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Whenever possible, these have been omitted from filming/ II se peut que certaines pages blanch<:s ajoutias tors d'une restauration apparaissent dans la taxte. mais. lorsque cela ctait possible, ces pages n'ont pas M tUmitt. r~7\ Additional comments:/ Copy has Mnuscrfpt annotations. Lx—i Commentaires suppiimentaires: This item is filmed at the reduction ratio checked below/ Ce document ejt f JImi au taux de reduction indiquc ci-dessous. ^OX 74X 18X n n L'Institut a microfilm^ la meilleur exemplaire qu'il lui a eti possible de se procurer. Les details de cet exemplaire qui sont peut- 'he study of .i,e live ^m^s ''' ,1'""^ """ '- "-e laboratory directions ™ust be sorethat ™":'„7sh' I' r" ''"^ by the teacher to suit local condMot and h ""^"''^ the class. Because of the fact th,? ^ '■''qu.rements of different locahties, it is not . 1 ""' «''^">' ^"^ i» ^an accomplish all thr:rh:; Z^ tisT Tt^ there is variety enoush to «,„f ™ . , ,. "°P'd that may often serve the purpl bettH "t"""- °"'" '^P'^ The »ork must also beXedt he '" '"' P^'""""- the students and to the 1,^ I . ^^^ ^"^ ^'P^ience of author's reasons for°hordrof«T'. '° *^ ^"'''^^'- The in the preface Of the ^^^ ^^Z^Z Cr" "' ''-" te "Lrofrs:-tr;-:it:L ■'7 r° "'•■^ --p-e any assigned lesso^ or^Xttlterj''""''' -""^ Ihe Suggestions to the Student" h. I written. ^tuaent have been entirely re- 1 he « Suggestions to the Teach^^r " i,, u that they are no longer indi deTin h. K I r™' '° '^*^"^^^ a separate pamphlet which . I u °''^' ^"* ^'^ P""ted in In this pamphlet a ;t'nt3 a^^to ,ab "r' '^ ^'^ P"*^^^"^^-^' room management, notes anH^ '"^°^^^°^ equipment, class- tion, collecting outfit field wort '"'"^'' supervision of dissec- A full-page cut of thl ' ^'"'''^^'^^^ «f '"aterial, etc. accompany the dire tions forTr' '" '^^" '"^^^^"-^ '^ - this occ^ion to ^f :^— ;^-- IV i iji Preface. ttieir kindness in furnishing the electro for this cut A few other cut. are added to illustrate the work of d ssect ng " strigVr:rvvi^': "^"^' ^^^^^^^ ^y^^ --t be too s rongiy urged. Without some real knowledge derived from fo\:;s trr;':r.ir.r.c irVr -^^ and from lectures. To a few fixed V,,f , ^ '°'" '^^'"^ firmly fasten that which he a.;„tMhllT""" "' ^" other, but Which would od^erwH: Itg^anrfle"™ "' corlr. H k" k r "' '"" """o^'' " P'^-^""' Zooloi," was W J , j; "" '"'" '''°''«°'- Alpheus Hyatt of the Bos"™ LTnS^SUntdl "'!'°'^ ^P-'<'-" Davfd Starr /orS^^'of inland Stanford, Jr., University; Professor N. S. Shaler Har- English H.vi, CI, IB -'• • ^^'^gen, Jr., of the ^nglish High School, Boston ; Professor R. E. Call • Mr E P irc;,!°r u^i'ir' '"' '""''-" ^- '"• ""^- f. J^' ^.r^^ °^ *^'' '^'''°" ^"^^ ^^^" "'tically read by Pro- Tc\/-^''\''''' ''^^'"^^ ^^^-^' C^dar Fallsf la" ElV^ tT ' ^^'' ^°™^^ ^'^^^' Bridgewater, Mass. ; M. T S^;. i^T'"^ °^ ''°"''"^' J- ^- ^°^^°"^' University of lilmois ; H. Garman, State College of Kentucky ; W S Tack man University of Chicago; H. S. Jennings. 'uniWyof Yort^"''/-xf- ^''"^^"' ^'"'^ ^°°P^^ «^g^ School, New tZ '-. J'.^'"^^'' University of Kansas; Louis Murbach, Detroit High School ; Frank Smith, University of Illinois w. B. Ward, University of Nebraska. The directions for the study of the honey-bee were written by Mr^ Charles H. Allen, Bloomington, 111., High School. thl\ '" gentlemen the author is deeply indebted, and offers tnem his most sincere thanks. '^'-i^my CONT'^ \TS. rHAPTHR *^ • • • VII I. Collection and PRESERVAxinv ,.„ t TT T. ^ *Kt.sitK\ATioN OF Insects. "• TiiE Grasshopper . . _ '''''••.. i ni. Other Insecta ' ' ' * • • io Cricket. Drago„"F,y;s,,;.h Bug. Butterfly. Hou,; ^.v' '' Beetle. Bumblebee, Ant-lion. "^' IV. ARACHNn)A AND MyriaPuDA . Centiped, Miliiped. '**••• 3° V. Crustacea Crayfish. Sow Bug, Cyclops. ' ' 33 VI. Annulata Earthworm. * * * • 47 VII. MOLLUSCA Fresh-water Clam. Snail 54 VIII. Pisces . • • . , Perch. 66 IX. Amphibia * • • • Frog. **•••. 8a X. Reptilia. Snake. Turtle. 95 XI. Aves * • • , Pigeon, Hen's Egg. '04 XII, Mammalia Rabbit. 123 XIII. Mammalia (confi„u^j^ . Rabbit. Dissection of Heart'. Head and kL * / " '^^ and Veins. Kidneys; Arteries V t^m^^j^'^T^'^^'^^wk'':': i ^1 ^* Contents. CMAm* XIV. Mammalia {eondudeJ) . . '**" Rabl'.i, Nervous Sy.tem. .Mugclc», Eye, Larynx. Skeleton. ' XV. Protozoa Amceba, Paramecium, Vorticella. XVI. PORIFERA , I68 Commercial Sponge. XVII. Qelentf.rata . 171 Hydra, Sea Anemone, Corals, Sea Fan. XV^III. ECHINODERMATA .... Starfish, Sea Urchin. * ' '^ XIX. Trochelminthes . 190 Index . >9i II III iNTRODUCTION. TO THE STUDENT. The .en.porary notes ty be „;„™wir '°°V"' '"^ -""• lent notebook. The lonouin„T u " '^""^ '" "">' ""ven- Get a pad of unruled panerK P'''."'.''°'^"er, is recon,mended. wide. On this, lit ZZs and" "" '"""'' '°"^ """ """ '"^es -de, using only one srro he paT"^"""^^ "' •" ^ they are filled. Keep them ,„ , . "^ *'"""'= "■= sheets as half an inch w^er ^d an^n rsh^r^f ."rn^heT' ""'""^' the envelope ■• Zoology •• ; or better h, ! '*"^^- ''''«' labeled with any co^venien;^ Mivisi™: "ofT" v""'""'^ much or as little of the note.s », ^ ° j ' """"J'"- As envelopes can be carrL t he ptZfarth"! "r'"- ^— able at short notice, and can be consledM "' '"^"- notebook, with all the notes of , ? ""^ "™" "here a Astillfurtheradvantage : .hL '1™';°"'" ""' "^ ^' ''^"d- «me subject, made late, cZV^ ""'" <"■ <'^^"'"g» "" the Which could not well be done w^h? , "v"" "«'" ?''«• As the notes rccumulate thoL 1, ''^ " ^""^ "°'*«>k. stored in larger envelope nd keTt s" br'"'"" "^* ™^^ >« ■ence. A part of the " nad " nf , ' ^"'" ^o"' ""ven- all class-room exercises, VhetherTbrTK''"""''' ^ ""''« "> recitation, to take any needed „„ "J'^"™""^ ^"""'e or a of all animals studied! whether thot ^""'^ ""'"''' "^ "■^"^ tailed examination „ dltc, „„ ' f^™ '" ''""^"•^ '"^ de- brought in from day to day M, ' , *' '''^'^'''""' ^P-imens y day. B^ny statemente made by teacher :j(l ..., .IBf «»■ IIJ!^ Vlll ^ M Introduction. or fellow-pupil are worth copying in the notes. Notes should also be made of your reading about the animals that are brought in Field Note.. — For field notes a well-bound notebook is usually better. It si- ild be leather-covered and smaller than the class- room note paper. In this book you should make record of your outdoor observations. In the directions for " Field Study " are many questions for you to answer. It is to be hoped that you will ask many other questions and record your answers If you can give no immediate answer, do not give it up. Keep on looking and keep on thinking. Your "field notes," "outdoor study," "Saturday book," or whatever you choose to call it should be your constant companion. If the book has not a loop to hold a pencil, see to it that you have two or three short stubs of pencil in your pockets. Equipment fo. Field Work. - Suggestions will be found in connection with the field study of insects, birds, etc. But the student should always carry a conveniem lens, for there are many specimens which ought to be examined when found Almost any small, compact lens of moderate power will be suffi- cient, such as the linen-tester, which folds into very small space the lenses in hard rubber or metal cases, etc. The tripod lens IS rather inconvenient to carry in the field, but better than many others for class-room work. When possible carry a field glass. It will enable you to bring close to you many birds and other animals that will not allow you to come close to them. Even if your excursion is for insects, or other specimens which you can easily approach, you do not know what opportunities you may have to see distant specimens. The modern field glasses, with prisms int.aad of lenses, are superior to those of the old style, and in addition are very light, hardly weighing more than ordinary opera glasses. They are, however, rather expensive. Common opera glasses serve very well for all the ordinary purposes of studying birds. Permanent Notes. — The permanent notes should be written with ink on ruled paper ten inches long by eight inches wide. 'Si^^V Introduction. other; U,e wider margin shol h^ . '"" " ''='« <"» *<= '"e drawings, good, .^u led ^I'i^I^:^''' '" "'""'"«■ ^o' and perforations should be used pl oVT' '""^'"^' «"« paper, with labeled covers, are furn shi k'' 'T '''"''' °' dealers. This system allow any S arr ' ^^''~'-"PP'y notes and drawings, irresDectiv/.f T ■ ""8'"""' °' *e n.ade. They may also be^u L i ""' "'"^» *^y «"e desired. When ^ou hand' ^ TyolTT'"' ''" '"' ™^ papers, write your name and the date o^ .h % '"^ *""="'" where it will not mar ,),. , " P'^^orated margin should appear the s"wect!our 7 "^'k""'^^- »" *<= ~ver and the date. Brief mlCl ^J- '"' "'"' <" *« school, yourself as well as 'o yTu?.: her "f "' "'''" "^'P'"'- "> usually to be derived from the tin P*™anent notes are enlarged." They shouldTe „ vl "^ "^ "°"^' "'^™'d and best language should b usej Th'. "T ^""^^ """ ^°"' -7 accurate, but they should I^ •, " "'°"''' ""= "ot only sentences. Brevity Jth'so^ o'wTd""^' ^^''"ong-draw^ Drawing,.-The1e shou d t« rmTd""'^" " "' ""• medium hard pencil and keen , !.». ? ^""'- "^™ " make outline drawings. Male ft" t7r T'" ''''^'''^' ""' they suityou, that isif they conftmt th I ?' """ ""'"■ « 'hem again and make them'heavt M t no'If'"' 'V'" does not correspond to something you Le "n T"" " Proceed slowly, and whenever you !re dls^lfi" J '^"'""^■ usmg the kneaded rubber eraser D^ „T k . '"' "'^ ""«• to begin another; keep •• do oring " T H °" "■' "^"'"« you start. Often it is desirable to It 7'"^ ™* "'''<^'' tinct than it appears inftf ^d ^'^sr 'T' """^^ ''^ representing the back of a bug orTL^l ,k '"''*""' '" lapping of the winsrs is ,1,. ' ""^ ""^^ of over- Butthflineofunororo,over,T""" ''" '" "" ''™"S'" <»«• tinct, whereas some rWg tla^^ToT '"^^.''^'^-M^dlv indis- ■age that is of no significance may be X Introduction. prominent. Bring out the important features; often ignore features that are of no significance. Drawing should show structure rather than mere appearance. Represent things not so much as they appear, but rather as they really are. To make the suggestions more definite, suppose you are to make a draw- ing of the perch. Prop the fish up so you get a square view of its left side. In the first place the drawing should be of good size, so there will be room to put in details without having them crowded. About eight inches will be a good size to place lengthwise on the drawing paper. It is better to make the orig- inal drawing of the same size you wish for the finished drawing. Determine the place of the drawing on the sheet, leaving about equal space at each end, and with the drawing a little above the middle, as the general label should always be beneath the draw- ing. First draw a straight line for the longitudinal axis. Next determine where the greatest depth of the fish is, and draw a line, the transverse axis, at right angles to the main axis. Note carefully whether or not the transverse axis is divided into two equal parts by the longitudinal axis, i.e. whether the body of the fish is more above or more below the main axis. Having these points located, proceed to draw the outlines of the fish, watching closely to see that you get the right proportions. Go no faster than you can give satisfaction to your own criticism. After com- pletmg the general outline, draw the lateral line. Then make a dot for the hindmost tip of the gill cover, which marks the pos- terior end of the head. Proceed to put in the details of the head, the parts of the gill cover, the mouth, the eye, etc In drawing the mouth, show it as it is and be careful not to be guided by any preconceived notion-, of it. Block out and then fill m the different fins. Unle^.s you have an abundance of time, do not attempt to represent the scales, and it is not essen- tial to show the colors. When the above features are satisfactory to you as drawn in pencil, proceed to trace over the lines with ink. This is not so easy, as you cannot readily erase. Have confidence in the ^f^mr^'^ Introduction. XI steadiness of your hand and you will nrobahlv ^,f i Sdor"'r' '""'"« •"' P^" lengthwise 'a. above sle^d seldom makes any such trouble. "g&esiea, Now comes the labeling Place the inK^i very close tn h \r , ""^^^ °" ^^^^ Part, or £f1 T, ?? -- ' ■•"«.-=-.r^: you can distribute them more evenly. Avoid drawing a dotted S in f "' ""i "■' """^'"^ "^ best labeled on the o™„ Itself in the most available place Print =,11 l,l,.i f"'^" gothic type, that is, without cLes at^he enl In e'li"? 'to' kn»:^. xu Introduction. m If water-color drawings are to be made, first draw the outlines in black ink. After this is dry, paint in the water color. Do not use colored pencil crayons. Only solid organs, such as the liver, should be represented in solid color. Hollow organs, such as the digestive tube, should be represented in outline to show that they are open. The following colors may be taken to represent the different systems : arteries, red ; veins, blue ; digestive tube, brown ; liver, green ; kidneys, purple ; lungs,' pink; nervous system, gray; reproductive glands, orange. Do not be discouraged if your first drawings do not satisfy you. Drawing requires time and patience. Without these even the most gifted artist produces nothing worthy. The majority of students say at first, " I can't draw." After some sugges- tions, and a little practice, almost every one can show creditable results. The first thing is to see clearly. See each line in the specimen, -md make each mark in your mind, before you put it on paper. a such simple drawings as are here required, failure to draw well, after a little experience, usually indicates failure to see well. It is more head work than hand work. Perhaps the best definition of drawing is that given by the little girl who said " drawing is thinking, and then marking around the think." Dissecting. — The instruments needed are : a pair of scissors, a pair of forceps with roughened tips that will hold objects securely, a scalpel, a cartilage knife, a blowpipe, two dissecting needles, and a lens. The needles may be made by thrusting the eye end of a strong needle into a wooden handle. These in- struments are usually sold i* --ts in a convenient carrying case ; the cloth-lined leatherette^ es are more compact than the wooden boxes. The cutting -iStruments should be kept sharp, for which a small oilstone is desirable. Often the reason why scissors do not cut is because they are loose at the joint. They should sharply snip a hair, or thin paper, at the very tip of the blades. Avoid straining the scissors by trying to cut tough or hard objects near the tip ; cut such things near the joint. Use the cartilage knife for the rougher work, where you are likely to i*^'' % m^^- Introduction. Strike bone ; keep the scalpel for the finer work R. .. . , keep the joint of the scissors rfrv n ^ ^^""^^"^ to dissecting, no. wacZ/Xn , ,Ti„g°°i"T'=„''r 'I " """^ oiled, watery liquids are usually kept out All ? "l *'" struments after dissectinir usin, „ ^^ '^'''" '^^ '"■ ofen a n,oist c.othtXTuI LT'sirth 'f ?h " """^'^ before you put them away If thev ,r. , '^ "' '''>' some time, rub them with ,n i^ ^ '° '™^'" """"'d ^r »ith vaseline. '" °"''' "«' °' ="'e'>tly smear them wolf; ~ 'Ts^.rt"'"'' '""' '"- *» •«^-- branesareTtterct wt^L^ '•'"' "".' '^•^"^"^ """-'■»■ the reason tha ea h bTade of h"'"' ".""" '"^ ^^'P"' '" the other blade, whe el tLC f "'"'! ""'"^ *' °''J^<^' '<>' way the obiect . ^^^iZ^'^^^ ^^ ^°- «' '"e lymg Hssues that should be left uniniured WM, ^ ° ''"' one hand, whether with scalpel or scissot 7 '""'"« """ ceps in the other hanH .„ .V j f '^°'S' always use the for- hold the edge :hne ou«inrar.:i:''"''f''">«-»^'<' especially necessary when cuLtTh I "'^■"''rane. This is Hold the forceps^as you C I f ;:f " ■■>'° »^ -"ty. tongs. Delicacy and not streLh^ ^ ^ P^'"' °* the forceps as yL would! pen,Tu [Ulhrw' ,"![ ""''"' restful position, and can often letrrest on h T "r" '" * sectingpan; your hand is thus le s^ L, *\"'P °' ""^ *»■ Do not touch objects with ,^^.4 , ^ '° ''^ '" >""«• "ght. you intend to ^XT ult ^ ™""^ '°"™"'™' ™'^« or turn it over, use , he fini" T '° P"'" "" "^S'" >^'de, scalpel. In much of .Lh?' "P"' "' *^ ''^"'"^ of the should be usTd chtse IfLhir""^ ''^ "^"'"^ "' *^ ^^^>Pel than cutting, l t^A^hZ, "".T^ """ P'^^hing, rather more than tte blade Ma^v f *' ""'P'' ^''°"" •« "^'d dragging or tearLg wh^tZ I'^rr"/""^,' "" "'" ''^"l enough to interfere serio"sty wittte „ T ''"'' '''^^'''"S the work unsightly, but obsc^Xir™; ™'L^S,;^ XIV Introduction. I true of such delicate tissues as that of the liver. The blowpipe should be used to inflate thin-walled tubes and cavities. It is also useful as a probe. A piece of copper wire, or an aluminum hairpin straightened out and tipped with sealing wax, serves well as a probe. For tracing very slender ducts use a bristle tipped with a very small drop of sealing wax. When dissecting specimens under water do not lift the specimen out to see any- thing. The soft tissues sink down together in a mass that pre- vents seeing as well as before, whereas while under water they are partly floated up and thus made more distinct. It may be necessary, however, occasionally to lift the specimen from the water to make a cut near the ends, or to make some new adjust- ment as inflating through the mouth. Always follow directions closely when dissecting. By not doing so you are likely to waste both time and material. Read the whole sentence before making a new cut. It is a good rule not to cut anything unless you know what it is. Keep your thinker just ahead of your cutter. If m doubt, ask help of your teacher. General Suggestions. - Arrange your table, and your position, so as to get enough, but not too much, light. If two work to- gether, be careful not to let the heads or hands shut out needed hght At the begin ,^,g of the term learn the rules regulating the laboratory, and carefully observe them. But whatever the rules, be sure and keep your own table neat and clean. If other students use the same table, put away all your belongings. If you have the exclusive use of It, keep books, instruments, etc., in order. Take pride in making your notes and drawings the best possible. The book is yours to keep, and, if well done, will hkely be useful to you later. It is a worthy ambition to desire to excel. In all your work, tAm4: about what you are doing. Do not let yourself drift along thoughtlessly. No work succeeds without live interest in it, and thoughtful attention. Try to think out the use of each part or organ, the ways in which the animal is adapted to its place of living and to all its surroundings. This habit of thinking about the things you are introduction. I. 2. 5. entertainment. ^ ^ '"^ ^'"^'"^ ^ ^^^rce of increasing Books of Reference 'ittarmV*?''''' '''-'"•>-. Abbot. / Animal L,fe, Jordan and Ke!!,,™ USE OF THE MICROSCOPE. General Rules t n/^ to touch anytting. . LT t^T J""""'' "°' »»°" them 3. If du.. Jets f„ a Js bC „;": lei ^"^^ '™" """• then wipe with chamois skin, oT dean^oft cWH '™k"" """ linen. Handle the micros,-nnL k .[ .,, °"'' *""=h as old Setttag up . m^^'^^^ *' P"'" l"''™ ti>e stage. intoplae;byi.s!tnweth.~T^arr" 1'°"" ^"^ ^^''^ the tube up V the coZf adj„s^merti>l''l°f "'"' .""' ™" tube is two or three inches frimThe I'tlei T^n T/ ^' ** jective with the thumb anH kJ '"e stage. Then hold the oL- hand screws it to pUce Sef Z t Z "l"" """' *» """^ not use force or A may r L^h teldT Tar' '"'^' "» touch the lens. threads. Take care not to ^oitg°'a'm':™r;r:^Lr s^r '-^ ^'^^^ » ^"^^ under the clips Placl^h' • ^ ** ""'"' "' ">« slide hole in the stLe Turn If '^™"' °'" ">= «"''^ »£ the through the hok upon Te mounTirH"" *V " *'""= '«>" ouni„ch.romLT:;,:r"^.trdtr;::-™ xvi Introduction. * i»-rts. Introduction. j^^jj raise '.hTZ ""''n """" '' '°°'' "'~"«'' "« «^'P'~' »-1 "owly sHde M? h^ K ' ^^ \" *" °''J«' "'■'"'"^'y- Move 0,1 sl.de t,l the object, or the pnrt you wUh to examine is ■^ Nev:r.um° hi h'h °J T" ^"'^ "'' '"^ «- ™-r.^'-« two or W^ '"""'.':'*'' <" '"- fi"e adjustment more than two or three turns in either direction. W« <* . Hlgh-power Objective. - Begin as with the use of , touches the coyer glass, watching closely with your head down on a level with the stage. Look through the eyepiece bv means of the coarse adjustment, slowly rais'e he ute t ,'thl object comes mto view. Then use the fine adjustment the he objecttve agamst the cover glass. If you do this, you may ruin the preparation and injure the lens. ^ thJ?' JM"P»rWn. -Use an opening in the diaphragm of about the same size as the front lens of the objective Om «f the Eyes. -Always keep both eyes open when usinir a microscope. This may be a little confusing at'^rst, bmyoTlill ioon learn to ignore what the other eye sees Heath! Co.^"'" "°""^' '" Microscopy," Clark (D. C Parts of a Microscope. A. Base. B. Pillar. C. Arm. D. Body. E. Nose piece. F. Objective. G. Eyepiece. H. Draw tube. I. Collar. J. Coarse adjustment. K. Milled head of coarse adjustment. L. Micrometer screw of fine adjustment. M. Stage. N. Qips. O. Mirror. P. Mirror bar. Q. Substage. S. Diaphragm. m inm. j^m^ c tS/ !^ ^ v> i ^ ZOOLOGY: DESCRIPTIVE AND PRACTICAL. PART II. PRACTICAL. CHAPTER I COLLECTING IW £CTS. sound c„.k Which ms we,, hal^";! '„" p s^'';,^,^^^ a lump of cyanide of potassium, about an inch lare a' d' h^f g-a. care mu,,. be I'rved t 'i ' ' ,''""'^" °' >"'•''^^"" is it a stomach poison Td^'T,: ^^o,™^^l~ itTf °"'^ are po.o„ous. It is much safer to handle i't w h Itep r\( these are not at hand, pick it up with a piece of LZ ,' '.J P.ece, of cyanide of potassium in the b^t tm ofT bott^'a' d I>our in just enimgh water to cover th,™ . .t l ' '' Paris till the water is all ,!„!,„ T^ ' k V'" '" P'"''" "' uncorked for a few hour^^- dr„rfh- , "''u'' """"" >« '"* wherp i, ^,„ t ' ^ ""' '""' " should be set awav »". "fiT/^^ mi * Practical Zoology. moths and butterflies, which often become damaged in a cyanide bottle. A drop or two of gasoline placed on the thorax and ab -'• « fence, it may be beca„" t was a .enlffTh'T ' "'" " °" * wasfeedine- vervoff,.n k„ f , ""= P'^"' «" «*ich it done eatinf k„lTs:Xrcr„:;e'„t rpr'^" '''"''°""''' '■^ stage. If so, it „i„ not nf ed food l" s' afe L°fff '"f '.'' '""'=' case, " ^"'e to offer food in any Larva should be kept in roomy cages AnH ,i„. go mto the soil to pass their n,,Ll, ■. . ' "'^"^ '""^ for any iarva whose'habit ^e nofk l"^:' "^ '"' '° P™""' -' cage may be made of a starrh 1 l convenient breeding Of the length of 'he w^™ t>t\'r:,-d,"f °''-^'""' """^ '^''^ end of the top. Then set the hf f^ " '"° ""^ '^'*est down, and fin'with soU as fir as tbe'lont ""' "'' '"'"^ P'« a glass cover to slide in and fi 1 'he re« of 7" "'"'^'- ^'" a hole for ventilation and coveMt with w" ter"'^'^ T'^ that does not pupate underground is reared inT,, u '™ harm will result. I, is well to have severaTsu' b b * °''' "" ness for the work. A iellv tumhi;. '""' '" ''"di- cage for small insectV A lal ' b """ '"*' "'" "' ' ■'"^'""S ■ng cage ; tie neSng over ^X™"' """ ' """ " " "''«■ PRESERVATION OF INSECTS thr^rcer:o?rth::/rih r. ^ "■•" "--^ l-roject above the back IV,?i "^ °' "'^ P'" ^^ould ;;ght win, cover, a'ttch dtt^ce^r^brerthr "^^ t' the pm '.merges between the second ^Z II T "^'"^ ^^^^ m H'' 6 Practical Zoology. most specimens (No. 4, Klager), though, if an extensive collection IS to be made, there should be an assortment of pins. LabeUng. — The name of the insect, with date and locality, should be on a small label, on the pin about halfway between the insect and the bottom of the box. The name of the order or family should be at the beginning of the group, whether this occupies a whole box or less. Boxes. — For ordinary small collections, the common cigar boxes are very convenient. Pupils can usually get them for nothing. The bottom should be lined with sheet cork, or thin slices of common corks can be fastened in at the place where the insects are to be pinned. It is best to devote a box to each order of in- sects, or even to families where many insects are collected. The boxes should be labeled on the outside near one end, so that they may be set on end on a shelf, and the label will show like the title on the back of a book. A set of shelves should be made of the right hight to accommodate the boxes as thus set on end. Spreading Insects. —Beetles, bugs, flies, etc., are usually mounted with the wings folded. But the wings of moths, butterflies, dragon flies, etc., should be spread. And it is well to mount some locusts, beetles, bugs, etc., with the wings spread, for the sake of com- parison. Spreading Boards. — For spreading the wings of insects, a spreading board or setting board is used. This consists of two strips of soft board, fastened to a base, with a groove between them for the body of the insect, while the wings rest on the two side strips. At the bottom of the groove there should be a strip of cork to receive the pin. Place the insect in the groove, pinned firmly to the cork. Then insert a pin into the wing, back of the large veins, near the anterior border, and draw the wings forward until the hinder borders of the two hind wings are in a straight line. First fasten the wings in this position with narrow strips of paper held by pins. Then place a larger piece of paper over the wings and pin firmly. Sometimes strips of mica are used instead Collecting Insects. of paper. Sometimes strips of alass ar*. „co^ *u enough to hold U,e wings to Xc. ' "" ""S"" ^'"^ uuuc uy piacmg them m a moist nlarp ti,^.. , placed on dry paper over wet sand • nr '\ ^ ""^^ ^^ .hey Jay b. ^^'tnd, d/ ITJ rpf oT cl'r '""r ^° retard the growth of mold '^ ''°'"= ^'="* "«' cent alcohol, in which it shnnH n„, • "^ '° "'*' "" then it should be trans er Mm T """' ""''" ''^'f " "''' ' f';"S """■ "" ' ■' - "" '■ ■"""'"; GENERAL PLAN FOR FIELD STUDY OF INSECTS for'aT b7 thT fT' '""^'r °"^ P'^" °^ ^'^'y -" -- well or an. But the followmg scheme will serve in a general wav for If^ «,?*' Practical Zoology. ntr i i' :•: Hi 2. What is its fitness for its place of living? a. In locomotion. Does it swim, creep, walk, jump, or fly? Or has it more than one of these modes of locomotion? How is it fitted for moving ? i. General form. Is it slender or stout? Rough or smooth? Does it fold the wings when at rest, or keep them extended? Why? c. Color. How is its color related to that of its surroundings? Would some other color be as suitable for it? 3. What does it eat? What kind of mouth parts has it, and how are they adapted for the food? Does it eat little or much? Does it store food, or depend on foraging daily? 4. Does the insect grow? If so, is the growth like that of other animals ? 5. What enemies has this insect? How does it escape or avoid them? 6. Has this insect a home? Or any regular place to which it resorts? Where does it stay at night ? In rough weather ? Does it work by day or at night ? 7. Does it lead a solitary life? Or is it social? If social, to what extent is there division of labor in the community? 8. How many kinds of insects in the community? How do the sexes differ in appearance, structure, and habits? 9. Do they live over winter? What provision is there for the continuation of the species? How long does an individual live? Are the different forms equally long-lived ? 10. What are the stages of its development? Is there a meta- morphosis, or merely an increase in size? How long is it in reaching maturity? 11. What senses does it use in its daily round? Are these well developed? Has it a sense of direction? Does it ever get lost? 12. If it visits plants, does it show preference for any particular plant? Does it visit many kinds of plants? What dop-: it get fi-om the plant? Does it do the plant any harm? Does it do the plant any good? Collecting Insects. 15- How do insects compare with other animals in strength? {V ! ' Is ! it| CHAPTER II. INSECTA. THE GRASSHOPPER. The Parts of the Body. (i) The foremost, or anterior, part is the head. (2) The middle part is the thorax. (3) The hinder, or posterior, ringed part is the abdomen. THE HEAD. < 1. Describe its shape and mode of attachment to the thorax. 2. The two slender projections are the feelers, or antennae. Observe how and where they are attached to the head. Use a lens to count the parts, or segments, of which each antenna is composed. 3. Note the situation and shape of the eyes. Examine one of the eyes under a microscope, using a one-inch objective ; make a drawing of what you see. These eyes are compound, and each of the parts is called a facet. 4. Just in front of the compound eyes look for a pair of the simple eyes, the ocelli. Find a third ocellus on the head, using a lens if necessary. 5. At the lower part of the front of the head is a movable flap, the upper lip, or labrum ; raise it with the dissecting needle. Ob- serve how it is hinged ; cut or break it off. 6. This lays bare the true jaws, or mandibles. Examine their black, toothed tips with a lens ; find, by prying, how they move. Study their action in the live grasshopper, raising the labrum. Study carefully the way in which they move, and how they are hinged ; then remove with the forceps, and again examine thoroughly. 7. Turn now to the back of the lower part of the head ; pry back the lower iip, the labium ; carefully remove it. 10 Insecta. j j 8. At the base of the labium is the brown tongue. 9. ^ttached to the base of the labium is a pair of short ioint.H appendages, the labial palps. What i, th^ Hi . u ' ^ ^ tongue and the labium ? ' '^' ''^'''°" '^^^^^^^ ^^e Jr^ ^n '^' "^^^^-"^'"ed parts have been carefully removed maxxlte. Make out that each maxilla consists of three parts- a. An outer, jointed part, the maxillary palp. ^ * "~ ^. A spoon-shaped piece covering c len's* t?/n ^r?' '"'"'''^ "'''''"' P^°P^^- ^--'"'ne with a ger;h:tsaT;ir ^^^ ^^-^^^^ ^^^ ^^^^^ -^-^"^ ^^^^^^ - 1: 11. Cut the head off a fresh specimen ; lay it on the table and make a carefu drawing of Ihe face, naming ail the parts 12. Draw the head as seen from the side. THE THORAX. 1. The Wide collar, or cape, back of the head is the main nart of the prothorax ; make a drawing of it as seen from theTde ' 2. Ihe remamder of the thorax is formed by the union of two parts, each bearing a pair of legs, the part to'whichre mLc^^ pair of legs is attached being the mesothorax. the hinder eSaril ing from the metathorax. Look for the line senaratinrth£? parts of the thorax. separating these two 3- Look just above the second oai. of 1picnor edge of thotv^'''^""^ T^"'' '^' ^'"^'^^^'^^ mesothorax, and meta- thorax in size, shape, and structure. THE WINGS. .nH'.K^"''"" 1^' P°''''°" °^ ^^' °"t«^ ("PPer or anterior) wine^ and their mode of overiapping. ^ ^^ .1 r i "1 a II Practical Zo6Iogy. 2. With the forceps seize one of the outer wings by its lower edge, near the anterior end, and draw it horizontally forward, till it makes a right angle with the body, and pin in this position. Seize the inner wing by its lower edge near the posterior end, and pull forward to its fullest extent, observing how it is folded ; pin this wing as expanded, and make a drawing of both wings as thus seen. Cut a piece of paper the same size and shape as the inner wing, and fold it as the inner wing is folded. 3. The framework of the wings is composed of veins. 4. Compare the inner and outer wings in size, shape, color, texture, position, and use. THE LEGS. 1. Note their number, arrangement, -and mode of attachment. 2. Study carefully one of the hind legs. a. A short segment, near the body, is the coxa. 6. A smaller segment is the trochanter. c. The large segment is the femur. d. The slender segment is the tibia. e. The remainder is the foot, or tarsus ; count its segments, and examine thoroughly, using a lens. Examine the joint be- tween the femur and tibia, moving the parts back and forth. Note, also, how these parts fit together when the leg is drawn up. Remove a hind leg, and make a drawing showing all these parts. 3. In how many ways does the grasshopper travel? In what order are the legs moved in walking? 4. Grasshoppers make a shrill sound (stridulation) by rubbing the inner surfaces of the hind legs against the outer wings. 5. In what different ways does the grasshopper keep from slip- ping when it jumps ? Remove the legs and wings ; rviake drawings )f the thorax as seen from the side, from above, and from below. THE ABDOMEN. 1. Count the abdominal rings. 2. Observe two grooves running along the under surface of the ^i4^^'4|»ilfflfiW«M^^^F^ # Insecta. »3 P>»nu., and .h. upper par, L tl^t^' ""''■"»" '» ""'d -h. count them. ' ""' ""'^"""S Pores, or .pirwle. ; Al/inl^c^ b:«.rtrirtf a'c^T'"? °""""""«- tubes, the trachee which brnTh^ "mphcated system of air body. Can the grlsslr be T ^ ^^'''"''" *^ underwater? 00^7: h thetiMu^ s '' ""'7 "' """ other strong flying i„,ec,s, 4 bees and fit'" ''T""^" "^ which fiU with air, and are said to aM hke' h n '" "" ^"• ing the insect in the air Rv ! ,„ ' balloons, in keep- •he abdomen, th«e ai7sacs 1/ ^e ten™m"t hT '"^ ""' °' walls; the white air tubes or tra.h.r ' ."^ '''' '^''" "^ite 5. Under the bases of the J^l?:; TI f^ ^. '"'"^ "'"• a pair of thin, shiny, oval m mC ,« '.'r'^^Z'"' ™^' " d^^m.^ The inner sur.ce of each tymplnt TtZ!:.- Z Alihr;ra?'jr^:r:ot.r''h'"'^-"'^'^ the ground, and then separld ^.s ^cl '• '" '''""' *"'° SototrwLhrdfr'-'F^- four ^ints, wht;^x^tTarr.zrr''r° r are smaller than the females Hro *u "^^P®®"**^- The males the sides, of both the mretd^hTfemale "tT' " "" '"" specimen and draw a side view of it. '""' "" ""« mTERNAl SreuCrURE OF THE GRASSHOPPER. >4 Practical Zoology. pan; pin the hindermost ring of the abdomen firmly to the bottom of the dissecting pan ; turn each hind leg outward and pin down. With sharp, fine-pointed scissors, nit through each side of the roof of the next to the last abdominal ring ; lift, with the forceps, the cover of this ring ; continue to cut forward, on each side of the abdomen, pulling the tcrgum upward and forward as it is loosened. Thus carefully unroof the whole abdomen. 2. The heart is a delicate tube, running along just under the tergum, and probably was torn away with the tergum. 3. On each side there is a row of air sacs, with their white air tubes. 4. In the anterior part of the abdomen a mass of yellow eggs is usually to be found ; this mass may be easily separated into two parts, right and left, from each of which a tube, the oviduct, leads to an opening between the parts of the ovipositor. 5. Under the eggs is the dark intestine, running lengthwise. 6. Remove the roof of the thorax ; more air sacs should be found here. In the upper part of the thorax are the white muscles which move the wings. Removing these muscles exposes more of the digestive tube ; as the food is swallowed, it passes upward into a brown tube, which soon turns backward into the thorax ; in ihe prothorax, the enlargement is the crop, in which is produced the dark liquid which the grasshopper ejects from the mouth when held captive. The crop may be removed, split open, washed, and examined under the microscope with a half-inch objective to show the rows of hooked teeth with which it is provided. A little farther back the digestive tube is surrounded by a set of double cone-shaped pouches, which extend parallel with the main chan- nel of the digestive tube. These are the gastric ceca. Behind them is the stomach, followed by the intestine. The products of digestion pass through the coatings of the digestive tube, and mingle with the currents of blood which pass along the ventral and lateral parts of the body. 7. The veins of the wings are a. ^bes, and are very different from the veins in our bodies. SK|-fs .i,*^' Insecta. >5 the whLI^r?T ! ^ r ""^ '^' g'-^^hopper consists mainly of . white cord extending along the floor of the whole body cavity In most of the abdominal rings the nerve cord has en argement^ caned g^^Uon.. from which nerves branch to the slr^uXg THE DEVELOPMENT OF THE GRASSHOPPER. I. Ute in summer watch grasshoppers to discover the process h tcr'n''^- .T' '''' ^^" '^^ °^^^'-^' •^-P them tniThey hatch, and watch the growth of the young ^ as vou^rin fi T '""""" T^ ' """^^^ °^ '' y°""g grasshoppers as you can find; cage and feed them, and watch their growth What changes take place during development ? ^ GRASSHOPPER CARD. Take a card six inches by four. Make a faint mark length- wise m the middle to aid in placing the parts symme tr cat Separate the parts of the grasshopper, and place Lm o 'e' card an their proper order. Before beginning, plan the whole trhlT"- "'?' "^ ""' ''' '''' ■' ^^'^'"^ a 'central ;ace s ri^o '.""r "'""^'^ ""''''' P^^^'"^ ''''' *° ^he card as it IS removed. In separating the parts use the forceps, being care ful to get hold of the very base of each piece ; then' Lold.^'g each Tnto T I 'T'^' '""^ ^'^ '''' ''''' ^' '^ ^° ""^ ^^ theV;;: into the glue, and carefully place just where it is to stav This method avoids smearing the card. Avoid getting too much glue. The mouth parts should surround the head ; the wings should be opposite the parts to which they were attached, as also the legs The legs should be separated to show all the segments; the «iorax should be separated into its parts, but the abdomen would better be kept entire. As the parts become very brittle when dry. It fs well, if the card is to be kept, to make a little bridge of a slip of paper, on which to string the rings of the thorax and abdomen. The soft parts should, of course, be removed To preserve the card, plar it in a shallow box and fasten it to the i6 Practical Zoology. bottom Perhaps the best way is to make a glass cover to the box and then seal it, dust and moth proof, by means of passe partout bmdmg. Toplci for Report!. -The Rocky Mountain Locust Scourge Cockroaches The Mole Cricket. Walking Sticks. Katydids. 1 he Praying Mantis. ri-*^:^' ■■^'^i-.'^^^.'^y:^m:i. I ^ \£l^ CHAPTER III. IHSECTA {Continutd). THE CRICKET. I. In what respects are the cricket and grasshopper alike? a. In what respects do they differ? 3. The female cricket has a long, slender ovipositor Comnari. Its parts w,th the parts of the grasshopper's Lpos or pS them apart with a dissecting needle. Use a lens ^ .rt\^ ^? °^ *y^""^' ■'°'"^^'' projections from the abdomen are the .tylets. Of what use are the stylets ? a^omen 5. Conrjpare the wings of the male and female. Look on the under surface of the outer wings of the male for a ve^ runn „' crossw.se, near the anterior end, which has on it . vow 'o" ee^h' By rubbmg this file on the veins of the other wing, the cScet makes ,ts ch.rpmg noise. Watch crickets to see how the ^ng are managed during this process. ^ of tcrt;;:;: '°°' ^^^ ^'^ ^-^^"^^ •^--^ -^- on the tibia 7. Make a drawing showing all that can be seen from above (dorsal view), and name all the parts shown Grasshoppers and crickets belong to the order of insects called Orthoptera, or straight-win aed insects. THE DRAGON FLY. 1. Compare the shape and relative size of the parts of body mth those of other insects. In some dragon flies L eyes have as many as 12,500 facets each. ^ 2. What kind of mouth parts has the dragon fly? «7 '?"tl 1 J i8 v!