810 



Darwin (-ian), competition, 

 656 

 food chain, 513, 514 

 influence, 23, 514 

 mutual aid, 32 

 natural selection, 147, 407, 

 418, 638, 640, 648, 684 

 oceanography, 38 

 reproductive isolation, 641 

 sexual selection, 622, 688, 



689, 690, 691 

 subsidence theory, 40, 598 

 web of life, 34, 508, 514, 

 516 

 Darwin, Erasmus, 28 

 Dauermodifikation, 602 

 Davenport, C. B., 46, 47, 54 

 Day degrees, 18, 111 

 Day-length, 18, 20, 21. See 

 also Photoperiodicity. 

 feeding in birds and, 126 

 Death, beneficial, 638, 663, 

 685, 691, 692, 694, 706, 

 707 

 causes of, 273, 425, 708. 

 See also Disease, Mortal- 

 ity, Predation, Parasitism. 

 curve, 296, 297, 299 

 heat, 103, 175 

 number, 278, 279 

 rate, 290, 291, 292 

 crude, 290 

 curve, 278, 296, 298, 



299 

 specific, 292 

 in World War I, 291 

 Death-feigning, wind and, 147 

 Deer, antler size, 637, 638. 

 See also Reindeer. 

 leadership in, 415 

 migration of, 541 

 population, predators and, 



706 

 white-tailed, 587 

 Defense, adaptations foi, 692, 

 693, 701, 705, 726. See 

 also Color, Coloration, 

 Glands, Mimicry, Protec- 

 tion. 

 from predators, 425 

 secondary sexual characters, 



691 

 of territory, 412, 413 

 Deficit, saturation, 336 

 DeGeer, 82 



Degeneration, 603, 713. See 

 also Evolution, regressive; 

 Vestigial organs. 

 Denitrification, 498 

 Denmark, bottom communi- 

 ties, 160 

 Density, economic, 419 



effect on microcUmate, 361 



SUBJECT INDEX 



Density, greatest, 419 



host, 700. See also Popula- 

 tion density. 

 lowest, 419 



mortahty and, 350, 351, 352 

 of populations, 264, 346, 

 419, 630. See also Popu- 

 lation density. 

 Density-dependent, aspects, of 

 cUmate, 344 

 of food, 345 

 factors, 331, 389 

 direct, 331 



favoring population de- 

 crease, 392 

 increase, 392 

 inverse, 331 

 Density-independent, aspects, 

 of climate, 344 

 factors, 331, 389 



favoring population de- 

 crease, 392 

 increase, 392 

 Depth, water, buoyancy, 136, 



137 

 Desert(s), 79, 81, 98, 183, 

 209, 219, 221. See also 

 Aridity, Climate, Mois- 

 ture, Water. 

 adaptations to, 187, 553, 

 590, 634, 652, 666, 668, 

 669, 671, 692, 705. See 

 also Xerocoles. 

 biome-type, 590, 591 

 Desiccation, 19, 20, 278 

 Desulfofication, 498 

 Determination, sex. See Sex. 

 Deuterogenesis, 636, 637 

 Development, 670, 679, 729. 

 See also Caenogenesis, 

 Embryology, Life cycles. 

 Metamorphosis, Ontog- 

 eny. 

 community, 562-580, 697 

 ecological, 10 

 fight, 18, 121 



rate and temperature, 109, 

 110, 112 

 and vapor pressure, 188 

 temperature threshold. 111 

 Developmental threshold. 111, 

 647, 670, 678, 688, 692 

 units, 111, 112 

 Diapause, 278 

 Diatomaceous ooze, 461 

 Diatoms, 312, 313, 317, 323, 

 341, 502, 503, 504, 520, 

 521, 686 

 Didinium nasutum, 368, 371, 



372, 658, 700 

 Diel, 544, 545, 549 

 cycle, humidity, 182 



in plant climate, 212 

 isolation, 611, 618 



Diel, late spring, diagram of, 

 545 

 periodicity, 432, 544-562 

 effect of altitude upon, 

 552 

 of man on, 553 

 in flies, 556 



in forest floor fauna, 557 

 in lake pH cycle, 547 

 in mammals, 546-558 

 sonification, tropical forest 

 animals, 548, 549, 553, 

 554 

 transport of carbohydrate 



in plants, 548 

 in tropical forest, 548, 



549, 550, 557, 558 

 in vertical migrations, 

 554-557 

 Diet of mammals, 530 

 Differentiation, reticulate, 625 

 Diffusion, 165 

 rates, 166 



temperature relation, 166 

 Digging adaptations, 608, 665, 



668 

 Dimorphism, sexual, 621, 683, 



684, 687, 689, 690, 691 

 Diplopods, 866, 635, 673, 705 

 Diptera. See Drosophila, Flies, 



Mosquitoes. 

 Directive factor, 656. See also 



Selection. 

 Disclimax, 574, 578 

 Discontinuity layer, 502, 503 

 Disease ( s ) , chestnut bark, 

 699. See also Epidemics, 

 Epidemiology, Malaria, 

 Parasites, Pathogens. 

 epidemiological studies, 60, 



271 

 host-parasite interactions, 



379, 628 

 insect-borne, 28 

 parasites and, 261, 701, 



707-710 

 wart, 642 

 wilt, 211 

 Disoperation, 30, 340, 395, 

 396, 698, 704, 705, 708, 

 709, 728 

 evolution of, 699 

 Dispersal. See Dispersion, Dis- 

 tribution. 

 Dispersion, adaptive, 643. See 

 also Barriers, Isolation, 

 Seed dispersal. 

 directed, 646 

 parasite, 260 



population, 264, 272, 286, 

 363 

 genetic variation and, 602 

 random, 364, 365 

 seed. See Seed dispersal. 



