SIZE. 



INDEX. 



SPARROWS. 



Size, relative, of the sexes of insects, 

 278. 



Skin, movement of the, 13; naked- 

 ness of, in man, 56 ; colour o*' the, 

 192. 



■ and hair, correlation of colour 



of, 197. 



Skull, variation of, in man, 26 ; 

 cubic contents of, no absolute test 

 of intellect, 54 ; Neanderthal, ca- 

 pacity of the, 55 ; causes of modi- 

 fication of the, 55 ; difference -of, 

 in form and capacity, in different 

 races of men, 168; variability of 

 the shape of the, 174 ; differences 

 of, in the sexes in man, 557 ; arti- 

 ficial modification of the shape of, 

 575. 



Skunk, odour emitted by the, 528 ; 

 white tail of, protective, 543. 



Slavery, prevalence of, 117; of wo- 

 men, 593. 



Slaves, difference between field and 

 house-slaves, 196. 



Sloth, ornaments of male, 534. 



Smell, sense of, in man and animals, 

 17. 



Smith, Adam, on the basis of sym- 

 pathy, 106. 



• , Sir A , on the recognition of 



women by male Cynocephaii, 8 ; on 

 revenge by a baboon, 69 ; on an 

 instance of memory in a baboon, 

 74; on the retention of their colour 

 by the Dutch in South Africa, 193 ; 

 on the polygamy of the South 

 African antelopes, 217; on the 

 polygamy of the lion, 218; on the 

 proportion of the sexes in Kohus 

 ellipsiprymnus, 247 ; on Bucephalus 



capensis, 



351 ; on South African 



lizards, 358 ; on fighting gnus 

 501 ; on the horns of rhinoceroses 

 506 ; on the ficrhtin? of lions, 521 

 on v.he colours of the Cape Eland 

 535 ; on the colours of the gnu 

 536 ; on Hottentot notions of 

 beauty, 578; disbelief in commu- 

 nistic marriages, 588. 

 — , F., on the Cympidae and Ten- 

 thredinidae, 254; on the relative 

 size of the sexes of Aculeate Hymen- 

 optera, 279 ; on the difference be- 

 tween the sexes of ants and bees, 

 292; on the stridulation of Trox 



sabulosus, 303; en the stridulatioa 

 of Mononychus pseudacori, 305. 



Smyntkurus Inteus, courtship of, 279. 



Snakes, sexual differences of, 351 ; 

 mental powers of, 352 ; male, ar- 

 dency of, 352. 



"Snarling muscles," 41. 



Snipe, drumming of the, 376 ; colo- 

 ration of the, 491. 

 -, painted, sexes and young of, 



476. 



, solitary, assemblies of, 405. 



Snipes, arrival of male before the 

 female, 212; pugnacity of male, 

 362; double moult in, 390. 



Snow-goose, whiteness of the, 492. 



Social animals, affection of, for each 

 other, 102; defence of, by the 

 males, 107. 



Sociability, the sense of duty con- 

 nected with, 9S ; impulse to, in 

 animals, 105; manifestations of, 

 in man, 108; instinct of, in ani- 

 mals, 109. 



Sociality, probable, of primeval men, 

 62; influence of, on the develop- 

 ment of the intellectual faculties, 

 128; origin of, in man, 129. 



Soldiers, American, measurements of, 

 29. 



and sailors, difference in the 



proportions of, 32. 



Solenostoma, bright colours and mar- 

 supial sack of the females of, 

 346. 



Song of male birds appreciated by 

 their females, 92 ; want of, in 

 brilliant plumaged birds, 401 ; of 

 birds, 450. 



Sorex, odour of, 528. 



Sounds admired alike by man and 

 animals, 92 ; produced by fishes, 

 347 ; produced by male frogs and 

 toads, 350 ; instrumentally pro- 

 duced by birds, 376 et scq. 



Spain, decadence of, 141. 



Sparassus smaragdulus, difference of 

 colour in the sexes of, 272. 



Sparrow, pugnacity of the male, 360 ; 

 acquisition of the Linnet's song by 

 a, 370 ; coloration of the, 473 ; im- 

 mature plumage of the, 466. 



, white-crowned, young of the, 



486. 



Sparrows, house- and tree-, 455. 



