Index -715 



Octane, organic compound, 77 



Octopuses, 649, 651, 652, 653 



Odonata, 658 



Oedogonium, 209, 210 



Offense, mechanisms of, 575-76 



Oil-in-water emulsion, 93, 94 



Oils, 81 



Oligochaeta, 649 



One gene, one enzyme concept, 529-31 



Onychophora, 656, 657 



Oogenesis, 477-79 



Oparin, A. I., 186 



Ophiuroidea, 664 



Opsin, 423 



Optic nerve, 422, 424 



Oral cavity, 296, 298-303 



Oral groove, 129, 130 



Oral pit, 283 



Order, taxonomic category, 593 



Ordovician period, 563, 565, 566 



Organelles, cytoplasmic, 28-29 



Organic acids, 82 



Organic substances, carbohydrates, 76-80; dis- 

 tribution in plants, 253; inorganic vs., 71; kinds 

 of, 76-89; lipids, 76, 80-83; proteins, 76, 83-89; 

 in protoplasm, 89; protoplasm components, 76- 

 90; simple compounds, 77 



Organisms, autotrophic, 587; biochemical rela- 

 tionships among, 557-59; cell and, 35-38; en- 

 vironment and, 573; first, nature of the, 187; 

 food substances, sources and uses in, 127; main 

 groups of, history of, 563; mosaic, 512; multi- 

 cellular, 36-37; multiplication of, 538-41; 

 poikilothermic, 582; reproduction in simpler, 

 55-60; saprophytic, 174 



Organizers, embryonic, 534-36 



Organs, 37; of attachment, 236, 238, 241; of 

 bryophytes, 241-42; electric, 431, 441-42; geni- 

 tal, of human female, 387; genital, of human 

 male, 384; luminescent, 442-43; nutritional, 

 609; sense, 419-26; systems, 37; vestigial, evolu- 

 tion and, 554-56. See also under name of organ 



Oriental sore, 627 



Origin of Life, The (Oparin), 186 



Origin, of musculature, 283; of skeletal muscles, 

 431, 432; of species (see Origin of species) 



Origin of species, 538-50; environment, geological 

 changes in, 545, 546; extinction of species, 545- 

 48; multiplication of organisms, 538-41; natural 

 selection, 541-43; stability of species, 544-45 



Ornithine, 342 



Orthoptera, 658 



Oscillatoria, 49 



Oscilloscope, 457 



Osculum, 292 



Osmosis, 115-16, 118-21; water equilibrium in 

 the cell. 118 



Osmotic energy, 185 



Osmotic system, 113, 115 



Osteichthyes, 667, 669-70 



Osteoblasts, 289, 406 



Ostia, 318, 386, 387 



Ostracodermi, 668 



Ovaries, 52, 380, 383, 386, 387, 398; endocrine 



organ, 400-02; hormones and estrous cycle, 400; 



human, functions of, 386-88 

 Overdosage experiments, endocrine glands, 399, 



403-04, 410 

 Oviducts, 381, 383, 388 

 Ovulation. 386. 387. 400. 401 

 Ovules. 219, 222 

 Ovum (see Egg cell) 

 Oxaloacetic acid, 153 

 Oxidases, 101 

 Oxidation, 144; biological, 144-45; of glucose, 



78; hypotheses, 14; principle, 14; -reduction 



reaction, 145 

 Oxidative metabolism, 132 n., 144-45, 149 n. 

 Oxidative phosphorylation, 145, 149 n. 

 Oxygen, 65, 75, 145; -carrying capacity of blood, 



363-64; food substance, 127. See also Free 



oxygen; Heavy oxygen 

 Oxygen debt. 436 



Oxyhemoglobin, hemoglobin vs., 364 

 Oxytocin, 412 

 Oysters, 649, 652, 653 



Pacemaker potential, 456 



Pain receptors, 420 



Painter, T. S., 507 



Palate, 297, 298 



Paleontology, 561, 592; fossil record, 559-70 



Paleozoic era, 563, 564, 565, 566-67 



Palmitic acid. 82 



Pancreas, 283, 296, 297, 310, 311, 398; duodenum 



and, relationship, 311; endocrine function of, 



408-09 

 Pancreatic amylases, 103 



Pancreatic juice, 296, 310, 311-12, 408; flow of, 314 

 Pancreatic lipase, 103 

 Pandorina, 59, 61 

 Pantothenic acid, 353 

 Paper chromatography, 164 

 Paralysis, 461 



Paramecium,, 30, 119, 129, 130, 357, 627-28 

 Paramylum, 596 

 Parascorbic acid, 265 

 Parasites, effect of parasitism on, 577-78; malaria, 



life cycle of, 579; neutral, 179-80; nutritions, 



178-81, 182 

 Parasitism, 575. 576-81; effects on the host, 578; 



effects on the parasite, 577-78 



