674 



INVERTEBEATA 



Determinate cleavage, 416 

 Deuterocerebrum o'i Astacus, 184 ; of Donacia, 



258 ; of Scolopendra, 283 

 Deuteroplasm, 1 9 ; definition of, 3 

 Deutovum of Mites, 242 

 Development of larva of Denialimn, deprived 



of first polar lobe, 330 ; deprived of second 



polar lobe, 331 

 Dexiotropic cleavage, definition of, 104 

 Diakineais, definition of, 6 

 Diminution of the chromatin in segmenting 



egg of Ascaris inegalocephala, 440 

 Diiwphilus, egg of, 1 1 

 Dipleurula larva, S61, 564 ; definition of, 



660 ; interpretation of, 661 

 ■ Diplopoda, 280, 281 ; development of, 284 

 Diplosomidae, 637 ; development of, buds 



of, 642-644 

 Dipnoi, 569 

 Diptera, 245, 272, 279 

 Directive mesenteries, definition of, 83 

 Disc of fixed larva of Asterias, 469 

 Discocdelis, 107, 109 

 Distaplia, 634, 638, 640, 641, 644 

 Dolichoglossus, 575, 584, 605 

 Dolichoglussus kowalevskii, 669; development 



of, 582, 583 

 DolicJioglossus pusillus, 570 ; development 



of, 583 

 BoUolnm, 639, 640, 641 ; development of, 



636, 637 

 Donacia, 261, 263, 266, 266, 267, 272 

 Donacia crassipes, development of, 245-260 

 Dondersia,, 325 

 Dorsal aorta, formation of, in A gelena, 229 ; 



in Amphioxios lanceolatus, 695 

 Dorsal arch in skeleton of larva of Echinus 



escidentus, 509 

 Dorsal blood-vessel, formation of, in Clepsine, 



163 ; in JUcJiinus escidentus, 518 

 Dorsal cell family in segmenting egg of 



Ascaris megalocephala, 440 

 Dorsal chamber of Uriicina crassicomis, 80 

 Dorsal ciliated epaulettes, formation of, in 



larva of Echinus esculentus, 511 

 Dorsal cord, formation of, in embryo of 



Phascolosoiiui, 376 

 Dorsal curvature of embryo of Donacia, 259 

 Dorsal muscle of Cyphonautes larva, 390, 392 

 Dorsal nerve-cord, formation of, in Dolicho- 



glossus kowalevskii, 583 ; in New England 



Tornaria, 578 

 Dorsal nerve-tube, formation of, in New 



England Tornaria, 578 

 "Dorsal organ, formation of, in Amphiura 



squamata, 500 ; in Asteruia gihbosa, 480 ; 



in embryo of Pedicellina, 400 ; in embryo 



of Scolopendra, 284 

 Dorsal retractor muscles, formation of, in 



larva of Dreissensia, 341 

 Dorsal sinus, formation of, in Nephelis, 163 

 Dorso-central plate, formation of, in Am- 

 phiura squamata, 499 ; in Asterina giibosa, 



478 



Dorso-lateral chamber of Uriicina crassi- 



cornis, 80 

 Dorso-lateral spine of Nanplins larva of 



Cirripedia, 201 

 Dorso-ventral muscles of Yimgia, 114 

 Doryphora, 267, 277 ; development of wings 



of, 271-273 

 Doryphirra decemlineata, development of, 



245, 246, 247 ; embryonic development 



of, 261 

 Doubly fertilized eggs of Ascaris inegalo- 

 cephala, development of, 451-453 

 Dreissensia, 349, 350 

 Dreissensia polymorpha, development of, 



332-348 

 Dytiscidae, 273 

 Dystiscus marginalis, development of eyes of, 



273-277 



Ear, formation of, in larva of simple 

 Ascidian, 620 



Ecardines, 407, 414 



Ecdysis in Astacus, 185 



Jichinocardium coi-datum, 504, 523 ; develop- 

 ment of, 522 



Bchinocyamus piisillus, 504, 522 



Echinodermata, 110, 287, 408, 416, 418, 

 435, 573, 686, 586, 689, 600, 645, 663, 

 657, 659, 660, 662 ; development of, 

 456-567 ; development of unfertilized eggs 

 of, 17 ; eggs of, 3 ; experiments on eggs 

 of, 30 ; fossil representatives of, 20 ; 

 larva of, 19 



Echinoidea, 287, 456, 461, 464, 482, 484, 

 530, 631, 538, 541, 542, 543, 544, 560, 

 562, 564. 566, 670, 571, 653 ; develop- 

 ment of, 504-629 



Echinopluteus, 280, 527, 532, 633, 561, 560, 

 565, 573 ; definition of, 490 ; description 

 of, 508, 509 



Echinus, 228, 463, 484, 505, 590, 653, 654 ; 

 entelechy of, 21 



Echinus esculentus, 604, 606, 523, 529 ; 

 development of, 506-522 



Echinus microtuherculalus, 604, 505 



Echinus miliaris, 504, 516, 523 



Echinus-rudiment of larva of Echinus escu- 

 lentus, formation of, 513 



Echiuroidea, 163, 372 



Echiurus, 167 



Ectoderm, definition of, 53 ; formation of, 

 in Cerebratulv.s lacteus, 119 ; in Donacia, 

 249 ; in Peripatus capjensis, 170 ; in 

 Flanocera, 105 ; in Tubularia, 55 



Ectodermal origin (supposed) of mid-gut in 

 Insecta, 262 



Ectodermal vesicles in larva of Doliolimn, 

 637 



Edwardsia stage in development of Urticina 

 crassicornis, 83 



Edwardsiae, 53, 86 ; arrangement of mesen- 

 teries of, 83 



Eggs of Amphioxus lanceolatus, 686, 587 ; 

 of Amphioxus lanceolatus, dehiscence of, 



