Brahman cattle, 499; bull, 500; Hereford hybrid', 

 500; Jersey hybrid, 500 



Brain, 270-274; alligator, 273; dog, 273; fish, 273; 

 frog, 273; human, 271; sheep, 271; sparrow, 273 



Brain stem, 271 



Braincase, of man, 226 



Bread mold, 77; 414; reproduction of, 414-415, 414 



Breaking habits, 294 



Breast bone, 229 



Breathing, 226-236, 228; air changes by, 231 ; and 

 air pressure, 229-231; center, 231-232; in high 

 altitudes, 233-234; mechanics of, 228-230; models 

 of, 236; movements, 228-229; rate, 232-233; regu- 

 lation of, 231-232; summary of, 234 



Breed, def., 495 



"Breed true," def., 468 



Breeders, early achievements of, 493; methods of, 

 493-505 



Breeding, 493-505; summary of, 504-505 



Bronchi, 227, 227 



Bronchial tubes, of man, 227; 228 



Brontosaurus, 537-538 



Bronze Age, 573 



Broomcorn, use of, 160 



Broth, for raising bacteria, 313 



Brown algae, 73 



Brown-tail moth, 396 



Bryophyllum, vegetative reproduction of, 448 



Bryophyta, 90-91 



Bryophytes, classification of, 73; 90-91 (see Moss) 



Bubonic plague, 328, 343; and insect carriers, 318 



Budding, def., 414; of hydra, 59, 414 



Buds, lateral, 154, 155; terminal, 154, 155; of 

 yeast, 413, 414 



Bugs, 46 



Bulb, def., 449: of tuUp, 448 



Bull, purebred, 497 



Bumblebee, 48 



Burbank, Luther, and plant breeding, 502 



Burdock, 90; seeds, 445 



Burning, 119 



Bush turkey, behavior of, 263-265 



Butterfish, and parasites, 380 



Butterfly, 41; life cycle of, 41-42, 42; Monarch, 42 



Cabbage butterfly, 393 



Cactus, 137; barrel, 160; water loss in, 160 



Calcium, in common foods, 173; dietary experiment 



with, 175; and parathyroids, 254-255 

 California Institute of Technology, and antibodies, 



338 

 California redwoods, 156 

 Callus, 241 

 Calories, def., 169: 169-174; calculation of, 171- 



174; in common foods, 172; need for, 170-171 

 Calorimeter, 169, 170 

 Calyx, 439 

 Cambium, 156; and grafting, 502; of root, 152, 153; 



of stem, 154 

 Cambrian period, 535-536; underwater scene of, 



535 

 Camel, 17 

 Camomile, 89 



Camphor, and insect control, 395 

 Canada lynx, 17 

 Cancer, 13, 360-361 

 Canine, tooth, 203 



Canis, 98, 9S; 99; dingo, 98; famiharis, 98 

 Canning, of food, 385; and vitamin C, 180-181 

 Cannon, Dr. Walter B., 200; and adrenin, 252 

 Capillaries, 206-207; of frog, 207; of lung, 227, 



2^28; structure of, 215; of sweat glands, 239; of 

 villus, 198; and wastes, 237-238 



Capillary action, in plants, 159 



Carbohydrates, 110, 112; in common foods, 172; in 

 diet, 174 



Carbolic acid, and surgery, 331-332 



Carbon, 108, 110, 111; cycle, 375-J76 



Carbon dioxide, in breathing, 231; and breathing 

 rate, 232; in photosynthesis, 140; as waste, 237 



Carboniferous period, 536-537; scene of, 536 



Cardiac muscle, 224 



Carnivores, def., 17-18, 19, 99 



Carotene, 140, 183; and vitamin A, 178 



Carriers, of disease, 347-348; other than man, 348 



Carrot, 88; wild, 87, 88 



Cartilage (gristle), 32; tissue, 132; of windpipe, 227 



Castings, of earthworms, 57 



Cat, 169; appendage of, 549; blood vessels of in- 

 testine of, 215; chromosome number of, 459; con- 

 tinuity of germ plasm in, 489; and heredity, 465; 

 and learning, 291; muscle cells of, 129; Persian, 

 97; skeleton, 548 



Catalyst, 190-191 



Caterpillars, 42, 42, 43; codling moth, 393-394, 394; 

 gypsy moth, 392, 393; tent, 393 



Cattalo, 501 



Cattle, Brahman-Hereford cross, 500; Brahman- 

 Jersey cross, 500; eifects of selection on, 496; 

 Texas-Brahman cross, 499—501 



Caucasoid, 574 



Causes of death, chart of, 360 



Cell, bacterial, 78, 311-312, 312, 313, 314; body, 

 106, 106, 107, 132; body of neuron, 274-275; 

 def., 61, 105—135; division versus fission, 413; 

 doctrine (theory), 125-126; functions, 118-128; 

 and growth hormones, 303-304; membrane, 106. 

 106, 107, 111; membrane in diffusion, 123-124: 

 parts of, 106-107; protozoan, 61-64, 62, 64; sap. 

 151; structure, 106-112, 106, 107; typical animal. 

 107; typical plant, 107; use of food in, 168; wall, 

 106, 107; wastes, 237 



Cell division, 456-459; animal, 458; plant, 457 



Cell wall, in cell division, 457 



Cells, 105-135, 111; activities of, 118-128; algae, 

 73-74, 74, 76; arrangement of, 129-135; blood, 

 208, 209-211, 210; in blood vessels, 215, 216; 

 body, 221; cartilage, 132; chlorophyll in 139-140; 

 comparison between plant and animal, 106-107; 

 conjugation of, 415-417, 416, 417; def., 124-125; 

 differentiation of, 131; and disease, 315; egg, 423, 

 428; embryo sac, 441; epitheUal, 132, 227; fat, 

 132; fertilization of, 417-418, 422-434; germ 

 plasm, 488-490; guard, 139; and heredity, 454- 

 519; and hormones, 246-258; involuntary muscle, 

 129; leaf, 139, 138-140; leaf epidermis, 139; ma- 

 laria, 350, 351; mucous membrane, 227; nerve, 

 132, 228, 274-276, 274, 277; palisade, 139; phloem, 

 153; and plant tropisms, 302-304; pollen, 442, 

 442; potato, 143; reproduction of, 412-453; root, 

 150, 151-153; root hair, 150; skin, 241-242; sperm, 

 423; spongy, 139; staining, 321; stem, 153-157; 

 stomach, 191; summary of, 111-112; sweat gland, 

 240; tetanus, 330; villus, 198; voluntary muscle, 

 132; yeast, 413 



Cellular respiration, 231 



Cellulose, 106, 110, 111, 198; and pneumonia vac- 

 cine, 339 



Cenozoic era, 533, 534, 538-539 



Centipede, 52; house, 52 



Central nervous system, of man, 270, 270 



Centrifuge, 209 



601 



