678 



INVEKTEBKATA 



Halecium, 62 



Haliotis, 301, 304, 320 ; metamorphosis of 

 larva of, 305 



Hatschek's nephridium, formatiouof, in larva 

 of Amphioxus lanceolatus, 600 



Hatschek's pit, formation of, in larva of 

 Amphioxus lanceolatus, 596 



Head blastema, formation of, in JVephelis, 

 162 ; in Phascolosoma, 375 ; in Poly- 

 gon-tins appendiculatus, 147 



Head of spermatozoon, definition of, 7 



Head- cavities, formation of, in larva of 

 Amphioxus lanceolatus, 595 ; in Sagitta 

 bipunctata, 431 



Head-kidney of New England Tornaria, 

 formation of, 577 



Head-pouch of larva of Muscidae, 278, 279 



Head -segment of larva of Terebratulina 

 septentrionalis, 410 



Head-shield in Astacus, 185 



Head-vesicle of embryo of Unio, 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 

 Paludina, 314 ; in Peripatus capensis, 

 174 ; in Cyathozooid of Pyrosoma, 634 ; in 

 Scorpion, 241 ; in New England Tornaria, 

 575 



Helix, yolk-sac of, 369 



Hemiaspis, 239 



Hemichorda, 568 ; development of, 569-586 



Hemimetabola, 245, 277, 287, 288 



Hemiptera, 245, 277 



Heredity, Weisrnann's theory of, 12 



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



Hermaphrodite, definition of, 2 



Hermelliformia, 128 



Heterochromosome, 14 



Heterochrony, 608 ; definition of, 46 ; in 

 development of Cephalopoda, 370 



Heterocoela, 37 



Heteronemertini, 118 ; development of, 118- 

 126 



Hexactinellida, 37 ; development of, 43 



Hexactiniae, 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 Cyphouautes larva in meta- 

 morphosis, 394 



Holoblastic, definition of, 26 



Holometabola, 245 



Holothuria 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 Phascolosoma 

 gouldii, 379 ; formation of, in arms of 



Ophiothrixfragilis, 498 ; in Phascolosoma, 

 379 ; in Sagitta bipunctata, 433 



Hoplocarida, 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 Gribrella oculata, 

 481 ; in larva of Echinus esculentus, 510 ; 

 in larva of Ophiothrix fragilis, 491 ; in 

 larva of Ophiura breoispina, 501 ; in 

 Solaster endeca, 481 



Hydroides, 313 



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

 98, 126 



Hydrophyllium of Siphonophora, 66 



Hydrothecae, definition of, 62 



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

 development of, 54-67 ; development corn- 

 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 coelomof Asterina gibbosa, 475, 

 480 



Hypopharynx, formation of, in Donacia, 252 



Hypophorella expansa, 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 



Ilyanassa, 332 



Imaginal disc for compound eye of Dytiscus, 



275 ; for adult oesophagus in Polygordius 



appendiculatus, 149 

 Imaginal discs in larva of Galerucella ulmi, 



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



Pilidium larva, 122 

 Imaginal pouches for wings and legs in 



Muscidae, 279 

 Imaginal ring for proctodaeum of larva of 



Muscidae, 279 ; for salivary glands of 



Muscidae, 279 ; for stomodaeum of larva 



of Muscidae, 279 



Imago of Donacia, 260 ; of Echinus escu- 

 lentus, 517 ; of Galerucella ulmi, 268 

 Immersed embryonic area in segmenting egg 



of Lepidoptera, 266 

 Inbreeding, definition of, 18 

 Indeterminate cleavage, definition of, 416 



