Involuntary nervous system, 270, 279, 279 



Iodine, and goiter, 249, 249-250; and sulfa drugs, 

 334; as testing agent, 110; in thyroxin, 246; radio- 

 active, 250 



Iris, of eye, 280, 280 



Iron, 108, 111; Age, 573; in common foods, 173 



Iron lung, 230 



Irradiation, and vitamin D, 181 



Irritability, 125; in neuron, 275 



Islands of Langerhans, and insulin, 252 



Isolation (quarantine), and disease, 343 



Isotopes, and goiter, 249-250 



Japanese beetle, 396, 396; quarantine sign, 396 



Java ape man, 566; head, S67 



Jellyfish, 40, 60, 61 



Jenner, Edward, and smallpox, 325-326; and vi- 

 ruses, 340 



Jewish "race," 575-576 



Jimson weed, and heredity, 481 



Juice, digestive, def., 191; 191, 192, 193, 194, 195, 

 196, 197, 199, 200 



Jukes family, 512 



Jute, 89, 383 



Kallikak, Deborah, pedigree of feeble-mindedness, 

 511-512 



Kangaroo, 552; reproduction, 433 



Kanred wheat, 502 



Katydid, 41, 45, 49, 50 



Kelp, 75 



Kernel, def., 452 



Kerosene, and mosquitoes, 353 



Kidneys, 238, 238, 256; of frog, 422; of sheep, 

 239 



Kilogram, 169 



Kingdoms, 101; animal, 15-71; animal classification, 

 65-66; plant, 72-94; plant classification, 90-91 



Kissinger, John R., and yellow fever, 352 



Knee jerk, 268 



Koala, and young, 553 



Koch, Robert, 332; and culture media, 313-314; and 

 disease, 320-322; postulates, 322; staining bac- 

 teria, 314 



Laboratory, place of work, 4, 8-9, 109, 481 



Lacleals, of villus, 198, 198, 206, 221 



Lactic acid, and milk, 323 



Ladybird beetle, 46; in insect control, 396 



Lady slipper. 83 



Lamarck, Jean Baptiste (Chevalier de), theory of 

 evolution, 559-560; and variation, 487-488 



Landsteiner, Karl, 212 



Langerhans, and diabetes, 251-252 



Lanolin, 308 



Larva, ant, 47; bee, 49; cabbage butterfly. 393 

 codling moth, 393 394. 394; corn borer. 392, 392 

 gypsy moth, 393; insect, 42; Japanese beetle, 396 

 mosquito, 352; Monarch butterfly. 42; potato 

 beetle, 391; silkworm, 43; tent caterpillar, 393 



Larynx, 226, 227, 227, 247 



Lava, 524-525 



Laveran, Alphonse, and malaria, 349 



Law, "of dominance," 468; of independent assort- 

 ment, 470-472; of segregation, 468-470; of unit 

 characters, 470-472 



Laws, to protect wildlife, 406 



Layering, def., 449 



Lead, 525 



Lead arsenate, and apples, 394 



Leaf, scar, 155; skeletonized, 158 



Learned acts, def., 287-288; conditioned response, 



288-289 

 Learning, 287-288, 293; and cat, 291; in children, 



289-290; and experience, 295; in fish, 290; and 



habits, 292-294; and maze, 291; and rat, 291; 



by reasoning, 294-296; trial and error, 290 

 Leaves, 137-147, 138; color in fall, 140; compound, 



85; differences among, 137; feathernet veining, 



83, 85; internal structure, 138, 139; palmate net 



veining, 83, 85; parallel veining, 83; parts of, 137; 



stoma ta. 138, 139, 139; structure, 137-140; use 



to plant, 144; veining, 83; veins of, 157; work of, 



140-145 

 Leech, 57 

 Leeuwenhoek, Anton van, 10-11; and spontaneous 



generation, 411 

 Legs, eohippus, 542; grasshopper, 45; horse, 542 

 Legumes, def., 378; 405 



Lens, (eyes). 280: adaptation to distance, 281 

 Lenticels, 153, 155; of birch. 154 

 Lepers, and community action, 343 

 Leucocytes, 210 

 Lichen, def., 374; 77, 375 

 Liebig's beef extract, 317 

 Life, defined as cell activities, 124-125; length of, 



359-360, 359 

 Light, and eye, 280-281, 280, 281; form of energy, 



119; of fringed gentian, 303; and gene action, 490, 



490; and plant growth. 486; and plant responses, 



303, 303 ; response of nasturtium, 301 ; as stimulus, 



261. 266; and tropisms, 301 

 Lightning, and nitrogen cycle, 378 

 Lily, flower, 439; flower x-ray, 439; water, 137, 138 

 Limestone, 60, 524 

 Limewater, 127 

 Linen, 89, 383 

 Linkage, 472; diagram, 473; sex-linked heredity, 



473 

 Linnaeus, Carolus, scheme of classification, 99-101 ; 



work of, 4-5 

 Linseed oil. 89 

 Lipases, 196 



Lister, Sir Joseph, and surgery, 331-332 

 Liver, 189, 192, 200, 256; effect of adrenin on, 252; 



work of, 198-199 

 Liver flukes. 58 

 Liverworts, 91 



Living matter (see Protoplasm) 

 Living things, difference from lifeless, 118; general 



structure, 131 

 Lizard. 16, 29 

 Lobster, 52, 53 

 Lockjaw (see Tetanus) 

 Locomotion, 125 



Locust grasshopper, 45 (see Grasshopper) 

 Loeb, Jacques, and parthenogenesis, 424 

 Los Angeles, tar pools. 527; water supply, 345 

 Lugol's solution, 1 15, 116, 420 

 Lumber. 383 

 Lumbering. 402, 402 

 Luna moth. 43 

 Lungs. 226-236, 227, 256; in amphibia, 31; in birds, 



16, 20; and excretion. 238; blood circulation, 219- 



220, 219; in fish. 33; in mammals, 16; in reptiles, 

 26; structure of, 227-228. 227; work of, 228- 

 234 



Lymph, 206; circulation of, 221, 222; def., 220-221; 



221, 220-222; glands (nodes), 210, 221-222, 222; 

 and wastes, 237-238 



Lymphatics, 206, 221, 221, 222, 222; of villus, 198 

 Lysins, 316 



608 



