THE EMBRYOLOGY OF BDELLODRILUS 
PHILADELPHICUS 
GEORGE W. TANNREUTHER 
Zoological Laboratory, University of Missouri 
TWENTY-SIX TEXT FIGURES AND EIGHT PLATES 
CONTENTS 
]ianigeOde eC So odie oletete epee echo oece Oa eee ORR MEI dic.o rcs. ao do! 144 
INSRHOHL IMHO doce reas es oo ce ete SEL aoa eine wter’s ocd on casts 146 
PEEL Ol nen Mare lODMEMe fc steak e aeais e+ » fad vie s Se aus be ene meat 147 
Rant CRP eMm ee TN eee a fer te tc os a 8G ag areleln hea teh re 149 
i wesinanionuror cleavare Cells. oo: Ah. 0b... 6. sak .noe baibe esd are eee 149 
Ply MeSIOMCleaVARE es. we won iste a8 6.0 cio a4 4 aay ee cece ge ene 149 
DOM Men peTrOGFOtClEAVAGER naam ve. Ps cus <i o «coset oiaeee eee ene ee 149 
besltransinonmal period Of cleavage... . ss. .ed.8 0. oo eee ee ee 161 
Ceapiliaeruleperlod OF ClEAVate.: ¢ oy ic:))s 04 a. consumed oe eb le meee ee 163 
DAK ewhirs bESOMlATO Dash eer kaise a? oild-s @ticc ap Gite otis eye 163 
AMM lNnexsecondesomatoblasteevacncie sere. «vic das 6 on cle se aes eee ere 169 
fi." “IE ave). Gaia) Ov ENN tingepn eek Coe Gea htec Of Recta cn eee Rs oh ec ca Srio.0.c 170 
Genera lehistonyaon toe eermebamds:s sy. . ss 4-2 se wie ios seem ee 172 
elnnemstranim ol ohe germ Pands. 2225.0. ... 2. 000 laa ous Ree eee 173 
ZPmvMindale siravumeor ihe-germ PANGS... 6... 4)... -- ee. ee ees Ge ee 175 
SRO IMeD Sir vem Or Ge aeriny DAMS: f—.< v.50: 2h ose «a's «oe ie ee eee 176 
Tlae Tefen tis inane eH NC lbs ts) oF OO ROT OL S|: cnet a ee On A pea Sota ce 177 
[Pel ep ETAVOUSESVSUCINE we ketl arr scses © Fecal, 4 22, F4, 05105 «cenie 4 cnc ale eeneeone ie 
Peel NEREXCTCUORVASYSUCIM Aa acc hepa Whose, vs Wile wool g!%) ele > Gard eleeu seers See tane clenats 184 
(Gir Me is 2 ech arog Ey ORS see SCREEN, eee he Al 186 
ACCOMM ALAMIVe SiG yO1iGiiheremt: fOPMS ss)... os « oh ed oe. ele eee See aes 187 
Pee Minewtirs eS OMMAUODIASUMA tsar & sish sc sectors sao sect 1.9 coe aeons eennyeenotee att 190 
Eu SSECOMCT GONNA OULAGiE . sare fc shee.2 Ses os «oh be Dae Rieter e Reece ts a 193 
3. Variations in the method of mesodermal formation.................... 199 
Se GCOsMeSO OLAS tee ae elie Bic 2 ur da ee eit ones tae eee ee 199 
EO OEIG-OIESOOPAS beara. ales cealte Sei sick Gs cedie hates «oy Meena oe ee ee ae 199 
PVAniahons mri ne source, OlemlvOC@erm: 2. 4- ae yee ees aes: 205 
General adaptation and interpretation of cleavage...................+-.25. 207 
iene hexcleavaceroins GelloGniluse. . oiaccc ati ocsot-tie omelets Gee be cis ees eee 208 
rlitei nec lear ewOleOtMenrtOGIMlS! ce. cvoe x tele atest dae ees Geese eens ea 212 
ene alles UUMMTT NEN Tay ee eae Meera scom in lieie ahs aise. scosa.at a checha haan ae es A Oueles aa vliccche sayesintelt Ss NG 213 
LL di GLEDAUTONRS HOM UENG | Se aa eee OR ee a oe MLN epta eRe Sturn Sc a cis cers A 215 
143 
JOURNAL OF MORPHOLOGY, VOL. 26, NC. 2 
JUNE, 1915 
