INDEX 



701 



Nutritive ratio, 340 



Nuts, how seeds are scattered, 109 



Odonata, order of insects, 79, 238 



Oil gland, 316, 317 



Oils, from animals, 541 ; in foods, 31 ; 



test for, 118-119; useful vegetable, 



529 

 Olfactory cells, 438 

 Olfactory lobes, in brain, 429, 433 

 One-celled animals, 217-222 ; amoeoa, 



217-219 ; Paramecium, 220-222 

 Operculum, of fish, 243, 245 ; of sponge, 



223 

 Opsonins, in blood, 388 

 Optic lobes, in brain, 429, 433 

 Orchard, and other fruits, 527-528 

 Orchid family, of flowers, 208, 209 

 Organ, meaning of, 43, 47-48 

 Organic nutrients, 30-31, in bean, 119- 



120 ; in seeds, 118-120 ; tests for, 131 

 Organism, meaning of, 43, 222 

 Organs, and tissues, 47-48 ; end, 428 ; 



of digestion, 368-369 ; of excretion, 



412-413. See Sense organs. 

 Oriole, Baltimore, 557-558 

 Orthoptera, order of insects, 59, 60, 238 

 Osmosis, 147-148 ; demonstrations 



showing, 147, 148, 149 ; physiological 



importance of, 149-150 

 Osmotic pressure, 148-149 

 Ovary, of flower, 83, 84 

 Ovules, in flowers, 83, 84 

 Oxidation, 25-26; of food, 328, 405, 



415 ; in our bodies, 124 

 Oxygen, 24, 25; cycle, 285-286; given 



off by green plants, 164-165 ; needed 



by plant, 121, 158; needed in body, 



403-405 ; properties of, 25 ; test for, 



25 

 Oxyhaemoglobin, 387 

 Owl, 549 ; screech, 558, 559 

 Oysters, as food, 531-532 ; mollusk, 



240-242 



Palate, of man, hard and soft, 363-364 



Palisade layer, of leaf, 153 



Palm family, 208 



Palpi, of beetles, 61 



Pancreas, a gland, 361 ; hormone of, 

 394-395 ; position and structure, 373, 

 375 ; secretion of, 374 ; work done by, 

 373-374 



Pancreatic juice, digestion done by, 373, 

 374 ; enzymes in, 374 



Pappus, in seed dispersal, 109 



Paramecium, 219-222; cilia, 220; con- 

 jugation of, 221-222 ; fusion of, 221 ; 

 response to stimuli, 425-426 



Parasites, fungi, 194; mistletoe, 228; 

 worms, 228, 492-496 



Parasitism, 288-289; social, cause of, 

 637 ; remedy for, 637-638 



Parathyroid, gland, 392 



Passenger pigeon, 594-595, 669 



Passive immunity, 476-479 



Pasteur, Louis, 1-2; life of, 661-663; on 

 bacteria, 181, 479; work on rabies, 

 480 



Pasteur Institute, 662-663 



Pasteurization, and bacteria, 459 



Patent medicines, bracers, 355 ; cure- 

 alls, 356-357 ; drugs, 355 ; heart de- 

 pressants, 355-356 



Pathogenic bacteria, 462 



Pearls, how obtained, 542-543 



Peas, factors necessary for germination, 

 120—121 ; Mendel's experiment on he- 

 redity in, 621-622 



Pelecypods, 240-241 



Pellagra, deficiency disease, 334, 335 



Pellicle, in Paramecium, 219-220 



Pepsin, in gastric juice, 371 



Peptone, form of protein, 371-372 



Pericardium, of heart, 396 



Peristalsis, 370 



Pests, insect, 562-566, 568-569; rats, 

 545-546 



Petals, of flower, 83, 84 



Petri dish, use of, 182 



Phagocytes, function of, 387, 388, 481 ; 

 Metchnikoff's theory concerning, 664 



Pharynx, of man, 364 



Phloem, 168 



Phoebe, 555-556 



Photosynthesis, 160-161 



Phototropism, 155-158 



Phylum, in classification, 177, 178 



Physical examination, 510-511 



Pigfish, life history of, 248 



Pith, 166 ; rays, 167 



Pituitary gland, 392, 393-394 . 



Placenta, function of, 117; of bean, 87 



Plankton, 295, 530, 587 



Plant, cause of growth, 123-124; cell, 

 46-47 ; comparison of animal with, 43 ; 

 growth of bean, 136 ; need of mineral 

 matter, 139-140 ; world, how it affects 

 mankind, 177-213 



Plant and animal breeding, 670-672 ; 

 Burbank, 671-672 ; de Vries, 671 ; 

 Mendel, 670-671 



Planting, selective, 633-634 



Plants and animals mutually dependent, 

 54-96; classification of, 179-213; 

 compared with animals, 43-45 ; dem- 

 onstration to show effect of light on, 

 155, 158; drug-producing, 529-530; 

 economic values other than food, 

 528-530; effect of light on, 155-157; 

 effects of surroundings on, 280-309 ; 

 factors affecting plants, 39-42 ; how 

 affected by environment, 290-297 ; 

 mechanism of response in, 424-425 ; 

 poisonous, 105-107 ; production of new 

 varieties, 632-635 ; raw material 



