692 



INVEETEBEATA 



Ventral cell-family in segmenting egg of 



. IMW/-/.S- megalocephala, 4-10 

 Ventral ciliated epaulettes, formation of, in 



larva of Echinus esculentus, 511 

 Ventral ganglion, formation of, in Say it /it 



t>ijiitctfn, 432 



Ventral nerve-cord, formation of, in Crio- 

 In, i/nm, 158 ; \\\ Nephelis, 162 ; in 

 citjiciisis, 174 ; in Polyyon/iiix 



147 

 Ventral organs, formation of, in Peripntnn 



rii/ii'iis-is, 174 

 Ventral plate in the embryo of Agelena, 224 ; 



in embryo of Unio, 351 

 Ventral retractor muscles, formation of, in 



larva of /irrissensia, 341 

 Ventral shield in embryo of Astacus, 186 

 Ventral sinus, formation of, in J\Vy<//<://X 163 

 Ventricle of heart, formation of, in Cyr/ax, 



350 ; in Loligo, 362 

 Ventro-lateral chamber of Urticina crussl- 



cornis, 80 

 Vertebra, formation of, in Ampl/iurc xij/itt- 



mattt, 499 

 Vertebrata, 29, 162, 568, 569, 584, 585, 



586, 605, 606, 608, 625, 636, 646, 662 

 Vesicula seminalis of Ascaris megalocephala, 



438 

 Vestibule, formation of, in larva of Antedon 



rosacea, 557 ; in larva of Pedicr//i/nt, 400 

 Vibratile cleft, formation of, in Cyphonautes 



larva, 390 

 Vibratile plume, formation of, in Cyphonautes 



larva, 391 

 Visceral ganglion, formation of, in larva of 



simple Ascidian, 622 ; in Dreiwiixin, 



342 ; in Loligo, 358 ; in Paluilina, 315 

 Visceral hump, formation of, in Loligo, 



361 ; in I'ntdlu, 300 

 Visceral muscles, formation of, in CV/W;Y///.s, 



158 ; in Jjoni/ciit, 256 ; in Polygordius 



appendiculatus, 147 

 Visual rods, of Cephalopod eye, formation 



of, 368 ; of ocelli of Dytiscus, 273, 274 

 Yitellarium of Gallidina russeola, 424 

 Vitelligenous cells of Platyhelmiuthes, 102 

 Vitelline membrane, definition of, 3 ; forma- 

 tion of, 9, 17; in egg of Ainjil/in.:'".-. 



587 ; in unfertilized eggs of Echinoidea, 



524 

 Volvox, 660 ; compared with blastula, 51 



Water-tubes of larva of A-stcrias, 466 



Water- vascular system of Eehinodermata 

 see Hydrocoele 



Wheel-organ, formation of, in A m/ili 'n>,< u 

 lanceolatus,6Q<l ; in Callidina //'.<:"/, 42 1 



Wheels in larva of Synj>(it ifigifntii, 535 



White bodies, formation of, in Loligo, 361 



Wings of Dnri/phura, development of, 271 

 273 



V\ ings, rudiments of, in larva of Galerun-ll, 

 til mi, 268 



Wing-sac of Buprestidae, 277 ; of Ceram 

 bycidae, 277 ; of Culicidae, 278 ; ii 

 Doryphora, 271 : in Insecta, various type 

 of, 277-279 ; of Lepidoptera, 278 ; o 

 Muscidae, 278, 279 ; of Scarabaeidae 

 277 ; of Tipulidae, 278 



Worm-like larva of Ophium lircrisjiiim, 56: 



Xiphosura, 221 



yi>l</in, 1 n-va of, 349, 369 



Yolk, influence of, on segmentation of egg, an< 



on the formation of layers in the embryo 



26, 657 

 Yolk -cells, formation of, in embryo o 



Donacia, 247 ; in embryo of /,<y'.v/// 



264 ; in embryo of Pyrosomn, 633 ; ii 



Scoloftendra, 282 

 Yolk-lobe in egg of Dent.alimn, 326. (& 



also Polar lobe.) 

 Yolk-membrane, formation of, in egg o 



Sepia, 355 

 Yolk-nucleus, definition of, 3 ; of egg o 



Cynthia partita, 610 

 Yolk-sac, development of, in Ifeli.v, 369 



in Loligo, 360 

 Y'linijia, 161 ; development of larva of, 112 



115 



Zoaea larva, 217 ; description of, 208 ; ii: 

 terpretation of, 210-212 ; of Anonmni 

 210, 213 ; of Brachyiira, 210, 213 ; o 

 Caridea, 209, 213 ; of Euphausidacea 

 208, 212 ; of Penaeidea, 209, 212 



Zoantharia, 53 ; development of, 76-86 



Zoanthella larva of Zoanthidae, 85 



Zoauthidae, 53 ; larvae of, 85 



Zoanthina larva of Cereanthidae, 85 



Zocecium, formation of, in Polyzoa Ecto 

 procta, 396, 397 



Zygonema, definition of, 4 



Zygote, definition of, 2 



Zygote nucleus, definition of, 9 



Zygotene thread, definition of, 4 



END OF VOL. I 



Printed by R. & R. CI.AKK, LIMITKD. 



