746 INDEX 



Harvestmen, 223 

 Hatching of chick, 663 



of lancelet, 625 

 Hatschek's pit, 302, 627 

 Haversian systems, 518 

 Head, 176, 193, ^6-] 



of cockroach, 228 



of dogfish, 311 



of frog, 346 



segmentation of, 568 

 Heart, 595 



of chick, 659, 661 



of cockroach, 233, 235 



of cod, 596 



of crayfish, 205 



of dogfish, 325 



of frog, 369, 640 



of pigeon, 410 



of rabbit, 447 



of reptiles, 596 



of snail, 268 



of swan mussel, 279 

 Heart-beat, 614 



regulation of, 614 

 Hearts, lymph, 373, 526 

 Heat production, 14 

 Heat transport, 454 

 Hedgehog, 475, 476 

 Helicotrema, 469 

 Heliozoa, 80 

 Helix, 264. See Snail 



aspersa and pomatia, 264, 269 

 Hemibranch, 322, 325, 589 

 Hemichordata, 309 

 Hemimetabola, 246 

 Hemiptera, 250 

 Hepato-pancreas. See Digestive 



diverticula 

 Heptanchus, 570 

 Heredity, 4, 680 

 Hermaphrodite duct, 269 

 Hermaphrodites, 6, 52, 172, 183, 269 

 Hermaphroditism, 6, 155 

 Hermit crabs, 147 

 Heterocercal tail, 312, 315, 553 

 Heterocoelous, 400 

 Heterodera, 143 

 Heterokaryota, 81 

 Heterometabola, 246 

 Heteronereis, 176, 178 

 Heterotype division, 694 

 Heterozygote, 681, 685 

 Hexapoda, 222. See Insects 

 Hexoses, 444 

 Hibernation, 476, 477 

 Higher organisms, 16 

 Hind-gut, 204. See also Procto- 

 daeum 



Hippocampus, 461 



Hippopotamus, 492 



Hippospongia, 87 



Hirudinea, 184 



Hirudo medicinalis , 179, 180, 184 



Histiocyte, 515, 525 



Histology, 504 



Holoblastic segmentation, 644 



of starfish, 293 

 Holocephali, 583 

 Holometabola, 247 

 Holonephros, 615 

 Holophytic, 41 

 Holothuria, 298 

 Holothuroidea, 297, 298 

 Holozoic, 41 

 Homokaryota, 81 

 Homocercal, 553 

 Homoiothermic animals, 454 

 Homotype division, 694 

 Homo sapiens, 478. See Man 

 Homozygote, 681, 685 

 Hoofs, 528 

 Hooke, R., 498 

 Hookworm, 143 

 Hormiphora plumosa, 117 

 Hormones, 18, 175, 190, 213, 227, 



248, 367, 470, 678, 726 

 Horns, 492, 528 

 Horse-leech, 186 

 Horses, 490, 558 



feet of, 490, 711 

 Host, 148, 155. See also Parasites; 



Parasitism 

 House-flies, 242, 244, 247, 258, 23g 



as transmitters of disease, 65 

 Hover flies, 259 

 numerals, 394 

 Humour, aqueous, 465 



vitreous, 465 

 Hydatid cyst, 133 

 Hydra, 89, 11 1, 147 



anatomy of, 90 



buds of, loi 



development of, 100, loi 



food of, 97 ' 



histology of, 92 



movements of, 97, 98 



nervous system of, 93, 94, 95 



regeneration of, 102 



reproduction of, 99 

 Hydra attenuata, 89, 99 



oligactis {=fusca), 89, 99 



viridis, 89, 99 

 Hydranths, 104 

 Hydrochloric acid, 444 

 Hydrogen ion concentration, 190, 



454 



