BIRDS, NAMES OF:--Apteryx, 45, 236; Duck, 46, 61, 65, 128, 224 _n._; Fowl, domestic, 59, 82 _n._, 97, 113, 114, 217; Goose, 72; --periodic habit, 124 _n._; Grouse, hybridised, 97, 102; Guinea-fowl, 79; Hawk, sterility, 100; --periodic habit, 124; Opetiorynchus, 83; Orpheus, 31; Ostrich, distribution of, 158; Owl, white barn, 82; Partridge, infertility of, 102; Peacock, 79, 97, 102; Penguin, 128 _n._, 237; Petrel, 128 _n._; Pheasant, 97, 102; Pigeon, 66, 82, 110 _n._, 113, 114, 116, 117, 129, 135; _see_ Wood-pigeon; Rhea, 158; Robins, increase in numbers, 88, 90; Rock-thrush of Guiana, 93; Swan, species of, 105; Tailor-bird, 18, 118; Turkey, Australian bush-turkey, 121 _n._, 122; Tyrannus, 31; Water-ouzel, 18 _n._, 120; Woodcock, loss of migratory instinct, 120; Woodpecker, 6, 16, 128 _n._, 148; --in treeless lands, 16, 131; Wood-pigeon, 122; Wren, gold-crested, 120; --willow, 105, 148 Breeds, domestic, parentage of, 71 Brothers, death of by same peculiar disease in old age, 42 _n._, 44 _n._, 223 Bud variation, 58; _see_ Sports Butterfly, cabbage, 127 Catastrophes, geological, 145, 147 Caterpillars, food, 126, 127 Characters, acquired, inheritance of, 1, 57, 60, 225; --congenital, 60; --fixed by breeding, 61; --mental, variation in, 17, 112, 119; --running through whole groups, 106; --useless for classification, 199 Cirripedes, 201, 229 Classification, natural system of, 35, 199, 206, 208; --by any constant character, 201; --relation of, to geography, 202; --a law that members of two distinct groups resemble each other not specifically but generally, 203, 212; --of domestic races, 204; --rarity and extinction in relation to, 210 Compensation, law of, 106 Conditions, direct, action of, 1, 57 _n._, 62, 65; --change of, analogous to crossing, 15, 77 _n._, 105; --accumulated effects of, 60, 78; --affecting reproduction, 1, 4, 78, 99; --and geographical distribution, 152 Continent originating as archipelago, bearing of on distribution, 189 Cordillera, as channel of migration, 34 _n._, 191 Correlation, 76 Creation, centres of, 168, 192 Crocodile, 146 _Cross-and Self-Fertilisation_, early statement of principles of, 15, 69 _n._, 103 _n._ Crossing, swamping effect of, 2, 69, 96; --of bisexual animals and hermaphrodite plants, 2; --analogous to change in conditions, 3, 15, 69; --in relation to breeds, 68; --in plants, adaptations for, 70 Death, feigned by insects, 123 Difficulties, on theory of evolution, 15, 121, 128, 134 Disease, hereditary, 43 _n._, 58, 222 Distribution, geographical, 29, 31, 151, 174, 177; --in space and time, subject to same laws, 155; --occasional means of (seeds, eggs, &c.), 169 Disuse, inherited effects of, 46, 57