464 
SLAVES. 
INDEX. 
SPECIES. 
Slaves, difference between those of 
field and house, i. 246. 
Smell, sense of, in man and animals, 
i. 23. 
Smith, Adam, on the basis of sym- 
pathy, i. 82. 
Smith, Sir A., on the recognition of 
women by male Cynocephali, i. 13 ; 
on an instance of memory in a 
baboon, i. 45 ; on the retention of 
their colour by the Dutch in South 
Africa, i. 242 ; on the polygamy of 
the South African antelopes, i. 267 ; 
on the proportion of the sexes in 
Kobus elUpsiprymnus, i. 305 ; on 
Bucephalus capensiSj ii. 29 ; on 
South African lizards, ii. 37 ; on 
fighting gnus, ii. 240 ; on the horns 
of rhinoceroses, ii. 248 ; on the 
fighting of lions, ii. 266 ; on the 
colours of the Cape Eland, ii. 288 ; 
on the colours of the gnu, ii. 289 ; 
on Hottentot notions of beauty, ii. 
345. 
Smith, F., on the Cynipidse and Ten- 
thredinidae, i. 314 ; on the relative 
size of the sexes of Aculeate Hyme- 
noptei’a, i. 347 ; on the difference 
between the sexes of ants and bees, 
i. 365 ; on the stridulation of 
Trox sabulosus, i. 380; on the stri- 
dulation of Mononychus pseudacori, 
i. 382. 
Smynthurus luteus, courtship of, i. 
348. 
Snakes, sexual differences of, ii. 29 ; 
male, ardency of, ii. 30. 
Snarlinh muscles,” i. 127. 
Snipe, drumming of the, ii. 63 ; colo- 
ration of the, ii. 226. 
Snipe, painted, sexes and young of, 
ii. 202. 
Snipe, solitary, assemblies of, ii. 
101 . 
Snipes, arrival of male before the 
female, i. 260 ; pugnacity of male, 
ii. 43 ; double moult in, ii. 80. 
Snow-goose, whiteness of the, ii. 
228. 
Social animals, affection of, for each 
other, i. 76 ; defence of, by the 
males, i. 83. 
Sociability, the sense of duty con- 
nected with, i. 71 ; impulse to, in 
animals, i. 79, 80 ; manifestations- 
of, in man, i. 84 ; instinct of, in 
animals, i. 86. 
Sociality, probable, of primeval 
men, i. 155 ; influence of, on the- 
development of the intellectual 
faculties, i. 160 ; origin of, in man,. 
i. 161. 
Soldiers, American, measurements 
of, i. 114. 
Soldiers and sailors, difference in the 
proportions of, i. 116. 
Solenostoma, bright colours and mar- 
supial sack of the females of, ii. 
22 . 
Song of male birds appreciated by 
their females, i. 63 ; want of, in 
brilliant plumaged birds, ii. 94 ; of 
birds, ii. 163. 
SoreXj odour of, ii. 279. 
Sounds admired alike by man and 
animals, i. 64 ; produced by fishes, 
ii. 23 ; produced by male frogs and 
toads, ii. 27 ; instrumentally pro- 
duced by birds, ii. 63 et seqq. 
Spain, decadence of, i. 178. 
Sparassus smaragdulus, difference of 
colour in the sexes of, i. 337, 338. 
Sparrow, pugnacity of the male, 
ii. 40 ; acquisition of the Linnet’s 
song by a, ii. 55 ; coloration of the, 
ii. 198 ; immature plumage of the, 
ii. 188. 
Sparrow, white-crowned, young of 
the, ii. 217. 
Sparrows, house- and tree-, ii. 170. 
Sparrows, new mates found by, ii. 
105. 
Sparrows, sexes and young of, ii. 
212 ; learning to sing, ii. 334. 
Spathura Underwoodi, ii. 77. 
Spawning of fishes, ii. 15, 19. 
Spear, origin of the, i. 234. 
Species, causes of the advancement 
of, i. 172; distinctive characters 
of, i. 214 ; or races of man, i. 217 ; 
sterility and fertility of, when 
crossed, i. 122 ; supposed, of man, 
i. 226 ; gradation of, i. 227 ; diffi- 
culty of defining, i. 228 ; repre- 
sentative, of birds, ii. 190, 191 ; 
of birds, comparative differences 
between the sexes of distinct, ii. 
192. 
