784 INDEX. 



Smith, Sir A., on the recognition of women by male Cynocepliali, 

 9; on revenge by a baboon, 78; on an instance of memory in a 

 baboon, 83; on the retention of their color by the Dutch in South 

 Africa, 219; on the polygamy of the South African antelopes, 246; 

 on the polygamy of the lion, 247; on the proportion of the sexes in, 

 Kohus ellipsij^rymnus. 279; on BucephnluH capensis, 398; on South 

 African lizards, 406; on fighting gnus. 571; on the horns of rhinoce- 

 roses, 576; on the fighting of lions, 594; on the colors of the Cape 

 eland, 612; on the colors of the gnu, 612; on the Hottentot notions 

 of beauty, 660; disbelief in communistic marriages, 671 



Smith, F., on the Cynipidae and Tenthredinidae, 286; on the rela- 

 tive size of the sexes of Aculeate Hymenopetra, 316; on the difference 

 between the sexes of ants and bees, 331; on the stridulation of Trox 

 sabulosus, 343; on the stridulation of Moiionychus pseudacori, 345. 



Smynthurus luteus, courtship of, 317. 



Snakes, sexual differences of, 398; mental powers of, 399; male, 

 ardency of, 399. 



" Snarling muscles," 46. 



Snipe, drumming of the, 427; coloration of the, 558; painted, 

 sexes and young of, 542; solitary, assemblies of, 461. 



Snipes, arrival of male before the female, 240; pugnacity of male, 

 411; double moult in, 442. 



Snow-goose, whiteness of the, 560. 



Sociability, the sense of duty connected with. 111; impulse to, in 

 animals, 119, manifestations of, in man, 123; instinct of, in ani- 

 mals, 124. 



Social animals, affection of, for each other, 115, defense of, by the 

 males, 121. 



Sociality, probable, of primeval men, 70; influence of, on the de- 

 velopment of the intellectual faculties, 146; origin of, in man, 147, 



Soldiers, American, measurements of, 34; and sailors, difference in 

 the proportions of, 36, 



Solenostoma, bright colors and marsupial sac of the females 

 of, 393 



Song, of male birds appreciated by their females, 104; want of, in 

 brilliant plumaged birds, 454; of birds, 512. 



Sorex, odor of, 603. 



Sounds, admired alike by man and animals, 104; produced by 

 fishes, 393; produced by male frogs and toads, 397; instrumentally 

 produced by birds, 426 et seq. 



Spain decadence of, 160. 



SparassuH smaragdidus, difference of color in the sexes of, 307. 



Sparrow, pugnacity of the male, 409; acquisition of the linnet's 

 song by a, 420; coloration of the, 539; immature ])lumage of the, 

 532; white-crowned, young of the, 553. 



Sparrows, house and tree, 518, 550; new mates found by, 463; 

 sexes and young of, 550; learning to sing, 651. 



Spathura Underiroodi, 440. 



Spawning of fishes, 387, 391. 



Spear, used before dispersion of man, 204. 



Species, causes of the advancement of, 156; distinctive characters 

 of, 190; or races of man, 191; sterility and fertility of, when 

 crossed, 194; supposed, of man, 198; gradation of, 198; difficulty of 



