458 



A HISTORY OF BIRDS 



R 



Rails, ancient characters of, 52. 

 Rhea and Guanacos, 124. 

 Ruff, display of, 159. 



Sand-grouse, descent of, 55, 56. 



— irruption of, 98. 



— care of young, 225. 



Screamers, archaic characters of, 48, 50. 

 Selection, interspecific, 318. 



— intraspecific, 321. 



— intraorganismal, 333. 



— artificial, 335. 



— sexual, 343. 



— natural, 356. 



— physiological, 357. 

 Shoulder-girdle, forms of, 379. 

 Skeleton, characters of, 16, 30, 

 Skuas, predatory habits of, 118, 320. 

 Skull, characters of, 30. 



Smell, characters of, 29. 

 Snipe, " bleating " of, 170. 

 Species, origin of, 305. 



— evolution of, 307. 



— physiological, 342. 

 Squamosal, evolution in, 372. 

 Steganopodous birds, descent of, 48. 

 Storks, types of, 48. 



Striped coloration, significance of, 252. 

 Struthious birds, fossil forms of, 77. 

 Swallow, migration route, 92. 



Tail, evolution of, 266. 



— feathers, uses of, 398. 



Tanager, change of colour in, 316. 



Tinamous, 51. 



Tongues, forms of, 420, 426. 



Tournaments, kinds of, 156. 



Turnices, 51. 



U 



Uropygium, 15, 16. 



Variation, continuous and discontinuous,. 



291. 

 Vertebras, peculiarities of, 33. 



W 



Warblers, order of migration of, 99. 



— display of, 347. 

 Weapons, uses of, 160. 

 White eggs, meaning of, 205. 



— plumage, significance of, 325. 

 Windpipes, modifications of, 401 et seq. 

 Wing, feathers of, 13, 377. 



— spurs of, 161. 



— sounds made by, 170. 



— claws of, 250. 



— skeleton of, 373 et seq. 

 Woodcock carrying young, 225, 230. 

 Woodpecker, method of storing nuts, 



140. 



— — grasshoppers, 142. 



obtaining sap, 142. 



— plumage, phases of, 273. 



— interbreeding of, 302. 



— mutation in, 305. 



— changed habits of, 409. 



Young, methods of feeding, 225. 



— neglect of, 232. 



— striped coloration of, 252. 



Zoo-geographical regions, 63. 



