INDEX 



575 



Hacmocoelous-triploblastic organiza- ] 

 tion, 246. 



Hsemoglobin, 92, 293. 



Halteria, 190. 



Haploid number of chromosomes, 

 229, 231, 447. 



Hatching, of frog, 414; of locust, 350, 

 367; of Planaria, 452; of turtle, 

 423. 



Hatteria, 531. 



Haversian system, 145. 



Head, of crayfish, 322; of Crustacea, 

 334; of locust, 344; of man, 44; of 

 Nereis, 312, 313; of vertebrates, 38. 



Hearing in insects, 366; in verte- 

 brates, 21. 



Heart, 56; of bird, 60; of chick, 430; 

 of earthworm, 290, 294; of fish, 

 59; of frog, 48, 56; of locust, 355, 

 356; of mammals, 60. 



Hemichordata, 13, 36, 241. 



Hemiptera, 374, 379. 



Herbivorous animal, 32. 



Heredity, 5; in development, 439, 

 445, 446, 456. 



Hermaphroditism, 201, 221, 272. 



Hermit crab, 335. 



Hertwig, 223. 



Heterotricha, 189. 



Heterozygote, 476. 



Hexactinellida, 241. 



Hexapoda, see Insect a. 



Hind-brain of frog, 416; see also 

 Cerebellum and Medulla. 



Hirudinea, 241, 309, 310. 



Histology, 2, 3, 140. 



Holothuroidea, 241. 



Holotricha, 189. 



Homarus, 326, 327. 



Hominida?, 528, 532. 



Homo neanderthalensis, 534, 535. 



Homo sapiens, 35, 534. 



Homology, 246, 500; serial, 325. 328. 



Homozygote, 476. 



Homunculus, 418. 



Hooke, 132. 



Hopkins, 75. 



Hormiphora, 279. 



Horse, evolution of, 513, 515, 517, 

 527. 



Host, 207, 259; reaction to parasites, 

 211. 



House-fly, 375, 384, 385. 



Human development, 449, 450, 451, 

 531. 



Human evolution, 528, 529, 530, 531, 

 533. 



Huxley, 321, 547. 



Hybrid, 462. 



Hybridization, 462; Theory of causes 

 of evolution, 564. 



Hydra, body plan of, 249; cell cycle 

 of, 217; cellular structure of, 249, 

 250; external features of, 247; 

 feeding of, 248, 263; germ cells of, 

 271; internal structure of, 249; 

 irritabilit}' and behavior of, 262, 

 319; life cycle of, 273; metabolism 

 of, 260; movements and locomo- 

 tion of, 248, 262; nervous sy.stem 

 of, 266, 267, 268; reproduction in, 

 270. 



Hydranths, 276. 



Hydrocorallina?, 277. 



Hydroid colonies, 274. 



Hydroids, 274. 



Hydro-medusae, see Hydrozoa. 



Hydrotropism, 304. 



Hydrozoa, 241, 274, 277. 



Hyla goeldii, 28; H. versicolor, 16, 22. 



Hymonoptera, 375, 387, 388. 



Hypnotoxin, 255. 



Hypopharynx, 346, 353. 



Hypophysis, 65. 



Hypostome, 249. 



Hypotricha, 190. 



Ichneumon fly, 388. 



Icthyosaurus, 505. 



Immunity, 211. 



Independent effector, see Effector. 



Indirect development, of insects, 370. 



Infundibulum, 65. 



Infection hypothesis, 490. 



Infusoria, 155, 175, 241. 



Ingestion, 81; in Hydra, 263; in 



