698 



INDEX 



Heart, auricles of, 395, 396; compared 

 to force pump, 397 ; in action, 396- 

 397 ; of fish, 246-247 ; of frog, 251- 

 252 ; structure of, 395-396 ; ventricles 

 of, 395, 396 



Heart beat, laboratory study on effect 

 of exercise on, 400 



Heart depressants, medicine, 355-356 



Heat, necessary for germination, 121 ; 

 regulation of body, 415 



Heath family, of flowers, 212 



Heath hen, 594 



Hemiptera, order of insects, 59, 61, 238 



Heredity, 604-605 ; applied to man, 

 636-640; bearers of, 626, 627-629; 

 in Andalusian fowls, 622-623 ; laws 

 of, 620-624; mechanism, 627-628; 

 use of knowledge of, 640 ; versus en- 

 vironment, 606-607 ; what determines, 

 626-631 



Heredity in Relation to Eugenics, Daven- 

 port, 638 



Hessian fly, 101, 105-106 



Hilum, of bean, 117 



Hogfish, life history of, 248 



Home, care of food, 498-499 ; care of 

 water supplies in, 500 ; disposal of 

 wastes, 500 ; improvement of condi- 

 tions in, 497-500; ventilation of, 

 497-498 



Homoptera, order of insects, 60, 238 



Honey, used for food, 536 



Honeybee, classification of, 59, 238 ; 

 laboratory study of, 58 ; life of, 70-73 ; 

 structure of, 58 



Hoofed mammals, 269-270 



Hooke, Robert, observed cells, 38-39, 

 657 



Hooks, in seed dispersals, 109 



Hookworm, life history of, 495 ; pre- 

 vention of, 496 



Hopkins' experiment, on white rats, 330 



Hormones, 361, 392 



Horse, geologic history of, 273-274 



House fly, carrier of diseases, 489-491 ; 

 foot of, 490 



Human body, structure of, 314-315 



Human machine, how it works, 313-322 



Human welfare, and food making, 162- 

 163 



Humus, composition of, 139 



Hunter, physician, 14-15 



Huxley, 657 ; on Darwin's work, 667 



Hybridization, method of breeding, 634- 

 635 ; practical results of, 624 



Hybrids, meaning of, 621 ; proportion 

 in different generations, 621-623 



Hydra, reproduction, of, 225 ; structure 

 of, 224-225 ; tentacles of, 224, 225 



Hydrophobia, treatment for, 480-481 

 Hygiene, definition of, 34 ; of muscles 

 and bones, 320 ; public, 508 ; school, 

 510 



Hymenoptera, order of insects, 59, 60, 



238 

 Hypocotyl, of bean, 117 



Ichneumon fly, 561 



Imbibition, 147 



Immunity, acquired, 475-476 ; active, 

 476-477; antibodies in, 481; Erh- 

 lich's work on, 664 ; establishing 

 active, 479-481 ; establishing passive, 

 477-479 ; natural, 475 ; meaning of, 

 474-475 ; mechanism of active, 481 ; 

 modified by certain conditions, 475 ; 

 passive, 476-477 



Imperfect flowers, 96 



Improved plum, developed by Burbank, 

 671-672 



Improvement, of living things by man, 

 604-640 



Incubation period, of a disease, 472-473 



Indehiscent fruits, seed scattered by, 

 110-111 



Infections, skin, 317-318 



Inheritance, social, 607-608 



Inorganic foods, 23, 31 



Insect, laboratory exercise on, 58 ; parts 

 of an, 58 



Insect control, methods of, 565-569 



Insect net, how to make, 7-8 



Insects, adaptations for carrying pollen, 

 72, 88-90; beneficial, 568; cage for, 

 10—11; characteristics of, 237; col- 

 lecting, 8-9 ; common forms of, 

 58-61 ; compared with crustaceans, 

 237; eaten by birds, 547-549; eco- 

 nomic importance of, 560-569 ; forest 

 and shade tree pests, 569 ; garden and 

 fruit tree pests, 568-569 ; harm done 

 by, 562—566 ; harm done to trees, 565 ; 

 household pests, 568 ; killing of, 8 ; 

 method of controlling, 566-569 ; 

 mounting, 9-10 ; orders of, 59-61, 

 238 ; protective resemblances, 79, 

 80-82 ; spreading, 9 ; useful, 560-562 ; 

 why so numerous, 80-82 



Inspection, of food supplies, 504, 505 ; 

 of public buildings, 503-504 



Inspiration, meaning of, 406-407 



Instinctive behaviors, 441-443 ; modi- 

 fication of, 442-443 



Instincts, 442 ; modification of, 442- 

 443 



Insulin, in treating diabetes, 395 



Interrelations, of plants and animals, 

 57 



Interrelationship, of man and other liv- 

 ing things, 455-672 



Intestinal glands, 377 



Intestine, absorption from large, 379 ; 

 absorption from small, 378-379 ; rela- 

 tion of constipation to large, 379-380 ; 

 structure of large, 379 ; structure of 

 small, 376 ; villi in small. 377-378 



