678 



INVERTEBKATA 



Halecium, 62 



Haliotis, 301, 304, 320 ; metamorpliosis of 



larva of, 305 

 Hatschek's nephridhim, formation of, in larva 



of Amphioxus lanceolatus, 600 

 Hatsclielc's pit, formation of, in larva of 



Amphioxus lanceolatus, 596 

 Head blastema, formation of, in Nephdis, 



162 ; in Phascolosoma, 375 ; in Poly- 



gordiics appendiculaiios, 147 

 Head of spermatozoon, definition of, 7 

 Head-cavities, formation of, in larva of 



Amphioxus lanceolatus, 595 ; in Sagitta 



bipmictata, 431 

 Head-liidney of New England Tornaria, 



formation of, 577 

 Head-pouch of larva of Mnsoidae, 278, 279 

 Head -segment of larva of Terebratulina 



scptentrionalis, 410 

 Head-shield in Astacus, 185 

 Head-vesicle of embryo of Vnio, 351 

 Heart, formation of, in Agelena, 229 ; in 



Astacus, 187 ; in dona intestinalis, 626 ; 



in Donacia, 257 ; in Dreissensia, 344 ; 



in Limulus, 256 ; in Loligo, 362 ; in 



Pcdudina, 314 ; in Peripatus capensis, 



174; in Cyathozooid of Pi/ro«oma, 634; in 



Scorpion, 241 ; in New England Tornaria, 



575 

 Helix, yolk-sac of, 369 

 Hemiaspis, 239 



Hemichorda, 668 ; development of, 569-586 

 Hemimetabola, 245, 277, 287, 288 

 Hemiptera, 245, 277 



Heredity, Weismann's theory of, 12 , 



Hermann's fluid, composition of, use of, 33 

 Hermaphrodite, definition of, 2 

 Hermelliformia, 128 

 Heteroohromosome, 14 

 Heterochrony, 608 ; definition of, 46 ; in 



development of Cephalopoda, 370 

 Heterocoela, 37 

 Heteronemertini, 118 ; development of, 118- 



126 

 Hexaotinellida, 37 ; development of, 43 

 Hexaotiniae, 53, 83, 86, 87 

 Hexapoda, 285 



Hieracium, asexually reproduced, 18 

 Hind-foot, formation of, in Loligo, 357 

 Hirudinea, 128 ; development of, 159-163 

 Histogenetic plasm, definition of, 13 

 Histolysis of Cyphonautes larva in meta- 

 morphosis, 394 

 Holoblastic, definition of, 26 

 Holometabola, 245 

 Ilolothuria tubulosa, 530 ; development of, 



541 

 Holothuroidea, 287, 456, 464, 545, 560, 



564, 565, 585, 656 ; pupa of, 28 ; develop- 

 ment of, 529-544 

 Homarus, 178, 191, 213 

 Homocoela, 37 

 Hooks, disappearance of, in Pliascolosoma 



gouldii, 379 ; formation of, in arms of 



Ophioihrix fragilis, 498 ; in Pliascolosoma, 

 379 ; in Sagitta hipunctata, 433 



Hoplooarida, 177 



Hormones, 652 



Horse-shoe Crab, 221 



Hybrids of Echinus esculentus and Echino- 

 cardium cordatum, 523 ; of Echinus escu- 

 lentus and Echinus miliaris, 523 



Hydra, 63, 64, 69, 70, 88, 383 ; egg of, 27 



Hydra-tuba, 70, 79, 80 



Hydrida, 53 



Hydrocoele, formation of, in embryo of 

 Antedon rosacea, 547 ; in larva ^ of 

 Asterias, 466 ; in larva of Asterina 

 gibbosa, 474 ; in larva of Cribrella oculata, 

 481 ; in larva of Echinus esculentus, 510 ; 

 in larva of Ophiothrix fragilis, 491 ; in 

 larva of Ophiura brevispina, 501 ; in 

 Solaster endeca, 481 



Hydroides, 313 



Hydromedusae, 53, 62, 64, 66, 67, 69, 72, 

 98, 126 



Hydrophyllium of Siplionophora, 66 



Hydrotheoae, definition of, 62 



Hydrozoa, 53 78, 79, 96, 161, 659, 661 ; 

 development of, 54-67 ; development com- 

 pared with that of Scyphozoa, 74-76 



Hylodes, development of, 22 



Hymenoptera, 245, 266, 386 



Hyocrinus, 559, 560 



Hypertonic solutions, use of, 17, 18 



Hypogastric coe\oraoi Asterina gibbosa, 475, 

 480 



Hypopharynx, formation of, in Donacia, 252 



Hypophorella expoMsa, larva of, 394 



Hypophysial canal, formation of, in larva 

 of simple Ascidian, 622 ; in blastozooid 

 of Urochorda, 639 



Hyposphere in larva of Polygordius, 140 ; 

 disappearance of, in larva of Polygordius 

 appendiculatus, 149 



Id, definition of, 13 



Idiochromosome, 14, 15 



Idiosome of spermatozoon, definition of, 7 



Hyanussa, 332 



Imaginal disc for compound eye of Dytiscus, 



275 ; for adult oesophagus in Polygordius 



appendiculatus, 149 

 Imaginal discs in larva of Qalerucella vlmi, 



267, 268 ; in larva of Muscidae,-278 ; in 



Pilidium larva, 122 

 Imaginal pouches for wings and legs in 



Musoidae, 279 

 Imaginal ring for prootodaeum of larva of 



Muscidae, 279 ; for salivary glands of 



Muscidae, 279 ; for storaodaeum of larva 



of Muscidae, 279 

 Imago of Donacia, 260 ; of Echinus escu- 

 lentus, 511 ; of Qalerucella ulmi, 268 

 Immersed embryonic area in segmenting egg 



of Lepidoptera, 266 

 Inbreeding, definition of, 18 

 Indeterminate cleavage, definition of, 416 



