di GENERAL INDEX. 



Page Sec. 



Generative apparatus of male ^.. . 380 . 976 



-of female ........ 380 . 977 



Spinning-organs of the ARANEIDJB 381 . 978 



Uses to which the thread of the spider is converted 382 . 979 



Cavern of Mason Spider (Mygate) 382 . 979 



Tent of Clotho Durandii . 383 . 980 



CHAPTER XIV. 

 CRUSTACEA. 



CRUSTACEA Tegumentary system of the 386 . 982 



Progressive coalescence of the elements of the exoskeleton and of 



the centres of the nervous system 386 . 983 



External organization of Talitrus 387 . 988 



the Lobster (Astacus marinus) .... 387 . 990 



Crab 387 . 991 



King-Crab (Limulus) 387 . 992 



Parallelism between these gradations and the progress of Insect- 

 metamorphosis 388 . 993 



Structure of articulated appendages 388 . 994 



in the Lobster 389 . 994 



Hermit-Crab ... 390 . 999 



Crab 392 . 1001 



Casting of the shell in Crustaceans 392 . 1002 



Structure of the articulations 394 . 1005 



Arrangement of muscular system 394 . 1005 



Structure of the alimentary canal 394 . 1006 



Hepatic apparatus 395 . 1010 



Organs of respiration and circulation 395 . 101 1 



Respiratory organs of the Lobster 395 . 1012 



Crab 395 . 1013 



Branchial chambers 397 . 1014 



Mechanism of the respiratory apparatus 397 . 1015 



Circulatory apparatus in the lower Crustacea 398 . 1018 



Decapoda 398 . 1019 



Course of the circulation 399 . 1022 



Lacunar system in the Crustacea 400 . 1023 



Nervous system 401 . 1024 



of Talitrus 402 . 1025 



Oniscus Asellus 402 . 1026 



Crab 402 . 1027 



Centralization of the nervous system during embryonic develop- 

 ment 403 . 1028 



Conclusions from the above facts 403 . 1029 



Distribution of the nerves 403 . 1030 



Nervus vagus 403 . 1031 



Sensitive and motor tracts of the nervous system 404 . 1033 



Susceptibility of pain in the Articulata 405 . 1035 



Structure of tegumentary crust 406 . 1038 



Power possessed by the Crustacea of voluntarily breaking off their 



limbs 407 . 1039 



Capability of reproducing them .... 408 . 1040 



Physiology of the process of reproducing cast-off limbs .... 408 . 1041 



Senses of the Crustacea 408 . 1042 



Structure of the organs of vision 409 . 1043 



Simple eyes 409 . 1044 



Agglomerated eyes 40^ 



Compound eyes ":.:*. v', ^ ; ~ . . . 409 . 1046 



Auditory apparatus 409 . 1047 



Generative system ~ * - 411 . 1053 



Male organs of Astacus fluviatilis, 411 . 1054 