^JCW.ki?tv Practical Zoology. life 3. How does the dragon fly compare with other insects in power of flight? To what bird should the dragon fly be com- pared in its habits? 4. Has the dragon fly a sting? Is it dangerous to man in any way? 5. Watch the dragon fly dipping the end of its abdomen into the water to lay its eggs. Compare the ovipositor with that of the grasshopper. 6. The larva of the dragon fly is called a nymph. It may be found on the bottoms of ponds and streams, and is very noticeable on account of its wide head aid prominent eyes, wide abdomen, ai.Mi short wings. 7. When the larvae are ready to transform, they crawl up out of the water, their skins split along the back, and the adult dragon flies escape, leaving their dry, empty skins, which may be found clinging to the stems of water plants, projecting logs, or rocks. 8. Draw a dorsal view. 9. The dragon fly belongs to the order Odonata, or nerve winged insects. THE SQUASH BUG. I. Find the sucking tube bent back under the thorax. Are there both simple and compound eyes? What peculiarities of the prothorax? Draw a dorsal view, showing how the wings overlap. Fasten the squash bug's wings out at right angles to the body, and make another drawing, showing how the outer wings appear when extended, and how the inner wings are disposed. 6. Draw a ventral view. Look for eggs. Compare young and old squash bugs. Squash bugs belong to the order Hemiptera, or half-winded insects. What is the propriety of this name? Insects belonging to this order are the only ones that are properly called "bugs." Topics for Reports. -The Periodical Cicada. Plant lice. The Cochineal Insect. Scale Insects. The Chinch Bug. 3- 4. 5- Insecta. THE BUTTERFLY. »9 II witl^' 'r° ''1°^ ■"°""''' '"' = ■">■• "^ "milkweed butterfly tTldT '^ "'""^ " ''''" "■' ''^" -"«»• '^ > Sood otle .. Notice the position ol .„. -ye. anr. tlieir relative si^e. .he^grX:^ '"' ^■"'""* ="'--'<'' C-P-' wi'H .hose of 3. The short projections in front of the head are the labial palps 5- The wings : — (a) Their shape and their mode of overlapping. y) The dark, shiny veins ; where are they strongest? highU^'erTf tr' '' ''' "'^" '"^ ' ^'''-' ^^^-'- ""der a mgn power of the microscope, making drawings (j/) Examine with a low power of the microscope a piece aLnlT' T J'' "'^" °" ^^' ^° ^^^ ^°^ they are atLched'and removed.' '' ' '"' °' ^'^ "'"^ "'^^^^ ^^^ -^'- ^-e been frot at::.' ''' ""'^ °' ^ '^""^^^^' ^"^ ^-^ ^'^^ - -n others^""'™'"' '^' ^'^'' ^""^ '°™P''' '^''' "'" '" ^^'^ *»^^^t ^«d in^^^iwf ' ' "^''"'u? °^ '^' ^""''■^>^ "^ ^^^" ^^^^" ^' ^est, nam- ing all the parts visible. 9. Compare the colors and markings of the upper and lower surfaces of the wings. ^ 10. Carefully compare a moth and a butterfly 11. Butterflies and moths belong to the order Lepidoptera, or scaly-wmged msects. The orders of insects are divided into families ; this butterfly belongs to the family Nymphalida. ^ Families are divided into genera; this butterfly belongs to the genus Anosia. ^ •i- 1h'>. ^ :-. h'i ^m ill:. 30 Practical Zoology. Genera are divided into species ; this species is plexippus So his butterfly belongs to the class, Insecta; order, Lepidoptera • amily, Nymphalidae ; genus, Anosia ; species, plexippus. The males are distinguished by an elevated black spot on one Df the veins, near the middle of the hind wings. Where is this butterfly found most abundantly? Development of the Cabbage Butterfly. The cabbage butterfly is small, yellowish beneath, paler above with black tips to the anterior wings. The male has one round black spot only on each upper wing, while the female has two, and sometimes three. I. Open the abdomen and look for eggs. They are yellow, oval bodies, ribbed lengthwise, with cross markings on the ridges resembling stunted ears of yellow corn. Look also for these eggs on cabbage leaves, or where the butterflies are seen hovering. Watch the butterflies closely as they light on the cabbage leaves to see the egg deposited on the leaf; on which side of the leaf are the eggs usually laid? How are they fastened to the leaf? Make a drawing of the egg as found attached to the leaf. 2. Get a chalk box with a sliding cover ; substitute a glass cover a httle longer than the box. Keep the box on end, so that the door will keep closed, yet may be easily opened. Put into this box a cabbage leaf with eggs on it; examine several times a day. What becomes of the egg? In another box, similarly arranged put some large cabbage worms; give them fresh leaves every day, and keep the box in a light, well-ventilated room. Watch closely, and keep record of the date of the beginning of the experiment, and note the date of any change ; describe carefully all actions and changes in the worms. Make careful drawings of each stage of growth ; — (a) The egg. (^) The larva, at different stages of growth ; keep one worm in a cage by itself, and make a drawing every third day. (f) The pupa, showing how it is suspended. Insecta. ^ (d) The perfect butterfly. There are several species of the genus Pieris, just as there may %lTr.^rr '" "■" '-"-"y- -^ in a directory we reTd What is the meaning of the word « raps " ? th,s,s generally caused by some parasite, the most nommon of wh,ch ,s an ichneumon larva. The adult of some ichneZon flv lays , eggs on the body of the cabbage worm ; these eggsTtcb out as worms, bore ra.o their host, and live on the juices and t.^es of the cabbage worm, till it dies from exhaust on (tholrhe ^bbage worm often lingers, and the parasitic larv=e complete their ttansformatton first), and the parasitic larvae become pupr^d hatch out as perfect ichneumon flies. '^ ' tio^tftt' M'' '" '"r "'''"' *■"" '° '=°™P'"^ *=!■■ transforma- tion often holes maybe found in them where the ichneumon flies have made thetr escape. If a pupa blacker than usual be fol" Z ■t m a vial, or p.ll box, and catch the ichneumon flies as they emerg^ Temrl'",?'^''^r^'''^'°*"'^°"'- The Silkworm. T^e" THE HOUSE FLY. The Parts of the Body. 1. The head, the foremost, or anterior, part. 2. The thorax, or middle portion. 3. The abdomen, the hinder, or posterior, part. The Head. I. Examine the eye with a strong lens, and under a lownower 22 Practical Zoology. 2. Cut off the head, lay it on a glass slide, and with a one-inch objective examine the short antennae in front of the head. 3. Look on the top of the head for simple eyes. 4. With a lens examine the under part of the head to see tht tongue. How does it move? Remove it and look at it with a one-inch objective. How is the tongue used? J The Thorax. 1. How many legs are there? To what are they attached? How many segments has each leg? 2. The wings ; how many are there? Back of each wing find a short membrane, the winglet. Note the folded portion connect- ing the wing and the winglet. 3. A little farther back are two slender stalks ending in rounded knobs ; these are the balancers, and are considered as representing the hinder wings found in most insects. Note the effect of re- moving the balancers. 4. The wings describe a figure 8 in flying, and make over 300 vibrations {i.e. go up 300 times and down 300 times) in a second. 5. On each side of the thorax, just back of the head, find a narrow opening with a yellow, liplike border; examine closely with the aid of lens and microscope. It is a breathing pore, or spiracle. The Abdomen. Are there spiracles on the abdomen? How many rings has the abdomen? Draw the fly as seen from above (dorsal view). The house fly lays its eggs about stables j after a day or two the egg hatches out as a maggot, which eats voraciously and grows rapidly ; in about a week it ceases eating, becomes dry and brown, resembles a seed, and does not move ; from this pupa- rium the fly emerges. The adult fly is short-lived, tho some live over winter. Watch the development of the egg which the flesh fly lays on meat and dead animals. How many kinds of flies do you know? How do they differ? How does the fly walk on the Insecta. 23 window pane? Examine the feet? In what order does the fly move its feet in walking? For the study of this point, take a fly that is sluggish from cold, or from partial drowning. Do flies, on the whole, injure man, or benefit him? Flies belong to the order Diptera, or two-winged insects. What other insects have but two wings? Topics for Reports. — The Mosquito and Disease. House Flies. Horseflies. Botflies. THF BEETLE. 1. What are the characters that appear peculiar at first sight? 2. Note the position and shape of the eyes. 3. The antennae, their attachment, parts, and mode of extension. 4. A small upper lip, the labrum. 5. A pair of strong jaws, the mandibles, often very large, and projecting forward as pinchers, or " horns." How do they move? 6. Back of these are two small jaws, the maxillae, bearing a pair of jointed appendages, the maxillary palps. 7. Back of (posterior to) the maxillary palps is another pair of similar appendages, the labial palps. 8. The part of the body back of the head is the prothorax. Why not call it the thorax ? 9. Pry up the hard outer wings. How do they meet each other ? Each outer wing is called a wing cover, or elytrum. In what direction does the beetle move the elytra in raising them ? How are they held during flight? Do they rise vertically? 10. How are the inner wings folded ? Compare the inner and outer wings in length and size. Cut a piece of paper of the same shape as the inner wing, and fold it as the inner wing is folded. How does the beetle perform the act of folding the inner wings? Capture live beetles and watch this process. 11. Make a drawing of the back, with the wings closed; an- other drawing, with the wings fully expanded, as in flight. 12. Count the segments of the legs. Examine each segment closely. Seize the foot of one of the hind legs with the forceps, .» u 24 Practical Zoology. 'ri: M and pull it about in all directions, to see how many joints the leg has, and what motions are allowed by each joint. The segment nearest to the body is the coxa. Then come, in order, trochanter, femur, tibia, and tarsus (foot). 13. What marks the line of division between the thorax and abdomen ? 14. Draw a ventral view on a large scale, showing especially the parts of the legs, and the mouth parts. 15. Watch a crawling beetle, to see in what order the legs are moved. 16. What can you tell of the habits of beetles? The different kinds of beetles, and their development ? What is a grub ? Com- pare beetles with other insects in strength. The large beetles are good insects for dissecting, to show the internal structure. Beetles belong to the order Coleoptera, or sheath-winged insects. Topics for Reports. — Fireflies. Blister Beetles. The Carpet Beetle. Water Scavenger Beetles. Whirligig Beetles. Carrion Beetles. THE BUMBLEBEE. 1. Find three simple eyes on the top of the head. How are they arranged ? 2. Describe the antennae. 3. The mouth parts : — a. A pair of true j-^ws. &. The long, hairy tongue. c. Above the tongue the two blades of the maxillae. ^. Below the tongue two thin, narrow labial palps. The last three form a proboscis. Pick the parts asunder, and make a drawing of the front of the head, showing all these parts. 4. How does the bee take its food? Is the homy stored by the bee the same as the nectar taken from the flower? 5. Compare the segments of the legs with those of the grass- hopper. How does the bee get pollen? What does the bee do with the pollen? Insecta. 25 6. Examine the wings ; compare the front and hind wings. 7. Get a bumblebees' nest ; examine the contents of the cells, and note the different stages of development of the young bees. 8. The sting is a modified fc.m of ovipositor. Near its base are poison glands, and a sac for storing the poison. Remove a sting with the poison sacs and examine under a low power of a microscope. 9. How do bees compare with other insects in intelligence? 10. Ants, bees, and wasps belong to the order Hymenoptera, or membrane-winged insects. Topics for Reports. — Bumblebees. Wasps. Solitary bees. Ants. STUDY OF THE DEVELOPMENT OF THE HONEY BEE. Through the glass sides of the hive observe the comb. The depressions or holes "n it are the cells. Find cells that are empty, others that are partially filled with a substance whose glassy sur- face reflects the light. These cells contain honey. Find cells apparently empty, but which upon close observation are found to have a small, oblong, white body at the bottom of them. These may be seen attached by one end to the bottom of the cell near its center. They are not as large as the head cl a pin, and are often overlooked. They are eggs. Record the date upon a small piece of paper, and paste it on the glass opposite the cells contain- ing eggs, and note the changes from day to day. Determine the number of days elapsing between the time the egg was laid and the time of hatching. Make several trials. Begin with empty cells, and note when the eggs are laid, as some of the eggs may have been in the cells a day or two before you found them. Determine the length of time the young bee is in the grub or larval stage. The larva may be seen one or two days after hatch- ing, floating in a small drop of gray-colored liquid at the bottom of the cell. Note its rate of growth. What care has it received? Has it been nursed, fed, and cared for, or has it, like Topsy, IWWHP ■fif ■ I f ^M 26 Practical Zoology. "jest growcd"? Find other cells near the brood (by brood is meant young bees in all stages of development) which are partially filled with a yellowish or brownish pastelike mass. This is stored pollen, or " bee bread." Its color varies according to the kind of flowers from which it is gathered. Now look for larvae in all stages of development, from the smallest, which are little larger than the ecg from which .hey came, to those which almost fill the cells they occupy, and in which the segments may be easily counted. Find other cells each covered with a brown cap. Observe them closely from time to time, and try to determine what they contain. Cells near the ends and top of the brood frame, which are covered with white caps of wax, contain honey. The caps of the latter may appear dark if the honey touches the caps, but usually there is an air space between the honey and the caps, and the caps appear white. Look for both of these conditions. What changes have you noted through a period of ten or twelve days in the cells in which you first found eggs? Can you now see the interior of the cells? Can you discover the bees placing brown caps on cells containing the largest larvae? If so, note the date and determine the length of time the caps remain on them. Determine how and by whom these caps are removed. Watch to see some of the occupants of these cells come out. Note any difference in appear- ance between these and older bees. If these directions have been followed through a period of several weeks, you have observed all of the stages of development of a honey bee, and noted the length of time the young bee was in each stage. Which of these stages corresponds to the caterpillar stage of a butterfly? Which to the cocoon stage of a moth ? Honey Bees at Work. Watch the bees as they come and go at the entrance of the hive. Dust a little flour upon some that are entering, and note to what part of the comb they go. Determine, if you can, whether they remain in the hive for some time or soon leave it again. Look for bees coming in loaded with yellowish or brownish pellets attached Insecta. 27 to the outside of the large segments of the hind legs. Where and how do they unload? What are they carrying? Why do they bring this substance? In the Intter part of the season bees som times carry propolis, a sort of glue, in the manner above sug- gested. This latter substance is used to seal cracks and crevices. Observe that some of the bees on the comb move about from cell to cell, putting their heads int^ the cells where there are larvae. What is the work of these be-^s^ Are they young or old bees? What is pollen? What is r. ctar? How does honey differ from nectar? What is beeswax? Is it gathered by the bees, or do they make it ? What difference in color between new honeycomb and the brood comb you have just been studying? Why this difference in color? Study of the Structure of Honeycomb. Obtain two pieces of empty honeycomb, one with cells the same size as those in the brood comb in the hive, and the other with cells somewhat larger. Note the shape of the cells. What geometrical figure is represented by a cross section of a cell? Why not have round or scjuare cells instead of this form ? Lay a foot rule upon a row of cells across the face of one of the pieces of comb. How many cells in one inch? Make several measure- ments to obtain an average nuaiber. The average diameter of the cells may be expressed by what common fraction? Repeat with the other piece of comb and compare results. For what especial purpose do the bees use each kind? Do they ever use both for the same purpose ? Draw a face view of each kind of comb, being careful to show correctly the relation of each cell to the cells adjoining it. Cut a piece of comb so as to show a freshly exposed edge. Note the shape of the bottom of the cell and the relation of those on one side of the comb to those on the other. Draw an edge view of a piece cf comb, using care to show this relation. Note the number of parts in the bottom of each cell. Shape of each part. Make a pinhole in each part of the bottom of a cell. Turn the comb over and find how many ceils have holes in the mm 38 Practical Zoology. bottom. Why this number? What new fact in regard to the relation of the bottom of a cell to the cells on the opposite side of the comb? Why should the bottom of a cell be of this form and not flat? Why this relation to the cells on the other side? THE ANT-LION. Field Study of the Unra. — In dry, sandy places look for conical depressions, as evenly made as if rimmed out by a mechanic. Many of these pits may be found near each other, in the neighborhood of ants' nests. Drop a few grains of sand into the center of the pit, looking closely meanwhile, for the protruding jaws at the bottom of the pit. Quickly scoop up the whole pit, aiming to go an inch deeper than Its greatest depth. This can be done very well with the hand, though a garden trowel is best. A tin cup or dipper would serve very well. Sift the sand thus scooped up through the fingers or over the edge of the hand, and look closely for the dull gray larva of the ant-lion (Fig. i6). It has an oval body, and a pair of long, hooked jaws. Place the larva on sand held in the hand, cup, or can, and see how it buries itself. Home Stuuy of the Ant-Uon Larva. - Take several larva home. Place each on sand in a separate tumbler or can. Two or three inches deep will be enough. Watch again how the larva buries itself. Watch patiently to find how it digs the pit. Drop an ant, a crippled fly, or almost any small insect into the pit and see what the larva does. How does it eat ? How much of its victim does it consume ? For the appearance of the adult ant-lion see Fig. 15, in the descriptive text. REVIEW OF INSECTS. Take any insect not yet studied, and examine it thoroughly. Write a full description, and make drawings of it. Which of the insects previously studied is this most like? To what order, then, does it probably belong? i~ i i£ . s^sHiie-fir ?f r^rffc iftEiiiaBSffi :MVt: ' ik Insecta. 29 Select two pages in your notebook that face each other On the left-hand page make a list of characters common to all the insects you have studied, numbering the points ; on the right- hand page write briefly the characters peculiar to each insect. I he first list ought to be a very nearly correct definition of an insect, so far as external features are concerned. The second list should serve as a definition of each of the orders of insects. All the orders of insects belong to the class InsecU. Write now a list, in vertical series, of the orders of insects studied, with the name of the insect representing that order oppo- site it, and include all within a brace opposite the word InwcU. Read Insect Life, Comstock. ft CHAPTER IV. ARACHNIDA AND MYRIAPODA. STUDY OF LIVE SPIDERS. Spiders and Spider Webs. — Find a spider at home near you, where you can conveniently watch it for some time each day. What is the shape of the web? Do all spiders make the same kind of a web? Does the same spider always make a web in the same way? How is the web situated? Does the spider stay on the web? If so, on what part of it? What reason for this position? If you cannot find a spider beginning a new web, destroy a web antl watch to see if a new one is begun soon. Does the spider take the same place for the new web? How does it begin the work? Is every part kept as first made, or is any part comparable to »'^- scaffolding erected by the carpenter? Do spiders repair bi. xen places in webs? If so, how is this done? How is food secured? Watch the whole process of capturing and eating food. Does the capturing of the food injure the web? Are spiders equally active at all times? Visit a spider in the evening and see if it is awake, and " ready for business " ? Are spiders affected by cold? Do they like sunshine ? Do they live over winter? What can you learn about, the development of spiders? Why are there sometimes so many spider webs floating in the air? What relation have these floating webs to the weather? Are these floating webs of any use to spiders? How are they set afloat, and what keeps them afloat? Can you discover the beginning of such work? How and where do spiders lay their eggs? Watch the development of the eggs. I Arachnida and Myriapoda. External Features of the Spider. 31 Spiders are best preserved in alcohol, as they shrink in dryinK 1. The anterior division of the body is the cepmOothorax' or united head and thorax. F"uowior«x, a. The large posterior division is the abdomen. 3. How many legs are there? To what are they atUched? How many segments are there in each? Examine the feet under a microscope Make a drawing of one of the feet. Can a spider chmb out of a tumbler? Compare it with the beetle in this respect. 4. With a dissecting needle pry apart the mandibles, at the front of the head. The duct of the poison gland open at thi tip of each mandible. f «^ "ic 5. Back of the mandibles f^nd a pair of small jaws, the maxilte 6. ro the maxillae are attached a pair of jointed appendages] . resembling a pair of legs, the maxillary palps. 7. With a lens look for the simple eyes above the jaws. How many are there, and how are they arranged? 8. VVith a lens examine the spinnerets at the posterior end of the abdomen. With a pair of forceps hold a live spider by one leg, and watch the beginning of spinning. 9. Besides air tubes, some spiders have one or two pairs of lung sacs, composed of several leaves, into which blood flows and is thus aerated. ' Place the description of the spider alongside the list of charac- ters common to insects, and note what features are common to the spider and all the insects ; also the points wherein they differ Spiders belong to the class Arachnida. Read Emerton's Spiders, their Structure and Habits. MYRIAPODS. One form of " thousand legs," commonly found under stones d under the bark of dead stumps and logs, is well known by its :yhndncal body, by its numerous, short, hairlike feet, and by its and i ' s . 32 Practical Zoology. habit of coiling its body into a spiral when disturbed. This is a milliped. 1 . How many segments has the body ? 2. How many appendages has each segment? 3. Make a drawing of the thousand legs. 4. What are the chief differences between this animal and insects? Another common form of thousand legs is that called centiped. It is, when full grown, about an inch long, with a broad, flat head, a brown, shiny back, the segments being generally about the same size, with one pair of jointed appendages to each segmtnt. The antennae are many-jointed. It is found under boards and about rubbish and manure heaps, where it feeds on insects and earth- worms. It usually runs actively when uncovered. 1. Examine the jaws and mouth parts carefully; how many pairs of jaws are there? 2. With a lens examine the legs. How many are there? 3. What kind of eyes are there ? How many, and how placed ? 4. Arrange the legs so they can be distinctly seen, and make a drawing as seen from above. 5. Make an enlarged drawing of the mouth parts as seen from below. 6. What are the differences between this form and the thou- sand legs mentioned above? 7. In what are the two alike ? Both belong to the class Myria- poda. Carefully compare them with the insects, and make a list of points common to insects and myriapods ; also a list of the characters which insects have and the myriapods do not have ; and a list of points peculiar to myriapods. CHAPTER V. CRUSTACEA. STUDY OF THE LIVE CRAYFISH. Field Study. Where to find Crayfishes. — Look under stones in shallow creeks, under ledges of rock, or overhanging banks of streams. Remember that crayfishes are nocturnal and are usually hiding during the daytime. Note all the kinds of places in which you find them, and where they are most numerous. Are they in deep or shallow water? In clear water or muddy? In fresh water or foul? In quiet water or in rapid currents? Over mud, or gravel, or sand? How they Escape. — In turning over stones or tin cans in a stream, note closely how the crayfi5;h escapes. Which end goes foremost? What is the chief organ of locomotion? How is this used ? How far does a frightened crayfish ordinarily go before stopping, if not closely pursued? Does it stir up mud in its flight? If so, how is this done? Does the stirring up of mud benefit the crayfish? If the crayfish goes some distance, is the rate of motion uniform ? Explain. Color of the Crayfish. — Note the color of the crayfish in rela- tion to its surroundings, especially the color of the bottom over which it passes. Is its color an advantageous one ? What if it had the color of a boiled crayfish ? Are all crayfishes of the same color? How account for the difference? Crayfish Holes. — Where are these most abundant? Do they all have "chimneys"? Is the chimney of the same color as the surface soil? How high are the chimneys? Are these built 33 -^' 34 Practical Zoology. ■ «. ilfcim 1 i:^ ':.; m IM. » > fr»r. m ' Ill-'' ai i ^' during the day or during the night? How does the crayfish build the chimney? How deep are the holes? What are they for? Do all kinds of crayfishes dig holes? In what part of the hole does the crayfish stay? Are the holes used equally at all seasons? Molted Shells. — If you find what appears to be a dead cray- fish, examine it carefully to see whether it is really a dead animal or only the cast-ofif shell. Do you find any dead ones ? Enemies cC the Crajrfish. — Have you seen any animal eating or attacking a crayfish? Or any evidences of such action? Home Observations. Walking. — If one has no aquarium, a dish pan or homemade trough serves very well. Watch a crayfish crawling in the waier. What appendages are used ? Can it walk in other directions than head foremo-t? Are the legs moved in regular order? Place a crayfish on the floor. Does it walk equally well in water and out? Why should there be a difference ? Swimming. — Frighten a crayfish by thrusting a stick at it to see how it swims. Study closely the parts used and their action. Suppose a crayfish could propel itself rapidly forward, how would the resistance compare with the resistance it meets while going backward? Note closely the condition and position of the tail fin while making the stroke and while darting through the water between strokes. Observe all the points of structure that aid the efficiency of the stroke ? What is true of the amount of resistance in the recover stroke ? With the thumb and finger, take a cray- fish just back of the big pinchers and hold it with the head up, so that the tail fin is covered with water ; if it is now excited, the effectiveness of the tail fin will be well demonstrated. , Mode of Defense. — With a stick or pencil, make motions at a crayfish to see how it defends itself. Allow it to grasp a pencil to show the strength of its grip. Does a crayfish prefer to fight, or would it rather avoid an attack ? In an aquarium does a crayfish w,-^ ■ i&.i. ::2Sn»A.iJKli'^BKJI Crustacea. 35 it stay in open places, or where the light is strongest, or does seek sheltered places? Feeding. — Offer a crayfish various kinds of food, bread, meat, cheese, vegetables, etc. Find what it prefers. Learn how it eats, what organs are used and how they are used. Does a crayfish eat much or Uttle? Is it a rapid or a slow eater? Examine the mouth parts in this connection. (In these experiments be careful not to let the water become foul.) The Water Currents to the Gills. — While a crayfish is at rest in shallow water, carefully introduce a few drops of ink near the bases of the hinder legs. Where is it drawn in and where does it reappear? Try placing the ink at various points along the edge of the carapace. Place a crayfish in a candy jar. Watch it '"om the front and below to see the vibratory motions of the outer branches of the maxillipeds. Their motions indicate the rate of movement of the gill scoop, or gill paddk:, within. Count the vibrations for a minute. How is it that a ciayfish, while breathing by gills, can live so long out of water? Senses — Note the range of motion of the eyes. Can an enemy approach a crayfish from any direction without being seen ? Can a crayfish see small objects as well as large ones? Does it notice slow motions as readily as quick ones? Does a crayfish see where it is going when it is frightened and darts backward by swimming? What advantage is there in having the eyes on movable stalks ? What disadvantages? In what ways is the eye protected? Touch one of the eyes. What follows? With a straw, broom-straw, or feather, test the sense of touch over all the outside of the body. Where does the crayfish seem most sensitive to touch ? Is there any special reason for having two pairs of " feelers " ? Which reach farther forward, the big claws or the antennae? Can the antennae extend back as far as the tip of the tail fin ? Make noises near the crayfish to test its sense of hearing. In ■ i! 11^^ tS Si*S» •sruwi-^^L ^-■'TV ' 36 "I 'i f Practical Zoology. these experiments take care not to produce such vibrations of air, water, or mud as might effect the sense of touch. Test the sense of smell by placing various odorous substances near the crayfish, when in air as well as in water. Is any attention paid to scents ? Recall any choice of food the crayfish has made? Is this choice determined by a sense of taste? Place various substances that affect your sense of taste on the crayfish's food. Does it make any difference in his choice? Place on the mouth organs drops cf various liquids that affect your taste. Is the crayfish affected thereby? Molting. — Sometimes when one has left a single crayfish in an aquarium he is surprised to find two. The molted shell looks Uke a complete crayfish. Watch a crayfish closely for this change. Before the molt a crayfish is dull and quiet. What are the first stages of the process, and in what order does he cast off the old shell? Feel of the newly emerged animal. For several days test the hardness of the shell. How long does it take for a " soft- shell " crayfish to become a " hard-shell " ? What makes the shell hard? Drop a piece of the old shell in weak hydrochloric acid (vinegar will serve). Hold a piece of shell in flame. Does it burn? Development. — Find a female crayfish with eggs. To what are the eggs attached? Watch till the eggs hatch out. How long are the little crayfishes when first hatched ? Do they go free or remain attached to the mother? If they separate from her, do they return to her? Does she make effort to keep near them or keep them near her? Does she feed them? What do they eat at first? Do crayfishes ever eat each other? Do they kill each other? External Parts of the Crayfish. I. Note the two distinct parts of the body, (i) the anterior, rigid part, the cephalothorax ; (2) the posterior, flexible part,' the abdomen. jiSM^msi Crustacea. 37 a. The covering of the cephalothorax is the carapace. Run- ning across the carapace is the cervical groove. The anterior projection of the carapace is the rostrum. 3. Bend (flex) the abdomen, and straighten (extend) it re- peatedly, observing how the segments are jointed together, and how they move one upon another. Count its rings or segments. 4. Separate the third ring (counting from the front) from the rings in front of and behind it. To do this hold the cephalo- thorax and fore part of the abdomen by the thumb and fore finger of the left hand, with the posterior end of the abdo- men projecting toward the right hand; then, grasping the dissecting needle firmly with the right thumb and forefinger, thrust the point or a dissecting needle obliquely forward between the third and fourth segments, and work it up and down, severing all connection between them without breaking either ; with scissors cut the membrane between the under sides of the rings, and entirely separate them. In like manner detach the third segment from the second. The ring has these parts : — a. The upper part, the tergum. i. The under part, the sternum. c. The side piece, the pleurum (projecting downward). //. Two appendages, the swimmerets. (See Fig. 46.) 5. Observe that each swimmeret has a main stalk, u protopod, and two branches, an outer, or exopod, and an inner, or endopod ; examine these appendages thoroughly. Lay the ring on its front side, make the branches of the swimmerets diverge enough to appear distinct, ai>d make a drawing of the whole ring as seen from behind. Compare the other segments of the abdomen with the third. In the male the appendages of the first and second rings are larger than those of the other segments and are specially modified. In the female the swimmerets of the first and second abdominal segments are smaller than the others. The abdomen of the female is wider than that of the male, probably for the purpose of pro- tecting the eggs and young, which are attached to the swimmeret* *? ! .~r^" ''■K' "WJioK -'-. TMBRTViBi ,■1 ._yt- \L 38 ; ii Practical Zoology. . ♦'- . -.^ 6. Study carefully the structure and action of the tail fin. Its middle piece is the telson, underneath which is the external opening of the intestine, the anus. Remove the telson, and without disturbing the side parts of the tail fin, separate the sixth abdominal ring from the fifth. Now carefully compare this (sixth) ring and its appendages with the third ring and its appendages. 7. Are the appendages of the thorax borne upon rings like those of the abdomen? If so, where are the rings? With forceps seize the base of one of the hindmost pair of walking legs, and move it backward and forward; are these borne on a distinct ring? Carefully clean the sternum between the other walking legs, and look closely for indications of rings. 8. With the forceps break away one side of the carapace, beginning at the lower edge. This lays bare the white, feathery gills. Cover the specimen with water in the dissecting pan to show the gills more clearly. Move the legs of this side back and forth, watching the gills. 9. Study now the hindmost of the walking, or thoracic, legs. Count its segments. Observe how the first segment is joined to the body. Flex the leg as far as possible, in every direction, noting the number of joints, and the motions allowed by each. With the forceps seize the squarish, basal segment of this leg, and pull off the leg. 10. Remove in like manner the legs in front of this, again being careful to get a firm hold of the short, wide segment next to the body. What is the relation between the leg and the gill nearest to it? Lay this leg on a paper in front of the one previously removed. In this way pull off all the legs of one side, from the hind- most to the foremost, laying them in order. Compare them all with the one first taken. In the legs bearing pinchers is there any real new part added, or is the pinching apparatus produced by some change in a part presented in all the legs? How do the legs which bear the big claws differ from the walking legs? Com- pare them, segment with segment. v»^i^^r^K-*^^w;.; Crustacea. 39 11. Anterior to the big legs are several pairs of appendage* surrounding the mouth. Probe between them to find the mouth. These mouth parts are numbered from the front, but on account of the way in which they overlap, it is easier to remove and study them in the reverse order. 12. The appendages just in front of the big claws are the hind- most of three pairs of jaw feet, or maxillipeds. Gently raise them to see how they cover the other mouth parts. Note that these maxillipeds, or foot jaws, have an inner branch (endopod), which meets the corresponding part of the opposite maxilliped, and an outer branch (exopod). Observe that both these branches are attached to one segment (protopod), next to the body. Seize this basal segment, and remove the whole maxilliped. Compare it with one of the swimmerets of the third ring of the abdomen. In the same way remove the second and first maxillipeds of this side keeping them in order. Are there gills attached to the maxilli' peds ? Is there more than one gill on each leg ? Are there other gills than those attached to the legs? Pick one of the gills to pieces under water to determine its structure. After removing the gills, look in this region for further traces of thoracic rings. 13. Anterior to the maxillipeds are two pairs of maxilla. These are very thin, and lie close to each other, so that if great care be not taken, they are likely to be pulled off together. Investigate closely, and then, inserting the forceps well down, remove them one at a time. Attached to the base of the hinder maxilla is a thin' double spoon-shaped structure, the gill scoop, or gill paddle. It lies in the front part of the cavity in which the gills are, the giU chamber. With the forceps move back and forth the second maxilla of the other side, to see how the gill scoop is thereby moved. The gill scoop, swinging back and forth, pushes the water out of the front end of the gill chamber. The water thus expelled is replaced by fresh water, which comes up under the lower edge of the carapace, about the bases of the legs ; thus the gills are constantly bathed with water containing a fresh supply of oxygen. , F^ym^'jmii'''f*^k:^.