Labor, division of, 178. Laboratory equipment, 418. Lacteals, 309, 324. Lactic acid, 150. Lactometer, 288. Ladybug, 209. Large intestine, 309; of frog, 243. Larva of milkweed butterfly, 32. Latent energy, 267. Lateral line, 234. Leaves, as food, 117; evaporation of water from, 85; cell structure of, 85; mosaic, 90; respiration, 96; section, |49|; skeleton of, |85|; structure, 85, |86|. Length measures, 417. Leopard frog, |188|. Lepidoptera, 30. Levers, |269|. Life comes from life, 399. Life cycle, 104; of plants, 103. Life history of malarial parasite, 217. Ligaments, 268. Ligature, applying, |326|. Light, a condition of environment, 21, |22|; and bacteria, 145; effect of, |22|; necessary for starch making, 91. Lighting the home, 376. Lily, narrow leaves, |90|. Limewater test, |64|. Lister, Sir Joseph, 403. Liver, 306; a storehouse, 307; effect of alcohol on, 312; of frog, 243. Living matter and alcohol, 291; plant and animal compared, 47; things, needs of, 266; things, varying sizes of, 51. Lizard, |188|. Lobster, |198|. Locomotion, 181; of frog, 241. Lowell, typhoid area, |384|. Lumber transporting, |110-111|. Lungs, air passages, 330; changes of blood in, 330. Lymph, function, 317; glands and vessels, 324, |325|. Lysol, 148. MacNichol, Dr. T. Alexander, 327. Macronucleus, 169. Malaria, cause, 217. Malarial mosquito, |218|. Malarial parasite, life history, 217. Mammal development, 247; embryo, |247|. Mammals, 191; adaptations, 192; as food, 202; classification, 192. Mammary glands, 191. Man, animals that prey upon, 230; and his environment, 266; circulation of blood, 318; improvement of, 261; in his environment, 26; mouth cavity, 300; place in nature, 195; races of, 196; stomach, 303. Manufacture of fats, 93. Measures, 417. Mechanics of respiration, 332, |333|. Membrane, mucous, 299. Mendel, Gregor, 257, 406. Mesenteric glands, 309. Mesentery, 297. Mesoderm, 177. Metamorphosis of frog, 244, |245|. Metchnikoff, 316. Methods, of cutting timber, 111; of breathing in vertebrates, 232. Micronucleus, 169. Micropyle, 59. Middle ear, |359|. Migration of fishes, 238. Milk, and tuberculosis, 381; composition of, |273|, |280|; germs in, 381; grades of, 381; under microscope, |150|, |305|. Milkweed, butterfly, 32, |33|. Milling and starch making, 92. Mink, 205. Mixed diet, 284. Moisture, |24|, |78|. Mollusca, 185. Mollusk, |185|. Mold, 133, 134, 135; yeast and bacteria, |143|. Morning glory embryo, |103|. Mosquito, malarial, |218|; yellow fever, 219. Moss plant, |177|. Mother of pearl, |206|. Motor nerves, 351. Mouth cavity in man, 300, |300|. Mouth parts of bee, 38. Mucous membrane, 299. Mucus cells, 299. Muscles and bones, hygiene, 268.