A. C. Bent, 1926, _U. S. Natl. Mus. Bull._ 135, p. 109 (great blue heron). W. P. Baldwin, 1946, _Auk_, Vol. 63, p. 589 (oyster catcher). G. Mackay, 1929, _Auk_, 46, p. 123 (goldfinch). D. Bannerman, 1936, _Birds Tropical West Africa_, Vol. 4, p. 244 (dusky flycatcher). SURVIVAL OF THE UNFIT A. W. Anthony, 1898, _Auk_, Vol. 15, p. 314 (frigate bird). J. Cassin, 1858, _United States exploring expedition ..., Mammals and Birds_, Philadelphia, p. 364 (brown booby). DECORATION IN THE HOME A. C. Bent, 1937, _U. S. Nat. Mus. Bull._ 167, p. 151 (red-tailed hawk), p. 296 (golden eagle). M. R. Lieff and N. P. Jordan, 1950, _British Birds_, Vol. 43, p. 56 (carrion crow). E. H. Forbush, 1929, _Birds of Mass., etc._, Vol. 3, p. 141 (purple martin). A. L. Rand, 1936, _Bull. Amer. Mus. Nat. Hist._, Vol. 72, pp. 487, 490 (weaverbird). INDEX adaptation, 31 Aeschylus, death of, 186 Aeschylus on vultures, 172 ani, feeding rates of, 168 anointing feathers, 25 anting, 27 anvil, thrush's, 15 apartment houses, 77 Arctic fox and snowy owl, 49 association of: burrowing owl, prairie dog, snake, 73 lizard, petrel, 75 parrot, duck, opossum, 75 social weaver, falcon, 74 baby sitters, 35 bad and good birds, 152 bathing in dust, 204 bathing in snow, 204 bathing in water, 22, 205 beehives, guiding to, 125 beeswax as bird food, 125 bird of paradise, 162 boat names, 84 booming of nighthawk, 135 bower, painting of, 16 brigands, birds as, 19 brush turkey, 54 bucket drawing by jay, 190 buried eggs, 45 buried young, 45 cassowaries swim, 149 cattle disease and oxpeckers, 129 _Chicago Tribune_ farm, 151 cliff dwellers, 78 colony, mixed, 73 colony nesters, 77 color, change in jay, 164 color and palatability, 63 communistic care of young, 37 community nests, 35 conditioning, 136 conservation, 151 co-operation, 117 co-operation: birds and monkeys, 51-53 cow and ani, 167 in carrying prey, 118 in fishing by pelican, 118 in killing skunk, 119 co-op nursery, 35 cormorant: fishing with, 57 training, 58 cosmetics, various, 26 counting, of photographers, 193 distinguishing more from less, 193 courtship feeding, 195 function of, 197 significance of, 195 covering eggs: by eider duck, 47 by grebe, 47 cows, use as hunting dogs, 167 credit and snowy owl, 48 cripples, cared for, 201 crocodile bird, 45 crow, intelligence of, 98 crows profit by experience, 99 curiosity, 210 dangerous prey, 198 death: caused by clam, 199 by porcupine, 202 by spiders, 200 decoration: function of, 209 in nests, 207 snakeskin in, 113 droppings things: 186 by crows, 16 by gulls, 16, 187 by lammergeier, 186 by sparrow, 187 reason for, 188 drumming: of grouse, 134 of woodpecker, 133 drunkenness, 32 duck, muscovy, 162