^^'m.i*^fMMr^-iJM^y- 40 Practical Zoology. iata 14- The mandibles are short, hard, and toothed. Each man* dible bears a jointed appendage, the mandibular palp, which curves around the anterior edge of the mandible in a groove. Move a mandible about to see how it is hinged. 15. Closely fitting against the posterior surface of each mandi- ble is a thin, leaflike structure, the metastoma. The metastoma differs from the maxilla in pointing outward and in being un- divided. Remove it and complete the series of mouth parts, — mandible, first maxilla, second maxilla, first maxilliped, second maxilliped, third maxiUiped. R move the corresponding append- ages of the other side, lay them in a row facing those of the oppo- site side as before removal, but not now overlapping each other, and make a drawing of the series, naming them. 16. The long projections in front of the head are the antenna. Seize one of them with the forceps, and pull about in all directions, to make out the large segment, at its base, under the head. On this basal segment find a small white cone, with a hole at its sum- mit. This is the aperture of the kidney, or green gland. Remove the antenna, with the whole of this big segment at its base. What, probably, is the use of the bladelike branch of the antenna just under the eye? v^ompare the antenna and its branches with a swimmeret. 17. Above the antennae are the antennules. 18. In the base of each antennule, just underneath the eye, is the ear sac. 19. With the forceps pull the eye about to see its range of motion. Pull it out by its stalk, and examine with lens and micro- scope its black tip, or cornea. Each distinct area is a facet, and the eye is compound. 20. After removing the cephalothoracic appendages, and the carapace, carefully clean and thoroly examine the framework of the cephalothorax, still looking for traces of thoracic rings. 21. The skeleton of a crayfish, like that of insects, is an external skeleton, or exo-skeleton. Compare it with the internal skeleton, or endo-skeleioHf of vertebrates. Crustacea. 41 Crayfish Card. Get a piece of stiff, smooth cardboard six inches by eight ; select some dark color such as will make a good background for the crayfish. With pencil make three fine lines lengthwise, one in the middle, the others an inch from the middle. Make a cross at the center of the middle line. Now dot all three lines at intervals of half an inch, starting from the center. Separate the parts of a crayfish as in previous study. For this the specimen should be slightly moist. If too dry, it will be brit- tle. If too wet, it will stain the card. If the work is interrupted, it is well to keep the parts on a damp paper or cloth, and covered so they will not be scattered. The parts of a crayfish are so compactly put together that it is impossible to see them all, while in their natural place. One object of this work is to make'a per- manent preparation with the parts separated enough to show them distinctly. The crayfish is supposed to be crawling along the middle line of the card, and to have become dismembered and strung out. The carapace is to be in the middle line, with its hinder edge half an inch from the center of the card. The ab- dominal rings are to follow this at intervals of half an inch. The appendages are to be arranged along the side lines at intervals of one half inch, with their bases at the side line, and extending at a suitable angle forward. To support the carapace and abdominal rmgs, make a cardboard bridge of the same material as the card This bridge should be just high enough to reach the under surface of the arch of the carapace. The rings should be strung on this bridge, and both the rings and the carapace sewed to the bridge at the top, with a thread of such color as to be as inconspicuous as possible. The ends of the bridge should be sewed to the card, and the lower edges of both rings and carapace fastened so they will not slip about. All needle holes through the card must be made from above to avoid leaving a rough place. Determine where each hole is needed, and pierce from the upper surface of the card, whether the thread is to be passed through from above ii I ii .i^,1^P.#wj.^„j;;;»|«,*,^5^.|;^^ 4« Practical Zoology. #3; i or below. In fastening the appendages, first decide just where the part is to lie. Then, directly under the basal part, make a hole from the upper side. Then pass the thread through, from below, over the appendage, and down again through the same hole. The loop thus made will hold the appendage securely and be little noticed if the thread has a suitable color. In this way fasten each of the longer legs at three points. Leave the eyes at- tached to the carapace, but arrange all the other appendages, from the antennules to the last thoracic legs. Label the whole series on one side, placing the name below each appendage. Dissection of the Crayfish. 1. Place the crayfish in the dissecting pan, dorsal s'lrface up, and cover it with water. Place a double-pointed tack astride the narrow part of each of the first pair of thoracic legs just back of the big pinchers. By pressing strongly with the thumb the tack can he set firm enough to need no hammering. Now pull the body of the crayfish back taut and tack firmly through the telson. 2. Insert the point of one blade of the scissors under the hinder edge of the carapace, about an eighth of an inch to one side of the middle line. Cut forward to the groove which sepa- rates the head from the thorax. Break away the whole of the side of the carapace. Push the gills downward, and cut them off at their point of attachment. Observe the thin wall separating the cavity in which the gills were, the gill chamber, from the body cavity. Clear away the other side likewise. 3. With the forceps pick away the narrow remaining strip of the carapace, carefully, as the heart lies just under it. The heart is an oblong, whitish body. Look for small white tubes, arteries, running forward from it toward the head. How many are there? Be on the lookout for other arteries. With the forceps gently Hft the hinder end of the heart ; note its angularity. Look for holes in the dorsal surface of the heart ; how many do vou find ? Look also for holes on the sides and on the ventral surface. Crustacea. 43 4. Under the heart, and projecting in front of it, are the repro- ductive organs : in the female, the ovary, in which the spherical eggs may be distinguished ; in the male, the whitish spermary oc- cupies a corresponding position. The ovary sends downward on each side a tube, the oviduct, or egg tube, to the first segment of the third thoracic leg, where it opens externally. The •permary has a much longer, coiled white tube, which opens on the first segment of the hindmost thoracic leg. 5. Carefully cut away the roof of the head. The space within the head is almost completely occupied by the stomach, a round- ish sac, with a thin wall, in which is a hard framework. (,ently scrape away the soft tissues around the stomach, and examine it closely. Observe the narrow gullet or esophagus leading from the mouth to the stomach. 6. Along the sides of the posterior end of the stomach and the anterior end of the intestine lie the large digestive glands. They ^e yellow or greenish in fresh, reddish in alcoholic, specimens. Pick one of these masses to pieces to learn its structure. Find the duct leading from each gland into the intestine. 7. Observe the white muscles which extend forward from the abdomen along each side of the body cavity. 8. Beginning at the front end of the abdomen, close to each side, cut with scissors through the roof of the abdomen to the telson. Seizing the forepart of this roof with the forceps, care- fully lift it and turn it backward. A thir layer of white muscle may adhere to it, or may remain connected with the organs in the abdomen. This is made up of the muscles that straighten (ex- tend) the abdomen. Pick them away carefully with the forceps. 9. Running lengthwise, in the middle line, is the intestine, a thin-walled tube, often of a dark color from its contents. Trace it back to the anus and forward to the stomach. Carefully re- move the intestine. 10. A large mass of muscle remains. This is composed of the muscles that bend (flex) the abdomen. How do these flexoi and extensor muscles compare in size? Why the difference? 44 Practical Zoology. I II. Draw the point of a knife blade or dissecting needle along the middle line of this muscle, at the bottom of the groove in which the intestine lay. After a thin layer has been cut through, the whole muscle may be easily separated into two rolls the whole length of the abdomen. Roll these carefully aside, pushing equally right and left; otherwise the nerve cord may be injured. Find in the middle line of the floor of the abdomen a slender white nerve cord, with enlargements at intervals. How many of these enlargements, ganglions, are there in the abdomen? What relation do the ganglions have to the segments? Observe the branches, nerves, given off to the muscles on each side. Trace the nerve cord forward to the thorax, where it disappears in the hard framework of the floor of the thorax. Break away as much of this framework as is necessary to follow the cord to the head Make out that the cord is double. How many gai.^lions are there in the thorax? Note the branches extending to the legs and other organs. From the large ganglion back of the gullet trace two branches forward, one on each side of the gullet, till they unite in a large ganglion above the gullet, thus forming'the esophageal coUar. From the ganglion above the gullet trace nerves to the eyes, antennae, and antennules. 12. Cut open the stomach, wash it out with water, and look on Its inner walls for teeth. 13- BeJow and in front of the stomach, find a pair of pale green bodies These are the kidneys or « green glands." Remove the stomach and study the structure of the kidneys. Find where thev open externally. ' 14. Study the joint in one of the big pinchers. Pick out the muscle from the end of the segment, and find the thin, tough white tendons. Seize these with the forceps and pull alternately, to see how the claw is shut and opened. Which is larger the muscle that opens the claw, or the one that shuts it ? Explain. 15. In what characters is the crayfish like the grasshopper? In what do these animals differ? Make a concise list of these points of hkeness and difference. ■'W%^ Crustacea. 45 1 6. Why should the name CruiUce* be applied to such mJ-riils as the crayfish ? Read The Crayfish, Huxley. Topics for Reports. — The Lobster Industry. Shrimps. Crabs Hermit Crabs. SeaSj^'ers. Fiddler Crabs. Cocoanut Crabs.' THE SOW BUG. Sow bugs are usually to be found under boards and stones, and m other damp places. Get the largest specimens for this study. 1. The first part is the head, or carapace. a. Find and describe the eyes. 3. VVhat are the peculiarities of the antenn»? How many? 4. The jaws and maxillae are closely pressed together, forming a short, blunt projection under the head. The tip of this blunt proboscis is usually black. A longitudinal groove shows the Une of union of the hinder maxillae. By pinching the body of a live sow bug, the mouth is sometimes more clearly shown by the exudation of a liquid, as in the case of a grasshopper. Where is the line of division between the head and thorax? Count the appendages which may be supposed to belong to the head ; how many rings do these indicate? 5- The line of division between the thorax and abdomen is indicated by an abrupt change in the size of the segments. How many segments has the thorax? Compare the numbers of seg- ments in thorax and abdomen with those of the crayfish. 6. How many segments are .there in the abdomen ? 7- How many pairs of legs are there? How many segments has each leg? Do the legs all extend in the same direction? 8. A series of thin, overlapping plates under the abdomen are the gills. In the anterior plates observe the white air chambers. Beginning at the foremost of these gills, pick them apart with a needle. Remove them, and with a lens make out the., shape and arrangement. 9. Under the thorax of the female there is a series of thin membranes attached near the bases of the legs. These are the 1^ 4^ Practical Zoology. egg covers. The eggs, after being expelled from the body, undergo their development in the space under the thorax in- closed by these egg-covers. Look for specimens carrying iggs in this manner. lo. In what respect are the sow bug and crayfish alike? In what respect do they differ from each other? The crayfish and sow bug both belong to the Crustacea. The class Crustacea is divided into several orders. The order to which the crayfish belongs is the Decapoda, or ten-footed; the sow bug belongs to the order Tetradecapoda, or fourteen-footed. CYCLOPS. Along the sides of aquaria, and sometimes in drinking water, there may be seen hiinute white animals swimming with a jerky motion. Cyclops has a pear-shaped body, and is just large enough to be seen readily with the naked eye. The females carry two egg masses attached to the sides of the abdomen. With a lens, watch these animals through the side of the aquarium. Place a female cyclops with a few drops of water in a watch crystal, or a piece of glass. Examine under a three-legged lens, or under a low power of the microscope. I. The foremost division of the body is the carapace. How many segments has the thorax ? a. The egg sacs are attached to the first ring of the abdomen. 3. The eye ; note its color, position, shape, and parts. 4. The antennae and other appe.ndages. 5. How does Cyclops swim? Make a careful drawing of cyclops as seen from above. Cyclops belongs to the subclass Entomostraca (water fleas). ■-■jm ijTg- ~s CHAPTER VI. ANNULATA. FIELD STUDY OF EARTHWORMS. 1. In what kind of places does the fisherman dig for earth- worms ? 2. Are they more abundant in one kind of soil than another? 3. Look for the coiled excrement, or " castings," at the mouths of the holes. How many Holes can you find in any square yard? Find the number in severa. . quare yards at different places in a rich meadow or pasture, and compute the number in an acre. 4. Do you find earthworms during the daytime ? If so, in what conditions? Hunt for them at night with a lantern. Are they far from their burrows? Do they appear frightened? Do they re- treat into their burrows? 5. If a worm is found partly extended from its burrow, seize and try to pull it out. Is it easy to do so? Why not? • 6. Carefully dig up a number of earthworms. How deep is the burrow? And what is its course ? In what part of the burrow is the earthworm? Does the depth at which the earthworm rests depend on the time of day? The condition of the soil? The weather? Is the worm always the same end up? Is the hole much wider than the worm ? Could it turn around in the hole? 7. Do earthworms ever plug up the mouths of their burrows? If so, when and with what material ? How is this work done? 8. Do you find evidence of what earthworms eat? Do they eat their food outside or in their burrows? Do they store food? Do they spend much or little time eating? 9. Having quietly approached an earthworm that is out, or partly out, of its burrow, suddenly make a loud noise. Does it 47 7W-.m.\:s^"''-^''-'W' ■ • I jut in I' M 48 Practical Zoology. seem to hear? Fire a pistol or cracker ; does it notice the noise? Stamp hard on the ground ; does this affect the worm? 10. In what month are earthworms most active? When least active? Do earthworms hibernate? How early are they seen in spring? How late in the fall ? 11. What enemies has the earthworm? Has it any means of defense ? On what does it rely for protection ? 12. Do you discover anything to prove that earthworms lay eggs? If so, when and where does this take place? LABORATORY STUDY OF EARTHWORMS. Get a box a foot deep and a foot or two square. Fill it with fine, rich, black soil and press it down firmly, leaving an inch or so of space above the sbil. Keep the soil fairly moist. Earthworms may be kept alive through the winter in boxes, or flowerpots of soil, covered with sod and watered occasionally. The soil should be kept cool and moist, but not wet. Put some dead leaves just under the sod, and occasionally place cabbage leaves or lettuce leaves on the sod for them to feed on. The boxes or flowerpots may be kept in a greenhouse or in a cellar. Cover the box with a large plate of glass. It is well also to have glass windows at the sides and bottom. 1. Place two dozen live earthworms on the soil. Watch them, as they burrow into the soil. Do the worms soon become settled, or are they restless ? How soon do they reappear at the surface ? 2. Test the worms with various kinds of food, meat, both lean and fat, bits of cabbage, celery, onion, turnip, apple, etc. Which do they prefer ? Do they show evidence of a sense of taste ? Of a sense of smell ? Do they eat on the surface or in their burrows? Do they eat the material at once or keep it for a time? Do they eat little or much? Do they exercise choice in selecting bits of food according to their size or shape? When do they eat? Is the process slow or rapid ? How is the eating done ? 3. Place an earthworm in a glass tube with good black soil, and watch it fix)m day to day. ^M'..: Annulata. 49 4. Try the effect of sound on earthworms, being careful that they do not get vibrations that affect the sense of touch during the experiments. ^ 5. Try the effects of hght, being careful not to apply heat at he same time. Place the worm in a glass tube, and let the ligh fall upon one part at a time, covering th^ rest of the tube with a cyhnder of black paper. Try also the effect of heat without 6. Repeat any experiments given under " Field Study " that may profitably be reviewed. nA'h^^V'!^^ appearance of the surface of the soil as a result .n the r^H . '^;^^"°™^^ ^^hat effect do earthworms produce m the condition of the soil ? STUDY OF A LIVE EARTHWORM. 1. Place a live, active earthworm on a large sheet of paper and most ? T rr ""r: ' "°^^ ^''^ ''^ ^^-^ -^^ ^'-'^ ^o-i^ most? Touch the end that is foremost to see if it will reverse it^^ motion. What changes take place in its body during locomotion? V' ^-an you explain how it progresses? - ^^ -. 2. Take the earthworm in the fingers of one hand and draw it over a finger of the other hand to feel the bristles ; of what use are they ? Can yqu learn how they are arranged ? Do they point more toward one end of the body than the other? Place the worm on glass; can it crawl as well as on paper? Why should the condition of the surface affect the worm's locomotion? 3. Touch various parts of the body to learn the degree of sensitiveness of different parts. ^^'^ -^U--- ' 4. Turn the worm over on its back; does it remain in this -^^ position ? 5- Take hold, of the posterior end of the worm and drag it backward along the paper, listen f^r any sound thus produced. How explain this resuh? t>^' '•' ' -^ 6. Rap sharply on the table ; does this affect the worm ? T ^A ■ '■' 7. Place the worm on a wet surface, and after a while on a dn? '"-«'- J 1 % iiH! ■I- •1 « 50 Practical Zoology. surface; does it appear equally comfortable in both conditions? Try also the effect of heat and cold, dust, mud, water, etc. 8. Obseive along the middle of the back a blood tube; watch its pulsations. Can you discover any other evidences of circula- tion of blood? ' EXTERNAL FEATURES OF THE E^RTpWORM. t-'i , ^- c • '•■ ■ '' ^ C 1. The end that usually goes foremost is the an1;fifior end : the other end is the posterior end. Are the two ends of the same color? The surface on which the earthworm ordinarily rests is the ventral surface ; the surface usually uppermost is the dorsal surface. The earthworm has right and left sides, that correspond to each other ; such an animal is bilaterally 83mimetrical. 2. The earthworm is segmented, or marked off into rings called segments. How many segments has your specimen? Are the segments all equal in width ?>'/V^^-- ^ - i^^-^ . 3. About one fourth or one fifth of the length from the head obsene a place where the segments are less distinct, often enlarged and with a different color._^^This is the gjrdle, or clitellum. How many segments does it occupy ? How many segments are anterior to it? 4. Is the worm exactly cylindrical, that is, is the cross section a circle? '"■-'^ 5. At the anterior end find the mouth. Overhanging it is a sort of upper lip called the prostomium. At the posterior end find the anus. Is it circular? / 6. Find the rows of bristles on the sides and ventral surface. How many rows are there and how many bristles in a segment? 7. On the ventral surface of about the fourteenth segment are the rather distinct openings of the oviducts, and on the fifteenth the openings of the sperm ducts. Between the ninth and tenth segments are the openings of a pair of sperm receptacles, and another pair open between the tenth and eleventh segments. The positions of these openings vary in different kinds of earth- worms, and they are not always easily discovered. Annulata. 51 DISSECTION OF THE EARTHWORM. Material : dissecting pan, forceps, scissors that cut well at the point, dissecting needles, two dozen pins. Ribbon pins are best for this work. Dissect under an inch of water and renew if it becomes turbid. 1. Lay the specimen lengthwise on the board, stretch it, and pin firmly at each end, slanting the head of the pin away from the worm. Cut through the skin of the back near the posterior end, and continue the cut forward a little to one side of the middle line' With the forceps lift the edge of the cut and run the dissecting needle along under it to cut the partitions that hold the body waU down. Turn the edges of the body wall out and pin them down, slanting the pins at an angle of about thirty degrees so they will be out of the way. 2. As soon as the edges of the cut are separated the intestine IS seen. It is cylindrical, nearly filling the body cavity. It is usually dark-colored from its contents. 3. Along the top of the intestine is the dorsal blood tube. 4. Observe now more closely the partitions which extend from the intestine to the body wall between adjacent segments. Com- pare the positions of the partitions with the external markings and bristles. Are there as many segments as indicated by the external appearance "> 5. Continue the cut to the anterior end, being careful not to cut into the intestine, especially in the part anterior to the girdle. Pm well out, and free the intestine by drawing the dissecting needle along its sides to cut the partitions. 6. In the region of the tenth segment are several pairs of white bodies, the sperm sacs. 7. Alternating with these are several red masses. They are the aortic arches, which spring from the dorsal blood tube and arch around on each side to join the ventral blood tube beneath the digestive tube. In some earthworms each aortic arch has several enlargements, making it resemble a necklace. The enlargements ; f ■ : : i i \\ h^\ '^4 ■li 52 Practical Zoology. •( i are sometimes called " hearts." In a recently killed specimen they may be seen pulsating. 8. In the first six segments is a wide portion of the digestive tube, the pharynx. It has threads of muscle connecting it with the body wall. The pharynx is used as a proboscis, being pro- truded from the mouth and everted. 9. The pharynx narrows behind into the guUet. This extends through several segments, but is hidden by the sperm sacs and the aortic arches. Clear these away. 10. In removing the sperm sacs there may be seen in the ninth and tenth segments two pairs of small, white, spherical bodies the sperm receptacles. The still smaller ovaries may be found in the thirteenth segment. 11. Back of the spermaries are two enlargements of the diges- tive tube. The first is the crop and the second the gizzard. 12. From the gizzard to the posterior end of the body extends the intestine. Is it uniform in diameter? If not, where is it wider and where narrower? 13- Cautiously dissect away the intestine. Under it is the ventral blood tube. From it as well as from the other principal blood tubes there are smaller branches to supply all the tissues 14. On the very floor of the body cavity, in the middle line is the nerve cord, resembling a white thread. Trace it from" behind for^vard. In each segment is an enlargement, or gangUon. From the ganglions proceed branches to supply the surrounding organs with nerve fibers. ^ 15. Under the anterior end of the pharynx the nerve cord separates into two parts, one passing up on each side to enlarge into a ganglion. These two ganglions are the cerebral ganglions or brain, and the ring of nerve cord around the pharynx is the nerve ring or nerve collar. 16. Attached to the ventral body wall, on each side of the digestive tube, are many small, threadlike, coiled bodies. Exami- nation with a lens shows a pair of these in each segment. They are the kidneys or nephridia. Each is a tube thrown into loom M^^d^mM^M.. ^^i^t^"^ ^ '>.;.■ Annulata. S3 The kidneys open to the outside usually between the inner and outer rows of bristles, but sometimes above the lateral row of bristles. And each tube kidney begins as a funnel, which is in the segment in front of the one in which the loops of the kidnev are found. ' 17. The outer layer of the skin is thin and easily peels off 1 his is the cuticle, and is noticeable on account of its pearly luster The bulk of the body wall is composed of two layers of muscles* the outer of circular and the inner of longitudinal fibers, by means of which the worm moves. 18 In a freshly opened earthworm mount a drop of the milky liquid found in the body cavity and examine it under a one-sixth objective. The corpuscles should be distinctly seen. CROSS SECTION OF AN EARTHWORM (MICROSCOPIC). 1. Examine cross sections under the microscope, with a low power, one-half or two-thirds inch objective. The body wall may be seen to consist of several layers. The intestine has an extension, the typhlosole, from its dorsal wall, occupying considerable of the space within, and adding much to the inner surface of the intestine 2. Examine with a higher power, one-fourth or one-sixth inch objective. There are five layers of the body wall : (a) the thin whtJTn ^H^ ' '''u''"' '"'"' °' ''''■"' ^^^ ^-yPodenniS' or epidermis, which produces the mucus which coats the outside of the worm • c) the layer of circular muscle fibers; (./) a thicker layer of iSu^ ""'''' *"'"' ^'^ ' ""'' '^^" ^''' "^ P^"^""^'^ 3. The dorsal blood tube lies embedded in cells on the dorsal wall of the intestine. Under the intestine is the ventral blood tube. Still lower IS the nerve cord, or ganglion, as the section may strike. Kead T/ie FormaHon of Vegetable Mold through the Action of Earthworms, Darwin ; or the chapters on the earthworm in (general Biology, Sedgwick and Wilson. Leichis' *°' ^^^^ ~ ^^"^^^' °^ Earthworms. Marine Worms. ^Alh !^ S 3' I CHAPTER VII. MOLLUSCA. FIELD STUDY OF FRESH-WATER CLAM. Look for clams in the shallow water of creeks and lakes. Note the natural position. How much of the shell is embedded ? Is the shell open or shut ? Can you see any openings by means of which the clam communicates with the water? Touch the clam and note any changes that take place. Quickly pull up the clam and note the extended foot. Watch clams to see if they move. Do they move with the same end always foremost? How does the foot point with reference to the direction of locomotion? Does a clam make a track? Can you tell by the track in which direction the clam traveled? Does the direction of travel have any relation to the current of the stream? Why do clams travel? If possible, make a series of observations to find out the rate of locomotion. Where are clams more abundant, on sandy or on muddy bottoms? How many kinds do you find? Do diffei- ent kinds show preference as to soil? Has the color of clams any relation to the surroundings? Do you find any evidence that dams have enemies ? Of what kinds ? How are clan;s protected from enemies? What conditions are unfavorable to clams? Do they prefer deep or shallow water? Do they occur singly or in groups? Dodifferentkindsoccupy the same region? AQUARIUM STUDY OF A LIVE CLAM. If a good aquarium is not obtainable, a battery jar, a tub, or a large pail will serve. Put in three inches of sand and add enough water to stand three inches above the sand. Let this stand over night to allow the water to become clear. 54 Mollusca. *- Poiltion of the Cl«n. - Drop several clams into the water and note carefully the place and position of each. Watch them as closely as possible to see if they change their place or position, and if so, learn how this is done. the^rr^T""^*'"^ '''™' '^^' ^^"" established themselves in heir natural posmon, to find out how they travel. Do they aJd?' \ r\ '^ V^*^^* -^^ - i^? ^^ the motion slow or rapid? Is It at a uniform rate, or irregular? Quickly pull up a c OS™ to'^e sTdT"f '1 "'' ^''. ^"^"^^"^ '°°^- P^" ^ al- dose to he side of a glass aquarium ; the foot may be protruded so close to the glass as to be seen. Why do clams travel? cin a clam crawl on a hard surface? Water Currents. -Note that a clam, when established in a natural position and left undisturbed, has the shell slightly open Near the upper edge of the more exposed end lookVtwo elliptical holes ; these are the siphons. Watch to see if there is any evidence of currents through these holes. Reduce the amount of water so that it ,s about half an inch deep over the siphons of a large clam. Look closely at the surface of the water over the siphons for evidence of water currents. Take a slender glass tube, dip one end in mk, place a finger over the upper end of the tube and lift out a httle ink. Carefully introduce a drop of this above the siphon opening The currents may also be revealed by a little mud, but care should be taken not to drop coarse mud or sand on the siphons. What happens when the margins of the siphons are touched? Pull up a clam that is in "full blast," watching closely the siphons. Describe what you observe. Senses of the Clam. - Test in various ways the senses of the clam Touch It hghtly and heavily; jar the floor near the aquarium. Thrd^ strong hght (without heat) upon it. Try heat without light. Test for all the senses you think a dam may possess. Protection of the Clam. - Note again the changes that take place when an active clam is taken from the water. Now try to open the shell with the hands alone. Why does the clam have such a _r S6 Practical Zoology. L"ong7'""' '"' ''' ''""'^ ^° '^^"^ ^^ ^° ^'«^^'y «"d ^«™«in shut EXTERNAL FEATURES OF THE CLAM SHELL. If a live clam is used, place it on a plate, or in the dissecting pan. I. Notice the two parts of the shell, _ the valvei r tk' ^T *!°"« ^^'^'^ ^he shell opens is the ventral margin 3. rhe edge by which the two valves join each pther is \he dorial margin, or hinge margin. line. ^f'^oX"'" """ '"'"'' ^° ^'^ ^^"^^^» ™-«- - the or Lm' Th'"^ ^f ' ''"""'^ ^'^'^'^ ''^^^^ "'^^^ ^^"ter is the beak, the cTam. '" ""''' ''^^ '^°"^' °^ ^"^^"«^' <^"d of 6 Toward the posterior end, back of the umboes, between the valves, and uniting them, is the hinge Ugament 7. Hold the closed shell with the hinge margin uppermost the The fr"' ?"T' "' ^'^ ""^'^^^ Pointing^way'from "ou The end pointing from you is the anterior end. The end pointing toward you is the posterior end. The upper edge is the dorsal margin. The lower edge is the ventral margin. The half-shell to your right is the right valve The half-shell to your left is the left valve. Fix these relations firmly in mind cond,i,o„ of the different parts of the shell, and consider tl,o DISSECTION OF THE CLAM. How to open a Clam. -It is difficult for beginners to ooen peTedTyTheTa f"^ l/ ^^' '^^^^ '' ' ^^^ ^ ^^ ^rn opened by the teacher. If any student is following these direc m^'-^^'^m'A^^ ^ -^ '^^'sm^,'^^%:^?^m^:%m Mollusca. 57 tions without the aid of a teacher, he will find directions for opening lams without using hot water, in the Suggations to the leacherof Zodlogy, m a separate pamphlet. Put the live clam for a i^>^ minutes into water as warm as the hand can well bear. This causes the muscles to relax, so that he shell can be readily opened. Pry apart the two valves and insert a half-inch block to keep them from shutting. I. Observe a soft white membrane, the manUe. adhering to the inner surface of the shell. lx,ok in at the posterior fnd for the two siphon openings. Now h^.ld the clam in the left hand with the left valve up and the ventral margin toward you. Inserl Innt" " ; ^"^''r '^' ^'"^' °^ " ^">P^' b^^-««" the mantle and the eft valve, and gently separate them by sliding the scalpel handle abng the inner surface of the shell. In this way proceed backward, around the posterior end of the shell, then for^vard along the dorsal margin. Back of and below the hinge is a large whue muscle which extends directly across from valve to valve. Cut this off close to the left valve if it is not already severed In like nianner loosen the mantle at the anterior end, and find another muscle connecting the two valves near the anterior dorsal margin. Sever as before, close to the left valve, and loosen the mantle completely from the left valve. i\.l'lT '^' '''"" '^' ' "^"^ '"'"'" '^" P^^^^""-^- ^Vhat makes the shell spnng open ? Repeat the closing and releasing until you have a satisfactory explanation of the method of opening. Be on Break off the left valve by bending it forth and back, twisting it on if necessary. ** 3. Lay the clam in the dissecting pan and cover it with water. Renew the water as often as it becomes turbid. To keen the clam level use the left valve, hollow side down. the^H'rr K^'r '^' f ' "''"''' '°^' ""^ ^°^^^^ '^' ^"dy.and that he right lobe lines the right valve. Notice the thicker margin of the mantle. Pinch this thick e^r^e • if \^ hi- nnt v 1 % ... "• ^ •t,*^> " -^ "2=> not uircaciy shortened as much as possible it may draw up slightly. Observe a thin. > I -5 \": 58 Practical Zoology. '■I i dark-colored membrane bordering the edge of the shell. This is the periostracum, an extension of the outer covering of the shell Scrape off some of it to see its relation to the limy shell. Care^ fully study the relations of the periostracum to the mantle. Pinch the edge of the right mantle lobe, and observe the effect on this free border Trace the right and left mantle lobes to their points of union before and behind. 4. Examine the thick. dark-colore-^mi^ J m '^'^^^'^jmam^mm Mollusca. 59 »hu8 drawing the body away from the dorsal margin. Just under the hmge a pale organ may be seen, pulsating every few seconds • this is the heart. xa. Holding the mantle stretched, again examine the upper siphonal opening ; probe to see how it extends forward above the united hinder portion of the gills. In the upper part of this cavity find a tube running back over the p- erior a«" i i - muscle, and ending in a conical elevation; this tube is Mic i testinr .,.'l the opening at its end is the anus; hence the siphon UiuImv- frcr:: his cavity is called the anal siphon ; the lower s,..h ., . r„. u k i ts water to the gills and mouth, is called t!u' bi'^ncbiai n\y ica ■ r il •iphon. Examine the gills from above. •.,. e- upi,;- :,^,„r 'l,,.sal margins; observe that the two outer w !!s -f , ,. b ,ni' ae a short distance apart at this edge, while below t. es: w, 'i. uni. • .^o that if the gill be cut across, these walls, as seen at *h if. arc i;Ve the letter If. These diverging walls are connected b) ...oss inanitions, thus forming a series of compartments within the gill, whereas if these partitions were absent, each gill would be a c f p, narrow undivided trough. The lateral walls of the gills are sievelike, and the surface of the gill and the edges of the holes are covered with cilia. The vibrations of these cilia drive the water which is around the gin through these holes into the cavities within the gill • the water from each compartment of the gill passes up into the chamber leading to the anal siphon. 13. Beginning at the upper edge of the anal siphon, in the middle Ime, cut carefully forward just above the intestine as far as the umbo. This lays bare the cavity in which the heart lies, the pericardial cavity. Carefully cut away the thin covering of' this cavity and make out the following parts of the heart : — a. The large yellowish ventricle in the anterior part of the cav- ity; time its pulsations; observe that the intestine runs directly through the ventricle, though it has no communication with it. An artery runs forward from the ventricle along the upper surface of the intestine; another artery runs from the ventricle backward under the intestine. Again pull the mantle ventralward to show^. ^^SS^^HF^i 6o Practical Zoology. b. A thin sac, triangular as seen from the side, with its apex join- ing the ventricle, and its base attached just above the upper edge of the gills; this is the left auricle. Each auricle receives the blood from the gills of the corresponding side. 14. Just in front of the posterior adductor muscle are the dark kidneys. 15. Above the kidney, and in front of the posterior adductor is a small muscle, which extends backward from the side of the body to join the valve near the posterior add u< tor. This muscle pulls the foot upward and backward, hence is called the posterior retractor muscle. 16. Below and a little back of the anterior adductor muscle, find the protractor muscle, which pulls the body and foot forward.' 1 7. Just above and back of the anterior adductor is the anterior retractor muscle, which pulls the foot and body up and backward. 18. To find the mouth, hold the clam, anterior end uppermost, still attached to the right valve ; press down the point of the foot,' and find the mouth opening posterior to the anterior adductor ; observe that the two outer palps unite above the mouth, and the two inner palps unite below the mouth. Back of the anterior ad- ductor a dark-colored mass may be seen within the body; this is the digestive gland, which surrounds the stomach. The intestine has several coils in the body before emerging on the dorsal surface a short distance in front of the heart. The intestine can be traced much better in an alcoholic specimen. 19. Beginning at the posterior adductor, cut away all the free flap of the left mantle lobe, following the upper edge of the gills (being careful not to cut away the labial palps) to the upper edge of the anterior adductor. Make a drawing of all the parts above named, as they lie in the right valve. 