INDEX. 783 



579; arched foreheads of some, 608; merino, loss of horns in females 

 of. 201; horns of, 266. 



Sliells, difference in form of, in inale and female GaHteropoda, 297; 

 beautiful colors and shapes of, 298. 



Shield drake, pairing with a common duck, 471; New Zealand, 

 sexes and youn^ of, 546. 



8ho<iter, J., on the Kaffirs, 661; on the marriage-customs of the 

 Kaffirs, 661. 



Shrew-mice, odor of, 604. 



Shrike, Drongo, 524. 



Shrikes, characters of young, 529. 



Shuckard, W. E., on sexual differences m the wings of Hymenop- 

 tera, 314. 



SLiyness of adorned male birds, 457. 



Siagoniam, proportions of the sexes in, 286; dimorphism in males 

 of, 889. 



Siam, proportion of male and female births in, 277. 



Siamese, general beard le.ssness of the, 639; notions of beauty of 

 the, 660. hairy family of. 687. 



Sidgwick, 11., on morality in hypothetical bee community, 113; our 

 actions not entirely directed by pain and pleasure. 136. 



Siel)o]d, (', T. von, on the ])roportion of sexes in the ApU8, 287; on 

 the auditory apparatus of the stridulant Orthoptera, 321. 



Sight, inheritance of long and short, 88. 



Signal -cries of monkeys, 98. 



Silk-moth, proportion of the sexes in. 282, 284; A'Uanthtcs, Prof. 

 Canestrini, on the destruction of its larva) by wasps, 284; difference 

 of size of the male and female cocoons of the, 315; pairing of 

 the. 360. 



Siraiadae, 178; their origin and divisions, 188. 



Similarity, sexual, 254. 



Singing, of the Cicadte and Fulgoridae, 319; of tree-frogs, 897; of 

 birds, object of the, 417. 



SirenUi, nakedness of, 68. 



Sirex juveruius, 831. 



Siricitfae, difference of the sexes in, 881. 



Siskin, 446; pairing with a canary, 472. 



Sitnna, throat-pouch of the males of, 402, 406. 



Size, relative, of the sexes of insects, 815. 



Skin, dark color of, a protection against heat, 228. 



Skin, movement of the, 14; nakedness of, in man, 68; color of 

 the, 219; and hair, correlation of color of, 225. 



Skull, variation of, in man, 29; cubic contents of, no absolute test 

 of intellect, 61; Neanderthal, capacity of the, 61; causes of modifica 

 tion of the, 62; difference of, in form and capacity, in different races 

 of men, 192; variability of the shape of the, 198; differences of, in 

 the sexes in man, 635; artificial modification of the shape of, 655. 



Skunk, odor emitted by the, 603; white tail of, protective, 621. 



Slavery, prevalence of, 133; of women, 677. 



Slaves, difference l)etween tichl and house-slaves, 224. 



Sloth, ornaments of male. 610. 



Smell, sense of, in man and animals, 19. 



j^mith, Adam, on the basis of syinpathy, 120. 



