xviii COMPARATIVE ANATOMY 



PAOE 



7. THE CIRCULATORY SYSTEM . . ... 475 



8. FAT BODIES LUMINOUS BODIES . ... 477 



9. THE RESPIRATORY ORGANS . . . 477 



10. SOUND-PRODUCING APPARATUS ...... 483 



11. SEXUAL ORGANS ........ 484 



12. DIMORPHISM POLYMORPHISM ... . . 490 



13. DEVELOPMENT AND LIFE-HISTORY . . . . 490 



14. PHYLOGENY ........ 503 



Literature ......... 504 



CLASS III. Arachnoidea sivc Chelicerota 



Systematic Review ........ 509 



1. OUTER ORGANISATION ....... 511 



A. THE BODY ... . . 511 



B. THE EXTREMITIES . . . . . . .515 



2. THE NERVOUS SYSTEM ....... 518 



3. THE EYES ...... 521 



4. GLANDS OPENING ON THE OUTER INTEGUMENT . . . 522 



5. THE INTESTINAL CANAL .... . . 523 



6. THE BLOOD-VASCULAR SYSTEM ...... 526 



7. THE RESPIRATORY ORGANS . . ... 528 



8. THE SEXUAL ORGANS .... . . 532 



9. ONTOGENY . . . 537 

 10. PHYLOGENY . . 539 

 Literature .... 542 



APPENDAGE TO THE ARTHROPODA 



Tardigrada . . 544 



Literature ...... 545 