20, Remove all the remaining soft parts except the adductor muscles. Since the chief characteristic of muscle is its ability to shorten, it should now be clear how the clam shuts its shell. Turn back to No. 2 of these directions and consider the relations of the mechanisms for opening and shutting. What actions take place Mollusca. 61 during the closing? What actions during opening? Thoroughly clean the insiae of the shell, and keep it for further study. DEVELOPMENT OF THE CLAM. Occasionally a clam may be found with the outer gills greatly thickened. Cut into such a gill and remove some of the con- tents. Place a little of th- material on a slide and spread it out in a drop of water. Examine with a low power of the micro- scope. The parts of the young clams should be seen. How does the shape of the shell compare with that of the adult ? THE NERVOUS SYSTEM OF THE CLAM. This dissection requires the utmost care and patience. Take a clam that has been hardened in alcohol, or by boiling. Dissect under water ; rinse the specimen often. 1. Immediately under the posterior adductor muscle find a double yellowish body; this is composed of the two visceral gan- glions ; dissect away the thin membrane covering them. 2. From these ganglions trace nerves backward to the gills and to the posterior borders of the mantle lobes ; trace also two nerves forward, carefully dissecting away the soft parts that cover them anterioriy, and trace them to the sides of the mouth where chey join 3. 3. The cerebral tiranglions ; these lie near the surface at the bases of the labial palps. Trace a small nerve which connects the two cerebral ganglions over the mouth. 4. From each cerebral ganglion trace nerves backward and downward to 5. 5. A pair of orange-colored pedal ganglions, lying together deeply embedded between the foot and the body. In the alcoholic specimen the stomach and intestine may be traced. Cross sections of alcoholic specimens may be made with a razor, which show admirably the relations of the different parts of the clam. 63 ■|| Practical Zoology. THE INSIDE OF THE CIAM SHELL. 1. Observe the color of the lining layer. Is it uniform ? How would you describe the surface finish. 2. The hinge teeth. These are of two sorts : (i) the cardinal teeth, blunt, toothlike projections near the umbo; (2) the lateral teeth, long, ridgelike projections below the hinge ligament. Note how many of each of these kinds there are in each valve. How do they fit into each other? What is their use? Do you find them in all clam shells? 3. The muscle scars: (i) the anterior adductor muscle scar, near the anterior dorsal margin ; (2) the posterior adductor muscle scar, near the posterior dorsal margin ; (3) the anterior retractor muocle scar, just above and back of the anterior adductor scar, not very distinct; (4) the posterior retractor muscle scar, just above and in front of the posterior adductor scar; (5) the protractor muscle scar, just below and back of the anterior adductor scar ; (6) the mantle line, running parallel to the ventral margin, from the anterior adductor to the posterior adductor scar. 4. The movements of the muscle scars. When the clam was smaller than it now is, where were the adductor muscle scars? Can you see any traces of the positions of these muscles at an earlier stage of life? Is there an evidence of growth over any part of the muscle scars that now show? Does the mantle line shift its position with growth? 5. The ligament. P:xamine the hinge ligament where it was broken off. Has it a definite structure ? What is its chief charac- teristic? 6. Take an empty shell with the valves still hinged together ; cut and fit into this a piece of paper showing the shape of the whole mantle. 7. Make a plaster of Paris cast of the inside of a whole shell. 8. Make a drawing of the inside of the right valve, labeling all the features above noted. Take a large flat shell and label (with ink) both the external 1^ ' if 1 Mollusci. «3 and the internal features ; it may be lound convenient to label part of the features in one valve and part in the other. Structure of the CUun Shell. — For this work get the thickest and heaviest shells, at least one valve for each member of the class. Weigh them and then roast them by laying them on an old shovel or layer of sheet iron, and placing them on the coals in a stove or furnace. After roasting handle them carefully so as to keep them entire. Weigh them again after roasting and compare with the former weight. Hold a roasted valve by the dorsal margin in the left hand, wth the inside of the valve toward you. With the fingers of the rigiit hand supporting the outside of the valve, press with the thumb on the ventral border '^f the valve, outside of the mantle line. The shell should separate "nto two parts, the inner begin- ning very thin at the mar"e line anu becoming thicker toward the umbo ; the outer portion extending the whole width of the valve, but becoming thicker from the umbo to the mantle line and thin- ner again from this line to the ventral margin. It will be seen that the plane of division is the plane along which the mantle line has traveled during the growth of the shell. Break a burnt shell across from the umbo to the ventral margin, and make a drawing of the edge thus exposed, showing the arrangement of these sets of layers. Composition of the Clam Shell. — Put pieces of the burnt shell into dilute hydrochloric acid. The acid decomposes the limy compound, setting free carbon dioxid. If a fresh shell is placed in acid, the mineral matter will be slowly dissolved, leaving the flexible animal matter, which is called conchiolin. The hinge liga- ment is nearly pure conchiolon, being simply a part of the shell in which no limy matter has been deposited. When the shell is burned the animal matter is burned. The remainder after roast- ing is of about the same composition as lime. Put into acid a piece of the ligament. Does it contain lime? Place an entire valve of a thin-shelled clam in acid for forty-eight hours; what remains? Are shells ever found in rocks? 64 Practical Zoology. } '■^f II ; i a Toptes for Report.. - The Oyster Industry. The Pearl Fisher- ies Pearls from Fresh-water Clams. Kitchen Middens. Clam- bakes. Wampum. Tridacna. Mother-of-pearl. Pearl Button Factories. The Chambered Nautilus. The Paper Nautilus. The Giant Sqmd. The Octopus. Snails as Food. THE POND SNAIL. handle be found convenient in scooping up the sand and mud frou. the bottoms of ditches and streams; the dirt bein. washed out the shells and other objects will be left behind. Get a number of live snails, and keep them in a fruit jar I. The broad disk on which the snail creeps is the foot wh'; ^^'J^'''^'" ^'^ the feelers, or tentacles; touch them; what would seem to be their use ? 3. The dark spots at the bases of the tentacles are the eyes • are they borne on a stalk in any common snails? ' 4- ^'atch the snail crawling on the glass ; near the front of the foot the mouth may be seen; observe its opening and shutting as the snail gathers food from the surface of the glass. Do snail. clean the glass or foul it? Most snails have a ribbonlike tongue Inn^H . '' " K '"'' '"' ^"^^^^'^ "'^^ ''''^ ' - this tongue i^ applied to an object, and drawn rapidly back and forth, it acts like a rasp. 5. Watch the snails, to see if any of them come to the surface to get air ; how is this done? 6. Collect also land snails and river snails. Keep them and watch them to learn their structure and habits. I. 2. 3- 4- 5- The Snail Shell. The pointed end is the apex. The opening at the large end is the aperture. The outer edge of the aperture is the lip The lines parallel to the lip are the lines of growth. The spiral groove on the outside is the .uture. Moll usca. 6J 6. The turns of the shell between the groove are the whorU. 7. The whorls, taken together, make the spire. 8. The lid closing the aperture is the operculum ; is this present in all the snails you find ? 9. Lay the snail shell beside a common screw; if the whorls turn like the threads of the screw, it is a right-hand, or dextral, shell, if they turn the other way, it is a left-hand, or sinistral, shell. 10. Make a drawing, naming all the parts, of the snail shell with the aperture toward you ; with the aperture away from you ; with the apex toward you. Read The Chambered Nautilus, Holmes. 1. \^. CHAPTER VIII. PISCES. HELD STUDY OF FISHES. Difficulties. - In order to study fishes in their own homes with any degree of success, the student should know what are some of the mam difficulties. First, a difficulty that is found in studying any wild animals, their shyness. The student must learn to ap- proach them carefullv. Second, the colors of fishes, as of many other anmials, is such as to render them very hard to see. Third the difficulty in seeir^^ them is increased by the refraction of light' leaving the water to ner the air, and also by the reflection of light from the surface, whi greatly interferes with seeing what is below This is especially noticeable in trying to see fishes from a boat in which case the angle quite oblique. Having in mind th'ese difficulties and the dett ination to overcome them so far as pos- sible, let us proceed to i iy the fishes in their homes. Frightening Fishes.- vVhen a fish darts away at your approach, endeavor to learn by what sense he first became aware of your presence Was it by sight ? If so, what can you do to overcome he trouble? Is it the color of your clothing, or of your beat? Is any given color, or group of colors, preferred for fishing boats? VV hich will frighten more, oars or a paddle ? Should the paddle be lifted from the water, or used wholly in the water by making the recover stroke with the edge of the blade cutting thru the water? What part does the sunlight play in the use of onr or paddle ? Does quickness of motion make any difference, the range of motion beinc^ the same ? In using an anchor, which is better, a rope or a chain > VVhich IS to be preferred, a wooden or a metal boat? Do fishes hear one who talks in a boat? Dn sounds made by hitting th, M cung tne Pisces. 67 boat, as with the heel, communicate with the water? Is it well to have bright metal, such as nickel or silver, on fishing rods? The Water Glass. — The difficulties of seeing into water may, to a considerable extent, be overcome by the use of a water glass. This is a box or cylinder with a glass bottom. When the glass bottom is pushed down into the water, the face over the open end shuts out most of the light from above, thus getting rid of the con- fusion from reflection. It is possible to make such a glass as part of the boat, so one can view what is under the boat. Food of Fishes. — Find what the fish you are studying prefers tb eat If you are fishing, examine the stomach of the first fish you catch to see what it has been eating. The wise fisherman will do his best to cater to the taste of the fish he would catch. Why does the fly-fisher drag the fly on the water, or make it dance about? Find the time of day at which a fish prefers to eat. Does this vary with any discoverable conditions ? Do fishes eat during the night? What do the various artificial baits imitate? Hiding Places. — What sort of places do fish hide in? Do they hide to escape enemies, or that they may catch unsuspecting prey that passes by their lurking place ? In what situations does the fisherman look for different kinds of fishes? Sociability. — What fishes live a solitary life ? What kinds go in schools? What advantages in community life ? What disadvan- tages ? Does a school of fish scatter when frightened ? Do they come together again soon? Position in a Current. — When in a current do fishes maintain any fixed relation to the current, that is, do they rest crosswise, or lengthwise, in the stream? If lengthwise, is the head up or downstream? Why this position ? Egg La3ring. — .At what season does the fish you are studying lay its eggs? Are they usually deposited in the same surroundings ? How long time is taken in depositing them ? Are they guarded ? ^ 'lat animals may destroy them ? What conditions are favorable I. at 68 Practical Zoology. or unfavorable to their development? If j^ossible, learn the rate of growth offish. Fish in Winter. — Do fishes migrate? Are most fishes to be found ,n the same place, winter and summer? Are they equally active at different seasons? AQUARIUM STUDY OF FISHES. Respiratory Movements. — Watch minnows or goldfish in an aquarium. Note the movements of the mouth and the gill covers in what order do these movements prdceed ? Watch closely to see If there is any water current in connection with these move- ments. If there is no floating matter by which to get evidence of a current, introduce a drop of ink near the fish's head and thus determine the direction of the current. Mode of Swimming. - How does the fish swim ? Watch especially he slow movements, during which tiie facts can be more readily learned What is the main propelling power? How is the course guided ? How is the shape adapted for movement in the water? .u^Tu°i ?.' ^^«— Take a light rubber band and pass it round ^e fish holding down the various fins in successive experiments, watch the resulting movements and conditions of the fish. How a Fish Floats. -Does a fish make effort to maintain its place m water? Does it make any apparent effort in rising or sinking? Do any fishes habitually remain on the bottom? Do any stay at the surface ? Is there any difference in their structure or habits that fits each for its place ? Comparison of a Minnow and a Darter—These two forms are to keep the lead hne down" and yon will be much more likelv LTe. rr^K l^'^'l "' ""'" '^'^^' "'^^ double-cone-shaped bodies. They ha .tually rest on the bottom. ^V uch carefully their moven^ens. What takes j^ce when they cease to make active effort Do they sw,m .n the same way as the minnows ? Open a minnow and also a darter to see if .h.re . any essential difference Pisces. 69 in the structure of the two. Why should the darters have this habit of staying on the bottom ? Senses of Fi8he«.— Watch the movements of the eyes of a fish. What range of movement have they ? Do the eyes move simulta- neously? Does a fish see any better than you do ? Devise means of testing the sense of hearing without affecting the other senses. Test the different senses in various ways. On which senses does the fish most rely for safety ? Food and Mode of Eating. — Offer a fish various kinds of food and find what it likes best. How does it take its food ? What relation has the shape or size of the mouth to the kind of food taken ? Does a fish eat much, or little, relatively? In feeding fishes take care not to give too much at one time, for fear of fouling the water. Do fishes suffer from overeating ? Sleep. — Do fishes sleep? Have they any special resting place or resting position ? EXTERNAL FEATURES OF A FISH. For this work, and the dissection that follows, the perch is pref- erable for inland students, though the bass, croppie, or sunfish serves very well. On the seacoast the cunner or the sea perch is more accessible. Lay the fish on a sheet of thick paper, on a plate, or in the dis- secting pan. I. Notice the shape of the fish as a whole ; how is it adapted for motion through the water ? Hold the fish with the back uppermost and the head directly away from you ; instead of speaking of the front and hind ends, it is better to call them the anterior and posterior ends. The upper surface, or back, is the dorsal surface, and the lower the ventral surface. The right and left sides are counter- parts of each otiier ; that is, the fish is bilaterally symmetrical. The perch is flattened from side to side, and is therefore said to be compressed. A fish is properly described as " flat " only when ..".tteneci on the dorsal ind ventral surfaces, or dcpresied, as in the case of the rays. f 70 Practical Zoology. In the following directions, relative and not absolute meuure. menu „e .n.ended Instead of using a foot n.le, uke a .^^ paper and mark the entire length, head, depth, etc., either bv T?K "' y J^'^r"- ^""'P"" •"-« » "'o be able o sav Close the mouth of the fish, and measure from the foremost pom. of the head, the tip of the .«»», to the front edTthe b.« of the ta,l fin ; this is the lengU. of the fish. Measure from the fp of the snout to the hinder point of the hard par. of th" flap whjch covers the side of the head ; this is the Jgth of the b«d How many times is the length of the head contained in the length of the fish? Measure from above downward a the deepest part ; this is the tojrtl, of the fish. How many time is « 'hefiX '" ''"*"" ^'""■'"* "" ""«* ""^ *« dTp* of toLri'nl °" *' ^f'' "' "" ■"""• «»•; ^P'"'' 'I'"" out cons'sts of t C'' ""f u"" ""■"""'"^ ' *"' f"""""* consists of flu ray., some of them apinout lay,, or apinea fun- jomted, or i«rtle«U..d), others ^ ray. (jointe'^i or a^'Sei . Study carefuny one of the soft rays, using a lens; spread the fin and hold ,t between you and the light to see the join's, which ap pear as fine cross hues on the soft rays ; count each kind of rays • •d!rhr '^ «""""■"",? """'"i"* "« "y^ This membrane is wUhtt-hf ftld" " ""'' ' ""' "' "" """' -"" -PPO"'"^ P^- Measure along the base of eac". '-n; this is the length of the fin ; extend the fin fully, and meps,;re the length of hTlongest ray , Mb. ,s the high, of the fin. Compare the Jgth and the hfgh, ItJ; '°™ "''"' ""' ^"'^^ "» " ^i"8le ; in others it is amded, formmg two or more dorsal fins. ftj^r'^''^". 'f "" ""^ *"' ^ " symmetrical? The fin in frant of and below the caudai is the anal , corap.,re this fin will, «1h i ' "''°"' """'* '■''"8 '" "■« middle line, are called median, or Tertical, flos. «^s«. ^^■8^' i -r'St ' i -a^ ,^ . ! ..--.■K-^ f^H 5|;l,l£M a^i^ 72 Practical Zoology. immediately in front of the eyes ; it is the anteorbital bone. This and several smaller bones just under the eye are known as sub- orbital bones. 5. Examine the nostrils in front of the eyes. How many are there? Probe them with a bristle tipped with sealing wax, or with the head (never the point) of a small pin ; do they open into the mouth? Do any of them communicate with each other? 6. The flap at the side of the head is the gill cover, and the opening back of it is the gill opening. The upper, hinder piece of the gill cover is the opercle ; along its lower posterior border, and rather closely attached to it, is the subopercle ; in front of the opercle, and below and back of the eye, bonlering the part known as the cheek, is the preopercle. If the margin of this be toothed, it is said to be serrate ; under the preopercle, and in front of the lower end of the subopercle, is the interopercle. The thin membrane below the gill cover is the branchiostegal membrane ; the curved bones supporting it are the branchiostegal tays ; count them. The narrow part of the body between the branchiostegal membranes is the isthmus. 7. Raise the gill cover and examine the gills ; each gill has a central bony arch ; on the hind and outer border of this arch is a fringe of red gill filaments ; on the front and inner border of the arch are the teethlike gill rakers. Are these alike on all the gills? A red streak along the arch, at the base of the filaments, is made by the blood tubes, which bring the blood to id carry it away from them. Thrust a finger into the mouth, and depress the tongue. What effect has this on the gills? What effect on the gill rakers? The slits between the gills, which allow communication from the mouth to the gill openings, are the gill clefts. How many gills are there? How many gill clefts ? After this study of the gills in their natural position, remove the foremost gill, severing it at its upper and lower ends, and note more fully the parts above named, especially the structure and arrangement of the gill filaments and gill rakers ; tear away some of the filaments, and find the groove '^"^in^drm ■2^-551^; W^MK' 1\ Pisces. 73 along the posterior, outer border of the bony arch in which run the blood tubes. Look on the inside of the gill cover for a red spot, the false gill- ^ 8. Observe th6' rheir color? Size? Shape? Is the shell thick or thin? How long from the time of beginning to "si't" till the young hatch out? Does the male ever " sit " ? Does the male ever bring food to the female while she is "sitting"? What proportion of .he eggs hatch ? Do birds ever lay eggs in the nests of other birds ? If so, do they lay them in nests of the same kind of bird? Are the 1* .f 1 io6 Practical Zoology. young able to get their own food as soon as they are hatched, oi are they helpless ? How fully feathered are they when hatched, and are the feathers the same in color and texture as in the parents? Which do they more nearly resemble, the adult male, or the female? On what are the young fed ? Is food ever especially prepared for the young? Do both parents bring food? Do the young require much or little food? Are their eyes opened as soon as they are hatched? How long till they leave the nest? Till they can fly? Are they cared for after they leave the nest? Is the nest a « home "? Do the young return to the same spot? Do they ever occupy an old nest? Do they use any of the material of an old nest ? Migration. — Make a list of the birds that you see remaining here during the summer. Make another list of those that stay with us during the winter. Why do some of these birds go south in winter while others remain the year round? Is the blue jay any more warmly clad than the robin? Or is there some other reason than mere ability to " stand the cold " that leads one to stay while the other migrates? Do you see birds in the fall and spring that are not seen here either in winter or summer? How do you account for these facts? Make a list of birds that are seen only during fall and spring. Do birds migrate singly or in flocks? Or in pairs? Do you see in winter any birds that are not here in the summer? Songs.— How many objects have birds in using the voice? How many distinct kinds of calls has this bird ? Can this bird be said to sing? Do birds have a language? Care of Feathers. — How do birds arrange their feathers and keep them in good condition ? Molting. — When do birds appear brightest a d freshest? What makes the difference? Are all birds alike in these changes? Examine birds to find evidence of change. Senses. — Can birds see well? Hear well? Experiment to test their senses. SI5S^S^^?^5m^^5? Avcs. 107 Attitude. — Note closely the attitude assumed by the bird when at rest. In the case of tree birds observe whether they rest cross- wise or lengthwise on a branch, whether erect or nearly horizontal, whether they prefer large branches or small ones, etc. Where and how do the different kinds of birds spend the night? What birds are astir at night ? Color. — Note the relation of a bird's color to its ordinary sur- roundings. What differences in the color and markings of the male and female? How do you account for these differences? INDOOR STUDY OF BIRDS. While the writer does not wish to encourage the caging of birds, it may sometimes be profitable to keep a bird in confinement for a time to study some of its habits that might escape observation in the free bird. A pigeon or canary will serve very well for this work. Suitable cages should be provided, and the bird should be well cared for. Try to make the bird feel as much at home as possible. Find what it prefers to eat, and learn its habits of eating and drinking. Learn how a bird winks. How does it sleep? How does it perch? Watch the breathing movements. Count the respirations for a minute when the bird is not especially excited. If possible, test the temperature of a bird by holding a clinical thermometer under its wing for a few minutes. (In this experi- ment be careful not to let the bird knock the thermometer out of your hands.) Close all the doors and windows and let the bird fly about the room to see how it flies. Study the actions of the wings and tail. Hold the bird by the body and when it flaps its wings learn what you can of their action. Can you determine definitely how the wing is moved in what we call the "down stroke " ? At what angle is the wing held during this stroke ? In the same way study the up stroke. Hold the bird above you and below you, with the head toward you and with the tail toward you, and note in which direction it fans the air most strongly. In this work make use of canaries, parrots, and other of the com- monly caged birds. Study the birds found in zoological gardens. m::^^mmimjimwm7^^^s^mW io8 i I: "^ m Practical Zoology. To what extent, and in what manner, do birdj evince emotion such as anger, fear, etc. ? Try bringing close together cages con- taining different kinds of birds. How much attention do they pay each other? Try placing a mirror close to a caged bird. Are birds affected by music ? By harsh or loud noises? If an owl can be captured alive, much can be learned from it. Give it a dead bird or mouse. See how it eats. Watch to see the pellets of hair and feathers that it ejects from the mouth after digesting the soft tissues. If a swimming bird can be kept, one may see how it swims. A tame duck may serve well for this. Drop a dead bird into a pail of water. Does it sink ? Pluck the bird and again drop it into the water. Does it sink or float? Explain. How is it that birds keep so warm while flying in very cold air, as in winter when it is below zero? Do birds have parasites? Do they make effort to get rid of them? Can you help the birds get rid of them ? EXTERNAL FEATURES OF A BIRD. How to handle a Bird. — Feathers are delicate structures and, if once crushed or broken, cannot be made over again. Never stroke feathers unless necessary. Above all, never draw a feather through the fingers. This ruins the texture forever. When needed smooth the feathers and deftly rearrange those that are displaced or twisted. When possible pick up a bird by the bill, not by the legs or tail. To take a bird in hand, pick it up by the bill and gently draw it into the other hand, back down. To lay it on the table, draw it lightly from the palm upon the table. To examine the tail feathers, hold the bird with its head toward you and with the thumb and fingers of the two hands take hold of the base of the tail and spread the feathers. Do not take hold of the tip of a feather, and it is seldom necessary to take hold of any part but the base of the quill. To examine the wing quills have the head of the bird toward you, and, passing the thumb and fingers by the front edge of the wing, hold the quills by their bases. Never pull a bird OackT-'-d on the table by the legs or tail. Avcs. 109 The Head. 1. The beak consists of the upper and lower mandibles ; hold the pigeon's head with one hand, and with the other take hold of the tip of the upper mandible ami see if it is movable. 2. Raise the upper eyelid, and look in the front angle of the eye for the third eyelid ; seize the edge of this with the forceps, and pull it backward over the eye. 3. Brush forward the feathers below and back of the eye to find the ear opening; observe the peculiarities of the feathers which cover this opening. 4. Examine the nostrils ; open the mouth and insert the head of a pin into the nostril, and probe, to discover its place of appear- ance in the mouth. 5. With the forceps pull forward the tongue for careful exami- nation. 6. Just back of the tongue is the opening, the glottis, of the windpipe, or trachea. 7. The mouth continues backward to become the gullet. The Legs. 1. Feel of the parts, beginning close to the body, to be sure to find the first division of the limb ; this is the thigh, or " second joint." 2. Below this is the tibia, or " drumstick." 3. The next division is the tarsus ; it is a consolidation of sev- eral bones that were distinct in the young bird ; this part of the bird's leg, then, really corresponds to the tarsus and metatarsus of the human foot, or that part between the ankle and the toes. Where, then, is the true heel ? 4. Bend and extend the toes to find how many bones there are in each. 5. The scales on the front of the tarsus are called scutella; hence the tarsus of the pigeon is said to be scutellate in front ; the back of the tarsus of the pigeon is reticulated. ,fef;« no Practical Zoology. 6. Bend the leg up close to the body in the position it has when the bird settles on its perch. What effect has this on the toes? Note the position of the toes when the leg is straightened. The Tail, 1. Count the quills of the tail; spread the tail to see their mode of overlapping ; make a diagram to show their mode of overlapping as seen from behind ; mpare the middle and outer tail feathers. 2. The feathers which lap over the base of the tail are the upper and lower tail coverts. 3. Raise the upper tail coverts to find the conical tip of the outlet of the oil gland ; press the oil gland to get a drop of oil. 4. In front of the lower tail coverts is the anua. The Wings. 1. Feel of the wing to make out the division into arm, fore- arm, and hand. a. The foremost angle of the wing is called the bend of the wing. To what part of your arm does ihii ./end of the wing correspond ? Just outside of the bend of the wing find the false wing, a cluster of short quills, borne on the thumb. 3. The long quills borne on the hand are the primaries ; count them. The quills on the forearm are the secondaries ; count them. When quills are found on the arm, they are called tertiaries. 4. The shorter feathers which overlap these quills above and below are the upper and lower wing coverts. 5. Extend the wing; compare its upper and lower surfaces; observe the shape of the quills, and the way they overlap one another ; put all these facts together and consider their effect in the down stroke of the wing. What is the result of this arrange- ment when the wing is moved quickly upward ? 6. Extend the wing aad hold it squarely in front of your face. Send a quick puff of breath squarely against the under surface of % ^* ,-, the Avcs. , , , the wrng. What effect docs this have on the individual feather, and the wing as a whole? 7. kei.cat the experiment with the outer surface of the mna notmg .Mrefully how each separate feather is acted on, and what IS the effect on the wing itself. What is the effect of the wing on the air current in each of these experiments? The Feathers. I. Pull out one of the large wing quills and study its parts • the central axis is the shaft ; the expanded part is the vane the' side branches of the shaft are the barbs, and the side branches of the barbs are the barbules. With a lens examine the up^.er and lower surfaces of the vane ; then tear one of the barbs loose from the barbs m front of and behind it. and study it carefully ; again watch closely while tearing two barbs apart, to see how the barbules are related to each other ; now examine the vane of the same qu.U at the very beginning of the vane, near the end that was attached to the wing. What is the difference between the arrange- rnent of the barbs in these two places? Observe the hole in the tip of the shaft ; run the point of a dissecting-needle along the groove ,n the under surface of the shaft toward the base of the shatt. In.s should lead the point of the needle into another openmg, communicating with the cavity of the shaft. Examine this region with a lens, and determine that the two sides of the vane meet at this point. Make drawings of a quill, as seen from above and below, showing all these points. With sharp scissors cut across the feather in the middle of the vane. Look at the cut end ; observe that the vane is attached to the upper edges of the shaft ; compare the place of attachment of the vane to the shaft, with the place of attachment of the wing to the body. Cut part of the wider side of the vane at right angles to the barbs ; with a lens, or a low pov .r of the microscope, examine the edge of this cut. Make ^awings showing these arrangements of the parts of the quill. What are the advantages of such arrangement ? itj.Mf-^ '\'iMXk m m 112 Practical Zoology. - /•-. i t. Take one of the body feathers, and compare it with the quilL In what lies the chief difference? 3. Find a feather that is wholly composed of "down," if there be such ; examine the " down " with a microscope. 4. Pick a small part of the breast, and study one of the fine, hairlike pinfeathers. How does it differ from the feathers already examined? 5. Take a primary feather that is in good condition and set it erect in the hole in the end of a trunk key. The hole should be deep enough to hold most of the length of the free end of the quill, but must not be so deep as to catch the vane and interfere with the free rotation of the feather. Instead of a key you may use a spool, piece of glass or metal tubing, or anything with a smooth hole of suitable depth and width. Now hold the feather, thus supported, vertically before your face and gently blow against it. How does the feather turn? In what position does it remain? Try this with the feather in different positions at the beginning of the experiment. Compare the results of this experiment with the observations made in blowing against the inside and outside of the wing, and explain the advantages of the shape, structure, arrange- ment, and mode of overlapping of the feathers. Try the breath on the secondary feathers as above directed. If you were using a quill for a pen, would it make any difference what kind of a feather you took ? Would it make any difference whether it came from the right wing or the left wing? 6. Study the arrangement of the feathers ; do feathers grow on all parts of the body? A fledgeling shows this point well. Push aside the feathers along the line of the ridge of the pigeon's breastbone and examine the skin ; do feathers grow here? Look for other unfeathered areas. Note how the feathers overlap. 7. Pick the feathers from one side of the pigeon, just to the middle line ; lay the bird on the feathered side, and make a draw- ing, showing (i) the outline of thf feathers, and (2) the outline of the body within. 8. Pick off all the feathers of a.pige or hen and weigh them. M n^mi *i%^.mm. *-*V'U Aves. "3 What is their weight? What fraction is this of the weight of the entire bird ? Use Jordan's A/anua/ of the Vertebrates for finding the names of our native birds. HOW TO PREPARE A BIRD SKIN. Material Needed.- i. A freshly killed bird, in good condition. 2. .Ars-nic, or arsenic and powdered alum in equal parts 3 Cotton. 4. Several sheets of paper ; stiffor paper than newspaper IS preferred. 5. A plate. 6. Scissors. 7- Knife (scalpd, if pos- sible). 8. Forceps. 9. String. 10. Corn meal, to sprinkle on for absorbmg blood or other li(iuid escaping. Process. - First make a wad of cotton and with the forceps push It mto the throat. This is to keep moisture from escaping and soihng the feathers. Do the same with the anal opcnin-r Break both wings as close to the body as possible. Now lay th^e bird on Its back, uith the head toward your left. Part the feathers along the breast and abdomen. Hold them apart with the thumb and fingers of the left hand, while with the scaii^cl you cut through the skin, beginning at the center of the breast and goin- strai"ht back to the anus. Here make a fork in the cut and go around The anal openmg. With forceps hoM up the edge of the skin while loosenmg it with the handle of the scalpel. He careful durin- the whole process to keep the feathers turned back so thev will not be soiled by coming in contact with moist tissues. Sprinkle with corn meal to absorb moisture. Ix)osen the skin on one side down to the thigh, and around the knee. Then with the thumb and fin-er take hold of the tarso-metatarsal joint (heel) and push the knee out, at the same time pressing the skin back so as to expose the knee. Run one blade of the scissors under the bend of the knee and cut through the joint (cut close to the ioint of the scissors to avoid strainaig them) . Cut through the remaining flesh, being care- ful not to cut the skin. Take hold of the leg with thumb and fingers of one hand, thus suspending the whole body. With the thumb and fingers of the other h..nd carefully scrape the skin away from 114 Practical Zoology. the flesh, using the thumb and finger nails. It will not do to pull on the skin, as it is too tender. On reaching the heel remove all the flesh, leaving the bone. Mow pour about half a teacupful of arsenic on a plate. Hold the everted leg over the plate and apply arsenic thoroughly to the skin and the bone. Take hold of the toes and pull the skin right side out again. Repeat viiis with the other side. After loosening the skin well back on the sides, lift the bird, rest the front end of the breast on the table, and turn the tail toward the back. Cut through the bones supporting the tail close to the bases of the tail feathers, but care must be taken not to loosen them. Over the rump there is almost no flesh and the skin adheres to the bone. Especial care must be taken here not to tear the skin. Continue toward the head, turning the skin wrong side out. From this point on, it is very convenient to have a suspended hook by which to hang the bird so you can use both hands in skinning. Otherwise hold the body just in front of the hips. If pressure is applied to the abdomen its soft contents may be forced out. When the shoulders are reached, skin as far as the elbow and cut off" the wings where the bones were broken. When the head is reached great care must be exercised. Proceed slowly, pressing the skin loose with the nails. At the ear, the thin sac, hning the ear down to the drum, must be pulled out. In skinning past the eyes be sure not to cut the eyelids. Continue to the base of the bill. Sever the neck close to the skull, cut out the base of the skull and remove the brain by scooping it out with the handle of the scalpel. Remove the eyes, tongue, and all soft tissues on the head. Now return to the wings and cut away all the muscle from the humerus. It is not safe to try to skin beyond the elbow because it would loosen the secondaries; but the fleshy inner sur- face of the forearm may be uncovered, part of the muscle removed, and arsenic pushed in to poison what remains. Remove any par- ticles of muscle or fat still adhering to the skin. Now lay the skin, still turned inside out, on the plate of arsenic. Roll it over and over in the arsenic and thoroughly rub the preservative on every part of the skin, skull, and other bones, especially at the wings, legs, Aves. JI5 nnd tail. Roll balls of cotton and place in the eye sockets. Now proceed to turn the skin. Placing the thumbs at the base of the skull, use as many fingers as can work in pulling (or rather rolling) the skin back over the head, the thumbs meanwhile pushing. Care and patience must be used here, otherwise a good skin may be ruined. When the skin has been turned back over the head it is easy to grasp the bill, and the entire skin is again outside out. It will probably look rather dilapidated, but do not be discouraged. Shake it, holding by the bill, to get rid of the loose powder and to rearrange the feathers. With forceps or scalpel handle arrange the leathers where needed. Lay the skin on its back. Make a slender roll of cotton for a neck, and with the forceps insert it so it will reach the base of the skull. Next make a body of cotton (you have the model before you) . In inserting the body, see that the feathers around the edge of the cut are not turned in. Draw together the edges of the ventral cut ; it is not necessary to sew, but the feathers should be made to overlap naturally. Cross the feet and tie them together, thus crossed. Make a stiff naper cylinder, and tie or pin it so it will not spread. Slip the skin in, head first of course, taking care that the feathers overlap properly. Especial attention needs to be paid to the region of the shoulders. Attach a label, with the name of the bird, sex, date, locahty, and your name. Lay away in a safe, dry place for at least a week, before removing from the cylinder. Birds may be mounted on a board with wings spread. DISSECTION OF THE PIGEON. In dissecting the pigeon place it on a smooth board about twelve inches wide and eighteen inches long. If a sheet of paper be fastened to the board by thumb tacks, the board may be kept clean for repeated use. In dissecting it is better to turn the board than to turn the specimen on the board. The wings and legs or any flaps of muscle may be stretched out and tacked down to suit convenience at different stages of the work. Pluck the pigeon before dissecting it ; dipping the hird in hot ivater makes this easier. t 4 J ii6 Practical Zoology. 