xvi COMPARATIVE ANATOMY 



PAGE 



6. The Body Cavity, the Musculatuhb which passes teansveesely 



THEOUQH IT, THE DISSEPIMENTS AND MeSENTEMES . . 211 



7. The Nbkvotjs System . . 215 



8. Sensory Obsans . . . 228 



A. Organs of Touch . . . . . 228 



B. Eyes . ... .229 



C. Olfactory Organs (Ciliated Organs) . 231 



D. Organs of Taste (Cup-shaped Organs) . 233 



E. Lateral Organs ... . . 233 



F. Auditory Organs ..... . 234 



G. The Lateral Eyes of Polyophthalmus . . 234 



9. Excretory Organs— Nepheidia . 235 



10. Respiratory Organs . . 246 



11. Blood-vascular System . . 248 



12. Genital Organs ... . 254 



13. Parthenogenesis . .... 266 



14. Asexual Reproduction by Gemmation and Fission . 266 



15. Stock Formation . . . 267 



16. Ontogeny of the Worms 268 

 Literature . . . . , 283 



CHAPTEE V 



ARTHEOPODA— ARTICULATA 



First Division — Crustacea 



Systematic Remeio ... ... 288 



1. Outer Organisation . , 300 



A. The Body . , 30o 



B. The Extremities . . 307 



C. The Respiratory Organs — Gills 324 



2. The Integument . 330 



3. The Musculature 33]^ 



4. The Esteric Canal 



A. The Fore-gut 



B. The Mid-gut 



C. The Hind-gut 



5. The Nervous System 



336 

 336 

 338 

 341 

 342 



6. The Sensory Organs . . . ggj 



A. Eyes 



351 



B. Other Sensory Organs . . 355 



