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The Histogenesis of Cysticercus pisiformis. 



By 



Robert Thompson Youiig, Ph. D., University of North Dakota. 

 (Studies from the Zoological Laboratory, The University of Nebraska.) 



Mit Tafel 8-11. 



Table of Contents. 



Page 



1. Introduction 183 



2. Material and Methods 184 



3. Histogenesis 186 



a) Earlier Stages of Development 186 



b) Parenchyma and Chalk Bodies 189 



c) Cuticula and Hooks 192 



d) Musculature 196 



e) Excretory System 201 



Ï) Nervous System. "Myoblasts" 210 



g) Sub-cuticula. Epithelial Question 224 



4. Cytogenesis and Nuclear Significance 233 



5. Conclusions 244 



6. Appendix 245 



1. Introduction. 



In order to obtain a true insight into the structure of the 

 Cestodes, which, while apparently complex, is actually simple, and 

 to find the correct answer to those questions concerning their organi- 



Zool. Jahrb. XXVI. Abt. f. Anat. 13 



