TEXT-BOOK 



OF THE 



^f/. 5'SZ 



Ifrs 



EMBRY0L06Y OF INVERTEBRATES 



BY 



Dr. E. KORSCHELT 



Professor of Zoology &^ Comparative 



Atiatomy in the University of 



Marburg 



Dr. K. HEIDER 



Professor of Zoology in the 

 University of Berlin 



Translated from the German 



BY 



EDWARD L. MARK Ph.D 



Hersey Professor of Anatomy i?i 

 Harvard University 



W. Mc M. WOODWORTH Ph.D 



Instructor in Microscopical Aftatomy 

 in Harvard University 



With Additions by the Authors and Translators 



PART I 



PORIFERA, CNIDARIA, CTENOPHORA, VERMES, 

 ENTEROPNEUSTA, ECHINODERMA TA 



SWAN SONNENSCHEIN & CO., Limd 



NEW YORK : MACMILLAN & CO 



1895 