1. Insert a large tube into the mouth and inflate the crop, com- pressmg the neck to prevent the escape of the air. Note the shape of the crop, 2. Beginning at the jxisterior end of the breastbone, cut through the skin along the line of the ridge, or keel, of this bone, and loosen the skin on each side, continuing forward over the crop being careful not to tear the crop; again inflate the crop, and examine it more fully. Observe the fine lines running crosswise and lengthwise in the walls of the crop; these are the muscle fibers, transverse and longitudinal. 3. Loosen the crop from the front of the breast and from the neck. Find the windpipe, or trachea, with its white rings of cartilage. 4. On each side of the neck is the jugular vein. If it does not show distinctly, let the bird's head and neck hang over the edge of the table, and the vein will soon fill with blood. 5. Close to the jugular vein is a white cord, the vagus nerve. 6. Insert the tube into the glottis, and inflate ; observe the swelling of the whole body, and the inflation of the thin-walled air sacs in the hollow in front of the breastbone. 7- Break the bone of the upper arm, the humerus ; cut through the skin and muscles, and push out through this opening the end of the bone next to the body ; note that it is hollow ; slip one end of a rubber tube over the end of the bone, and inflate; what is the result of this experiment? Keeping another tube connected with the windpipe, determine whether air can be sent in through the windpipe and out of the humerus, and vice versa. 8. Slit the skin back over the abdomen to the anus, loosen It well back on each side, and cut through the abdominal wall just behind the breastbone ; inflate once more, and observe the abdominal air sacs. 9. Cut down into the muscle of the breast, close alongside the ridge (keel) of the breastbone, and around the outer border of the breastbone ; thus loosen and raise a great flap of muscle the pectoralis major. Note the nerve and blood tubes entering ■I : Aves. "7 Its inner surface; separate it from a smaller muscle lying under it, which will be known by the glistening appearance of the muscle sheath ; sever the attachment of the pectoralis major to the breastbone, and all other organs except at the extreme front end; here the muscle narrows into a tough white cord, or tendon ; trace this tendon to its attachment to the bone of the arm ; now lay the pigeon on its back in one hand, and pull this muscle backward, noting the effect on the wing! In like manner loosen all the posterior attachments of the sub- clavian muscle which was covered by the pectoralis major, lying in the angle between the keel of the breastbone and the body of the breastbone ; prove its action, this time holdin- the pigeon right side up. Compare these two muscles in size%nd in the amount of work they have to do. The hinder attachment of each of these muscles is called its origin ; and the place of attachment of the tendon to the wing bone is the insertion. Cut through the body wall around the margin of the breastbone, through the ribs, coracoid bones, and wishbone, and entirely remove the breastbone. 10. Covering a considerable part of the abdominal organs is the reddish brown liver. 11. Lift the liver and disclose, at the left of the body cavity a hard mass, the gizzard. Slit the abdominal wall in the middle line back to the anus, push aside any fat that may cover the in- ternal organs, and turn the gizzard to the left of the bird to find where the intestine arises from it ; trace the intestine from the gizzard backward. 12. The part of the intestine nearest to the gizzard is the duodenum. 13. In a long loop formed by the duodenum is a pinkish organ, the pancreas. 14. Trace the intestine, tearing away the fat and the thin walls of the abdominal air sacs, observing that it is held in place by a thin, transparent membrane, the mesentery. 15. The intestine has two short side branches, the ceca. p I i Ii8 Practical Zoology. 1 6. Just before the intestine ends, it widens, forminff the cloaca. 17. Turn the gizzard to the right of the bird; entering it from the front, find a mottled, bulging tube, the glandular atom- ach; pull the crop forward, to shew the connection between it and the glandular stomach. To the right of the glandular stomach is the small, red spleen ; pull the gizzard backward, and cut off the glandular stomach as far forward as possible ; remove the gizzard and intestines. Note the relations of the tubes which enter and leave the gizzard ; open the gizzard, observing the thick outer muscular coat, from which the gizzard is some- times called the muscular stomach. Note also its tough lining; examine the contents of the gizzard ; why does the gizzard have such a thick coat of muscle ? Do all birds have this kind of gizzard ? 18. In front of the liver is the heart, in a thin sac, the pericar- dium. Cut into its posterior wall, and turn the heart forward, to see the dark vein, the postcaval vein, running to it from the liver ; pull the heart backward, to see the whitish arteries running forward from it. The main artery runs forward, and turns to the right before going backward, while in man the corresponding artery turns to the left. Prick a hole in one of the large veins near the heart ; insert the point of a blowpipe, and inflate the heart ; its red, conical part is composed of the ventricles ; the dark base is made up of the two auricles. Tie a thread around the veins at the anterior and posterior borders of the liver, and cut this organ away. 19- On each side are the pink lungs. Pick away the thin membranes bordering the outer hinder borders of the lungs ; look for holes through which the lunga communicate with the ab- dominal air sacs ; look for the trachea. Remove the lungs, not failing to see how dot -ly they are attached to the back, being indented by the ribs. 20. In the hinder part of the body cavity are the dark- colored, irregular kidneys. Tear them away, observing how Aves. 119 the they are composed of several lobes, which fit into the hollows of the pelvis. After removing the kidneys, observe the white nerves extending outward from the sides of the spinal column to pass to the thighs. 21. In front of the kidneys are the two white oval spermaries, in the male ; in the female, the ovary, often showing many eggs in different stages of development. The kidneys and reproductive organs send tubes to the cloaca ; the tube which conveys the eggs from the ovary to the cloaca is the oviduct. 22. Remove the heart, cut off the auricles, and look down into the ventricles ; cut across the middle of the ventricles, and make a drawing of this cross section. 23. Observe the fold of skin extending across the angle be- tween the arm and forearm ; dissect away the skin, and find a membrane within the skin fold. 24. Observe the muscles connecting the hinder edge of the breastbone and the pelvis (which were cut through in opening the abdoTien) ; these are the abdominal muscles. How does the bird perform the act of breathing? Compare the bird, snake, frog, and man, in their modes of breathing. 25. Bend the leg up close to the body, to the position of perching ; what effect does this bending of the leg have on the toes ? How doe.*' the bird stay securely on the perch when asleep ? Dissect the leg to find the mechanism by which the toes are clenched as the leg is bent. 26. Dissect out the tongue, and compare it with the tongue of the snake. 27. Clean away as much as possible of the soft tissues, and keep the skeleton for later study. THE BRAIN OF THE PIGEON. Cut away the top of the skull with a sharp knife, using great care not to injure the soft brain, and make out the following parts : — I. In fi-ont, the large cerebrum, consisting of two hemispheres, which are separated by a deep groove. '■L..&5*r: 1 20 Practical Zoology. a. Behind the cerebrum is the undivided cerebellam. 3. Running backward from the under side of the cerebellum is the spinal cord ; trace it back into the backbone. Make drawings of the brain, as seen from above and as seen from the side. I THE SKELETON OF THE PIGEON. Notice the lightness of the whole skeleton. What part of the pigeon's weight is bone ? Compare the eye cavity with that of man. The lower jaw does not join the skull directly, as in man, but is joined to an irregular bone, which, in turn, joins the skull. This is the quadrate bone. The hole by which the spinal cord leaves the brain cavity is the occipital foramen ; in front of this foramen is a little, rounded projection, the occipital condyl*. Observe how this condyle fits into a cavity in the first vertebra of the neck. Count the vertebrae of the neck, or cervical yertebrae. Observe the consolidation of the vertebrae in the back; note the joint in each rib, and the arrangement for bracing the ribs together. Press the breastbone alternately toward the back and away from it, meanwhile watching the joints in the ribs. The " wishbone " corresponds to the two " collar bones " of man. Alongside the two branches of the wishbone are the cora- coid bones ; what especial need of such bones in this place ? In the wing find, in the arm, the humerus ; in the forearm, the ulna and radius. The hand has only part of the fingers developed ; a little bone, representing the thumb, is present (which bore the feathers of the "false wing"). In the thigh is the femur; in the leg is the tibia ; and alongside it, the small fibula. The bone above the foot represents the consolidated bones of the human ankle and foot as far as the toes. What evidence is there of such consolidation ? THE HEN'S EGG. So place a hen's egg in a basin of water that it cannot roll, mark the upper side plainly, and boil it hard ; keep track of the side that was uppermost. Avcs. 121 T. Crack the shell, and pick it away ; put a piece of it in strong vinegar, or other acid. Of what is the shell made? 2. Note the thin membrane lining the shell. 3. Does the egg completely fill the shell? Where is the air space? Does the lining membrane, in this region, adhere to the shell or to the " white " ? How can a fresh egg be distinguished, without breaking? Does a fresh egg, in water, lie in the same position as when on a table ? What is the use of this air space ? .*.. How is the yolk situated in the white? How in reference to the position during boiling? Compare a number of eggs, to see if there is any regularity about this. 5. Note the round spot on the yolk, where it comes nearest to the surface. This is the germ spot, in which the chick begins to form. 6. With a sharp knife, split the egg lengthwise. Is the white alike throughout ? Is the yolk alike throughout ? Has the yolk a coat? Cut and tear these parts to make out their structure, if they have any definite structure. 7. Boil an egg hard, as before ; mark a line lengthwise around the egg, passing through the point that was uppermost while boil- ing ; carefully brenk away the shell on one side, and with a clean cut remove this half of the white and yolk ; place the other half in the position it had while cooking ; make a drawing of this section, using different colors to show the shell, shell membrane, air space, white, yolk, germ spot, etc. 8. Prop an egg on end, and boil in this position. Is the yolk in a different position in consequence? The white of the egg has interlacing fibers and partitions which keep the mass together; the white cannot be mixed with water till these membranes are cut or broken ; hence an egg, to be eaten raw, should be whipped to break these membranes. The white is not a part of the true egg. In dissecting a bird, the eggs, of various sizes, according to their stages of development, may be found in the ovary. At this time the egg consists of the yolk, with a thin coat ; the white is deposited around this later, during its descent through the oviduct ; ■:- \r 122 1 1 / 1 Pra, lical Zoology. the shell is last formed, and is absent in the case of most animals. In the development of birds all their nourishment, before hatching, must be stored in the egg ; hence its large size. 9. Set a hen on a dozen eggs ; mark the date ; open and examine an egg each day ; if the egg was fertilized, the cells of the germ spot multiply by divibion, and soon take definite arrangement ; at the end of twenty-four hours the backbone is outlined ; during th( second day the brain begins to develop, and the heart appears ; on the fourth day the legs and wings make their appearance as flattened buds ; during the first few days it is hard to say whether the embryo was that of a bird, a reptile, or a mammal ; after this, the characters peculiar to birds become evi- dent, the feathers begin to develop, and, later, the particular kind of bird may be recognized. Egg-laying animals are called oviparous. If the young develop within the body of the parent, receiving nourishment from the blood of the parent, the animal is said to be viviparous; "or, the young may complete its development while the egg remains in the interior of the body of the parent, but quite free and un- connected with it, as in those vertebrates which are termed ovo- viviparous." The study of development is called embryology. Topics for Reports. — Ostrich Farming. Origin of our Domestic Fowls. Origin of the Domestic Pigeon. Varieties of Pigeons. Game Birds. The Guinea Fowl. The Turkey. Hawking. Carrion- eating Birds. Birds whose Plumage is used for Ornament. Birds and Millinery. Laws for Bird Protection. History of the English Sparrow. The " American " Eagle. The Fishhawk. The Whip- poor-will. Introduction of New Game Birds. The Road Runner. The Mocking Bird. The Water Ouzel. Hawks and Owls. Read American Natural History, Hornaday. ,.„„„.„§ "'-»w ■B ^SME^ ^^^^^H fe<~*:' V -^;t^ CHAPTER XII. HAMHALIA. THE RABBIT. Field Study. 1. Learn where to look for rabbits at different seasons. Keep in mind that they are timid creatures and seek shelter, and that they prefer to be near a good supply of food. 2. In what kind of places are rabbits usually found in warm weather ? Look in tufts of grass along hedges and fence cor- ners. Do rabbits seek more sheltered places in winter ? Is this on account of cold ? Or for concealment ? The smoothed and sometimes slightly hollowed place in which a rabbit squats is called its " form." Is this form equally exposed on all sides ? Can it enter and leave in any direction ? Has the direction in which it is headed any relation to the wind ? In what position dors it rest ? Are the ears erect or laid back while it sits in its form ? Does a rabbit leave its form in the daytime, if undis- turbed ? Does it sleep during the day ? Are the eyes open or shut while it sits in its form in daytime? As you quietly ap- proach the rabbit squatting in its form, does it seem aware of your presence ? Does it ever turn the head to see you ? Does it need to turn the head to see you ? Can a squatting rabbit see an object in any direction without turning its head ? Stand near a rabbit in its form and watch its eye. Does it wink? How much of the time is a rabbit in its form ? How much of the time out of it ? Find a rabbit in your neighborhood and frequently visit it t< become as well acquainted with it as possi- ble. On moonlight nights visit a form that you have lately 123 i ] r 124 Prtctical Zoology. s-.^ mi 1 S'y"-* found occupied. Is " Brer Rabbit " at home ? Are rabbits sociable? Do they associate with each other more at one season than at another? Do they seem to have any special means of communicating with each other ? Do they ever give signals of danger? Does one ever call another to share food that it has found? Do they ever aid each other in any danger or injury ? Has the rabbit a voice ? If so, on what occasions is it used ? How do rabbits protect themselves from cold? How does the squatting position economize heat? Do rabbits ever stretch out and lie at full length ? Or are they al- ways bunched up when resting ? In what situations do you find rabbits in warm weather? In very cold weather? In dry weather ? After heavy rains ? Do rabbits ever burrow ? Do they hide in holes ? What are the effects of substituting barbed wire fences for rail fences and hedges ? What is the effect of grubbing out bushes in clearing land for cultivation ? How does the cul- tivation of farm and garden crops affect rabbits ? Is the num- ber of rabbits ordinarily increased or diminished in " settled " districts ? 3. Study carefully the rabbit's modes of locomotion, the slow hopping as well as the running. Study the tracks and be sure you can tell by which foot each track is made, and how the legs are moved. Can you tell by the tracks whether or not the rabbit was frightened ? How far can a rabbit jump ? Are the front and hind tracks farther apart when running than when hopping ? Can a rabbit run hr without stopping? Follow a frightened rabbit ; does it run far in a straight line ? Can you stop a run- ning rabbit by whistling ? Do rabbits ever zigzag when running away ? If so, why ? Are rabbits long-winded r Compare a rabbit and a greyhound in this respect. What reasons for the difference ? Can a rabbit swim ? Does it often take to water ? 4. What evidences do you find in fields and among bushes as to the rabbit's food ? When does it eat ? Does it need much or little food ? Does it usually go far from its form for food ? Mammalia. 125 Does the kind of food vary much with the season ? Does it need to make much lort to get its food? Do rabbits drink water ? Look along creeks and around springs for evidences of their visits. Is it clear that they come to such places to drink ? Does the amount of water in their food make any difference in the amount of water that they take as such? Do they need the same amount of water at ditTerent seasons? What reasons for these differences ? Do they ever suffer for water in severe win- ter weather, when streams are frozen over ? 5. What harm is done by rabbits? Do they do any good? What means are employed to keep them from doing damage ? What means to kill them off ? 6. What are the enemies of rabbits ? In what different ways do they avoid or escape enemies ? Is there any advantage in having the exposed part of the tail so white and conspicuous t What kind of shelter does a rabbit seem to prefer when pursued by dogs ? Do rabbits ever " double " on their tracks? Or re- sort to other tricks to escape pursuit? What is meant by " circling " ? 7. In spring and early summer look for the nests containing young rabbits. They are not conspicuous, being pocketlike depressions lined with fur, and narrowed at the opening, which is at the level of the surface. If a nest is found, watch it closely day and night. If you have a dog, be careful not to allow him to accompany you, for even if he does not disturb the nest while with you, he may return and kill the young. Does the mother stay with the young ? If not, does she remain near ? When and how often does she visit the young, and how long does she stay with them ? Do rabbits have more than one litter in a year ? How many in a litter ? Is their natural rate of increase slow or rapid as compared with most mammals? Are the young of the same color as the adults ? Are there any peculiar markings ? How long does it take a young rabbit to reach full size ? Are young rabbits as speedy or as cunning in escaping enemies as the old ones ? I Si 126 Practical Zoology. HOME STUDY OF RABBITS. 1. For this study use a wild rabbit caged, a tame rabbit, or a Belgian har^-. Study many of the points to which attention has been called in the suggestions for the study of wild rabbits in their homes, such as the modes of hopping, jumping, running, modes of moving the feet, the tracks, etc. Study also the vari- ous attitudes of rest and motion, of timidity, of effort at con- cealment, of hunger, the use of the ears and eyes. Do they give any signals when alarmed ? Do tame rabbits recognize dogs as enemies? After an alarm do rabbits soon become quiet, or does fright have a more lasting effect ? Has a rabbit any means of defense against enemies ? Are the claws ever used when it is attacked by a dog ? Or when it is seized by a man, as when pulled out of a brus._ heap or a hole ? Do rabbits ever fight each other ? 2. Find what food the rabbits prefer. Does a 'rabbit eat much, relatively ? Does it eat rapidly or slowly ? Watch the process of eating. How do the jaws move ? What is the use of the " harelip " ? If possible, in this connection, get a well- cleaned rabbit's skull, and study the teeth and the hinge by which the jaw joins the skull. Why is there a vacant spacj between the gnawing teeth and the grinding teeth ? How are the front teeth kept sharp ? How do the ridges run on the grinding surfaces of the back teeth ? Why is this so ? 3. Is a rabbit's eye large or small, in proportion to its size ? Is its sense of sight keen ? Test this in various ways. What is the shape of the pupil of the eye ? Is it relatively large or small ? Does it vary with the amount of light ? Do you ever see color in the pupil ? If so, in what situations ? Is the iris of the same color in all rabbits ? Compare wild and tame rab- bits in this respect. Test a rabbit's sense of hearing. Is the fact that a wild rabbit often sits motionless in its form, sometimes till actually kicked out, any proof that it did not hear or see the hunter ? What is it probably thinking in such a situation ? aee- i^j'\^ »«v-.3b*— 'g^pr.. I. m Mammalia. 127 Test the sense of smell in rabbits. Does it use this sense in Judging food ? Has it a keen sense of taste ? Try to test the sense of taste without also bringing into use the sense of smell. Test the sense of touch. What is the use of the " whiskers " ? Do you think a rabbit possesses any sense that you do not have, or lacks any that you have ? 4. Are rabbits cleanly in their habits ? Do they wash their paws and faces as do cats ? Do rabbits shed hair ? Do they change their color during tlic year ? Do rabbits have parasites ? If so, what kinds ? Do they do anything to get rid of them ? Can you do anything for such troubles ? Are rabbits espe- cially subject to any diseases ? If so, what are they, and what can you do to prevent disease, or to cure it if it has become established ? is I'' - l EXTERNAL FEATURES OF THE RABBIT. 1, Note the shape and proportions of the body. The ante rior part of the body, distinguished by the ribs, is the chest, or thorax; the soft-walled, posterior part is the abdomen. Note the relative size of the fore and hind limbs. Are the soles of the feet bare or hairy ? How many toes has each foot ? Are there claws ? Are they weak or strong ? How do they differ from those of a cat ? In the hind limb how much belongs to the foot ? 2. How many kinds of hair do you find on a rabbit? The short hairs, making the most of the coat, are the fur. How do the hairs of the fur differ from the other hairs ? Press hair and fur aside till you can see the skin ; is the color the same in the deeper parts as near the outside ? Pull out hairs of different sorts ; has an individual hair the same color from end to end ? Are the different hairs of the same thickness and strength ? Are they all rooted to the same depth in the skin ? Are the hairs glossy or dull-surfaced ? Do they seem oily ? Do they become wet easily ? Compare them with the hairs of a mink or muskrat in these respects. Examine different hairs under a micioscope -i I I I r^^ ■ ■^^i 128 Practical Zoology. ::■•*.:■( What are the qualities thai make some kinds of hair or fur pref- erable to others for making furs, felts, and fabrics ? What are some of the chief articles made of fur after it is separated from the skin ? 3. Examine the eyes and eyelids. Can you find a third eye- lid? Is it useful? 4. Examine the mouth. What is the use of the " hare-lip " ? What is the shape of the nostrils ? Look closely at the inside of the cheek. How many front teeth are there and how are they arranged ? Are they alike in size and color ? Have any of them any peculiar markings ? Examine the tongue and palate. 5. Examine the ears. Hold one of them up toward a good light. 6. Examine the tail. What is its usual position ? Can you make it stay in any other position ? Is its color uniform ? Of what use is it ? Use Jordan's Manual of the Vertebrates in finding the names of all the mammals met with in your neighborhood. DISSECTION OF THE RABBIT. The rabbit should be dissected on a board eighteen inches long by twelve inches wide. This should be covered with heavy manilla or straw paper, fastened down by tacks. The specimen should be a freshly killed, uninjured one, those ob- tained from the markets being usually so mutilated as to be unfit for this work. I. Lay the rabbit on its back, stretch out the front and hind limbs and tack firmly through the feet. Slit the skin in the middle line fron\ the base of the neck to the pelvis and strip it well back along the sides. Compare the walls of the thorax and abdomen. With forceps pinch up a fold of the wall of the abdomen, and with scissors cut through the wall in the middle line. In all this work be careful that the lower point of the scissors does not injure anything within. Cut forward in the middle line to the breastbone. Mammalia. 129 When the chest is first opened, look in to see the position of the heart. The attachment along the inside of the breastbone must be cut close to the bone. When the breastbone is reached, let the cut fork to each side along the line where the bony part of the ribs ends and the cartilaginous part begins. At the anterior end cut across the breastbone and entirely remove it. Extend the slit in the ab- dominal wall to the pelvis. Make slits outward in the middle of each side of the abdominal wall ; turn the flaps outward, pin- ning them down if necessary. There are now disclosed the two parts of the body cavity, the chest cavity, or thoracic cavity, containing the heart and lungs, and the abdominal cavity, con- taining the digestive organs. Between these two cavities, and the sole partition separating them, is the thin muscular dia- phragm. Examine the diaphragm from the anterior side. Can you see that its centra, part is thin and nearly transparent? This is the tendinous part of the diaphragm. Note the shape of the diaphragm as seen from the front. Gently press the liver backward to see the posterior surface of the diaphragm. Take hold of the diaphragm with thumb and finger on its opposite surfaces to learn its thinness, its smoothness and flexibility. Is the diaphragm flat or arched ? How is it arched ? The Organs of the Abdominal Cavity. 1. Observe that the ventral wall of the abdomen is composed of muscle. Its smooth lining is the peritoneum. Feel of it. 2. Study the abdominal organs in their natural position. Filling most of the space of the abdominal cavity is the coiled intestine ; next to the diaphragm is the dark-colored liver ; back of the liver, and partly covered by it, is the stomach ; and in the posterior part of the abdomen is the bladder. 3. Pull the intestine backward, and make out the shape, size, position, and color of the stomach. Observe how the liver and stomach fit together; push the liver forward, and turn the stomach back to find ? white tube entering its anterior surface ; 11 : m^^&smmmamsMi.^w€^::T:^7^m^9mri- ir 130 Practical Zoology. this is the gullet, or esophagus. Just back of the stomach is a small, red body, the spleen. 4. Find now the connection between the stomach and intes- tine. Make a drawing of the stomach, showing its shape and the connections with the gullet and intestine. 5. Trace the intestine; that part which forms a long loop near the stomach is the duodenum. Within this loop is an irregular, fatty-looking mass, the pancreas. Find the pancreatic duct entering the intestine. This is more easily found in the dog. 6. Observe that the intestine is held by a thin membrane in which are branching blood tubes , this is the mesentery ; find its supporting attachment. In tracing its course drag the in- testine out of the abdominal cavity, but do not tear the mese;;- tery. 7. The large, greenish side branch of the intestine is the cecum. All the intestine from the stomach to the entrance of the cecum is the small intestine; that part of the intestine posterior to the entrance of the cecum is the large intestine. 8. In handling the liver remember that it is very delicate and easily torn, also that it contains much blood, and if torn is likely to bleed enough to interfere with the dissection. Do not touch the liver with any sharp instrument ; even the finger nails may tear it unless one is careful. Pull back the liver to see how snugly it fits against the diaphragm. Are the two attached to each other ? Note the divisions, or lobes, of the liver. Tip the liver up and forward to see the stomach, and how the organs fit each other. On the posterior surface of the liver find the dark bile sac. If its duct to the intestine is not readily seen, press on the sac and some of the bile may be forced along the tube, thus showing its course. Later snip a small hole in the bile duct, insert a bristle tipped with sealing wax, and find where the duct enters the intestine. 9. Tie the gullet in two places half an inch apart and cut through between them. Do ihe same with the hinder part of the Mammalia. 131 Harge intestine, the rectum, and sever it. Remove the stomach and intestines, carefully cutting the mesentery along its whole attachment to the intestine, and uncoil the latter. How many times is the length of the body, including the head, contained in the length of the intestine ? Compare the lengths of the small Intestine, cecum, and large intestine. Cut out about an inch of the small intestine in the middle of its course, slit it open length- wise, wash it thoroughly, and examine, under water, its inner surface with a lens, to see the threadlike projections, or villi. In the same way examine a piece of the large intestine. These points may be made out in the intestine of a dog, or from specimens of the calf's intestine obtained from the butcher. Tie the postcaval vein just in front of the diaphragm and just back of the liver ; cut away and remove the liver. 10. Observe the two bean-shaped kidneys attached to the dorsal wall of the abdomen. They are covered by a thin layer of membrane, the peritoneum, which lines the whole of the abdominal cavity, and turns downward to form the mesentery, which, like a sling, holds the intestine in place ; the mesentery also covers, and almost completely surrounds, the stomach as well as the liver. An artery, a branch of the aorta, extends into each kidney, and from each kidney there runs a vein to join the large postcaval vein. There is also a tube, the ureter, from each kidney, running l ^k to the urinary bladder. The Heart and Lungs in Natural Position. I. It should be noted that the heart and lungs collapse when the chest is opened, and that they do not now show their natural size. Slit the skin along the middle of the throat and find the windpipe. Cut a slit in it lengthwise. Insert a tube, connected by rubber tubing with a pair of bellows ; or inflate by the breath. The lungs may be swelled to their natural size, filling the chest. This will also show the natural relations of the heart and lungs. Note how the lungs nearly surround the heart. Compare the 132 Practical Zoology. color of the lungs when inflated with the color when collapsed. Notice the subdivisions, or lobes, of the lungs. 2. In another rabbit, later, open the abdominal cavity without injuring the thorax. Pull back the liver, and the pink lungs will show through the thin central part of the diaphragm. Keeping the eye fixed on the lung, prick a hole through the diaphragm near one side, and note the collapse of the lung. Is the lung of the other side affected by this operation ? Open the chest and note the thin partition separating the two sides of the chest. This partition, the mediastinum, is a double membrane, and the heart lies between its two layers. The following study of the heart and lungs may be made with the heart and lungs of i.ne rabbit ; but if the same organs of a pig, sheep, or calf can be obtained, it will be better to use them on account of their greater size. ' ' Topics for Reports. — The Fur-bearing Animals, such as the Beaver, Otter, Sable, Mink, Muskrat, etc., with Accounts of their Homes, Habits, and the Modes of trapping them. The Hudson Bay Company. The Native Ruminants of North America, such as the Musk Ox, Caribou, Moose, Elk, Deer, Sheep, Goats, and Antelope. The Kinds of Bears native to North America. The Mountain Lion. The Coyote. The Timber Wolf. The Wild Cats. Prairie Dogs. The Weasel. The Badger. Jack Rab- bits. Porcupines. The Buffalo. Read American Natural History, Hornaday. CHAPTER XIII. BIAMMALIA (.Continued). DISSECTION OF THE HEART AND LUNGS. The heart and lungs of a sheep, pig, or calf are better to study on account of their greater size. 1. Hold up the mass by the windpipe, with the heart away from you. The end now uppermost is the anterior end, that below is the posterior end; the lung to your right is the 'right lung, the one to your left is the left lung ; the surface nearest you is the dorsal surface, and that opposite is the ventral surface. 2. Observe the windpipe, or trachea, with the stiff rings of gristle, or cartilage. The thick part of the anterior end is the larynx. 3. Running along the dorsal surface of the windpipe is a soft red tube, the gullet or esophagus. At about the middle of the windpipe separate the gullet and windpipe for three or four inches. Note that next to the gullet the windpipe is soft and yielding, where the gaps of the C-shaped cartilages are filled with muscular and elastic tissue, Make a slit two inches long in this soft membrane. 4. Inflate the lungs as follows : Take a wooden faucet, slip the small end of the faucet into the slit just made in the wind- pipe, and hold or tie firmly, but do not cut off either gullet or windpipe. Inflate through the spout, then shut oflf the air ; if the lungs have not been punctured they should now remain distended. In holding up the lungs, take hold of the windpipe above where the faucet enters, and hold in such a way as to pull the windpipe up and at the same lime press the faucet down. If this is done, it will not be necessary to tie the faucet in. Note 133 m .SK S«S2MK?,ft4i2Erf'-;. - 134 Practical Zoology. (a) the conical shape of the whole ; compare this with the chest cavity, as shown in a skeleton ; (^) how the lungs nearly sur- round the heart ; (r) the concave posterior surface of the lungs where they fitted the convex anterior surface of the diaphragm ; (d) the groove between the dorsal surfaces of the lungs in which the spinal column fitted; («r) the smooth, undivided dorsal surface of the lungs, and their division ventrally into lobes; (/) the relative lengths of the dorsal and ventral surfaces of the lungs. The anterior end of the lung is the apex ; the posterior end is the base. Open the valve of the faucet. »v'hat makes the air go out? Again inflate. Does it require effort to do so ? Why ? Cut off the end of one lobe and again inflate. Does the air escape ? Throw a piece of lung on water. Pinch a piece of lung, holding it near the ear. The smooth, moist, glistening membrane covering the lung is the pleura. 5. Observe a large whitish or yellowish tube running in the groove between the dorsal surfaces of the two lungs. It is usually covered with fat. It may have been cut off short, so that its open end is easily seen near the windpipe. This is the main artery, the aorta. Take hold of its free end and separate it from its attachment to the other tissues, cutting close to it with the scissors, so far as where it arches over the root of the left lung. Now turn the free end forward. 6. Find where the gullet is cut off posteriorly ; slit it open for an inch or two, and note its whitish lining, the mucous coat. The thick red coat is the muscular coat ; it has an inner layer of circularly arranged muscular fibers and an outer longitudinal layer. Beginning posteriorly, separate the gullet from the wind- pipe, cut off the windpipe about the middle, and entirely remove the gullet and larynx. 7. Examine the windpipe ; insert a finger, and stretch it ; note its C-shaped cartilages. Its lining is a mucous membrane. 8. Lay the heart and lungs on their ventral surface, with the posterior end near you. Using the handle of the scalpel as a chisel, clear away any tissue covering the windpipe, and trace it Mammalia. »35 to the lungs ; its branches are the bronchi. How many bronchi are there ? Here are often found small, oval, brownish masses, the lymphatic glands, embedded in connective tissues. Scrape these loose with the scalpel handle. 