INDEX 



561 



Immunity reaction, 230 



Improved breeds, 403 



Independence of characters, 359 



Indian race, 502, 526 



Indian corn, breeding of, 393; ori- 

 gin of, 393 



Individuality of the chromosomes, 

 289, 300 



Industrial competition, 552 



Infections, 207, 218; low-grade, 

 223; overcoming of, 229; pre- 

 vention of, 228 



Infectious disease, 180 



Influence of Darwin's work, 420 



Ingredients, soil, 38 



Inheritance, human, 505; of gen- 

 ius, 520; of mental traits, 514 



Inhibitory genes, 387 



Injury, chemical, 210; mechanical, 

 189, 207, 210 



Ink, 209 



Insanity, 522 



Insectivorous plants, 435 



Insects, and disease, 236; and 

 flowers, 445; beneficial and 

 harmful, 236; tracheal system 

 of, 101 (fig.) 



Instinct, 162; reproductive, 168 



Intangible barriers, 454, 475 



Intellectual characteristics, 534 



IntelUgence quotient, 515 



Interaction of organisms, 7 



Interbreeding, 397 



Internal respiration, 98; senses, 136 



Interrelations of organisms, 423 



Interstitial hormone, 174 



Intestinal juice, 95; putrefaction, 

 217 



Inulin, 64 



Invertase, 67 



Iris of the eye, 146 



IrritabiUty, 117, 135, 148 



Ishmaelites, 521 



Isolation, 549 



Ivy, 112 (fig.) 



Jackass brandy, 263 



Japanese race, 527 



Java man-ape, 497 (fig.) 



Jenner, Edward, 233 



Joint motions, 129 



Juice, gastric, 94; intestinal, 95; 



pancreatic, 94 

 Jukes family, 521 



KalUkak family, 521 

 Kanred wheat, 391 

 Kephir, 265 

 Kidneys, 104, 105 (fig.) 

 Kingdom, animal, 411 

 Koumiss, 265 



Labor, division of, 24, 31 



Lactase, 265 



Lactic acid, 264 



Lactose, 264 



Lamarck, Jean, 427 



Lamarckism, 427 



Land animals, distribution of, 473; 

 respiratory organs of, 100 



Language, 536; spoken, 537; writ- 

 ten, 538 



Law of fihal regression, 517; of in- 

 dependent association, 359; of 

 independent assortment, 363; of 

 reassortment, 351; of segrega- 

 tion, 351, 356 



Laws and results of distribution, 

 475; of heredity, 350-389; first 

 law, 356; second law, 363; third 

 law, 364; fourth law, 364; fifth 

 law, 374; sixth law, 374 



Leaf galls, 208 



Leaves, adjustment of, 114 (fig.); 

 as absorbing organs, 59 (fig.) ; as 

 organs of gas exchange, 60 



Legumes and bacteria, 275 



Length of fife, 251 



Lens, crystalline, 146 (fig.) 



Lethal genes, 399 



Leuwenhoek, A. van, 14 



Lichens, 1% 



Life, distribution of marine, 480; 

 duration of, 249; enrichment 

 of, 544; security of, 545 



Light and plants, 39, 206; as a 

 stimulus, 135; penetration of in 

 sea water, 484 



Limits of photosynthesis, 41 



Linkage, 364; in vinegar fly, 366; 

 sex, 374; strength of, 371 



Lipases, 67, 94, 266 



Living causes of disease, 207; 

 machine, the, 45 



Locomotion, 22, 119 



Lower animals, excretory or- 

 gans of, 104; water frontage in, 

 85 



Luminous rays, 39 



