,michigan 7,t4 ,l4 ,hankinson71 ,minnesota 7,j4 ,e4 ,tilden71 ,hawaii 7,j4 ,e4 ,tilden71 ,massachusetts 7,p4 ,b4-,a4 ,no4 #abag71 ,pennsylvania 7,e4 ,n4 ,t47 and ,guatemala 7,w4 ,a4 ,kellerman74 ,in all cases the mature spores are brown and scrobiculate1 and the number of chromatophores is three or four4 ,s4 nova-angliae nov4 sp4 ,cellulis vegetativis #ej-fj #bjj-cej1 dissepimentis planis2 chromatophoris #c-e1 anfractibus arctis #b4e-d4e2 cellulis fructiferis non inflatis2 zygosporis ovoideis #ej-fe #hj-abj3 membrana media sporarum reticulata et dense punctata1 flava4 ,vegetative cells #ej-fj #bjj-cej1 end walls plane2 #c-e chromatophores making #b4e-d4e turns2 fertile cells not inflated2 zygospores ovoid #ej-fe #hj-abj3 median wall reticulate and densely punctate1 yellow in color4 ,this species was first found in the collections of ,mr4 ,bullard from ,beaver ,dam1 ,brook ,pond1 ,natick2 the pond west of ,winter ,pond1 ,winchester2 and the ,middlesex ,fells1 ,mass4 ,recently the same form was found in a large prairie pond south of ,coffeen1 ,illinois4 ,its position in the genus is near ,s4 malmeana ,hirn4 ,in herb4 ,e4 ,n4 ,t4 ,collections ,no4 #bieb1 #biec and #bijj4 ,s4 diluta ,wood4 ,i first came across this species in ,mr4 ,bullard's collection from the pond west of ,winter ,pond1 ,winchester1 ,mass4 ,on going over ,wood's description1 its identity with ,s4 diluta is unmistakable4 ,the position1 color and form of the spore1 and the shape of the fertile cells is perfectly represented in ,wood's figure4 ,the dimensions also correspond4 ,wolle is responsible for confusing this species with ,s4 nitida 7,dillw47 ,link1 but a glance at ,wood's figure is sufficient to show that it is very different from that species4 ,the ,p4 ,b4 ,a4 specimen ,no4 #eac 7labelled ,s4 nitida7 from ,bridgeport1 ,conn41 belongs here4 ,miss ,grace ,stone also sent me a collection of this species from near ,new ,york ,city4 ,in the ,u4 ,s4 ,national ,herbarium is another specimen from ,bois ,sabbi1 ,louisiana1 ,april #gth1 #ahia1 7,a4 ,b4 ,langlois74 ,recently the species has been collected at ,donnelson1 ,illinois1 by ,mr4 ,frank ,harris4 ,the vegetative cells are usually shorter than in ,s4 nitida1 the spores are ovoid1 not ellipsoid1 and the spore wall is verrucose1 or reticulate-verrucose1 chestnut brown in color4 ,in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #bijj4 ,s4 crassa ,ktzing4 ,var4 formosa nov4 var4 ,varietas gracilis1 cellulis vegetativis #hj-ie #hj-bgj2 zygosporis #hh-ajj #abj-aej #gj-ij2 ceterum ut in typo4 ,a small variety1 vegetative cells #hj-ie #hj-bgj3 zygospores #hh-ajj #abj-aej #gj-ij2 otherwise similar to the type4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #aici4 ,this variety occurs in a pond east of ,ashmore1 ,ill4 ,s4 submaxima ,transeau4 ,this species which was described from ,illinois has been found with nearly the same dimensions in the collections from ,middlesex ,fells1 and ,south ,peabody ,station1 ,mass41 sent me by ,mr4 ,chas4 ,bullard4 ,s4 micropunctata nov4 sp4 ,cellulis vegetativis #cj-cf #abj-cjj1 dissepimentis planis1 chromatophoris singulis anfractibus arctis #c-g2 cellulis fructiferis modo binis vel quaternis inter cellulas vegetativas distributis1 modo continuis1 altero latere 7in quo conjugatio sequitur7 inflatis1 altero rectis2 tubo conjugationis plerumque ex cellula mascula emisso2 zygosporis ellipticis #cg-db #eg-ajj membrana media micropunctata et lutea4 ,vegetative cells #cj-cf #abj-cjj1 end walls plane2 #a chromatophore making #c-g turns2 fertile cells scattered in twos or fours among vegetative cells1 or continuous1 inflated on the conjugating side1 outer side straight2 conjugating tubes formed almost wholly by the male cell1 zygospores ellipsoid #cg-db #eg-gj1 median wall minutely punctate1 yellow4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #bdgj1 #biec4 ,this species was first found in the ,west ,big ,four ,pond1 east of ,charleston1 ,illinois4 ,it has since been found in a collection from ,chocorua1 ,n4 ,h41 sent me by ,mr4 ,chas4 ,bullard4 ,it evidently belongs in the punctata group of the ,spirogyras1 but in form and markings of the spore1 and the shape of the fertile cells it is amply distinct from its nearest allies2 ,s4 punctiformis ,transeau and the next species to be described4 ,s4 reflexa nov4 sp4 ,cellulis vegetativis #cj-dj #abj-cjj1 dissepimentis planis2 chromatophoris singulis anfractibus arctis #c-h cellulis fructiferis binis vel quaternis inter cellulas vegetativas distributis1 inflatis et valde reflexis2 tubo conjugationis ex cellula mascula emisso2 zygosporis ellipticis1 #dd-ed #ij-aej1 membrana media glabra et luteo-brunnea4 ,vegetative cells #cj-dj #abj-cjj1 with plane end wall2 #a chromatophore making #c-h turns2 fertile cells in groups of #b or #d1 inflated or enlarged and strongly reflexed2 conjugating tube formed by the male cells2 zygospores ellipsoid1 #dd-ed #ij-aej1 median wall smooth1 yellow-brown4 ,type in herb4 ,e4 ,n4 ,t4 ,collection ,no4 #bffa1 #bffd1 #biab4 ,this species has been under observation for four years and has been collected from ponds near ,casey1 ,lerna1 ,coffeen and ,donnellson1 ,illinois4 ,the large1 smooth spores1 the reflexed conjugating cells1 and the tube produced wholly by the male cells are the distinguishing characteristics4 ,s4 hydrodictya nov4 sp4 ,cellulis vegetativis #ge-ajj #baj-cfj1 dissepimentis planis1 chromatophoris #g-aj1 modo subrectis longitudinalibus1 modo spiralibus anfractibus arctis 4#a-4e2 cellulis fructiferis inflatis vel subinflatis2 tubo conjugationis ex cellula mascula emisso2 zygosporis lenticularibus vel globoso-lenticularibus1 #hj-abj #aaj-aie1 membrana media scrobiculis obsita1 brunnea4 ,vegetative cells #ge-ajj #baj-cfj1 end walls plane1 #g-aj chromatophores1 either straight1 or spiral making 4#a-4e turns2 fertile cells inflated or subinflated2 conjugating tube formed by the male cell2 zygospores lenticular or globose-lenticular #hj-abj #aaj-aie1 median wall brown1 pitted4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #bffa1 #bffe4 ,coffeen1 ,illinois4 ,this is one of the most remarkable forms described in this genus4 ,it combines large size1 the lenticular spore form1 and the habit of forming the conjugating tube entirely by the male cell4 ,the conjugating tube has walls heavier than those of any known species4 ,conjugation is both lateral and scalariform1 and occurs between scattered cells1 very rarely continuous for #f-h cells4 ,in the fruiting condition the filaments form a mesh-work which suggests the specific name4 ,it has thus far been found only in the ,fath ,pond1 north of ,coffeen1 ,illinois4 ,s4 protecta ,wood4 ,a study of ,american specimens of this species from ,massachusetts1 ,connecticut1 ,new ,jersey1 ,michigan and ,illinois1 shows that like ,s4 ,grevilleana there are always some cells with two chromatophores4 ,i have twice found this species producing aplanospores4 ,s4 tenuissima 7,hass47 ,ktz var4 rugosa ,transeau4 ,p4 ,b4-,a4 specimen ,no4 #def1 ,easton's ,pt41 ,newport1 ,r4 ,i41 belongs to this variety rather than the type1 as shown by the scrobiculate spore wall4 ,in ,mr4 ,bullard's collection there are also specimens of the variety from ,pennannock1 ,n4 ,j41 and from ,spy ,pond1 ,lake ,st41 ,arlington1 ,mass4 ,s4 ,farlowii nov4 sp4 ,cellulis vegetativis #bd-cj #gj-ahj1 dissepimentis replicatis2 chromatophoris singulis1 rarius duobus1 anfractibus arctis #b4e-f2 cellulis fructiferis inflatis 7ad #ci-fj72 zygosporis ellipticis1 polis plus minus acuminatis1 #cb-de #dh-ic1 membrana media glabra1 lutea4 ,vegetative cells #bd-cj #gj-ahj1 end walls replicate2 #a 7rarely #b7 chromatophore making #b4e-f turns2 fertile cells inflated to #ci-fj2 zygospores ellipsoid1 ends more or less pointed1 #cb-de #dh-ic1 median wall smooth1 yellow4 ,type in herb4 ,e4 ,n4 ,t4 ,coll4 ,no4 #biee1 #bief1 #bieg4 ,in ,mr4 ,bullard's