9. Lay the lungs on their dorsal surface, with the anterior ends toward you. Note how easily the heart may be moved about in its case, the pericardium. Slit the pericardium along its ventral side, and note the smoothness of its lining and of the surface of the heart. Observe the pericardial fluid. 10. Carefully compare the right and left sides of the heart. Running obliquely across the surface of the heart is a groove in which are blood tubes, often covered with fat. The part at the right of the groove is the right ventricle ; at the left is the left ventricle. 11. At the base (anterior end) of the heart on each side are the right and left auricles. 12. Tip up and toward you the apex of the heart. Compare its width and thickness ; compare the ventral and dorsal surfaces as to length, convexity, etc. Press the two ventricles, and com- pare them in firmness. 13. Turn the heart to the left, and examine the right auricle ; find a large, flabby, red tube entering its anterior surface, the precaval vein. Prick a small hole in it, and insert the blowpipe ; hold firmly around the opening and inflate. This shows the outline of the right auricle. Meanwhile, watch closely the dorsal part of the auricle ; the postcaval vein should now be discovered entering the auricle from the posterior region. Look for it out- side, and on the dorsal side of the pericardium, where it runs anteriorly from the diaphragm. 14. Turn the heart to the right, and observe a large, light- colored tube arising from the base of the right ventricle be- tween the two auricles ; this is the pulmonary artery. Again turn the heart to the left, and raise the right auricle ; find the aorta arising from the center of the base of the heart. Care- fully separate the aorta from the pulmonary artery, and trace 136 Practical Zoology. it as it arches over the left bronchus and runs down between the two lungs by the side of the gullet. Clear away any fat or other tissue adhering to it. 15. From the arch of the aorta arise the branches runnin'* to the head and fore limbs. 16. In the same way trace and clear the pulmonary artery. 17. When the fork of the pulmonary artery has been reached, lay the heart and lungs on their ventral surfaces, with the posterior end toward you ; turn the windpipe back toward you, and with the scalpel handle trace the branches of the pulmonary artery into the lungs. Cut them off close to the lungs. 18. Keeping the parts in the same position, trace the pul- monary veins. These are to be found on the ventral side of the bronchi ; their general outlines may be shown by inflating as follows: Cut off the first branch of the aorta as close as possible to the arch, insert one blade of the scissors in this opening, pointing away from the heart, and make a slit two inches long. Insert a cork toward the heart. It should fit snugly, so that air may not escape. For a pig's heart a cork three fourths of an inch in diameter at its larger end is about right. Make a very small hole in the tip of the left auricle, insert the blowpipe, holding firmly around it, and inflate. This should distend the left auricle and the pulmonary veins. With the handle of the scalpel scrape away fat or con- nective tissue that covers them, and trace .them to the left auricle. How many are there ? Cut off the left bronchus close to the lung, and turn the windpipe to the right. Clear the pulmonary veins from any tissue that lies under them. Turn now to the ventral surface of the heart ; lift the ventral margin of the flap of the left auricle, and with scissors cut into the left auricle through the bottom of the groove between the left auricle and the left ventricle. Make a slit an inch long, follow- ing the groove. Pass a probe into the opening, then directly icross the cavity of the auricle, to the dorsal wall of the nuricle. Here are the entrances of the veins from the right Mammalia. »37 and left lungs. Use the finger as a probe, enlarging the open, ing a little if necessary. Cut off the pulmonary veins near the lungs, cautiously avoiding other blood tubes; trim away the pericardium. If the preceding work is interrupted at about this point, wrap the heart in paper ; write your name upon the wrapper, and keep the heart in a cool place for later study. 19. With the scissors slit down one bronchus into the lung, noting its branches. Follow the outside of another bronchus, tearing away the lung tissue with the scalpel handle. Structure and Action of the Heart. — i . Briefly review : precaval vein ; postcaval v**in ; right auricle ; right ventricle ; pulmonary artery ; pulmonary veins ; left auricle ; left ventricle ; aorta. Hold the heart suspended by the end of the aorta, and dance it up and down to show the elasticity of the aorta. Cut off the aorta where the slit was made at the arch, and feel the inner surface. 2. Run a probe into the precaval vein, through the right auricle, and out of the postcaval vein. Cut along the upper side of the probe, and explore the cavity of the right auricle. Feel the inside of the auricle and veins. Observe that the cavity of the auricle extends farther into the heart than the notch between the auricle and ventricle. At the extreme left of the right auricle is the mouth of the cardiac (coronary) vein, which, running around between the left auricle and left ventricle, brings blood from the ventral walls of the heart. Near the mouth of this vein also empty the veins seen in the dorsal wall of the heart. Pick out any clots that may be found. Slit the anterior wall of the auricle, being careful not to cross the groove between the auricle and ventricle, and note the muscular columns within the appendage of the auricle. 3. Cut away the whole of the appendage of the right auricle. Remember that the pulmonary veins from the right lung run very close to the right auricle, and be careful not to cut into them. Tf necessary', pin down the flap of the left auricle, so that water may not enter the left half of the heart in the next ■ -a/.-«- '38 Practical Zoology. experiment. Hold the heart in the left hand, with the ventral surface in the palm, and the tips of the fingers against the right ventricle. Hold the heart under a faucet, or pour from a pitcher, and let the water run first gently, then strongly, through the right auricle into the right ventricle. Watch the tricuspid valves as they float up and separate the auricle from the ven- tricle. Empty the heart and fill it again, and as soon as the valves rise, press with the fingers on the outside of the ventricle. What effect has this pressure? Let the nozzle of the faucet project down between the valves, and again turn on the water. Where does the water escape ? 4. Empty the heart and examine the valves. They will be found lying close against the walls of the ventricle. Note the white tendinous cords attached to the valves. 5. Push the finger past these valves to the very bottom of the ventricle ; from the outside cut through the wall of the ventri- cle at this point, and cautiously cut upward in both directions along the border of the ventricle. Raise the outer wall of the ventricle, and study the valves more thorouglily ; with the scalpel handle raise them from the walls of the ventricle. How many flaps are there ? How are they arranged ? The conical eleva- tions of the muscle to which the tendinous cords are attached are the papillary muscles. How are the valves held in place ? How are they acted on, and how do they act ? 6. Find the connection between the right ventricle and the pulmonary artery ; pass a probe up into the pulmonary artery. Cut away enough of the wall of the ventricle to show the beginning of the artery. Cut off the pulmonary artery just before it forks to the two lungs ; slip over the faucet the end of the artery connected with the heart, and turn on a little water. Watch closely the base of the artery ; turn on more water, and look from below at the base of the artery, to see the filling of the pocketlike semilunar valves. Note their number, shape, and arrangement. What is the effect of the stream of water upon them, and what is their effect upon the stream of water ? : W Mammalia. «39 7. Examine the left auricle, and find where the pulmonary veins enter it. Cut away the lobe of tht^ left auricle ; examine its inner surface, and find the openings of the pulmonary veins. Hold under a faucet, an e the action of the mitral valre, between the left auricle and ...e left ventricle. Insert the nozzle of the faucet between the valves, and again turn on the water. Where does it escape ? Cut off the aorta half an inch from its base, and repeat the last experiment with the water, meanwhile closely watching the semilunar valves of the aorta. 8. Above the pockets of the semilunar valves look for the openings of the cardiac (coronary) arteries, which supply the walls of the heart. Probe them. How many are there ? 9. Pass the handle of the scalpel between the semilunar valves of the aorta into the left ventricle ; it passes back of one flap of the mitral valve. 10. Cut open the left ventricle. Note the strong muscular columns, the strong papillary muscles ; the mitral valve, though ending in two main flaps below, is continuous at the top. The valves between the auricles and ventricles are sometimes called the auriculo-ventricular valves. This may be shortened to " aur- vent " valves, and will be easily remembered, as the parts of the word indicate the two cavities between which the valves lie. Compare the walls of the right with those of the left ventricle. Why this difference ? Note the partition between the ventricles. Is there any direct communication between the right and left halves of the heart ? 11. Slit open the aorta between two of the semilunar valves, and study the valves more closely. In the middle of the free border of each valve note the little thickened point, the corpus arantii. When the valves close, these three little points fill up a small, three-cornered opening that would otherwise be left between the valves. These valves are sometimes called the ventriculo-arterial, or, for short, the " vent-art " valves, as they lie between the •, ntricles and the arteries. Again examine the cardiac arteries. I40 Practical Zoology. 12. In another heart, carefully cut around the base of the pulmonary artery, tie its outer end tightly over the end of a glass tube or spool, and show the action of the semilunar valves, by blowing suddenly and forcibly into the tube. To keep the glass tube from slipping out, slip an inch of thick rubber tubing on the end of the glass tube, so that the rubber tube is even \vith the end of the glass tube. The valves work better when moist and flexible ; therefore keep the preparation standing in a jar of water until it is to be used. Slit open the artery, and study the valves. 13. Longitudinal and cross sections of a frozen heart are instructive. The Distribution of the Arteries and Veins in the Cat or Rabbit (injected). — Directions for injecting are given in suggestions "To the Teacher." i. The main artery, the aorta, is a thick- walled tube, springing forward from the center of the base of the heart. It soon arches over to the left, and runs along the middle of the dorsal wall of the chest cavity. 2. At the bend, or arch, the aorta gives off two branches (three in man). The first of these soon subdivides, giving off a branch to the right fore limb, the right subclavian artery ; two branches running along the side of the windpipe are the right and left carotid arteries. The second branch of the aorta runs to the left fore limb, and is the left subclavian artery. 3. During its course through the thorax the aorta is called the thoracic aorta. Trace it to the point where it runs through the diaphragm. It then becomes the abdominal aorta. Turn the stomach and intestine over to the right, and observe the ab- dominal aorta nmning along the dorsal wall of the abdomen. Just posterior to the diaphragm, a branch is given off which subdivides, and gives branches to the stomach, liver, and spleen. Farther back a large branch is given on" to the small intes- tine. Follow it as it branches into the mesentery. This is the anterior mesenteric artery. Find the branches of the aorta that lead to the kidneys, the renal arteries. Some other branches may Mammalia. \.'i be s«en, and finally the aorta divides into two la^ge branches, the common iliacs, supplying the two hind limbs. 4. Turn the stomach and intestines to the left, and observe the two veins running forward from the two hind limbs. These are the two external Uiac veins. By their union they form the postcaval vein. 5. Observe the veins from the kidneys, the renal veins. 6. Trace the postcaval vein to the liver. Observe the vein that gathers the blood from the intestine, the mesenteric vein. This vein is joined by a vein from the stomach, the gastric vein, one from the spleen, the splenic, and one from the pan- creas, the pancreatic ; together these form the portal vein, which empties into the liver. Unlike other veins, the portal vein subdivides, distributing the blood into the liver. The blood thus distributed through the liver is re-collected, and by the hepatic veias joins the postcaval vein, close to the diaphragm, and almost wholly concealed by the liver. 7. The postcaval vein passes by the liver, through the dia- phragm, and on to the right auricle. 8. On removing the skin of the neck, there should be found on each side the large jugular vein. Each of these is formed by the union of the internal and external jugular veins. 9. Just before each jugular vein enters the chest cavity it is joined by a vein coming from the corresponding fore limb, the right and left subclavian veins. The union on each side forms the innominate vein. The two innominate veins, uniting, make the precaval vein, which enters the right auricle. In the rabbit there are two precaval veins. THE VALVES IN THE VEINS. Dissect back the skin from the throat of the ra )bit, cat, or dog, till the jugular veins are well exposed. Let the head of the animal hang over the edge of the table ; note that as the blood presses back toward the head it causes marked bulging at certain points ; with the handle of the forceps slightly stroke 142 Practical Zoology. the vein toward the head, watching the bulgings. Dissect out the jugular vein from the head to the shoulder ; insert the nozzle of a syringe, first into one end and then into the other, and show the effect of forcing currents in each direction. Cut the vein open along one side, pin inside out to a piece of a shingle, and examine the thin, pocketiike valves. Test the elasticity of the vein. Note the smoothness of its inner coat. Remove a piece of an artery and experiment in the same way with it. THE KIDNEY. The structure of the rabbit's kidney may be made out by the following directions, but the sheep's kidney, being larger and essentially similar, may be conveniently used. If the sheep kidney be used, its dissection may be made later. 1. Observe the depression in the inner border of the kidney, the hilum. 2. From the hilum trace a slender white tube, the ureter, back to the bladder. Find also the renal artery and vein, branching as they enter the kidney through the hilum. 3. With a sharp knife split the kidney like a bean, beginning at the outer border, stopping the cut when a white membrane is reached near the hilum. With forceps pry about to explore the cavity between this white membrane and the body of the kidney. Note the branches of this cavity into the kidney. Note also the extension of the white membrane into these cavities. Make out that the blood tubes extend tlirough these white branches to the outer parts of the kidney. Count these branches. 4. In the center of the white membrane find the opening of the ureter, by which the urine is conveyed to the bladder. Pass a probe through this opening into the ureter. 5. Note the difference in color of the outer and inner parts of the kidney. At the line of change of color find where the blood tubes first branch into the real kidney substance. Examine carefully the cut surface of the kidney to see its markings. ^•Wi %•*!■?!? Mammalia. '43 6 Make a drawing of one half of the kidney as seen from the inside, showing all the above-named points. 7. Cut across the middle of the kidney at right angles to its length, and make a drawing of this cross section. The projec- tion of the kidney substance into the cavity opposite the ureter IS the urinary pyramid, and from its apex, from many fine holes. issues the urine which the kidney has secreted from the blood. DISSECTION OF THE HEAD OF A RABBIT. 1. Remove the skin from the head. Observe the cartilages of the ears and cut them off close to the head. 2. Below and back of the ear is an irregular pinkish mass, the parotid salivary gland. The duct which conveys the saliva runs forward over the cheek and opens on the inside of it The duct IS usually hard to see, as it is thin-walled, slender, and of about the same color as the sheaths of the muscles on which it hes. It may easily be mistaken for a nerve, several of which should now be in sight. This duct is much more readily traced m a dog. With sharp, fine-pointed scissors cut into the edge of the duct, insert a black bristle, and push toward the front 3- Just back of the angle of the lower jaw find a roundish body, the submaxiUary salivary gland. Its duct runs forward mside the lower jaw and opens under the front part of the tongue. It is rather difficult to trace in the rabbit, but is much easier in the dog. 4. The infraorbital gland is just below the front of the eye and its duct opens near that of the parotid gland 5. The sublingual gland is a small, slender gland close to the mside of the lower jaw in front of the base of the tongue, and its duct opens near that of the submaxillary. 6. Observe the muscle that covers the outside of the back part of each lower jaw. This is the masaeter muscle. Place the fingers on the angles of your own jaw'and note the action of the masseter muscles in shuttinjr the teeth firmly together. In the rabbit note the attachment of the masseter muscle to the w^'^gri^mm'wmPifffsvmm^^ii^^iimrM -]'• 1 144 Practical Zoology. under edge of the cheek bone. Trim the muscle entirely away, noting carefully all its connections, 7. The temporal muscle is attached to the thin wing, or process, of the jaw in front of the hinge, and passes up inside of the arch of the cheek bone and spreads over the temple. The shortening of the masseter and temporal muscles is what shuts the jaws together. Remove this muscle, observing closely all its relations. Place the tips of the fingers on your temples and shut the teeth firmly together ; the hardening of the tem- poral muscle is felt. 8. After removing the submaxillary glands a muscle may be found on each side attached to the inside of each half-jaw near their union in front. These are the digastric muscles; prove that when they she rten they depress the lower jaw. Trace these muscles to their connections at both ends. Review these points till you see clearly how the jaw is opened and shut. 9. Cut away the soft membrane on the side of the mouth. Note its inner surface. Split the two halves of the lower jaw apart in front by a strong knife used from below. Entirely re- move one half-jaw, noting a muscle attached to the inner surface of the back part of the jaw. Look at its inner side for the hole where] the nerve and blood tubes entered it. Do you find a hole ^n the outside of the jaw ? 10' Examine the tongue ; how much of the space does it fill when the mouth is closed ? What is its shape ? The projections on its surface are called the papillae. 11. Examine the roof of the mouth. Press against it to find whether or not there is bone back of the soft membrane. This is the hard palate ; note any markings or peculiarities of appear^ ance. Follow it back till you reach the soft palate, which has no bony wall just beyond it. Follow the soft palate back, cutting away as much a& is necessary of the lateral wall, making the opening cut along the level where the teeth meet. 12. Back of the soft palate is the cavity called the phar3mx; it is a continuation of the mouth. Trace forward the passage Au* WL jm^4»Jl .•Sir- f' ' "i Mammalia. «45 from the pharynx, over the soft palate, into the nasal passaw. above the hard palate. Trace the pharynx downward Td backward to two passageways ; the farther one is the gullet or food tube, leading to Ihe stomach ; the nearer opening h the glottis, or opening to the windpipe, leading to the lungs Be- tween the glottis and the base of the tongue find the epiglottis a spoon-shaped cartilage, which most of the time stands up close to the base of the tongue ; but when food passes it turns down and back and covers the glottis, so that food does not enter the air tube. Study these parts and their movements till their action is clear to you. 13. Split the soft palate and turn the parts aside to find on the sides of the pharynx the small openings of the Eustachian tubes, that lead outward on each side to the cavity of the middle I i CHAPTER XIV. MAMMALIA {Concluded). The Brain and Spinal Cord of the Rabbit. — It will be found helpful to have at hand a well-mounted skeleton of a cat or rabbit. Note carefully {a) the cavity of the cranium, ib) the cavity in the spinal column, and {c) the sides of each neural ring where the bone is to be cut by the bone forceps, as indi- cated in Figure i. 1 Fig. I. Diagram for dissecting Spinal Cord. I. Cut along I a with cartilage knife, a. Cut along 3 a with cartilage knife. 3. Cut along 4 with bone forceps. It is best to remove the skin completely before beginning the work, as the fur is likely to be troublesome. Cut away the muscles from the back of the neck and along the sides of the backbone. This can be done rapidly by making long, deep cuts with the cartilage knife along the sides of the backbone, in the planes indicated in the accompanying figure. 146 :-.ir*'-s^¥ ■ yfei' is^rx .. :U l^it.'TW-ii^ "' Mammalia. H7 Between the skull and the first vertebra is a space covered by a thin membrane, through which the spinal cord may be seen. Carefully cut through this membrane, and insert the point of one blade of a pair of bone forceps at one side of the spinal cord. Cut through this side of the arch of the vertebra ; repeat this on the other side, and so on, through the whole length of the spinal column, removing the dorsal parts of the vertebra;, held together in one strip by the connective tissue. The bony cavity in which the spinal cord lies is the neural cavity. The work may be more easily done if the rabbit is supported on the edge of a short piece of •♦ two by four " scantling nailed to a baseboard eight inches wide and a foot and a half long. Now look for the spinal nerves, which leave the spinal cord in pairs, right and left, between the successive vertebra;. It will probably be necessary to cut away considerably more bone to expose the nerves. The whole of this work requires the utmost care and patience, and involves a good deal of hard labor. Note carefully the variations in the diameter of the spinal cord in its course. The anterior swelling is called the cervi- cal enlargement, and the posterior is the lumbar enlargement. When the spinal nerves have all been laid bare, c< int and compare them in reference to : (i) size ; (2) intervals between successive pairs ; (3) angles at which they leave the spinal cord. Carefully cut away the bone around some of the nerves in the region of the shoulder, and find the two roots by which each nerve is connected with the cord, one nearer the back, the dorsal root, and one nearer the ventral surface of the body, the ventral root. Trace these two roots, and note that they unite and form a spinal nerve. On the dorsal root, just before it joins the ventral, is a small swelling, the ganglion of the dorsal root. In the region of the shoulder carefully trace several of the nerves as they unite to form the brachial plexus, from which nerves supply the fore limb. In the region of the hips trace several of the spinal nerves I ift-^t, 148 Practical Zoology. to their union in the large Klatic nerve, which runs down the thigh. Turn now to the head, and cut into the bone between the eyes. Cautiously working backward, the whole of the brain may be unroofed. Great care must be exercised, for here we have one of the softest of the tissues of the body lying very closely beneath one of the hardest. It is possible to do this work with a strong knife, but the bone forceps save a vast amount of extra work. The bone must be broken away bit by bit. Compare the color of the brain with that of the spinal cord. The tough membrane covering the brain is the dura mater. The fore part of the brain is the cerebrum. Note the groove separating it into the right and left hemispheres. Observe the ridges, or convolutions, of its surface. The prolongations of the brain between the eyes are the olfactory lobes. Back of the cerebrum is the cerebellum. Look at the human skull to see whether there is a bony partition corresponding to that which separates the cerebrum from the cerebellum in the rabbit. The widening part of the spinal cord within the skull is the spinal bulb. Make a drawing of the brain and spinal cord, showing as many as possible of the points above noted. If desired, the brain and cord, with a short part of each nerve, may be re- moved from the body and laid on a cushion of cotton in weak alcohol. Directions for preparing the Brain of a Cat or Rabbit. — Direc- tions have been given above for uncovering the brain. To remove the brain, it will be necessary to cut through the tough dura mater that covers it. Removing this, there will be found an inner covering, the pia mater, a membrane richly supplied with blood tubes, from which the brain gets its nourishment. After the dura mater has b«en removed, the anterior end of the brain may be gently lifted ^*^^ ^T '■*' 'JB^' iM' Mammalia. 149 with the handle of the scalpel and the under surface studied following the directions in finding the cranial nerves The brain may be studied while it is fresh, but it is more easily handled after it has been hardened. Lay the brain in weak alcohol, about twenty-five per cent. It should rest on a layer of cotton, otherwise it may be very much flattened bv its own weight, and get a good deal out of shape. Later transfer It to fifty per cent alcohol, and then to Seventy-five per cent • or use a solution of alcohol and formalin as follows : ninety-five per cent alcohol, sixty parts ; two per cent formalin, forty parts The hqu,d need not be changed if used in sufficient volume' When It IS well hardened, it may be sliced with a sharp scalpel as directed. ^ The Brain of the Rabbit (A/coAo//, Specimen). - The brain of a cat or dog is better, being larger. Take a brain well hardened and review the parts as named above. It is very desirable tJ have a specimen in which the arteries have been injected 1. Press down the cerebellum, to see the deep groove between it and the cerebrum. The thin membrane covering the brain and dipping into the grooves is the pia mater 2. Press down the spinal bulb and tear away the pia mater where it passes from the cerebellum to the spinal bulb Note between the bulb and the cerebellum, a space covered by a thin membrane Cut into this membrane ; the cavity is the fourth v«itricle of the brain. Observe the two ridges bounding the sides of the fourth ventricle. At the point of their divergence observe the opening of the central canal of the spinal cord ' 3- Gently separate the cerebral hemispheres, and note the transverse band of white fibers connecting them nf t ^''^"'•'? *^^ ""'^'' '""^^^ °^ ^^^ ^'^'""^ a"d find the roots of the cranial nerves. ^e Crwial Nerves. - i. The olfactory lobes (probably cut or broken oif) extend forward from the fore part of the cerebral hemispheres. 2. Note that the optic nerves join each other before reaching ISO Practical Zoology. the brain. Only the first and second pairs of cranial nerves directly enter the cerebrum. 3. Back of the optic nerves, near the middle line, is the third pair of nerves. 4. The fourth pair extend up on each side into the groove between the cerebrum and the cerebellum. 5. Back of these is the larger fifth pair. This pair supplies part of the face, and sends branches to the teeth. It is the nerve affected in neuralgia of the face. 6. Back of and inside of the fifth pair is the sixth pair. 7. The nerves of the seventh pair are larger, and are farther back and outward. These are the facial nerves, and control the muscles of the face and the facial expression. 8. Close to the seventh are the eighth, or auditory nerves. 9. The ninth, tenth, and eleventh arise close together, farther back and well up on the sides of the spinal bulb. 10. The ninth supplies the back of tongue and the pharynx, and is called the glosso-pharyngeal nerve. 11. The tenth pair pass down out of the brain cavity, give off branches to the pharynx and larynx, and are distributed to the heart, lungs, and stomach. These are the vagus nerves. 12. The last pair of cranial nerves, the twelfth, arise near the middle line of the spinal bulb. This pair supply the muscles of the tongue, and are called the hypoglossal nerves. Draw the brain as seen from below, showing all these nerves. Separate the cerebral hemispheres, and with a sharp knife split the brain lengthwise in the middle line. Make a drawing of the inner face of one half. Note the branched appearance, the arbor vita, of the cerebellum. Trace the cavities of the brain. THE LEGS OF THE RABBIT. Most of the following structures may be made out from a shin bone of a sheep, readily obtained from the butcher. I. After removing the skin from the legs, observe the muscies, .: 'JRi'T^: Mammalia. ,., '^Tt\' *'"• e"»*™i"S •nembrane, the miud, ,|„.u, Study the shapes of the muscles. AM^t '!"'}''"^ ""'•'' °' "^^ "■'''" »'''"''« ">» heel cord, or Achilles tendon, passing upward from the heel along the back of the leg. The tendon is the termination of the cflf Is dc which hes on the back of the shin bone. Trace this muii; toward the body, and note that it passes between wo rgefl^ the th,gh. Separate these two flat muscles, using mainly the handle of the scalpel. Remove any fat that may be in the wlv •cUtic nme. Trace th.s nerve toward the body, cutting awav any muscles or soft tissue covering it. How far'can you 7^ It? Now follow the nerve outward. Is it of the Le sizi throughout? What are its relations to the muscles? ends e^'' T^hf H^ u" ^^","!"'^''' "^ ^"ape, color, covering, ends, etc The end by which ,ts tendon is attached to the hee bone .s the ta«,ti.n , the other, less movable end is the ^ From what bone does it arise, and by how many tendons ? "ui across the muscle at its thickest part, the belly of the muscle and study .ts structure. Note that the tendons at the ends l,h,k. T. "° ™"«""°"' "ith the muscle sheath and towa d ,hTl!^°"' T"'"^ !''""«'' ""= """^'^- P"" ">» tendon tow ad U,e body; this straightens, or exte-ds, the foot, the calf lie .h ,^ '"•*" """"'= "" '"' '™"'°' 'he ^hin bone, P~ve that Its action ,s to bend, or flex, the foot. I. is a flexor i-ind Its origin and insertion. 4. By further dissection find > ow the different movements of the toes are effected. which oils the joint Rubadropofitbeuveenthethumband^nger. hot?. '"'2 S.'''''"'"^ ^""^^ ^^'^'^ '^^'d the ends of the bones together. These are the ligaments. Carefully studv their arrangement and uses. 152 Practical Zoology. 7. Note the thin layer of autlUge over the ends of thn bones. Feel of it. Cut it. What are its properties, and what Its uses r 8. With the forceps strip off a little of the muscle sheath from one of the muscles and note the color of the latter. Cut one of the muscles across in its middle and examine the cross section Lach fiber has its own thin sheath, and the small bundles of fibers have separate sheaths, which make the white markings seen m chipped dried be-.-f. 9. Tear oflF a few fine fibers of the muscle, mount on a slide m water or glycerine, cover with a cover slip, and examine first with a low and then with a high power. The fine cro.s- markmgs of the fibers give to this kind of muscle the name of •triped, or striated, muscle. 10. The covering of the bones is the periosteum. Thoroughly clean one of the long bones and make a drawing of it. Saw it m two lengthwise and make a drawing of the surface thus ex- posed. Put a bone into weak acid, and after a day or two com- pare it with another that has been burned. THE MUSCLES OF THE EYEBALL. With bone forceps, or a strong knife, cut away the bone at the outer angle of the eye socket of the rabbit (almost any mammal W.11 serve for this, but the bone is so thick in the calf or sheep that it will be difficult work without the aid of a good pair of bone forceps). 1. With scissors trim away the white membrane around the front of the white of the eye ; this was continuous with the lining of the eyelid, and is the conjunctiva. 2. Find a muscle running along the roof of the eye socket, which passes over a loop of tendon, near the edge of the orbit,' and turns outward to its attachment to the top of the eyeball.' This is the superior oblique muscle. 3. Beneath the eye find a muscle, having its origin in th(' inner front part of the socket, and passing outward to be r Mammalia. •5J nternl «ctu., and wternid «cta., ar. attached to the top l"! torn and M.les of the- cyehall ; find the origin „f .he.se 5 t' of the superior oblique, a. the botton, „f the eye ,00^, Within M ■"/,'^"P"''.'""»^l^'--'"»ched .0 the back of the eye Within hLv ,„ .•!..ri,,|rical optic nerve. „cnn ( „. ^ ^' t e , ye.— Uu; eye of the rabbit nay be useri, I 111 u ^i ^i fh(. (j^ ')etter. it ' "''^'" '^'^" ''*'''' ' '"^ P^f^of the eye, the cornea. Note V"To, ■ ;,' '' " ^"" r' "' '^^' '""^•' ^"^''^* «^ »he eyehds. whl^h r " "''"'•"''"^'^^^'h'^'^h membrane, the conjunctiva the eJei; :' ''t 7' '"' ^^^"^ '""^ cornea, separates fron tne eyeball rn f' < .vard and line the eyelid 3. The several muscles of the eyeball, a mass of fat which forms a cush on .' • the eve anrl r.th... «; u . , . ^ *^>^'^"^ ot"<' ti.ssue, shoud be tr mmeH away, leavmg the optic nerve. irimmed 4. Place the eye in its natural position, and make drawin^^s of ^. as seen from the front and from one side, naming th^ section, tach member of the c-li«» i;hn..u i, cli«s«.t T„ 1 , ihould have an eye to dissect To supply a large class it is best to send to a slaurfi- . ring house m the nearest large city. ,f ,he eye muscles an 1 other external parts have already been studied' i, will not be necessary to remove the muscles and fat around the eye in to support the eye during dissection. The eve may be con- ^niently dissected on a small piece of board or shingle; and f It IS desirable to turn the eye, it is better to do so by turning ec. oT • r "" '^l "^"^"^ ^"^''^ '» ""= -PP«« -'I 'he dis section may be injured by trying to move it Caution. - After the eye is opened be careful oot to compre.. .■;?rsr,^!S5ai3*«^1il?- »54 I'i! u '.rt Practical Zoology. it. If the eye be held In the hand while trying to cut its tough outer "oat, the jellylike contents are easily squeezed out, ruin- ing the dissection. Let the eye rest on the board aU the time, and after first cutting into the cornea it is not necessary nor ad- visable to touch it with the fingers. When studying the lens, be very careful to tip it up gently and compare its front and back surfaces before removing it from the eye. 1. Lay the eye on the board, with the cornea uppermost. Hold the eye firmly with the thumb and fingers of one hand ; with the thumb and forefinger of the other hand hold the blade of the scalpel half an inch from its tip ; with a steady motion push the blade horizontally through the cornea, near its edge. 2. The liquid in the cavity back of the cornea is the aqueous humor. 3. Slightly enlarge the cut horizontally ; then with the forceps take hold of the upper edge of the cut, and with the scissors cut around the margin of the cornea and remove it. 4. The dark membrane now exposed is the iris. Pinch the eye slightly at the sides to make the iris show more distinctly. The hole in its center is the pupil. With the forceps raise the edge of the iris around the margin of the pupil to see that it is here unattached to the structures underneath. Observe the color and markings of the iris. 5. From one end of the pupil cut outward to the outer margin of the iris ; then cut around its outer margin and re- move it. Observe the color and markings of the posterior surface. 6. The body now laid bare is the crystalline lens. Touch it. 7. Lay a piece of newspaper i-/ose to the eye, on which to receive the lens, which sometimes pops out suddenly. With a very sharp blade make a quick, light gash across the surface of the lens to cut through the thin coat which envelops it, the lens capsule. Usually the lens may be made to come out by applying gentle pressure to the sides of the eye with the thumb and finger. If not, enlarge the opening thus made, and carefully pry up the ^a^S^^mm ksM^^itp^Jk ^*. ki'f^'T':,lL"r3lSH! Mammalia. ^^ ^.trr &;tt tzr i:^:^ f«>» one Side. L^n, '^d'Z:: .ZMZZT' """ ^' ^«" rJ;/^!"'"":"'" '"""""« ">' ''"P »f eye coatin. as di reeled belo«r, be extremely careful not to drag the dear Ln nke v„reous hu,„„r. The strip must „ot be unwound 'i. peeling an apple, but must be left in rtace Th-T . ' '" lifted gently by the forceps, and he deT ieHvl ke """" '' be cut through horizontally, ^i.h the scissors /«'h ^T """' now cut outward about one half of an inch from 'edl^fT round^diating h.c. ridr rcL^^rrr '"'^ -- "^ .o. The substance^miinr he rema,„d r of I"'" ' ' the Titiwus humor. remainder of the eye cavity is ne^e JilT'' "*" "'''°"' '''"^"'' "" '""""-^^ of the optic enter fZ above * ""^ '" ' *'"''°'' "> '« "« "g"" .'!' wt,"";? T' ~" "'■ "•' ^>" » "-^ •""Otic cct. 13. Inside the sclerotic is the dark choroid coat the L.„ T":- ""'■''' •""''P'"^™'. pinkish or whitish coat is hTytrink^d id'r "?' "r"'"" ■' '^' p""'""* be™: i- f; ii h ir .56 Practical Zoology. Drag out the vitreou« humor and note the soft whitish oi pinkish retina; observe that it is a continuation of the optic nerve. Tear away the retina, noting its consistency. Note the color and luster of the inner surface of tlie choroid coat. The dark layer on the inside of the choroid coat is the pigment laye- (outer part) of the retina, which adheres to the choroid, and is torn loose from the rest of the retina. The reflection of light from this surface of the choroid coat causes the color seen in the eyes of some animals. Turn the remaining coats inside out, and tear the choroid coat from the sclerotic. Observe the blood tubes passing from one to the other. I DISSECTION OF THE LAP.