INDEX 



Adrenalin, properties of, 141 



Aesthetic appreciation (in birds), 197 



Aepyornis, 0^4 of, 271 



Air-sacs, functions, 127-8 



Albinism, 40-41 



Allen, G. M,, on colour patterns, 



42-3 

 Ancestry of birds, 345 sqq. 

 Antlers (of Cervidae) as •sex-cha- 

 racters, 218, 223 

 Aquatic bird-life, 145 sqq. 

 Arboreal bird-life, 144 1 



Archaeopteryx, tail of, 55, 69 ; • 



clescription of, 345-6, 365 

 Auk (spp.), underwater proj^rcssion, 



146 ; courtship behaviour, 



190 

 (Chimerina cornuta), seasonal 



characters, 220 

 Avocet {Recurvirostra avocetta), 



courtship behaviour, 185 



Backbone, adaptations in, 66 



Bats, flight of, 71, 81, 82 



Beebe, C. M., on bird-moulting, 

 32-3 ; on insect destruction, 

 88 



Behaviour, instinctive, 338 sqq. ; 

 intelligent, 341 sqq. 



Bill, adaptations of, 92 sqq. 



Bipedal progression, adaptations to, 

 57 sqq. 



Bird associations, 157 



Birds of Paradise (Paradiseidae), di- 

 morphism, 210, 216 



Bittern (Botaurus stellaris), pose, 1 1 



Blackbird {Turclus merula), egg of, 

 273 ; nest of, 294 



Blackcock {Lyrurus tetrix), habitat, 

 158 ; courtship behaviour, 

 189 



Blood of birds, characteristics, 2 

 sqq. ; function and com- 

 position, 132 sqq., 138 ; 



temperature, 136-7 ; see 

 Warm-bloodedness. 



Bobolink (Dolichonyx orizivorus), 

 moulting, 32 



Bones, structural features, 47 ; 

 tendency to fusion, 48 ; 

 adaptations to flight, 49 sqq. ; 

 adaptations to bipedal pro- 

 gression, 57 sqq. 



Brain, of birds, characteristics, 7, 

 121-2 



Brooding, parental, modes of, 291 



Bustard, Great {Otis tarda), sex- 

 characters, 221 



Buzzard {Buteobuteo), variations, 371 



Ca;ca, functions of, 108 

 Capercailzie {Tetrao urogallus), 



habitat, 158 ; introduced, 



Britain, 411 

 Carinate type, 1 1 



Carr, Dr. H. A., observations, 178 

 Cassowary (Casuarius), problem of 



ancestry, 356 

 Characters acquired, terminology of, 



369 

 Sex ; see Sex-characters. 



Chick (of common fowl), abnormal 

 forms of embryo, 267 ; hatch- 

 ing of, 269 



Claspers (of Chimaeroids) as sex- 

 characters, 221 



Claw, pectinated, of nightjar, etc., 

 16 



Coloration of birds, 33 sqq. ; modi- 

 fications, 38 ; variations, 40 ; 

 external uses, 42 sqq. ; pro- 

 tective, 21, 42, 45, 158-9 ; of 

 nestling's mouth, 304 



Comb, of fowl, relation to egg- 

 laying, 252 ; Mendelian 

 aspect, 391, sqq. 



Conservation of birds, ij.15 



Convergence of adaptations, 95, 145 



430 