collection there are specimens of this species from ,lexington1 ,arlington1 and ,middlesex ,fells1 ,mass4 ,the ,p4 ,b4-,a4 specimen ,no4 #cfb1 labeled ,s4 ,grevilleana1 from ,medford1 ,mass41 belongs here1 rather than to ,s4 ,grevilleana1 in which the spores are distinctly ovoid with broad rounded ends4 ,s4 groenlandica ,rosenvinge4 ,this interesting form is characterized by quadrately inflated fertile cells1 highly refractive cell walls1 and unusually long cells and spores4 ,in ,mr4 ,bullard's collection there are specimens from ,stony ,brook1 ,south ,framingham1 ,middlesex ,fells1 ,wayside ,inn1 ,north ,eastham1 and ,malden ,fells1 ,massachusetts4 ,the ,p4 ,b4-,a4 specimen ,no4 #cfc labelled ,s4 inflata1 ,orange1 ,conn41 belongs to this species4 ,s4 fallax 7,hansgirg7 ,wille4 ,this species is one of several forms near ,s4 insignis 7,hass47 ,ktzing4 ,if ,wille's description is correct and identical with ,hansgirg's material1 then ,s4 inconstans ,collins becomes a synonym of ,s4 fallax4 ,hansgirg's figure suggests that the filaments in his material are homosexual4 ,while ,wille's description and figure suggests that the filaments are reflexed and that conjugation does not regularly occur between parallel filaments1 with the spores all in one filament4 ,it is difficult to decide just where these rough-spored forms belong as the earlier authors did not pay much attention to spore markings4 ,in this connection the note by ,professor ,nordstedt in connection with specimen ,no4 #ieh in ,wittrock and ,nordstedt's ,algae ,exsiccatae is of interest4 ,until these forms have been clearly separated by a study of the original collections it seems best to use ,s4 fallax for ,s4 inconstans1 of which the type is ,p4 ,b4-,a4 ,no4 #aefh4 ,here also belongs ,p4 ,b4-,a4 ,no4 #aegj1 ,middlesex ,fells1 ,mass41 and ,p4 ,b4-,a4 ,no4 #aega1 ,wakefield1 ,mass4 ,s4 floridana nov4 sp4 ,cellulis vegetativis #ef-ff #abj-cce1 dissepimentis planis2 chromatophoris #d-e1 subrectis vel anfractibus arctis 4#e2 cellulis conjugatis abbreviatis1 inflatis 7ad #ace7 et geniculatis2 canalis conjugationis brevis et latis2 zygosporis ellipticis1 #ge-aje #ie-ace membrana media glabra1 lutea4 ,vegetative cells #ef-ff #abj-cce1 end walls plane2 #d-e chromatophores1 nearly straight or making a half turn2 conjugating cells geniculate1 shortened2 fertile cells inflated up to #ace2 conjugating tube very short and broad2 zygospores ellipsoid1 #ge-aje #ie-ace median wall smooth1 yellow4 ,type in ,u4 ,s4 ,national ,herbarium1 collected by ,j4 ,d4 ,smith1 in ,s4 ,w4 ,florida1 ,march1 #ahgh4 ,in its dimensions ,s4 floridana is intermediate between ,s4 stictica 7,eng4 ,bot47 ,wille and ,s4 ceylanica ,wittrock4 ,in several publications the statement is made that ,s4 ceylanica is intermediate between ,s4 stictica and the common forms of ,spirogyra4 ,a study of authentic material of this species has shown that it has not intermediate characters1 but with its spores having a minutely pitted median wall1 it seems to be intermediate between ,s4 floridana and ,s4 illinoiensis ,transeau1 the most specialized form in the ,sirogonium group of the genus4 ,throughout the study of these collections the writer has been greatly assisted by ,mr4 ,hanford ,tiffany1 now a teacher in the ,charleston1 ,illinois1 ,high ,school4 ,it is a pleasure to acknowledge my indebtedness to the many collectors who have sent me specimens for study4 ,,organization ,,of ,,the ,,ohio ,,state ,,university ,,scientific ,,society4 ,as the result of the sentiment expressed at the #aiad meeting of the ,ohio ,academy of ,science that the official organ of the ,academy1 8,the ,ohio ,naturalist10 should be broadened and made more comprehensive in scope1 and feeling that the ,ohio ,state ,university had no publication representing the scientific work being done at the institution1 the members of the ,biological ,club of the ,university1 in whom the publication of the 8,ohio ,naturalist0 