^'NX. The Larynx of the Calf. (As the larynx of the rabbit is so small, it will be better to examine a larger one.) — i. The front of the larynx is readily distinguished by the projection of cartilage known as the Adam's apple. 2. Along the back of the larynx runs a thick, muscular tube, the gullet, with a whitish lining, the mucous membrane. 3. Trim away the muscles and other tissues from the front and sides of the larynx. The large cartilage forming the greater part of the front of the larynx is the thyroid cartilage. 4. Observe the band of muscles attached to either side of the thyroid cartilage and passing horizontally back around the gullet or esophagus. Cut away this muscle as completely as possible, and entirely remove the gullet. Note that the whitish or yellowish mucous membrane which lines the gullet is continuous with the lining of the larynx. Study now more fully the shape of the thyroid cartilage. 5. Back of the upper part of the thyroid cartilage, covering the upper entl of the larynx, is the arched epiglottis. Feel of it to learn its consistency. Press it upward and forward, then downward and backward ; observe that it now covers the entrance to the larynx ; note the position it takes when released. Mammalia. '57 6. Just back of the upper angle of the thyroid cnrtil.v.e finci a muscle connected with the base of the epiglottis; pull this tZ^t\s "' '"''^^ '^''' ''' shortening produces on the 7- Under the thyroid cartilage in front observe a narrow ring of cartihge not much wider than one of the rings of the trachea Move this up and down to prove that it is distinct from the thy- roid. This is the cricoid cartilage. 8. Observe the sheet of muscle passing from the cricoid to the thyroid. Again move the cricoid toward and from the thyroid. What does this muscle do? Cut away this muscle from one side and see that the cricoid cartilage widens as it passes backward. How are the cricoid and thyroid hinged together? 9- Projecting upward and backward from the top of the larynx are two curved yellowish cartilages, the arytenoid cartilages. Move them about to see that they are movable, and that they rest on the upper edge of the back part of the cricoid cartilage 10. Move the arytenoid cartilages backward and forward, mean- while watching the inside of the larynx from its lower opening The projecting ridges, which meet just back of the Adam's apple are the vocal cords, \\hat effect is produced on the vocal cords by the movements of the arytenoid cartilages? 11. Obser%'e the connection of the thyroid cartilage with the cricoid by means of a downward projertion of the former Cut away all of this half of the thyroid cartilage. Notice the slender hyoid bone loosely connected with the upper horn of the thyroid. 12. Examine now the muscles which move the arytenoid cartilages. a. On each side of the posterior surface of the cricoid is a muscle passing upward to be attached to the corresponding arytenoid ; this is the posterior cricoarytenoid muscle. Dissect it loose from the cricoid at its origin below. By pulling, determine its action on the arytenoid, and through the arytenoid on the vocal cord ^. Arising from the upper edge of the side of the cricoid cartilage, and passing upward and backward to the arytenoid is ijS Practical Zoology. the lAteral crico-arytenoid muscle ; cut it away at its origin close to the cricoid, and demonstrate its action on the arytenoid cartilage and vocal cord. c. A broad muscle arising along the whole length of the angle of the thyroid, whose fibers converge to the arytenoid cartilage. This is the thyr^ -arytenoid muscle ; cut it across near its origin, dissect it loose, and by pulling it toward its origin prove itt action. d. On the posterior surface of the arytenoids is the small arytenoid muscle. 13. Cut between the arytenoid cartilages and remove one of them. Examine the joint between the arytenoid and cricoid. Note the synovia lubricating the joint. Trim away the muscle from the arytenoid cartilage and study its shape more fully. Fit it again to its place, and recall the motions given by each muscle. 14. Now examine the arytenoid cartilage and the vocal cord of the opposite side ; move the arytenoid back and forth, watch- ing the vocal cord. 15. Remove the epiglottis, and cut into it to see its structure. 16. Dissect away the parts of the other side from the inside, reviewing the above points. THE SKELETON OF THE RABBIT. Carefully clean the skeleton after dissecting away the muscles. In preparing the skeleton in this way the student will learn many facts as to the relations of the bones to the other tissues, that he would not learn if he began with a well-mounted museum skeleton. In removing the muscles, observe that the muscles of the limbs lie parallel to the bones ; that the bones are largest at the ends, while the muscles are thickest near the middle, thus making the two fit each other better. Note that in the limbs the muscles narrow at one end, or both, into a tendon, which, usually at one end, passes over a joint to be attached to a bone Mammalia. •59 n the next part of the limb. Examine the IlgamenU that hold bones of the limbs, note a small quantity of slippery liquid tZ tXr- ''■'''"'"« ""= ''™^^' """^ '"e ner'^eTand bll tubes passing ,n and out of the holes along the sides of ^^ Weigh a rabbit freshly killed, but from which the blood has not been removed. Thoroughly clean the skeleton, and^en^ Se Zk'eS". "• ""■" •'^" °' '"^ ""»'« -'«■« °^ -tt" i's* ot the skull and spinal column, and the appendicular „-, consrstrng of the limbs and the bones suppor.i„nhem ...i V^^ .'■'"."' "" '"'""^ "^ """"^^ »""«•• The bones •urroundrng the brain constitute the cnmil part ; those parts L front make up the facial part. Note that the ace is ,le sn7,^^l T7 • ' ""'"""^ <'°"""" ""8™™) through which the spmal cord passes to join the brain; the cavity, or orbit o1 Z ^:nX^ """^ '°[ *' °P"^ ""- ■' *e ".^ .perturb a f^cl7lJ,t. T"'' *". '•"'"'"y ""*»«'• " "' holes. On each side of the foramen is a smooth, rounded elevation • these are he oolplta, condyles. See how they fit the first ve^eb^" what k,nd of a jomt do they make ? Study again the way the bwer law ,o,ns the skull, and consider the motions .ha. .his'o in sS oiac^tT' "/"" ""^ corresponding join.s in the bKuiis Ot a cat, cow, and man. 3. Make a more careful stwdy of the teeth than before as what IS thei shape . How many above ? How many below > Are they all alike? How are they arranged ? Are thev III marked aUke? How do the upper and lower inci^s meet 1 i6o Practical Zoology. squarely, edge to edge, or does one pair naturally rest back of the others ? If so, which are in front in the resting position ? Can the lower jaw be moved forward and back ? Do the lower incisors always come up in the same position in relation to the upper incisors ? Note the angle at which the incisors are set. Now examine the grinding teeth, or molars. How many are there in each half-jaw ? What is their shape ? Are there ridges on their grinding surfaces ? If so, in what direction do they run? How is this related to the chief chewing motion? Are all the molars set at the same anjjie ? Why any diflference ? At this point, if possible, look again at a live rabbit and watch the process of eating. How are the jaws moved, and how do the motions stand related to all these facts about the teeth ? 4. Take a well-cleaned lower jaw of a rabbit. Embed it in sealing wax on a small block of wood, with the inner face of the jaw uppermost. With a grindstone, grind away half of the incisor and the surrounding jawbone. Is there a distinct root ? Is the tooth equally hard throiighoiu ? IhL front jjart is enamel. The bulk of the tooth consists of dentine, or ivory. Grind away half of the molars and the bone in which they are set. Do any of these teeth continue growing after the rabbit has reached maturity ? Is it a serious matter for a rabbit to lose one of its front teeth ? Why ? 5. Each separate piece of the backbone is a vertebra. The vertebra of the neck arc called cervical vertebra. The vertebra; that bear ribs are thoracic. Following the thoracic vertebra are the lumbar vertebra. After these, are several grown together and supporting the bones of ilie pelvis; they constitute the sacrum. Last, the vertebra of the tail, the caudal vertebra. How many are there of each of these kinds? How many in all? Review the whole spina! column, comparing the different parts. Take a vertebra from the middle of the thorax and examine it carefully. Its main part is the body or centrum. On the dorsal side is an arch, the neural arch, through which the spinal cord passed. Above the arch is a projection, the neural spine, the Mammalia. I6i row of neural spines forming the ridge of the backbone. Extending outward on each side are the two transverse processes. Near the end, on the dorsal surface, are the two smooth facets, where the vertebra joined the vertebne befoie and behind it; these are the articulating processes. Do all the vertebra; have the same number of the processes ? Where the same number is present are they alike? What range of motion is allowed between two vertebra; ? Is this equal in different parts of the spinal column ? 6. Study carefully the first and second vertebra;. The first is the atlas. Has it a body ? Note how the twf) hollowed facets on each side of the hole fit the two occipital condyles of the base of the skull. How is the nodding motion of the head accom- plished ? The second vertebra is the axis. I'rojecting forward from it is a peg which extends into the opening in the atlas; this peg is the odontoid process. Observe that when the head turns from side to side it is by turning on this a.xis. 7. Examine one of the middle ribs. Find that it joins the backbone in two places, by its head on the side of the vertebra, and by a little projection called the tubercle, with the tip of a transverse process. What range of motion has a rib? Note that at the ventral end the rib is cartilaginous. What is the advantage of this fact ? Compare the series of ribs. Examine the breastbone. Is it of one piece ? Is there any cartilage in it ? What are the uses of the ribs ? Is there a collar bone ? 8. In the fore limb look at the shoulder blade or scapula, iow does it make up in strength for its thinness ? Why should It be flat? Note the shallow cavity by which it articulates with the bone of the upper arm, the humerus. This is a baU-and- socket Joint. I^>k closely for a slender collar bone, or clayicle. In the forearm the longer bone is the ulna; the other is the radius. Do they rotate on each other as in our forearms? ("ompare them also with the corresponding bones of a cat. Do they need the .same freedom of motion as in a cat, squirrel, ape, or man ? The bones of the wrist are the carpal bones. The 1 62 Practical Zoology. bones of the palm are the metacarpal bonea. Beyond them are the finger bones, or phalangea. Find how many there are of each of these sets. 9. In the hind limb each half of the pelvia consists of the long hip or Innominate bone. Note the deep socket of the ball-and socket joint. Fitting into this is the rounded head of the femur or thigh bone. Compare this joint with that of the shoulder' Which has the greater range of motion ? Which the greater strength? Study the kneejoint. Note the kneepan, or patella in the tendon running over the kneejoint. The large bone of the leg, or shank, is the tibia. Beside it is the fibula; is it wholly free from the tibia > If it is found united with the tibia, where and to what extent ? Corresponding to the carpus of the wrist, there is a series of short bones in the foot constituting the taraua. Then comes a row of longer bones, the meUtaraal bones. And after these are the toe bones or the phalanges Kow many in each of these series and how arranged ? Are the bones of the same number as in the fore limbs ? CHAPTER XV. PROTOZOA. AMCEBA. Amceb^ are to be found in standing water, where they live in fr on r '°'""f °" ''^ '''''' ^"^ ^^^-^ -' submerged Xs or on the upper layer of mud or ooze at the bottom, luch watl; wuh mud and plants should be collected sometime betorehanj and kept undisturbed in the laboratory oetorehand I. Take a drop of water from the bottom or the surface of a leaf mount on a slide, and cover with a cover slip. ExamLe 3. Structure. -The following parts should be identified — a. A clear outer margin, the ectosarc. ^' ;f ^^"^"^ *"" ^'■^""•^'" '""er portion, the esdoMrc c. A denser, spherical body within the endosarc is the nucleus .rl "^^^""^ ^^^* ^'■o'" ^™e to time contracts and dis- appears. Th,s IS the contractile vesicle or vacuole. Are i^ pulsations regular.? Time them. .rrn„?'^'J rT^"" '^^' "^^ "°* P"'^^^^ but are filled with granuks of food materials. These are called food vacuo.,. 4. Movements. -Watching the amoeba closely shows that it not only changes its form, but also its position ; it not only moves, but moves from place to place. It has not only motion! but locomotion. By closelv watching an amoeba it may be seen 163 i64 Practical Zoology. that at one place there is a bulging out of the ectosarc, some- times forming a long projection called a pM-'^pod. The granu- lar endosarc then flows into this projection, ^nd by repetition of this process the whole anaba moves forward. Is there any part that can be called the head ? Does it move constantly in any one direction? Make sketches at intervals to show the changes in form. 5. Feeding. — It may be discovered that occasionally an amceba ingulfs a particle with which it comes in contact. This is its mode of eating, for it has no mouth. Does it show choice in what it thus takes in ? Is there any refuse of digestion ? If so, where and how does it leave the body ? 6. Feeling. — Does the amceba ever appear to feel an object against which it presses > Does it avoid obstacles ? What evi- dences as to its having a sense of touch ? 7. Reproduction. — Can you find an amceba that is dividing into two parts ? This is its simple mode of reproducing, and is called division or fission. If possible, find out how long it takes to complete the division. Make sketches to show the process of division. PAR.\MECIU.M. THE SLIPPER ANIMALCULE. Paramecia are often found in water containing decaying ani- mal or vegetable matter. If a white film forms on the sur- face of such water, look through the sides of the jar, and there may often be discovered tiny white particles moving actively about. Mount a drop of this water, with a little of the scum, and examine with a low power of the microscope, say a two- tlurds or one-fourth inch objective. Small oval or elliptical bodies may be seen swimming around at a lively rate. These are paramecia. Find one that is fenced in by surrounding matter, or prepare another mount ; a few threads of cotton often serve well as a "corral." With a higher power, one fifth or one sixth, examine a Paramecium, whose movements are thus restricted. Note : — 'M^.^^^:^&^Mf \mmr^ji?i Protozoa. 165 u I J*** ^^^' °''*' °' «"'PticaI, often decidedly slIpper-shaDed It further resembles a slipper in being somewhat Ha^Tned '" 2, StruGtur,. - The clearer, firmer, outer layer is the ectOMrc Themore jellylike inner partis theendoMrc. Cov ring ttX" «arc ,s a th.n, transparent layer, the cuUcle. Kxtendin^ fro m he ectosarc through the cuticle are many fine, hairlike p^^'etio he Sde itT th! r"T '^ ^'"**"' ^^"''^ ^^^' th! J.cronu"eu. reside It IS the much smaller mlcronucleu.. These nuclei -ir. hard to see. Place a little dilute acetic acid on h ^^^ to the cover slip to bring out the two nuclei. 3. Locomotion. -The Paramecium swims by means of rh. for^r: : 1.:^^ f\ ''"-' ' '^-' --^^' ^'^ -" at P^ITnto i n '""'" •'' '^'''' • ^^'^^^h it when trying o pass mto a narrow opening. Are the cilia nf »h« ■ V, over the body > Place a drnn Z ■ V . '^'""^ '"*^ ^" the edireTf h/ ^^ "'^'"'^ '°'"^'°" «" ^^e slide at wic eage ot the cover s ip. The cilia th„. .* j , better. ' *""** stamed, show accumulate at the end nf tK« 11 / u particles that gullet anda^d stinPt ^f"' ^''°'"" '''^P''^^^^^^ ^'^^ the Do tL f !i f ^''^' '" ^^ ^^y ^^« ca"ed food vacuoles iiiove aoout .' iJo they move in any regular ordpr > r,„ find a place where .he residue is e'xpeUed "ro" the ^.1°" end I^HIT"* ':«"°'"- About one third of the way from each end, look for a clear space, which contracts and disappear^ a^rt contraction or diUtion > lifcS, fo^r^Jd^::;" aT^r.- mr- V^Vf:- MKROCOTY RESOIUTION TEST CHART (ANSI and ISO TFST CHART No. 2) 1.0 Ujir ' |4J IM IM 12.8 13.2 3.6 1^ Li ■» MM u 1.4 1^ 1.8 1.6 ^ /APPLIED IM/OE inc 1653 East Main Street Rochester. New York 14609 (716) 482-0300- Phone (716) 288 - 5989 - Fax USA 1 66 Practical Zoology. hi'l the disappearance of a vacuole. Do the two vacuoles contraat at the same time ? 6. Means of Defense. — Observe in the ectosarc many small, oval sacs, with their ends toward the surface. These are the thread cells. They contain a thread, which can be shot out, serv- ing as a means of defense. 7. Reproduction. — Do you find a Paramecium that is becom- ing constricted in the middle like a dumb-bell or hourglass? Paramecium divides into two by narrowing in the middle, pre- ceding which is a division of the nuclei. If such a specimen can be found, watch the process to completion, if possible. Draw and describe all the stages of division, or fission. VORTICELLA, THE BELL ANIMALCULE. Vorticellae are often found on the stems and leaves of water plants, or on stems and leaves that have fallen into the water. Mount slender stems from water and examine with a low power. If you find a bell-shaped form attached by a slender, flexible stalk, and especially if the stalk is suddenly thrown into a coil, jerking the bell close to the stem to which it is attached, you may be sure you have vorticella or a near relative. Some of these forms occur in colonies, all growing from one main stalk. Some have the power of coiling the stalk, while in others the stalk is not contractile. Some of the colonies can be seen by the naked eye, appearing like tiny spots of mold. If such a colony is found, the part of the stem or leaf to which it is attached should be carefully cut out and mounted on a slide. With a higher power the details of form and structure may be studied. I. Form and Structure. — The body is bell-shaped, with a long, slender, flexible stalk in place of a handle. The outer layer is a thin cuticle, next is the ectosarc, and the inner is the endosarc. The extension which nearly fills the mouth of the bell is the disk. The border of the bell is the peristome. On one side find a groove between the disk and the peristome. This •IV-i a-^-, "^T^^ -^W Protozoa. 167 Hii ZJ"'""'' ^^'"'■^^ '^' ^^^'^ ^'°"g tJ^e margins of the d^k and the penstome. The extension of this groove into the body forms the gullet. Vorticella has a long, curved macro- nuc eus and a small, spherical micronucleus. but these are not easily seen. Add a little dilute acetic acid. 2. Movements. - Observe carefully the stalk during and after the coihng. The stalk does not contain any of the endosarc, but only the ectosarc and cuticle. Note also the changes in the shape of the body and the rearrangement of the parts. In what order are the parts folded in during the act of closing, and in what order are they expanded when the vorticella extends agam ? Tap on the slide while watching to see these changes Make sketches showing the fully expanded and the closed forms' Why does the vorticella thus draw itself close to its support.? 3- Feeding and Digestion. _ Watch the vibrations of the cilia Can you see that food particles are swept into the oral groove and down to the blind end of the gullet? Add powdered car- mine or mdigo to the water. Can you see food balls at various points m the endosarc ? Are they stationary, or do they move ? If they move, do they go in any regular order ? Look closely for by the return current. Does a vorticella move toward food? Could It do so ? Does it need to do so ? Does vorticella show choice m the particles that it takes as food ? trac'tio^r*'*"""^'""^ *^^ ^""^""'^^ ''*'"°^'- '^^'"^ "^ ^°»- 5. Senses.- What senses does the vorticella appear to possess ? 6. Reproduction. - Look for two vorticella on one stem. You may find one m the early stages of division. When one of these becomes separated, learn how it swims away. Study vorticella^ s^^tirof rt"^^^^^^^^^^^ "^^^^ ^' ^-^'^^-^' -^'-"^ Inf?^:^lEal!^"^'"-"'^"^- ^-^--^^-^. Malari. '.VL^K !; 1 •«rr«i^*"v^ U: '>L CHAPTER XVI. PORIFERA. SPONGES. Each pupil should have a small specimen of a commercial sponge, showmg large holes at the top, but not with large holes runnmg straight through. The teacher will need several specimens of larger sponges- one of the simple calcareous sponges, in alcohol ; a piece of commercial sponge in alcohol, showing the sponge flesh still in place ; a siliceous sponge ; and slides showing sponge spicules The pupil should make out the following points from his specimen of common sponge : 1. Its elasticity; test first the specimen dry, and again after wetting it. Compare the elasticity of different kinds of sponges. 2. The fibrous structure ; with forceps tear off a bit of the sponge and examine with a lens. Then examine under the microscope. 3- The sponge was attached by its basal surface to ro^k Fmd where it has been trimmed away with shears ; perhaps if this has not been thoroughly done, some bits of rock may be found clinging to the base. 4. Examine now the different channels by which the sponge IS perforated. ^ a. Large, craterlike tubes, opening at the top of the sponge Lookmg into these, it may be seen that they give off branches. If you can see right through the sponge by looking into these opemngs, you may know that too much of the base has been cut away, and your specimen is not a good one. With a razor or 168 Porifera. 169 sharp knife, cut the sponge in two down one of these large tubes, and examine from the inside. b. Trace the branches of the large tubes by gently pushing into them a probe (a wire with a little knob on one end). These lead, usually, to holes seen on the outside. c. Grooves on the surface of the sponge, some shallow, others already becoming inclosed by the union of the tufts of fibers outside of them ; in this way is formed another set of tubes {d). d. Tubes running parallel to the surface of the sponge, whose cut-off ends may be seen near the margins of the split sponge. Hold the half sponge up to the light to see the radiating fibers and the concentric series of holes indicating the mode of growth of the sponge. e. Minute branches of the above tubes penetrating the sponge in all directions. It must be borne in mind that the sponges we buy are only the skeletons of sponges. In the living sponge the skeleton is entirely embedded in soft living matter, and the skeleton cannot be seen on the exterior ; in fact, its fibers are not very evident in a section of a fresh sponge. The outside of the sponges whose skeletons we buy, when alive resembles, in color and gen- eral appearance, the back of a kid glove, varying from dark reddish brown to almost black. The consistency of the living sponge is about the same as that of beef liver. If one of these live sponges be watched, a current of water is found to come out of the larger holes at the top, and currents pass in through the numerous smaller holes on the exterior. If the sponge be handled, many of the smaller holes close and entirely disappear. In order to understand a little more clearly the structure of the common sponge, and to see how the currents of water are maintained, an examination of a simple sponge will be useful. Our simplest sponges have no elastic skeleton composed of horny fibers like those of the commercial sponge, but have Uttle needle-shaped and three-pronged spicules of limy matter. £W lyo Practical Zoology. One form common on the northern Atlantic coast is a simple or branched white tube, an inch or so in height, and somefimes as thick as a pigeon's quill. These are in clusters, aUached by one end and open at the other. Embedded in the wall of each tube are the spicules above mentioned, projecting both on the outside and on the inside, ihe inside of the tube is lined with cells bearing cilia which, by their vibration, drive the contained r. ?u' u^^ ""^^^'^ °^ '^' '"'^^ ' to replace which, water enters through many holes which pierce the wall of the tube In sponges a little more complicated, the cilia, instead of lininc. the main tube, are limited to small pouches, or lateral branches of the mam tube, extending into the body wall and communi- cating wuh the exterior through small pores. In others the cilia are found only in certain enlarged portions of these radiating tubes. This represents the condition in the commercial sponges certain cavities are lined with cilia and are connected on the one hand with the smaller tubes entering the whole surface of the sponge, and on the other with the large tubes opening at the top. Ihese cilia cause the currents above mentio. od Thus the sponge gets both food and oxygen. Sponges (including, besides those already mentioned, siliceous sponges, whose spicules are flinty) constitute the branch Porifera. Read Commercial and Other Sponges, Hyatt, Topics for Reports. - Sponge Fisheries. ' Experiences of Divers. Sources of our Sponges. Fresh-water Sponges. .^wi^M'': 'Wtft, wrw '^'.„iiiiniuiiJil"''Cv— " '• ( .'-.■'■'-.. J ill - *■ • ^ . \ ■ CHAPTER XVII. OELENTERATA. THE FRESH-WATER HYDRA. The fresh-water hydra has a cylindrical body, varying in diameter from the size of a fine needle to tha. of a common pin, and from one fourth to one half an inch in length. It is found m fresh-water ponds and streams, usually attached by one end to submerged stems, leaves, etc., frequently on the under surface of a lea . Surrounding the free end of the hydra is a circle of threadlike appendages, the tentacles, which often are longer than the body itself. ^ Two species of hydras are found: one green, the other brown or flesh colored, often whitish. Put the leaves and stems to which the hydras are attached into shallow dishes, such as fruit dishes, and keep them in a light but shaded place ; watch their behavior when thus kept undisturbed. Cut off a bit of leaf bearing a hydra, and transfer it to a deep watch cr>-stal half full of water. Without the aid of any lens watch the hydra for several minutes. When it is expanded, gently touch it with the tip of a pencil or other blunt object. Examine a hydra with a hand lens; are all parts colored alike? Place the watch crystal on the stage of a microscope and examine with a one-inch objective. The following points of structure should now be made out : — 1. That the body is a hollow tube closed at one end and open at the other. This opening, within the circle of the tentacles is the mouth. ' 2. That the tentacles are also hollow tubes, closed at their caX^ ' ^"^ ** ^^ inner communicating freely with the body 171 172 Practical Zoology. 3. That the body wall consists of two layers, which are con- tinuous with the corresponding layers of the tentacles. How do these layers differ from each other ? The body is, then, a double-walled sac, and the tentacles are simply extensions of this sac. Watch the movements of the different parts of the body. Can hydras move from place to place? If so, how is this accomplished? Look in the body cavity for foreign matter which has been taken in through the mouth as food. Look also for minute particles obtained by the digestion of such food matter. These particles may often be seen in motion, caused by contractions of the body walls, or by the action of flagella lining the body cavity. Look for knoblike extensions of the side of the body. Buds are formed as out- growths of the body walls with a cavity continuous with the body cavity. Place in a dish by itself with some aquatic plants a hydra bearing buds, and watch from day to day the develop' ment of the bud into the form of the parent. Observe the free circulation of food material from the parent to the bud Watch the formation of tentacles. Look also for a thinning away of the free end of the bud. What is the greatest number of buds found on any one speci- men ? Are buds borne on buds ? By means of a pipette trans- fer a hydra in a large drop of water to a slide. Cut two strips of paper a quarter of an inch long and one sixteenth of an inch wide, and lay one on each side of the drop of water. Carefully place the cover slip on the water, with its edges resting on the papers so as not to crush the specimen. Examine now with a quarter or one-fifth inch objective. Ob- serve the cells of which the body walls are composed. Note the knotty appearance of the tentacles. In these projections of the tentacles and in the walls of the body are certain distinct oval cells, the thread cells. Place a drop of acetic acid on the slide at one edge of the cover slip, and touch the opposite edge of the cover slip with a piece of blotting paper, meanwhile watch- ing the specimen closely. Examine carefully to see the thread J!9K'^ Coelenterata. «73 cells which have been discharged as a result of the irritating acid. Small animals coming in contact with the tentacles are paralyzed by means of these thread cells which are suddenly shot out ; the tentacles then carry the victim to the mouth, and It IS swallowed. Note the simplicity rf the structure of hydra -the absence of any distinct nervous system, and all special organs of circulation and respiration. On the side of a hydra, near the base, may sometimes be seen a conical elevation, the ovary, in which the eggs are produced. Also on the side of the body, but near the tentacles, may sometimes be found several elevations, the sper- maries, m which the sperm cells are produced. THE SEA ANEMONE. Look for sea anemones attached to rocks. The beginner in this sort of collecting and observation is usually not prepared for what he sees ; he does not usually reali^t that the name "sea anemone " is exceedingly appropriate, and he is not likely to look for brilliant forms, like sunflowers, asters, and chrysanthe- mums. Watch them both in their expanded and in their con- tracted condition. When they are expanded gently touch them. Are they firmly or loosely attached ? Do they ever move about ? Have they any means of getting food ? In its general form the sea anemone resembles a hydra, having a cylindrical, hollow body attached by one end to some foreign object, and at the free end a mouth surrounded by tentacles In Its internal structure, however, the sea anemone presents some new features. The mouth, instead of opening directly into the body cavity, as in the hydra, opens into an esophagus which hangs like a bag suspended in this cavity ; the esophagus has no bottom, but at Its lower end communicates freely with the body The body wall and esophagus may be represented by a glove finger with its tip cut off and the open end turned back part way into the larger part of the finger. ■fll'S^^.Y ^'IhiL ■s i 174 Practical Zoology. The cavity oi the body is divided into a series of radial com-, partments by fleshy vertical partitions, the mesenteries, which ex- tend inward from the body wall, some reaching the esophagus and being attached to it, others not extending so far inward as the esophagus. Each tentacle communicates with one of these radial compartments, and is to be regarded as a mere extension of part of the body cavity. Alcoholic specimens should be sliced transversely and longi- tudinally. In a transverse section of the lower part of the body there will be seen the body wall with a series of partitions ex- tending inward and ending in a free edge. The section across the upper part of the body shows an outer circle, the body wall an inner circle, the stomach wall, and, connecting the two, the' radially arranged partitions, or mesenteries. Like the hydroids, the sea anemone is well provided with thread cells. Food is taken into the mouth, digested in the stomach, then passed, mixed with sea water, into the body cavity, through which It IS made to circulate by the contractions of the body walls The indigestible portions of the food are expelled from the stomach through the mouth. STONY CORALS. {Coral Proper.) In a piece of stony coral, or compound skeleton of a colony of coral polyps {Galaxea is a good form to study), make out the following points : — 1. The nature of the material itself; test by putting a very small piece into weak acid, or by touching the specimen with a drop of acid. 2. The cup, or theca, formed by an individual polyp, often traceable as a long tube. Observe : — a. The outer wall of the cup. b. The partitions, or septa, extending inward from the wall of the cup. 3. Between the cups, the porous limy secretion, which was . ^".-W'^^-'^i^:?. Coelenterata. ,^. of^l^t^ ""i,T '"™°"' ''«P<'^"i"g limy matter in the bas. I'^rLr; rrt^rr/ij;; ;7f ^' '^•'«" ^'-^-^ '- similar deposit in these U^ Z it J^lC""'T''- r" " is forn,ed by the individual^ ypBv The ^. 7" ^ "' '"^ •he polyp, and the con.inuaZ'of th J ly deTsit th''"' V' con,es an elongated tube. By budding are'forr^he IZcht »/;h?'"M" "'* '^"P'' ' P°™"' ''""i™ °' the same material b s fi iL" !' '""'• ?" '^ ''^°''''<' ■■" *^ commorfles ' base, fillmg up, m some forms, the spaces between the cuds ■ TZ when one polyp dies, its cup is covered over and bur ed out o1 sight by this secretion of the common base 5. Make a drawing of a mass of stony coral, showine the Zm; h k I'" ""'■ '° ''" *' 'P'"^"'" '= 'o <^'e^ 'hem thor- oughly by boiling some of the outer layer in caustic potash. In this layer are holes from which the polyps protruded. In this *iisiBis*.;'. ^ ^-^mt.. 176 Practical Zoology. lZ"l: f '"' 'u' r^'"''""- " ^*^°"y •" '^^ Jiving matter between nmg lengthwise near the inner surface of this hv« pZ rela.,„n between them and the^ubes above no edTh.short trated by livmg matter like the outer layer. In the precioufrert Zi^ofr" '" 'T'k" '" '"^ '"""= -^- ^"' i^ "Tea- removed "^' '"'' "*' """^ "''*''''« '^'yer has been fosT---"^^^^^^ -les, also eigrml^lrwhK^e^L'par t 'b7:teri:^- "'* *' ■»'^p^ -«. '"ourif ,4" T<»ic. tat Keportt. - Coral Islunds and their Formation. ^e^MTS sen esh ity he ly e- :d e- n CHAPTER XVIII. ECHINODERMATA. STUDY OF A LIVE STARFISH. Of ^ZIT" ^""l '"" "''' ''" ^°"^^ ™^y '"^'^^ Profitable study Of starfishes m their native haunts a. i • . ^ shore, looking in tide dooIs Im , ' '''^" "^'"^^ ^'°"g ^he Wharves, etc! for s^^^h ;.^Te^rvr V"^^'^^^^^ — nP Are they .ore abu"o'nt:\rn/:[ r;''^' than another ? Do thev seem tr. ,.. t I , °^ surface .he. cCor any relation^'eolri; ^rt^i ; r '^ T ' , "" in strong light or do th,.,, c. . "unaings? Are they found they J. J uV::^i:r:j TLtc^r-' "" vertical walls of rock > Can,; "° f" ""'"hem on the Resurface. « so^L s'^ng^T X „ P-U o^^ ''''''T '" a smooth surface on which vou find i, a u ' ^"^J" '™"' or more or less curled !> M^ 2' '"<=>■, "'-^d "a^ Do they Change the ^sl„ of h ' a"" LTv^ ?'"," "'"' they found singly or in erouos ' LT ^ "''"' ' '^'^ onies? Do yoVfind theTe^aingf ° f'To'X.'V'.K '" "'' and how? Has the sit,.«HV.n u " ^°' ^hat do they eat any relation to a tdtpTy/ h^Xv ""' '"^'^ " """""^ the temperatu^e of the water' IT. k ^ '"'^ '"'f "'""'= "^ '° extreme changes in emperllure ~ It h ' """'""'l "''^'"' ''^ found > Havf starfishes'::" n^turaf nemlf'" H?" .T ""^^ r r'httre of" ^°"''-- -« "° -- --Mr^ r it .^a r ' -- ™ LL VeftTV-- Put a Iwe surfoh'n T' ''"^"«°^'"''^''"S>ourhand.> w-it. .o:r:t^\::i:rrrc;:::-trs:d::t «77 178 Practical Zoology. f^Lf'lTH''^^' r ''^ ^"^^^^^ " '^ -? ^-tch the a Slender suppc such as a cane, or large glass tube > Can you learn about its food and mode of eating? Try to /et at home^ Do you find any evidences as to the mode of develop- ment and growth of starfishes ? Do the aHnlt« h... °^^^^°P- the young? Do starfishes do any gofd . I^^ave^^^ '"' importance ? Do they do any harm^ ' h1 ''^^^^.^^""^'"'^ be checked ? ^ ^^"^ "'^^ *^"' ""^^^g^s EXTERNAL FEATURES OF THE STARFISH. For this work there is needed : — 1. A set of dried specimens, one for each student ; such a set may be used with successive classes and will last o years tf carefully handled and kept in a dry place. ^ 2. Alcoholic specimens for dissection 3. It is desirable to have a set of prepared slides showing cross sections of a decalcified ray of a young starfish aTdf ground-down section of a calcareous plate, etc 4. An injected starfish and a number of injected rays. Dried Specimen. I. Observe, first, the shape of the body as a whole The amstCr N '!':>^"'r' "' -d-'»g-t-sionsare Ae arms, or ray,. Note that the rays are bilaterally symmetrical. I^?' aTu r" ° ""^ '■^^'- °''^"^«= 'hat the body cavity is bounded by a leathery wall, in which au embedded hard pll spiinfen' t "'f ""^ °f ""' ''"'^'"''" "^ *e alcoholic specimen. By p.ck.ng with forceps, prove that there is soft matter, both on the outside and on the inside of the h^d plates! Vi'-V Echinodermata. acid, chromic or other acid. Observ^ Z ,1?^ ^' ""1^ """" present, but lacks the hard parts ' ^^ "»" '^ "'" you„/:^:;;:K^l1^hrc:^ -;'™ :L\''""'''>^'* "^°' ^ .ha. the caicareo piates :::^X:^^^>:Z^. ^^- order to remove all thVorJ ^ "^ '" """''^ !«'»* '" oughiy d^, s;;,h'do':„':s":idr„?a'r«r'"'"''^""'°^- perfectly clean oilstone celnt.^ f '"' P""'*' °" » glass slide bymeansof a'd^ ?l ""''" °^ '^e plate to a boiled on the sTde „„ it on T '"'"'' ''^'^'" ""'^^ "- ^een indented by thftLlb ' irprLltn ;: "f "'"r"^ means of a file, and when quite tht ^ ^"^ ""^^ ''>' sharp knife, finally smo^thinrt * ' "T ^"^^""^ "'* ^ men should be examfaeTf ^^ . ^" °''''°"^- ^he speci- scope, in order to arrtin T T '° '™' """" «■» ">'"<- has been reached Wsso " 1 I ?' ""P"' "'^^^ °' "-inness or better, if pro^rly ma" ^ed metX t? '" "' '"''^"""^' and carefully nush thp c T ^^''^"^ ^^^'^ ^ lamp, .urpentine, '.he^ thortugh X:" frL^^ ^'^"''' ^""""'"^ i. with a camel's-hair brish fnH ""' ""'"f''"*' ^r"* Uie ordinary manner ' """^ '" ^'-^''^ b^'^m in fertnt°e;rs XrbofyTa"; °V^ ''T '"" '''"^ » <"'- surface of each rav ™, k '™^ ""^ ™'^<'l' of the oral .ube fee or .„ loT m™ "' ^'"^■^'''' "="■"- "' '"e Plat«. One row "o p£s on eTch H "'J ",? "' """"«"•' piates on each side of these ambulacra! 'ISTM'i. i8o Practical Zoology. plates are known as the interambulacral plates. Examine these closely for comparison with the sea urchin. 6. The wartlike elevation on the aboral surface is the madre- poric body. Note that it is situated opposite one of the Inter- radial angles. Examine it with a lens. 7. Make drawings of the oral and aboral surfaces of the starfish. Alcoholic Specimen. 1. Briefly review the points noticed in examining the dried specimen. Bend the rays ; their flexibility is now much less than in life. 2. Compare the spines of different areas as to their shape, size, and degree of mobility, i 3. Between the spines are soft, tapering projections, the aboral tentacles. 