INDEX. 



429 



nidse, i. 905 ; on the relative size of the 

 Bexes of Aculeate Hymonoptera, i. 337 ; 

 on the difference between the sexes of 

 ants and bees, i. 354; on the stridulation 

 of Trox satodosm, i. 369 ; on the strid- 

 ulation of Mononychw pseudacori, i. 

 871. 



Smynthurus luteiis, courtship of, i. 338. 



Snakes, sexual differences of, ii. 28 ; male, 

 ardency of, ii. 29. 



" Snarling muscles," i. 122. 



Snipe, drumming of the. ii. 60 ; coloration 

 of the, ii. 216. 



Snipe, painted, sexes and young of, ii. 

 193. 



Snipe, solitary, assemblies of, ii. 97. 



Snipes, arrival of male before the female, 

 i. 251 ; pugnacity of male, ii. 41 ; double 

 moult in, ii. 77. 



Snow-goose, whiteness of the, ii. 21S. 



Social animals, affection of, for each other, 

 i. 73 ; defence of, by the males, i. 79. 



Sociability, the sense of duty connected 

 with, i. 68 ; impulse to, in animals, i. 76, 

 77 ; manifestations of, in man, i. 81 ; in- 

 stinct of, in animals, i. 82, 83. 



Sociality, probable, of primeval men, i. 

 149 ; influence of, on the development of 

 the intellectual faculties, i. 154 ; origin of, 

 . in man, i. 155. 



Soldiers, American, measurements of, i. 

 108. 



Soldiers and sailors, difference in the pro- 

 portions o'f, i. 110. 



Solenostoma, bright colors and marsupial 

 sack of the females of. ii. 21. 



Song of male birds appreciated by their 

 females, i. 61 ; want of, in brilliant- 

 plumaged birds, ii. 90 ; of birds, ii. 156. 



Sorex, odor of ii. 266. 



Sounds admired alike by man and ani- 

 mals, i. 62 ; produced by fishes, ii. 22 ; 

 produced by male frogs and toads, ii. 25; 

 instrumentally produced by birds, ii. 61, 

 et seqq. 



Spain, decadence of, i. 171. 



Spara&ms smaragduliis, difference of 

 color in the sexes of, i. 328. 



Sparrow, pugnacity of the male, ii. 38; 

 acquisition of the Linnet's song by a, ii. 

 52 ; coloration of the, ii. 189 ; immature 

 plumage of the, ii. 180. 



Sparrow, white-crowned, young of the, 

 ii. 208. 



Sparrows, house- and tree-, ii. 162. 



Sparrows, new mates found by, ii. 101— 



Sparrows, sexes and young of, ii. 203; 

 learning to sing, ii. 319. 



Spathura Underwoodi, ii. 74. 



Spawning of fishes, ii. 15, 18. 



Spear, origin of the, i. 225. 



Species, causes of the advancement of, i. 

 165; distinctive characters of, i. 206; or 

 races of man, i. 209 ; sterility and fertil- 

 ity of, when crossed, i. 214 ; supposed, 

 of man, i. 21S ; gradation of, i. 218 ; diffi- 

 culty of defining, i. 219 ; representative, 

 ■>f birds, ii. 182, 1S3 ; of birds, compara- 



tive differences between the sexes of dis- 

 tinct, ii. 1S4. 



Spectre-insects, mimicry of leaves by, i. 

 401. 



Spectrum femoratum, difference of color 

 in the sexes of, i. 350. 



SpEEcn, connection between the brain and 

 the faculty of, i. 56. 



"Spel" of the black-cock, ii. 58. 



Spencer, Herbert, on the dawn of intelli- 

 gence, i. 36 ; on the origin of the belief in 

 spiritual agencies, i. 63 ; on the origin of 

 the moral sense, i. 97 ; on the influence 

 of food on the size of the jaws, i. 113 ; on 

 the ratio between individuation and gene- 

 sis, i. 310 ; on music, ii. 320. 



Sperm-whales, battles of male, ii. 229. 



Sphingid^e, coloration of the, i. 383. 



Sphinx, Humming-bird, i. 3S7. 



Sphinx, Mr. Bates on the caterpillar of a, 

 i. 402. 



Spiders, i. 327 ; male, more active than fe- 

 male, i. 263 ; proportion of the sexes in, i 

 306 ; male, small size of, i. 32S. 



Spilosoma menthrasti, rejected by tur- 

 keys, i. 3S6. 



Spine, alteration of, to suit the erect atti- 

 tude of man, i. 138. 



Spirits, fondness of monkeys for, i. 12. 



Spiritual agencies, belief in, almost uni- 

 versal, i. 62. 



Spoonbill, ii. 57 ; Chinese, change of plu- 

 mage in, ii. 171. 



Spots, retained throughout groups of birds, 

 ii. 126 ; disappearance of, in adult mam- 

 mals, ii. 2S8. 



Sprengel, C. K., on the sexuality of plants, 



Spring-boc, horns of the, ii. 239. 



Sproat, Mr., on the extinction of savages 

 in Vancouver Island, i. 230 ; on the eradi- 

 cation of facial hah- by the natives of Van- 

 couver Island, ii. 332 ; on the eradication 

 of the beard by the Indians of Vancouver 

 Island, ii. 363. 



Spurs, occurrence of, in female fowls, i. 

 271, 275; development of, in various spe- 

 cies of Phasianidas, i. 2S1 ; of Gallinaceous 

 birds, ii. 41, 43; development of, in fe- 

 male Gallinaceae, ii. 155. 



Squilla, different colors of the sexes of a 

 species of, i. 326. 



Squirrels, battles of male, ii. 228 ; African, 

 sexual differences in the coloring of, ii. 

 272 ; black, ii. 2S0. 



Stag, long hairs of the throat of, ii. 256 ; 

 horns of the, i. 270, 273 ; battles of, ii. 

 229 ; horns of the, with numerous branch 

 es, ii. 241 ; bellowing of the, ii. 261 ; crest 

 of the, ii. 268. 



Stag-beetle, large size of male, i. 336; 

 weapons of the male. i. 364; numerical 

 proportion of sexes of, i. 305. 



Staunton, H. T., on the numerical propor- 

 tion of the sexes in the smaller moths, i. 

 302; habits of Elachista rufoeinet'ea, i 

 308 ; on the coloration of moths, i. 384 

 on the rejection of Spilosoma mmthrat 