had been vested1 called a meeting of representatives of the various departments interested in science at the university to discuss the advisability of publishing as successor to the 8,naturalist0 a journal to be known as the ,,ohio ,,journal ,,of ,,science4 ,the first meeting was held in ,may1 #aiae1 and committees appointed to outline preliminary plans4 ,at subsequent meetings the reports of the committees were discussed1 interest in the plan continued to develop1 until at a meeting held ,october #ac the following self-explanatory ,constitution was adopted4 ,the society as now constituted represents twenty-four departments of pure or applied science at the university4 ,,raymond ,j4 ,,seymour1 ,secretary ,pro ,tem4 ,,constitution4 ,,article ,i--,,name4 ,the name of this society shall be the ,ohio ,state ,university ,scientific ,society4 ,,article ,,ii--,,object4 ,it shall be the purpose of the ,society to promote scientific work in the ,university by holding meetings for the presentation and discussion of the results of scientific work2 by co-operating with other agencies in arranging for scientific lectures and in the entertainment of visiting scientists and scientific societies2 by publishing the ,,ohio ,,journal ,,of ,,science and by furnishing opportunity for the discussion and promotion of any project of scientific interest which may properly come within the scope of such an organization and1 in general1 by furthering in every way possible the interests of scientific work in the ,university and the ,state4 ,,article ,,iii--,,membership4 ,any member of the instructional staff in the ,ohio ,state ,university interested in scientific work shall upon application be eligible to election to membership in the ,society4 ,students of the ,ohio ,state ,university interested in scientific work shall be eligible to membership when endorsed by two faculty members of the society4 ,,article ,,iv--,,officers4 ,,section #a4 ,the officers of the society shall consist of ,president1 ,vice-,president1 ,secretary and ,treasurer4 ,these officers shall perform the duties common to such positions4 ,,section #b4 ,the ,executive ,committee shall consist of the officers and the ,editor of the ,,ohio ,,journal ,,of ,,science4 ,it shall have power to arrange programs for meetings1 to represent the society when co-operating with other organizations and to conduct all affairs of the society not otherwise provided for4 ,,article ,v--,,editorial ,,board4 ,the ,editorial ,board shall be responsible for the management of the ,,ohio ,,journal ,,of ,,science4 ,it shall consist of representatives1 one from each department of science in the university represented in the society membership4 ,this board shall elect annually an ,editor and two ,associate ,editors4 ,,article ,,vi--,,elections4 ,election to membership shall be by vote of the ,executive ,committee4 ,the officers shall be elected by ballot at the annual meeting in ,may4 ,nominations shall be presented by a nominating committee which shall consist of the ,editorial ,board4 ,one member of the ,editorial ,board shall be elected by each department from among the members of such department represented in the society and in case any department fails to elect a member for this board the ,executive ,committee shall elect for the department4 ,,article ,,vii--,,publication4 ,the ,editor and ,associate ,editors of the ,,ohio ,,journal ,,of ,,science shall have immediate direction of the publication4 ,the department editors shall be responsible for the approval of papers from their several departments1 and all papers offered for publication shall be submitted to such department editors4 ,the selection for publication from available material shall be determined by the ,editorial ,board4 ,,article ,,viii--,,quorum4 ,a quorum for the transaction of regular business shall consist of at least fifteen members with a representation of at least one-third of the departments