4. Observe a circle of projections surrounding the spines; delicately pinch them with the forceps to determine their con- sistence ; remove some of these bodies to strong alcohol ; mount temporarily in turpentine on a slide, cover, and examine with a low power. There should be distinguished a short stalk bearing a pair of pinchers ; these bodies are the pedicellaria. In the live starfish these pinchers may be seen continually snapping; they are supposed to serve in removing foreign matter from the body. 5. The soft, cylindrical projections along the median tract of the oral surface of each ray are the ambulacra or tube feet. Remove one of them and examine it with care. Note the arrangement of the series. 6. Press apart the tube feet and find running along the median line of the ambulacral groove, a yellowish or whitish ridge, the nerve of the ray. Trace it to the soft membrane bordering the mouth, the peristome, and find the nerve ring around the mouth. 7. Trace the nerves also to their outer ends and find a reddish or yellowish elevation, the eye-spot, borne at the base of a median terminal tentacle, resembling a tube foot. Echinodermata. i8i Cn^J^'' ^^^"'^^ " ^°™^ °° ^ ^''^^"^*' ^"t "^'""te, plate. thlTn'.! ^'""? '"1 °^^ 'P''^'"'"^ ^" ^^ ^^^^ ^^^'^^^^ the size, hzs single ocular plate with its eye-spot is always at the end of the ray Count the ambulacral plates in a short and in a lon« ray. Where do the new plates develop? * DISSECTION OF THE STARFISH (IN WATER). 1. The ray opposite the madreporic body is the anterior ray ^LT 1? '''" "'"'' '^' °"*''" ^"^' ^°d fr«"^ this point cut along the upper part of each side of the ray, an inch or two toward the disk; raise the flap thus freed, and, avoiding inte^a^ organs, continue the cut on each side to the disk boLf r^H^ '° '^' '^'^ ^'" ^"^ " P"^"- °^ ^'^"g^ted, branched bodies, the digestive glands, or ceca. Note how each cecum is held m place by the thin mesentery. 3. Along the middle line of the aboral wall, inside, is a yeUowish streak the e^ensor muscle of the ray with f r eps prove Its general structure. ^ 4. Along each side of the ridge in the floor of the ray, observe rows of thin-walled sacs, sometimes distended, but more ofl colkpsed m alcoholic specimens. These are the ampulhe or ambtUacral vesicles. Watch the ampulla while pressing on'the TJ. k' u """I '"'■'^- ^^ ^ 'P^"^™^" '■'^J^^ted with coloring matter be at hand, it should now be examined hJ; ^^^'uv^ ^^.' °^ '^' '^^ ^"^' °" ^^^"^ ^•^^' an elongated body resembhng a bunch of grapes, and of a lighter color than the ceca; these are the ovaries and spermaries, and are very much alike m appearance in the two sexes, and only distinguishable by color (the spermaries being lighter colored), or by microscopic examination m the living specimens. Find the point of attach- ment of one of them. The openings in the interradial angle are not very evident. ^ 6. Cut along the sides of the two rays lying on the right and left of the antenor ray, connect the cuts at the interradial angles and turn back the cover of the three rays and disk. Within^he ^''miti I82 Practical Zoology. * ly t^/tl *"■":'"'' "°™^^''- E-mine .hi. organ care- f Oh ^ , P™"' """ "^^ """"h ""'' "Pl"^ its interior. aiL? 7'^' '"«' '""^^ °f ""= ^"'""•^h "'<^"di„g a short reU-.«or muscle, of the stomach to the sides of the ridge in the ray su,^„„; """"; "" ^•°"'^^'' '^ °"- f-d Protmded nd tsTft D f- r? °K " °^^'"' ='■"' digesting and absorbing US sou parts the stomach is retracted the'sto'rIJIci;'' fi^''r"*.'' ''' ^"^^"^^ ^^^' ^^^- ^hem toward the stomach; find the un.on of their tubes and the entrance of heir common duct into the stomach. Observe the place where lobe otLrr^ ''-'''''' ^" '-'--- ^^ ^'^ -~H fr.?.If ^""^ '"V^^ mesentery along the aboral wall and wholly free the ceca of this ray from all attachment above. Note tha^ the mesentery i- ;. uble. into tif "l"* *^' u''''^"^ ''"^''*'^ ^'^^ P°"^ ^^ter through the mouth into the stomach to show its shape. acro°ss tt ^ °'^''. '"^^ ''^' ^^^^'^ ^^^^ b^^" ^P^ned. cut 1.1?.,^ T" "^"''^ °^ ''^^ ^^^^ ^'°«^ to the stomach and leave them attached to the aboral walls. II. Find the extremely short intestine connecting the stomach agesof thefnui:;^. THf^tr^st:,:::^" "■''^"<'- the disk Ze"'.o i" ""'"; ''"' '° *' ^''°^''' "^"- ™' -"°^^ cec^i'ToL'""'"! °' "' "'«'"' """ ^^P°^'d, showing the cut'tfng?cr^i:^;ct;ha;r™^''' ^-^ -"■°- '' ^- '^rrTZ-c^' ^, Echinodermata. 183 15. Traced to its lower end, the stone canal may be found to enter a membranous hollow ring, whose outer border rests TT !i' ^"r.'"'^"'' °^ '^' ^^'^ P^^^« surrounding the mouth ; this tube is the circumoral water ring. Connected with Its mner surface, find several pairs of pouches, which in the contracted state are mere buttonlike projections. How many of these are there, and are they all in pairs > Observe also the pouches, like ampulla, connected with the upper part of the hard ring around the mouth. Press on the water rmg at the level of the peristome, and watch the effect of this action on these last-named pouches or vesicles. Is there any connection between them and the water ring? card um. Carefully tear it away. Alongside the stone canal is do'ubtfu" '°™^^'"''' "^^""^ ^^^ "*^«"*'" but whose function is 17. Cut across the middle of a ray in two places, about an mch apart, and make a careful study of the part included between the cuts. Remove the hepatic ceca, observing again how they are suspended by the mesenteries. Cut into the ahoral wall in the middle line and spread open the ring. Observe the depressions in its inner surface ; in the bottoms of these de- pressions find small holes. What is the relation between these holes and the nearest structures seen on the outside? 18. Slowly peel away the thin membrane which lines the interior of the ray, noting especially the connection between this menibrane and the depressions above noticed. Also watch closdy the aboral tentacles while tearing away this lining mem- 19. Turn now to the outside of the ray and gently scrape the surface. A thin layer here may also be easily removed Thoroughly clean a small area, noting that the aboral tentacles come away with this layer. icniacies , J^HH 7^1 T '■''^^^" ^ '°"«^ ""^'^ ^y^' i° ^hich are embedded the calcareous plates which constitute the skeleton. r^/*.m- 1 84 Practical Zoology. Bend this membrane to see thp r^i *• , , Pla.es .0 .he n-embrane^:? tl": jf :"- " "' "'"'~"' as wen as be^t a^eL "";U"t"r "''"" °' ""' '"''•^^• calcareous plates are deL„„^? ? ! '■"portant point, as the Part of l^Zlt^Trlrjl'T '"''"'T- ing. by .eans of which mot," , i 'tt^ed' TZ t """T' tions in the membranf^ in ,-fc *u- ^'"^^^^a- -Note the perfora- Where the abo^auircks^tTor "'""' '^""" *' P'"« carefully ^ ambulacra! plates and examine them cutoff e"„d of *f' lir^he'^f t ^"""'^r"' """''' """ '"^ U.S the poi„. of . d}t;r;Ltbera„;x:" t^thi ampulla In frLj. ' ^^"' ^'^^'"'"^ ^^^ distended wir:t.o:e"dt^drwr;,atL;Trrt^ ^ '"-'«> preparations. I„U preparaltra^dl": ^- Cop^™eS Echinodermata. 185 of a properly prepared ray, it may be seen that the water tube of the ray sends off side branches to the tube feet, and also that the cavmes of the tube feet and ampullae are continuous. By the contraction of the ampullae the tube feet are extended, and by the muscles in their walls they are moved from side to side and applied to the surfaces on which the starfish rests. The end is fixed by means of the suckerlike disk at the tip of the foot to some foreign object ; then, by the contraction of the tube feet the starfish pulls its body along. ' The water finds its way through the madreporic body into the stone canal, thence to the water ring around the mouth, and from this to the radial canals. The water thus taken in probably serves for respiration as well as for locomotion. 26. Make a drawing of a cross section of a ray, showing 33 many as possible of the above-noted points of structure. A slide with a series of very small starfishes shows well how the rays are formed as outgrowths of the disk. Read Seaside Studies in Natural History, Agassiz. Topics for Reports. — Starfishes and the Oyster Industry. THE SEA URCHIN. Study of a Live Sea Urchin. At low tide search the tide pools for sea urchins. For collec- tion and study, follow the directions given for the study of the hve starfish. Keep sea urchins in a salt-water aquarium and study their habits. Turn a sea urchin upside down in the aqua- rium. Can It turn back? How does it accomplish this, and how long does it take to right itself ? The requisites for this work are, cleaned skeletons, or tests, alcoholic specimens, microscopic sections, etc., as in the case of the starfish. The Cleaned Test. I. Observe the radial distribution of the parts around an axis at one pole of which, the oral pole, is a large opening. At the »^i^f f'i'j«.-> i86 (l ! M !l Practical Zoology. opposite pole, the aioral Mc is <. .,r„ i several small plates near tC. . T^"^' "'* composed of 2. Note thai ?h. , ! < "'" °' *''''^'' i» ">« »■>»' openrng Pu, one of the plat s iirT^" °' "'^""^ P^" "^""^ occurs. '^ "'° " '""' <'""«« »^W and note what which the calcareous matter his h '"''""'"' '•'• ""^ '™"' other^acld. Oh_ .at^^IdXrars^rfstr,; toteth:ute\trrxr:r r-^r on the inside of the calcareous ptoe" """""^ '"" caTe ottht staTfis^'anT"' ^k"'" "^''°" °'^ P"«'' - '" *« inclosed in Ihe b^^ wal'l iT'tT'^ '' "^^ "'^'^ """"^ meshes were penetrated hvth )^r °™' ^ ""™* "ho" wall. It should'oTbe cfeir tha^t , '""f "''^''"" °' *" """^ Str-^h^sr"'-"*^^^^^^ ^y/ea.e„fe"o;rC^^^^^^^^^^ a f i nrljacent interradial sutures > The perforated plates are the ambulacral pUtes, and the unper. forated, the Interambulacral plate.. Compare these two sets of plates with the corresponding parts of a starfisn. 9. The ambulacral plates form the ambulacral areas Trace each of the ambulacral areas to its aboral end, and find at its apex a small plate wedged in between two adjacent genital plates These smaller ones are the ocular plates. Note the small open- mg from which projects an unpaired tentacle, the end of the radial water tube. 10. Carefully compare the hard parts of the starfish and sea urchin Wherein are they alike, and wherein do they differ? What changes in growth would be necessary to convert one of these forms into the other ? What part of a starfish is homolo- gous with the anal ares of a sea urchin .> 11. Make careful drawiijgs of the oral surface, of the aboral surface, and of the side of the test. Alcoholic Specimen. For the sake of review and comparison, it is w'ell to have the cleaned test before you during this study. 1. Observe the soft membrane, the peristome, on the oral surface and the teeth projecting from the mouth. 2. At the aboral pole look for the anus and genital plates • 3. Examine one of the largest spines; move it about to' see Its range of motion. Remove it and make out how it is articu- lated to the test. The fleshy tube ensheathing the base is muscular tissue, by the shortening of which the spine is moved. Clean the spme and make a drawing of it. 4. Note any variations in the size and shape of the spines in various regions. 5- Study carefully the arrangement of the spines, using the cleaned test for comparison. \ ,jBri'".^^ i88 Practical Zoology. iec^ont^rtut 'ft" '" "?? '''"^ «"^ ^'' *"^"'- pro. DiSSKTION OF THE SEA UrCHIN. Of ^ITr'l'th^iT"' '"'■ °' ■"""•''" "'* *« blade the .ntesune ,0 the anus, describing carefully its cou«l ..•"^mf:^- Echinodermata. 189 Place m water the pieces of test left after dissection and macerate 1. 1 the spines are readily detached. Then clean and keep them for the next class. They will be useful for pulling to pieces to make out the structure of the test. Topic, for Reporti. — Boring Sea Urchins. CHAPTER XIX TROCHELMIITTHES. '' ""•^ mtestine. «« Pharynx are the stomachan! Kotjfers are classed with th- ence of a distinct digesHve Zj""T '■ """'8'' ''"'=11, the pre, organs of sightandh^eanlt^^he'^r"""™"-^"';',^ ■n'o water .h:;revt ';"' "" "'"• '" ^«»". -d ,e. when put atudy carefully : - . '• J?;^'"^^^^^ locomotion. ^- The action of the disks and cilia 3. The„ot,onsofthepha^nx. ^ Ma.e dTI;!— : rCr h^lh^^.^ r ^ ^^ a .hole. the contracted state. ^ °''^ ^'^ '" ^h^ expanded and in Read the "General ru Zoology ■ u R^^ff „ ^^^'•a'^^ers of Rotifers " in p , of 7n^/ Rot'fera " in ciaus anr? TT ■ Packard's o/Zoo/ogy,- " Trochelminthes 'Mn P , ^^^^'^^'^ T.^r-iooJi ^ook of Zoology, ''-'' '" Pa'-ker and Haswell's rJr^ 190 INDEX. um where of plant arium, or IJs of the in a two- circular Jrticella. )h«iynx, ich and >e pres- n\, and ^ more en put e. tid in ird's Abdomen of craxfish, 3611 Of grasshopper, la. Of rabbit, 137. Of spider, 31. Abdominal cavity of rabbit, 139. AbornI pole of sea urchin, 186, Surface of starfish, 178. Achilles' tendon, 90. Adam's apple, 156. Adductor muscles of clam, 58, Air bladder of fi,h, 74, 76. Chambers of sow bug, 45. Sacs of grasshopper, 13, 14. Sacs of pigeon, 116. Sacs of snake. 98. Space in egg, lai. Tubes of grasshopper, 13. Ambulacra of sea urchin, 188. Of starfish, 179, i8o. Ambulacral plates of sea urchin, 187. Of starfish, 179. Vesicles of starfish, 181. Amoeba, 163. Division of, 164. Movements of, 163. Amphibia, 83. Ampullze of starfish, i8i. Anal plates of sea urchin, i8d. Animalcule, bell, 166. Slipper, 164. Wheel, 190. Annulata, 47. Anosia, 19. Antennae of crayfish, 4a Of grasshopper, 10. Antcnnules of crayfish, 4a Anteorbital bone of fish, 73. Anterior end of earthworm, 5a Of fish, 69. Ant-lion, 38. ' Ants, 35. Anus of frog, 84. Aorta offish, 76. Of frog, 85. Of mammal, 134, 1^5, 14a Aortic arches of earthworm, 51. Aperture of snail shell, 64. Apex of heart, 136. Aquarium, fishes in, 68. Arachnida, 30. Arch of aorta, 14a Neural, of vertebra, 78. ?ectoral,of fish, 77. ches. aortic, of earthworm, 51. Arterial bulb of fish, 76. Arteries, cardiac, 139. Of crayfish, 43. Of distribution, t4a Of frog. 85. 88. Of pigeon, 118. Of snake, 98. Artery, xarotid, 14a Iliac, 141. Mesenteric, 140. Pulmonary, 135, 136. Renal, 140. Subclavian, 140. Artific al light, in collecting, 4. Atlas, 161. Auditory nerve, 15a Auricle of clam, 60. Offish, 76. Aur-vent valves, 139. Aves, 104, Axis, i6r. Balancers of fly, 33. Ball-and-socket joint, 161. Barbs of feathers, in. Barbules, in. Beak of bird, 109. Of clam ■hell. 56. Bee bread, a6. Glue, 191 191 Beeswax, a/. Beetle, 23. Bell animalcule, 166. Bile sac of fish, 75. Of frog. 85. Of rabbit, 13a Of snake, 98. Of turtle, 102. Bird, beak of, 109. Ear of, 109. External features of, 108. Glottis of, 109. Head of, 109. Heel of, 109, Leg of, 109. Nostrils of, 109. Oil gland of, no. Scutella of, 109. Skin, preparation of, ua. Tail of, no. } Tarsus of, 109. Thumb of, 110. Tongue of, 109. Trachea of, 109. Windpipe of, 109. Wing of, no. Birds, 104. Bladder, urinary, of fish, 76. Urinary, of frog, 87. Blood tube of earthworm, 51, 52. Board, sprea,.ing, 6. Body cavity of earthworm, 51. Cavity of fish, 74. Cavity of rabbit, 139. Of clam, 58. Of hydra, 171. Bones, anteorbital, 7a. Carpal, 161. Collar, 161. Dentary, 71. Hip, 162. Hyoid, 157, Innominate, 16a. Metacarpal, 162. Metatarsal, i6a. Premaxillary, 71. Quadrate, 120. Bottle, cyanide, i. Boxes, insect, 3, 6. Brain of earthworm. 5a. Index. Brain of fish, 79. Of pigeon, 119. Of rabbit, 146. Branchiosfegal membrane, 73, Rays, 7.-?, Breathing of frog, 83. Pore of fly, 22. Breeding cages, 4. Bristles of earthworm, 49, 50, Bronchi, 135. Buds of hydra, 172. Bugs, i8. Bulb, spinal, of fish, 79. Of frog, 88. Bumblebee, 24. Burrows of earthworm, 47. Butterflies, preserving, 3. Butterfly, milkveed, 19. Monarch, 19. Cabbage butterfly, 20 Cages, breeding, 4. Calf muscle of frog, 90. Canal, stone, of starfish, 18a. Capillaries of frog, 88. Carapace of crayfish, 37. Of turtle, loi. Carbolic acid, 7. Card, crayfish, 41. Grasshopper, 15. Carpal bones, 161. Cartilage, 152, 159. Arytenoid, 157. Cricoid, 157. Thyroid, 156. Of windpipe, 133. Castings of earthworm, 47. Ceca of fish, 75. Of grasshopper, 14. Of pigeon, 117. C starfish, 181. Cecum of rabbit, 130. Cells of honeycomb, 27. Pigment, 73. Cenosarc, 175. Centiped, 32. Centrum of fish. 78. , Of rabbit, 160. Cephalothorax of crayfish, 3d. Of spider, 31. .»'»-- '}|-JV"*,5 i'M'-t- ...fl;, ■. \ Cerebellum of fish, 79. Of mammal, 148. Of pigeon, 120. Cerebral hemisphere of fish, 79. Cerebrum of fish, 79. Of fi-og, 88. Of mammal, 148. Of pigeon, 119. Cervical groove, 37. Vertebrae, 160. Chest of rabbit, 127. Cavity of rabbit, 129. Chirping of cricket, 17. Chloroform, i. Choroid coat, 155, Cilia of clam, 58. Of Paramecium, 165. Of rotifer, 190. Of sponge, 170. Ciliary processes, 155. Circulation in frog's web, 87. Clam, auricle of, 60. Body of, 58. Cilia of, 58. Development of, 61. Digestive gland of, 60. Dissection of, 56. Foot of, 58. Fresh-water, 54. Ganglions of, 61. Gills of, 58. Heart of, 59. Hinge ligament of, 56. Hinge teeth of, 62. Kidneys of, 60. Labial palps of, 58. Locomotion of, 55. Mantle of, 57. Mouth of, 60. Muscles of, 58, 60. Nervous system of, 61, Pericardial cavity of, 59, Position of, 55. Protection of, 55. C-i.ses of, 55. Siphons of, 55. 58, 59. Ventricle of, 59. Water currents of, 55. Clam shell, 56. Beak of, 56. Index. Clam shell, composition of, 63. Hinge ligament of, 56, 62. Inside of, 62. Lime in, 63. Lines of growth in, 56. Muscle scars of, 58, 62. Periostracum of, 58. Structure of, 63. Umbo of, 56. Clavicle of rabbit, 161. Claws of rabbit, 127. Clitellum of earthworm, 50. Cloaca of frog, 86. Of pigeon, ii8. Of snake, 99. Coat, choroid, 155. Mucous, 134. Muscular, 134. Sclerotic, 155. Ccelenterata, 171, Coleoptera, 24. Collar bone, 161. Esophageal, 44. Collecting insects, i, 3. Color of birds, 107. Composition of clam shell, 63. Compound eyes, 10. Compressed fish, 69. Conchiolin, 63. Condyle of pigeon, 120. Of rabbit, 159. Conjunctiva, 152. Contractile vacuole, 163. Vesicle, 163. Convolutions of brain, 148. Coral reef, 175. Stony. 174. Cord, spinal, of fish, 79. Spinal, of frog, 89. Vocal, 157. Cork, 6, Cornea of crayfish, 40. Of ox eye, 153. Corpuscles of frog, 88. Coxa of grasshopper, 12. Cranial nerves, 149. Crayfish, 33. Arteries of. 42. Card, 41. Chimneys, 33. '93 J i J Crayfish, colors of, 33. Dissestion of, 4a. Esophagus of, 43. Gullet of, 43. Heart of, 42. Holes of, 33, Muscles of, 43. Ovary of, 43. Spermary of, 43. Stomach of, 43. Cricket, 17. Crop of earthworm, 52. Of grasshopper, 14. Of pigeon, 116. Croppie, 69. Crustacea, 33, 45. Crystalline lens, 154. Ctenoid scale, t^. Cunner, 69. Cup of coral, 174. Cuticle of earthworm, 53. Of Paramecium, 165. Cyanide bottle, i. Cycloid scale, 73. Cyclops, 46. Darter, 68. Decapoda, 46. Dentary bone, 71. Dentine, 160. Depressed fish, 69. Development, 122. Of cabbage butterfly, 20. Of clam, 61. Of crayfish, 36, Of grasshopper, 15. Dextral shell, 65. Diaphragm, false, of fish," 74. Of rabbit, 129. Digestion in vorticella, 167. Digestive gland of clam, 60. Tube of sea urchin, 188. Diptera, 23. Disk of rotifer, 190. Of starfish, 178. Of vorticella, 166. Dissection, of brain, 146. Of clam, 56. Of crayfish, 42. Of earthworm, 51. Index. I Dissection, of eye, 153. I Of fish. 73. Of frog. 84. Of grasshopper, 13, Of head of rabbit, 143. Of heart and lungs, 133. Of kidney, 142. Of larynx, 156. Of pigeon, 115, Of rabbit, 128. Of sea urchin, 188. Of snake, 97. Ofspinal cord, 146. Of starfish, i8i. Of turtle, loi. Distribution of a; cries, 140. Of veins, 140. Division of amoeba, 164. Dorsal surface of earthworm. <;•. Of fish, 69. Downy feathers, us. Dragon fly, 17. Duodenum of pigeon, 117. Of rabbit, 130. Dura mater, 148. Ear bone offish, 80. Drums of grasshopper, 13. Of bird, 109, Sac of crayfish, 40. Earthworm, 47. Body cavity of, 51. Brain of, 52. Bristles of, 49. Crop of, 52. Cuticle of, 53. Dissection of, 51. Epidermis of, 53. External features of, 5a Ganglions of, 52. Girdle of, 50. Gizzi -d of, 52. Gullet of, 52. Hearts of, 52. Hypodermis of, 53. Intestine of, 51, 52. Kidneys of, 52. Locomotion of, 49. Mouth of, 50. Muscles of, S3, ' It' : ' •/ ■ .-» I £■-*■■■ w ■-■■ ■ii''' Index. »95 Earthworm, nephridia of, 53'. Nerve cord of, 5a. Nerve ring of, 52. Ovaries of, 52. Pharynx of, 52. Typhlosole of, 53. Ectosarc, 163, 165, 166. Egg of cabbage butterfly, ao. Of crayfish, 36. Of grasshopper, 14. Of hen, 120. Of honeybee, 25. Shell, 121. Elytra of beetle, 23. Embryology, ■"•^. Endopod, 37, ^^. Endosarc, 163, 165, 166. Enlargement, cervical, 147. Lumbar, 147. Entomostraca, 46. Epidermis of earthworm, 53. Of fish. 73. Epiglottis of calf, 156. Of rabbit, 145. Epithelium of earthworm, 53. Esophageal collar, 44, Esophagus of crayfish, 43. Of rabbit, 130. Of sea urchin, 188. Eustachian tube of frog, 84. Of rabbit, 145. Exopod,37, 39. Extensor muscle, 151. Of crayfish, 43. Eye, compound, 10. Dissection of, 153. Muscles of fish, 79. Muscles of ox, 15a, Offish, 71. Spot of starfish, 180. Facets of eyes, 10, 17, 40, Facial nerves, 150. False diaphragm, 74. Gill, 73. Family, 19. Feathers, in. Feelers of crayfish. 35. Of grasshopper, 10. Feeling in amseba, 164. [ reeling in crayfish, 35. In Paramecium, 165. In vorticella, 167. Femur of grasshopper, la. Of pigeon, 120. Of rabbit, 162. Fibula, 120, 162. Field study of insects, 7. Filaments of gills, 72. File on cricket's wing, 17. Fins of fish, 70. Median, 70. Paired, 71. Fish, air bladder of, 74, 76. Aorta of, 76. Arterial bulb of, 76. Auricle of, 76. Bile sac of, 78. Brain of, 79. Cerebellum of, 79. Cerebrum of, 79. Dissection of, 73, Ear bone of, 80, External features of, 69. Eye muscles of, 79. False diaphragm of, 74. Feeding, 69. Fins of, 70, Food of, 67. Gills of, 72. Kidneys of, 76. Liver of, 74. Mesentery of, 75. Muicles of, 78. Neural spine of. 78. Olfactory lobes of, 79. Optic lobes of. 79. Optic nerves of, 79. Otolith of, 80. Ovary of. 75. Oviduct of, 75. Pectoral arch of, 77. Pelvis of, 77. Pharyngeal teeth of, 77. Scales of, 72. Senses of, 69. Skin of, 78. Spermary of, 75. Spinal bulb of, 79. Spinal cord o( 79. ^fc'5S5S! 196 Fish, spleen of, 75. Stomach of, 75, Tongue of, 71. Urinary bladder of, 76. Vagus nerve of, 75. Venous sinus of, 76. Ventricle of, 76. Vertebrae of, 78. Fission of amoeba, 164. Flat fish, 69. Flesh fly, 2a. Flexor muscles of crayfish, 43. Of mammal, 151. Floating of fish, 68, Flying of birds, 104. Food of birds, 105. Of fishes, 67. Vacuoles, 163, 165. Foot of clam, 58. Of grasshopper, la. Of rotifer, 190. Of snail, 64. Frog, 8a. Aorta of, 85. Arteries of, 85, 88. Bile sac of, 85. Breathing of, 83. Capillaries of, 88. Circulation in web of, 87. Cloaca of, 86. Corpuscles of, 88. Dissection of, 84. Eustachian tube of, 84. External features of, 83 Gullet of, 84. Heart of, 85. Kidneys of, 87. Liver of, 85. Lungs of, 86. Mesentery of, 86. Nervous systems of, 88. Olfactory lobe of, 88. Olfactory nerves of, 88. Optic lobes of, 88. Optic nerves of, 88. Ovaries of, 87. Oviduct of, 87. Pancreas of, 86. Pericardium of, 85. Skeleton of, 91, 9a. Index. Frog, spermary of, 87. Spinal bulb of, 88. Spinal cord of, 89. Spinal nerves of, 89. Spleen of, 87. Swimming of, 83. Urinary bladder of, 87. Veins of, 88. Fur of rabbit, 137. Ganglions of clam, 61. Of crayfish, 44. Of earthworm, 53. Of grasshopper, 15. Of spinal nerve, 147. Gastric ceca of grasshopper, 14. Genital plates of sea urchin, 186. Genus, 19, 21. Germ spot in eggs, 121. Gill chamber of crayfish, 30. Clefts, 72. False, 73. Filaments, 72. Openings, 72. Paddle, 39. Rakers, 72. Scoop, 39. Gills of clam, 58. Of crayfish, 38. Of fish, 72. Girdle of earthworm, 50. Gizzard of earthworm, 52. Of pigeon, 117. Glands, digestive, of clam. 60. • Digestive, of crayfish, 43. Green, of crayfish, 40, 44. Lymphatic, 135. Oil, of pigeon, 110. Salivary, of rabbit, 143. Glandular stomach of pigeon, 118 Glottis, of bird, 109. Of frog, 84. Of rabbit, 145. Of snake, 98. Grasshopper, 10. Card, 15. Green gland, 40, 44. Groove, cervical, 37. Grub, 24. I Gullet of craj-fish, 43, Index. 197 Gullet of earthworm, 5a. Of frog, 84. Of mammal, 133. Of rabbit, 130. Of snake, 98. Of vorticella, 167. Hairs of rabbit, 137. Head of bird, 109. Of rabbit, 143. Heart of clam, 59. Of crayfish, 42. Of earthworm, 53. Of fish, 74, Of frog, 85. Of grasshopper, 14. Of pigeon, 118. Of rabbit, 131. Of snake, 98. Of turtle, loi. Structure of, 137. Heel of bird, 109. Cord, 90. Hemal arch of vertebra, 78. Spine, 78. Hemiptera, 18. Hemispheres of brain, of fish, 79. Of frog, 88. Of mammal, 148. Of pigeon, 119. Hepatic veins, of fish, 74. Of rabbit, 141. Hilum of kidney, 143. Hinge ligament, 56, 63. Teeth, 62. Hip bone, 162. Hive of bees, 35. Honey, 24, 35. Bee, development of, 25. Comb, 25, 27. House fly, 21. Humerus of pigeon, 120. Of rabbit, 161. Humor, aqueous, 154. Vitreous, 155. Hydra, 171. Hymenoptera, 35. Hyoid bone, 157. Hypodermis of earthworm, 53. Hypoglossal nerves, 150. Ichneumon fly, 31. Incisors of rabbit, 159. Innominate bone, 163. Insect net, 3. Pins. 5. Insecta, 10, 29. Insects, collecting, 1. Field study of, 7. Relaxing, 7. Review of, 38. Spreading, 6. Insertion of muscle, 9a Interambulacral plates, 180. Intestine of crayfish, 43. Of earthworm, 51, 53. Of fish, 75. Of grasshopper, 14. Of rabbit, 130. Of sea urchin, 188. Of snake, 99, Iris, 154. Isthmus of fish, 73. Jaw feet of crayfish, 39. Joints, ball-and-socket, 161. Kidneys, dissection of, 143. Of clam, 60. Of crayfish, 44, Of earthworm, 53. Of fish. 76. Of frog. 87. Of pigeon, 118. Of rabbit, 131. Of snake, 99. Structure of, 143. Killing bottle, i. Kneepan, 163. Labeling insects, 6. Labium of grasshopper, 10. Labrum of grasshopper, 10. Lantern, collecting insects by, 4. Of sea urchin. 188. Larva of honey bee, 36. Larynx, 133. Lateral line, 73. Left-hand shell, 65. Leg of bird, 109. Ofgrasshoiq>er, la. 198 Index. ^3 = Leg of rabbit, 15a Lens capsule, 154, Crysulline, 154. Lepidoptera, 19. Ligament, 151. 159. Lime in clam shell, 63. Lines of growth, 56. Lip, of snail shell, 64. Upper, of earthworm, 501 Liver of fish, 74, Of frog, 85. Of pigeon, 117. Of rabbit, 139, 130. Of snake, 98. Of turtle, 102. Lobes, olfactory, of fish, 79. Optic, of frog, 88. Locomotion of amoeba, 163. Of clam, 55. Of earthworm, 49. • Of Paramecium, 165. Lung sacs of spider, 31. Lungs, dissection of, laa. Of frog. 86. Of pigeon, 118. Of rabbit, 131. Of snake, 98. Of turtle, loa. Lymphatic glands, 135. Lymph hearts, 83. Macronucleus, 165. Madreporic body, 180, i8d. Maggot, aa. Mammalia, 123. Mandibles of crayfish, 40. Of grasshopper, 10. Mantle of clam, 57. Maxilla of crayfish, 39. Of grasshopper, n. Of spider, 31. Maxillary bone, 71. Maxilliped of crayfish, 39. Median fins, 70. Mediastinum, 132. Membrane, mucous, 134, 156, Mesentery of sea anemone, 174. Offish, 75. ^^ Of pigeon, 117. Of rabbit, laa Mesentery of starfish, 181. Mesothorax of grasshopper, ii. Metacarpal bones, 162. Metastoma, 40. Metatarsal bones, 162. Metathorax of grasshopper, 11. Micronucleus, 165. Migration of birds, 106. Milkweed butterfly, 19. Milliped, 32. Minnow, 68. Molars of rabbit, 160. Mollusca, 54. Molting of birds, io5. Of crayfish, 36. Monarch butterfly, 19. Mounting insects, 5. Mouth of clam. 60. Of crayfish, 39. Of earthworm, 50. Of hydra, 171. Of Paramecium, 165. Of sea urchin, 187. Of snail, 64. Movements of amoeba, 163. Of vorticella, 167. Mucous membrane, 156. Muricea, 175. Muscle, digastric, 144. Extensor, 151. Flexor, 151. Insertion of, 9a Masseter, 143. Of frog, action of, 9a Of starfish, 181. Origin of, 90, 151., Papillary, 138. Pectoralis, 117. Scars of clam shell, 58, 62. Sheath, 91, 151. Striated, 91, 152. Striped, 91, 152. Subclavian, 117. Temporal, 144. Muscles, abdominal, of pigeon, ng. Extensor, of crayfish, 43. Flexor, of crayfish, 43. Of clam, 58, 60. Of crayfish, 43. Of earthworm, 53. Index. 199 Muscles of eyeball, 15a. Of fish, 78. Of fish eye, 79. Of grasshopper, 14. Of larynx, 157, 158. Of pigeon, 116. Of starfish, i8a. Myriapoda, 30, 31, 32. Nectar, 34. Nephridia, 52. Nerve collar, 5«. Nerve cord of crayfish, 44. Of earthworm, 52. Of grasshopper, 15. Of starfish, 180. Nerve, optic, 153. Ring, of earthworm, 52. Ring, of starfish, 180. Sciatic, of frog, 89. Vagus, of fish, 75. Vagus, of pigeon, 116. Nerve-muscle preparation, 9a Nerves, auditory, 150. Crr nial, 149. Facial, 150. Hypoglossal, isa Of crayfish, 44. Olfactory, of frog, 88. Optic, of fish, 79. Optic, of frog, 88. Spinal, of frog, 89. Spinal, of rabbit, 147. Nervous system of clam, 61. Of fi-og, 88. Of grasshopper, 15. Of rabbit, 146. Nestinr of birds, 105. Net, insect, 2. Neural arch, 78. Spine, 78. Nostrils of birds, 109. Of fish, 72. Nucleus, 163. Nymph, 18. Nymphalidae, 19. Observation hive, 25. Ocelli, 10. Ocular plates, 187. Odonata, 18. Odontoid process, 161. Oil gland of birds, no. Olfactory lobes of fish, 79. Nerve of frog, 88. Nerve of mammal, 148, 149. Olfactory nerv of frog, 88. Opercle of fish, 72. Operculum of snail, 65. Optic lobes of fish, 79. Of fi-og. 88. Nerve of fish, 79. Nerve of frog. 88. Nerve of mammal, i"'). 153. Oral groove of Paramecium, 165. Pole of sea urchin, 185. Surface of sea urchin, 187. Surface of starfish, 178. Orbit of eye, 159. Order, 19. Origin of muscle, 90, 151. Orthoptera, 17. Otolith, 80. Ovary of crayfish, 43. Of earthworm, 52. Of fish, 75. Of fi-og. 87. Of hydra, 173, Of pigeon, 119. Of sea urchin, 188. Of snake, 99. Of starfish, 181. Of turtle, 102. Oviduct of crayfish, 43. Of earthworm, 50. Of I. h, 75. Of frog, 87. Of grasshopper, 14. Of pigeon, 119. Of snake, 99. Oviparous animals, 122. Ovipositor of cricket, 17. Of dragon fly. 18. Of grasshopper. 13. Ovoviviparous animals, laa. Paired fins, 71. Palate of rabbit, 144. Palatine bones, 71. Palps of butterfly, 19. 200 Index. 'I # ;N Palps of clam, 58. Of crayfish, 40. Of grasshopper, 11. Of spider, 31. Pancreas of frog, 86. Of pigeon, 117. Of snake, 99. Papillae of rabbit's tongue, 144. Paramecium, 164. Parasites, 21. Partitions of earthworm, 51. Patella, 163. Pectoral arch, jj. Fin, 71. Muscle, 116. Pedicellariae of starfish, 180. Pelvis of fish, ^^. Of rabbit, 16a. Of turtle, loi. Perch, 69. Sea, 69. Perching of birds, 119. Pericardial cavity of clam, 59. Fluid, 135. Pericardium of frog, 85. Of mammal, 135. Of pigeon, 118. Of snake, 98. Periosteum, 152. Periostracum of clam shell, 58. Peristome of sea urchin, 187. Of starfish, i8o. Of vorticella, 166. Peritoneum of fish, 74, 76. Of rabbit, 129. Phalanges, 162. Pharyngeal teeth of fish, 77. Pharynx of earthworm, 52. Of rabbit, 14a. Of rotifer, 190. Pia mater, 148, 149. Pieridae, 21. Pigeon, air sacs of, 116. Arteries of, 118. Brain of, 119. Ceca of, 117. Cerebellum of, laa Cerebrum of, 1x9. Cloaca of, 118. Crop of, 116. Pigeon, dissection of, 115. Duodenum of, 117 Gizzard of, 117. Heart of, 118. Kidneys of, 118. Liver of, 117. Lungs of, 118. Mesentery of, 117. Muscles of, w-j. Ovary of, 119. Oviduct of, 119. Pancreas of, 117. Pericardium of, 118. Skeleton of, 120. Spermaries of, 119. Spinal cord of, lao. Trachea of, 116. Pigment cells of fish, 73. Pinchers of crayfish, 44. Pin feathers, 112, Pinning insects, 5. Pins for insects, 5. Pisces, 66, Plaster of Paris, i. Plastron of turtle, loi. Plates, ambulacral, 187. Anal, of sea urchin, 186. Epidermal, of turtle, loi. Genital, of sea urchin, 186. Pleura, 134. Pl^urum of crayfish, 37. Of grasshopper, 13, Plexus, brachial, 147. Poison, 1. Poison gland of bee, 25. Pollen, 34. Pond snail, 64. Pore, breathing, of fly, aa. Porifera, 168. Position of clam, 55. Posterior end of earthworm, sa Of fish, 69. Premaxillary bone offish, 71. Preservation of insects, 5. Prima-ies, iio. Proboscis of bee, 24. Processes of vertebrae, 161. Propolis, 27. Prostomium of earthworm, 50. I Protection of clam, 55. ^^,'*.'. . ^'-mr : Wi^^SF^r^^ Index. 20 1 Prothorax of grasshopper, 11. Protoplasm, 163. Protopod of crayfish, 37, 39. Protozoa, 163. Pseudopod, 164. Pulsating vacuoles, 165. Puparium of fly, aa. Pupil, 154. Pyramid, urinary, 143. Quadrate bone, laa Quill feathers, iii. Rabbit, 133. Abdomen of, 127. Abdominal cavity of, 139. Bile sac of, 130. Body cavity of, 139. Brain of, 146. Cecum of, 130. Chest of, 127. Chest cavity of, 139. Diaphragm of, 139. Dissection of, 128. Duodenum of, 130. Epiglottis of, 145. Fur of, 137. Glottis of, 145. Gullet of, 130. Heart of, 131. Intestine of, 130. Kidneys of, 131, Legs of, 150. Liver of, 130. Lungs of, 131. Mesentery of, 130. Peritoneum of, 139. Pharynx of, 144. Rectum of, 131. Skeleton of, 158. Spinal cord of, 146, 147. Spleen of, 130. Stomach of, 129. Thoracic cavity of, 139. Thorax of, 127. Villi of, 131. Radius of pigeon, 120. Of rabbit, 161. Rays, 70. Of sta fish, 178. Rectum of rabbit, 131. Red coral, 176. Reflex action of spinal cord, 89. Relaxing insects, 7. Reproduction of amoeba, 164. Of Paramecium, 166. Of vorlicella, 167, Reptilia, 95. Retina, 155. Right-hand shell, 65. Roots of nerves, 147. Rostrum of crayfish, 37. Rotifer, 190. Salivary gland, 143. Scales, 19. Ctenoid, 73. Cycloid. 73. Of butterfly, 19. Of fish, 73. 'Of snake, 96. Of turtle, loi. Scapula, 161. Sciatic nerve of frog, 89, 90. Of rabbit, 148, 151. Sclerotic coat of eye, 155. Scutella of birds, 109. Sea anemone, 173. Fan. 175. Feather, 175, Perch, 69. Urchin, 185, 188. Secondarirs, no. Segments of earthworm, 50. Senses of clam, 55. Of crayfish, 35. Of fishes, 69. Septa of coral, 175. Shaft of feather, in. Sheath of muscle, 91. Shell bag, 3. Sinistral shell, 65. Siphons of clam, 55, 58, 59. Skeleton of crayfish, 40. Of frog, 91, 92. Of pigeon, 120. Of rabbit, 158. Of sponge, 168. Of turtle, loa. Skin of fish, 78. 7t(* Iwi' • . ijil-i , . «* ii^.-;'- Qyi^iSmi^M^:^! X ^ 202 Slipper animalcule, 164. Snail pond, 64. Shell, 64. Snake, 95. Air lacs of, 98. Arteries of, 98. Bile sac of, 98. Cloaca of, 99. Diuection of, 97. External features, 96^ Glottis of, 98. Gullet of, 98. Heart of, 98. Intestine of, 99. Kidneys of, 99. Liver of, 99. Lung of, 98. Ovary of, 99. Oviduct of, 99. Pancreas of, 99. Pericardium of, 98. Scales of, 96. Skin, preparation of, 99. Spermary of, 99. Sperm duct, 99. Spleen of, 99. Stomach of, 98. Teeth of, 97. Tongue of, 97. Ureters of, 99. Veins of, 98. Ventral plates of, 96. Snout of fish, 70. Songs of birds, jo6. Sounds made by grasshopper, la. Sow bug, 4S. Species, ao, ai. Sperm duct of snake, 99. Receptacles of earthworm, 53. Sacs of earthworm, 51, 52. Spermaries of crayfish, 43. Of fish. 75. Of frog, 87. Of hydra, 173. Of pigeon, ng. Of sea urchin, 188. Of snake, 99. Of starfish, 181. Spicules of sea fan, 176. Of sponge, 169. Index. Spider, JO. Web, 30. Spinal bulb of fbh, 79k Of frog. 88. Of mammal, 148. Spinal cord of fish, 79. Of frog, 89. Of pigeon, lao. Of rabbit, 146. 147. Reflex action of, 89. Spinal nerves of frog, 89. Of rabbit, 147, Spines of fish, 70. Of vcrtebraj, 78. Of sea urchin, 187. Spinnerets of spider, 31. Spinning of spider, 30. Spiracles of fly. aa. Of grasshopper. 11. 13. Spire of snail shell. 65. Spleen of fish. 75. Of frog. 87. Of rabbit. 13a Of snake. 99. Sponge. 168. Cilia of. 170. Simple. 169. Skeleton of, 168. Spreading board, 6. Insects, 6. Squash bug, t8. Starfish, 177. Dissection of, 181. External features, 178. Sternum of crayfish. 37. Of grasshopper. 13. Sting of bee. 25. Stomach, glandular, of pigeon, 118. Stomach of clam, 60. Of crayfish, 43. Offish. 75. Of frog. 86. Of rabbit. 129. Of sea urchin. i88. Of snake, 98. Of starfish. 181. Of turtle. loa. Stone oanal of starfish, 18a, Stony I. 's, 174. Striated mascle. 91. f:m -;fij7M^^:'/m^iUif .^ '^T^j ^ Index. aoj StriduUtion of graMbopper, i*. Striped muscle, 91. Structure of clam shell, 63. Of heart, 137. Of kidney, 143. Stylets of cricket, 17. Sugaring, 4. Sunfish, 69. Sutures, interradial, of sea urchin, 187. Of rabbit's skull, 159. Of snail shell, 64. Swimmerets of crayfish, 37. Swimming of crayfish, 34. Of fish, 68. Of frog, 83. Symmetry, bilateral, of earthworm, sa Of fish, 69. Synovia, 151, 1S9. Tadpole, 93. Tail of bird, iia Fin, of crayfish, 38. Tarsus of bird, 109. Of grasshopper, xa. Of mammal, i6a. Teeth, pharyngeal, of fish, 77. Of rabbit, 159. Of sea urchin, 187. Of snake, 97. Telson of crayfish, 38. Tendon, 158. Achilles, 90. Tentacles of hydra, 171. Of snail, 64. Of starfish, 180. Tergum of crayfish, 37. Tertiaries, no. Test of sea urchin, 185. Tetradecapoda, 46. Theca of coral, 174. Thigh of bird, 109. Thoracic cavity of rabbit, 199. Thorax of rabbit, 127. Thousand legs, 31. Thread cells of hydra, 172. Thumb of bird, no. Tibia of grasshopper, 12. Of pigeon, laa Of rabbit, i6a. Toes of bird, 109. Tongue of bM.a4. Of bird, 109. Of fish, 71. Of grasshopper, II. Of snake, 97. Trachea of bird, X09, ll6w Of rabbit, 131, 133. Of snake, 98. Tracheae of grasshopper, 13. Transformation of dragon fly, it. Trochanter of grasshopper, la. Trochelminthes, 190. Tube feet of sea urchin, 188. Of starfish, 179, x8o. Tubercle of rib, 161. Turtles, xoa Bile sac of, xox Dissection of, lox. External features of, xoi. Heart of, xoi. Liver of, xoa. Lungs of, xoa. Ovary of, xoa. Pelvis of, lox. Scales of, lox. Skeleton of, xoa. Stomach of, xoa. Vertebrae of, xoa. Tympanum of frog, 84. Of grasshopper, X3. Typhlosole of earthworm, 53. Ulna of pigeon, lao. Of rabbit, x6i. Umbo of clam shell, 56. Ureter of mammal, X4a. Of snake, 99. Urinary bladder of frog, 87. Pyramid, 143. Vacuole, contractile, X63. Food, 163. Pulsating, of Paramecium, x6s. Pulsating, of vorticella, 167. Vagus nerve of fish, 75. Of pigeon, 116. Valves, aur-vent, 139. Of clam shell, 56. Mitral, 139. Semilunar, 138. TJMMHieiUiVitt^liiiyA'i'im^'.^r-^^ii Kl ■■ii'ytY'iB^ ^'Xr^i4 '! li 204 ValvM, tricuspid, ijl. In veins, 141. Vent-art, 139. '■'•ne of feather, iii. Veins, cardiac, 137. Cava], 135. Distribution of, Z4a Of frog, 88. Gastric, 141. Hepatic, of fish. 74, Hepatic, of mammal, 141. Iliac, 141. Innominate, 141. Jugular, of mammal, 141. Jugular, of pigeon, n6. Mesenteric, 141. Pancreatic, 141, PorUl, 141. Postcaval, 141. Precaval, 141. Pulmonary, 136. Renal, 141. Of snake, 98. Splenic, 141, Subclavian, 141. Valves in, 141. Of wings of insect, 13, 14. Venous sinus of fish, 76. Vent-art valves, 139. Ventral plates of snake, 96. Ventral surface of earthworm, so. Of fish. 69. '^ Index. Ventricle of brain. i4f. Of clam, 59. Of fish, 76. Of mammal, 135, 13I, Vertebrje of fish. 78. Of pigeon, lao. Of rabbit, i6a Of turtle. 10a. Vesicle, contractile. 163. Ambulacral, 181. Villi of rabbit. 131. Viviparous animals, im, Vocal cords, 157. Vomer of fish, 71. Vorticella, 166. Walking of birds, 104. Of crayfish, 34. Of fly. 23. Wasp, 25. Water currents of clam, «. Glass, 67. Ring of starfish, 183. Tubes of starfish. 184. Wax. bees', a6. Wheel animalcule, 190. Whorls of snail shell, 65. Windpipe of bird, 109. Wing of bird, no. Of fly. motion of, aa. Of grasshopper, n. Winglet of fly, aa. -* -^ "Tl^^'S^^ ^r^c-^jj^,?. ^^r^m ri'^--.