470 



problem of, 230; theories of, chap. 8; 



versus environment, 316 

 Hetcrogenesis, 373, 377 

 Homogeny, 109 

 Homologous, 109 



Homology, 88, no, in, 112, 119 

 Homoplasy, 109 

 Hooded rats, 354 

 Hormone, 116, 315 

 Horns, evolution of, 228, 364, 403 

 Horse, 34, 39, 42 

 Horseshoe crab, 115, 190 

 Human nature, 193; changes in, 223, 224; 



variability of, 222, 223, 224 

 Human race, origin of, 195 

 Human races, 208 

 Hutton, James (1726-1797), 284 

 Huxley, Thomas Henry (1825—1895), 



372, 406 

 Hybrid, 256 

 Hybridizing, 276 



Hybrids, inter-specific, 177; sterility of, 68 

 Hydra, 86 



Hypermorph, 209, 211 

 Hypomorph, 209 

 Hypotheses and guesses, 285 



Icelanders, 361 



Immunity, 117 



Incipient organs, 356 



Independent assortment, 266, 267 



Individual, and the group, 460; and evolu- 

 tionary point of view, 460 



Induced changes, 323 



Induction, parallel, 324, 326 



Inheritance, of acquired characters, 309, 

 313; of modifications, 399 



Inherited habits, 309 



Instinct, 458; and natural selection, 357 



Institutions, adaptive significance of, 463 



Interdependence, 153 



Intergradation between species, 163 



Intergrading forms, 356 



Internal secretion, 162, 364; and sec- 

 ondary characters, 365 



Inter-species crosses, 68 



Interspecific sterility, 276 



Intersterility of species, 357 



lodin, 212 



Irritability, 58, 59 



Isolation, 190, 305, 360, 361, 362; 

 physiological, 361 



Jennings, Herbert Spencer (1868- ), 



180, 352, 353 



Index 



Johannsen, Villem Ludvig (1857-1927), 

 178, 179, 181, 349, 350, 351, 370 

 (portrait facing p. 353) 



Jonson, Ben (i 573-1637), 434 



Jordan, David Starr (185 1- ), 191, 



361 



Jukes family, 361 



Kallima butterfly, 362, 363 



Kammerer, Paul (1876— 1924), 324 



King crab, 3 5 



Kellogg, Vernon (1867- ), 403 



Kolliker, Albrecht von (18 17— 1905), 



373 

 Korchinsky, Sergius, 377 



Kovalevsky, Alexander O. (1844— 1901), 

 138 



Lamarck, Jean Baptiste (1744-18 29), 175, 

 282, 286, 292, 293, 302, 303, 304, 305, 

 306, 307, 309, 310, 314, 316, 317, 358, 

 359> 398, 426, 436; Philosophic Zoolo- 

 gique, 301, 302, 303 (portrait facing 

 p. 304) 



Lamarckism, 307, 320 



Lancelet, 138 



Lankester, Ray (1847— 1929), 109 



Laws, scientific, 411 



Leibnitz, Gottfried "Wilhelm (1646-17 16), 

 281 



Leonardo da Vinci (1452— 15 19), 28 



Lewes, George Henry (18 17-1878), 415 



Life as adjustment, 443 



Life, origin of, 14, 409 



Limiting factors for plant growth, 338 



Linkage, 248, 266, 267, 268, 269 



Linked characters, 270 



Linnaeus, Carl (1707-1778), xiii, 64, 

 205, 282, 297, 303, 436 



Loeb, Jacques (18 59-1924), 423 

 Lyell, Charles (1797— 1875), 284, 286 



Malaria, 459 



Malthus, Thomas Robert (1766— 1834), 



330, 331, 336; Essay on Population, 



330 

 Mammal, definition of, 150; evolution of, 



75; in relation to reproduction, 151 

 Mammary gland, 204; supernumerary, 



205 

 Mammoth, 34, 46 

 Man, ancestry of, 202, 203; and evolution, 



465; and God, 466 



