442 



INDEX 



Neuroptera, 242. 



Nicotine, 142. 



Nictitating membrane, 110. 



Nitrates, supplied to soil, 340, 341, 



342. 

 Nitrogen, 8; 



cycle, 104, 105; 



fixed by bacteria, 341 ; 



in food", 120 ; 



needed b}^ plants, 65. 

 Noguchi, Dr., investigator, 282, 411. 

 Nos3, diseases of, 181-182. 

 Nucleus of a cell, 45, 46. 

 Nutrients, 53, 119; 



fuel values, 119; 



in common foods, 124 ; 



summary, 61. 

 Nutritive ratio, 130. 

 Nuts, 325, 329 ; 



value as food, 121, 124. 



Oat smut, 337. 

 Oats, 328. 

 Odonata, 242. 

 Oils, 53, 119; 



animal, 355; 



test for, 54 ; 



vegetable, 331. 

 Olfactorv nerve, 203. 

 Olive, 331. 

 Ommatidia, 33. 

 Onions, 324, 325; 



cells of epidermis, 45. 

 Operculum, 244. 

 Ophidia, 247. 

 Opium, 143, 144. 

 Opsonins, 164, 276. 

 Optic nerve, 205, 206. 

 Orbit of eye, 205. 

 Orchards, 329. 

 Orchids, 36. 



Order, in classification, 235. 

 Organ, 14, 47 ; 



see Leaves, Ears, Excretion, etc. 

 Organic nutrients, 53 ; see Nutrients. 

 Organic soil, 314. 

 Organism, 14. 

 Orthoptera, 27, 242. 

 Osmosis, 71, 72, 73. 

 Osmotic pressure, 72. 



Ovaries, 167. 



Ovary, in plant, 32, 226. 



Ovule, fertilization, 225. 



Owls, 360. 



Oxidation, 9; 



in germinating seeds, 57, 58 ; 



in the human body, 57, 168, 177. 

 Oxygen, 9; 



cycle, 103; 



given off by plants, 82, 85 ; 



in air and water, 8 ; 



in respiration, 179; 



oxidation, 9. 

 Oxyhsemoglobin, 163, 178. 

 Oysters, 242, 348, 349; 



conservation, 371 ; 



enemies of, 361 ; 



pearl, 356. 



Pain, sense of, 202. 

 Palate, hard and soft, 150, 

 Palisade laver, 81 ; 



of leaf, 77. 

 Pancreas, 154, 155, 167, 168. 

 Paper, 316. 



Papilli) of tongue, 202. 

 Paramecium, 08, 99; 



compared with amoeba, 108 ; 



receives stimuli, 193 ; 



responses, 195, 196. 

 Parasites, 3 ; 



destruction of food by, 361 ; 



fungi, 335, 337; 



human, 399; 



protozoa, 278, 281-283 ; 



worms, 287-290. 

 Parathyroid gland, 166. 

 Paratyphoid, 276. 

 Park, Dr. William H., cited, 262. 

 Parotid gland, 149. 

 Parsnip, 325. 

 Passenger pigeon, 375. 

 Pasteur, Louis, life, 408, 409, 410; 



pasteurization, 259; 



quoted, 3; 



work on rabies, 275 ; 



work on vaccination, 274. 

 Pasteurization, 259, 302. 

 Patent medicines, 143, 144. 

 Pathogenic bacteria, 260. 



