828 



Principle(s), of minimum, 

 198, 205, 206, 224, 402, 

 490, 635, 641, 726 

 of partial equivalence, 223, 



490 

 of periodic activities, 559 

 of photosynthetic layer, 506 

 of primary biotic gradient, 



482 

 of productivity, 507 

 of strata], convergence, 474 

 equivalence, 469, 470, 



471, 474 

 indices, 479 

 of stratification, 442, 507 

 and community ontogeny, 



484 

 and serai age of com- 

 munity, 484 

 taxonomic complexity and 



stratification, 484 

 trophic level, and energy 

 utilization, 521 

 and production rate, 

 521 

 of universality of communi- 

 ties, 436, 482 

 Priseres, 578 

 Probability, prior, concept of, 



222 

 Procerodes, 61, 360, 361 

 Proclimax, 574 

 Producers, 508, 510 



primary, in fresh water, 

 503, 504, 505 

 in photic zone, 501, 502, 

 503 

 Productivity, 519 



community, 521, 522 

 marine, 520, 521 

 photosynthetic, 506, 507 

 of plankton, 346 

 principle of, 507 

 relation with serai position, 



577 

 values in lakes, 519 

 Profile, soil, 217, 218 

 Profundal zone, 451, 452, 453 

 abundance of organisms 

 in, 453 

 Pronghorn, group protection, 



398 

 Protection, 163, 421, 425, 426, 

 631, 649-651, 665, 671^ 

 673, 682, 685, 686, 692, 

 701, 705, 708, 712, 713. 

 See also Color, Defense, 

 Parental care, Shelter. 

 group, 395, 396, 397, 398, 

 687 

 Protective coloration, 665, 692, 

 705. See also Color, Color- 

 ation, Mimicry. 

 Proterozoic, 81, 648 



SUBJECT INDEX 



Proto-cooperation, 11, 130, 

 395, 397, 410, 412, 419, 

 698, 710 

 Protoplasm, origin, 75 

 Protozoa. See also Malaria, 

 Paramecium. 

 activity, relation to pres- 

 sure, 137ff. 

 to temperature, 107 

 allelocatalytic phenomena 



in, 357flF. 

 competition in populations 



of, 658 

 contractile vacuoles and 



salinity, 171 

 cyclomorphosis, 686 

 development, community, 



564£F. 

 food web, position in, 516 

 interspecies competition in, 

 368 

 predation in, 371, 700 

 marine planktonic, 447flF. 

 mating types in, 408ff. 

 osmosis in, 169 

 overwintering of, 538 

 parasitic, 628flF., 632, 707ff., 



727 

 pH relations, 173flF. 

 populations, S19, 372, 406, 



407, 658 

 rate of evolution, 680lf. 

 regressive evolution in, 676 

 soil, 52 



symbiotic, 247, 712ff., 716flF. 

 Provincialism, chmatic, 78, 83 

 Pselaphidae, 465, 484, 524 



557, 665, 720 

 Pseudohibernation, carnivores, 



106 

 Pseudo-orthogenesis, 638, 640 

 Psittacidae, forest, 493 

 Psychology, 435, 619-622, 

 633, 634, 641, 678. See also 

 Behavior. 

 Psycho-physiological mech- 

 anism, 701 

 Psyllidae, 473 

 Pteridophytes, 603 

 Pteropod ooze, 461 

 Ptinidae, 559 

 Pulse, autumnal, 503, 504 

 spring, of fresh-water algae, 

 503, 504 

 of marine diatoms, 502 

 vernal, of algae, 502, 503, 

 504 

 Pumas, 706, 707, 723 

 Punti verdi, 502 

 Pupal emergence, barometric 



pressure and, 135, 136 

 Pupation rhythm in insects, 



552, 553 

 Putrefaction, effect of pres- 

 sure on, 137 



Piitter hypothesis, 240, 444, 



500 

 Pyramid of numbers, 22, 257, 



522, 523, 525, 699 



Qio rule, 107 



Quadrat samphng, 48 



Quail, 284, 326, 363, 374, 



376, 398, 723 

 Quarterly Review of Biology, 



64 

 Quaternary, 81. See also 



Pleistocene. 

 Quetelet, L. A. J., 54 



Rabbits, 119, 180, 323, 374, 



475, 476, 643, 668, 723 

 Raccoon, 530 



Races, 117, 604, 605, 606, 

 607, 608, 614, 619, 625, 

 626, 628, 644, 652, 653, 

 654, 663, 682, 708. See 

 also Subspecies. 

 physiologic, 615 

 Radiation, 74, 87-91, 599, 

 600, 653 

 adaptive, 611, 630, 642, 

 661, 662, 663, 664, 666, 

 718. See also Evolution, 

 convergent; Phylogeny. 

 annual variation, 89 

 behavior, 666 

 effect of clouds on, 89 

 infra-red, 87 

 in plant climate, 212 

 sky, 89, 90, 91 

 solar, 86, 87, 90 



lethal action, 127, 129 

 ultraviolet, 74, 75, 87, 88, 



127, 128, 129 

 unit, ecological, 91 

 Radiolaria, Haeckel on, 39 

 Radiolarian ooze, 461 

 Rain(s) forests, 79, 147, 425, 

 434, 435, 482, 593, 645, 

 646. See also Forests, 

 tropical. 

 monsoon, 145 

 wdnter, regions of, 80 

 Rain-shedding structures, 425, 



434, 435, 645, 646, 669 

 Rainfall, effects of, 207, 210, 



211, 321 

 Rainfall-temperature relations, 



210, 211 

 Rana. See Frogs. 

 Random searching, 380 

 Range, factors determining, 

 215, 706, 707 

 relation to pyramid of num- 

 bers, 524 

 Rarity, 634, 640 

 Rate of natural increase, 293 

 Rats, 276, 279, 707, 724, 725 

 726, 728 