included in the society4 ,,article ,,ix--,,amendments4 ,amendments to the constitution may be made by the concurrence of three-fourths of the members present at a duly called meeting1 notice of such amendment having been given to all members at least one week in advance4 ,,by-,,laws4 ,,article ,i4 ,the membership fees of the society shall be twenty-five cents per year or one dollar for a period of five years and such fee shall entitle the members to participation in all activities of the society but shall not include the subscription to the ,,ohio ,,journal ,,of ,,science4 ,,article ,,ii4 ,the subscription price to the ,,ohio ,,journal ,,of ,,science shall be two dollars to non-members1 and one dollar and seventy-five cents to members4 ,,article ,,iii4 ,the fiscal year of the society shall coincide with that of the ,university--,july #ast to ,june #cjth4 ,the publication to be issued during eight months1 beginning with ,november4 ,,article ,,iv4 ,regular meetings shall be held on the second ,tuesday evening of the months of ,october1 ,november1 ,march1 ,april and ,may4 ,the meeting in ,may shall be the annual meeting for the election of officers and an editorial board4 ,other meetings may be called by the ,executive ,committee1 or by the ,president on petition of five members4 ,,article ,v4 ,the ,university ,instructional ,staff shall be understood to include any member of the teaching force4 ,,article ,,vi4 ,amendments to the ,by-laws may be adopted at any regular meeting by vote of a majority of the members present1 notice of proposed amendment having been given at time meeting is called4 ,the ,college ,book ,store ,reference books in all departments of ,higher ,education4 ,biological ,supplies and ,advanced ,text ,books new and secondhand4 ,,opposite ,,the ,,university ,,entrance4 ,,columbus1 ,,ohio4 ,the ,bucher ,engraving ,co41 ,,columbus1 ,,ohio ,scientific ,illustrations given extremely careful attention by highly skilled artisans using the most modern equipment ,,die ,,stamping4 ,,plate ,,and ,,letter ,,press ,,printing4 ,,spahr ,,glenn1 ,,printers and ,,publishers4 #ej ,,east ,,broad ,,street4 ,,columbus1 ,,ohio4 ,the ,ohio ,state ,university ,,columbus ,,william ,,oxley ,,thompson1 ,president4 ,ten ,colleges and a ,graduate ,school ,college of ,agriculture ,college of ,arts1 ,philosophy and ,science ,college of ,education ,college of ,engineering ,college of ,homeopathic ,medicine ,college of ,law ,college of ,medicine ,college of ,dentistry ,college of ,pharmacy ,college of ,veterinary ,medicine ,graduate ,school ,summer ,session 7,eight weeks7 ,for general information1 catalogue1 or special bulletin describing each college1 with fees and announcement of courses ,address3 ,l4 ,e4 ,,wolfe1 ,secretary ,entrance ,board1 ,,the ,,ohio ,,state ,,university ,,footnotes3 ,a ,contribution from the ,botanical ,laboratory of the ,ohio ,state ,university1 ,no4 #ia4 ,b ,hallas1 ,e41 ,om en ny ,zygnema-,art med ,azygosporer4 ,bot4 ,tidsskrift #bj3a-af4 #ahie4 ,c ,see ,fig4 #c1 ,plate ,,xxv1 ,amer4 ,jour4 ,bot4 #a3cja4 #aiad4 ,d ,borge1 ,o41 ,beitrage zur ,algenflora von ,schweden4 ,e ,transeau1 ,e4 ,n41 ,annotated list of the ,algae of ,eastern ,illinois4 ,trans4 ,ill4 ,acad4 ,sci4 #f3fi-hi1 #aiac4 ,f ,west1 ,g4 ,s41 ,a contribution to our knowledge of the ,freshwater ,algae of ,columbia4 ,memoires de la ,societe neuchateloise des ,sciences ,naturelles #e3ajac-ajea4 ,neuchatel1 #aiad4 ,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,underscores are also used to designate a subscript4 e4g4 ,c#f ,h#f4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,carat symbol 80 designates a superscript4 ,small capitals have been converted to ,,solid capitals4 ,illustrations have been moved so they do not break up paragraphs4 ,old or antiquated spellings have been preserved4 ,typographical errors have been silently corrected but other variations in spelling and punctuation remain unaltered4