INDEX. 



383 



in different classes of animals, 

 111; diverse habits of, 156. 



SEXUAL SELECTION, 156; its nor- 

 mal action to develop colour in 

 both sexes, 247; among birds, 

 283. 



SIDGWICK, Mr. A., on protective 

 colouring of moths, 62. 



SIMOCYONID.E, 300. 



SITTA, sexual colouring and nidi- 

 fication of, 243. 



SITTELLA, sexual colouring and 

 nidification of, 243. 



SNAKES, mimicry among, 101. 



SONG of birds, instinctive or imita- 

 tive, 220. 



SPECIES, law of population of, 28 ; 

 abundance or rarity of, depend- 

 ent on the adaptation to condi- 

 tions, 33; definition of, 141, 

 161 ; the range and constancy 

 of, 143; extreme variation in, 

 163, 164. 



SPEED of animals, limits of, 292. 



Sphecia craboniforme, 90. 



Sphecomorpha chalybea, 96. 



SPIIEGID.E, mimicked by flies, 97. 



SPIDERS, which minac ants, 98 ; 

 and flower buds, 99. 



Spilosoma menthastri, 88. 



STAINTON, Mr., on moths rejected 

 by turkeys, 78, 88. 



STALACIITIS, a genus of Erycinida?, 

 the object of mimicry, 84. 



STINGING insects generally conspi- 

 cuously coloured, 72. 



STREPTOCITTA, 196. 



STUKNID.E, sexual colouring and 

 nidification of, 244. 



STUKNOPASTOR, 239. 



ST. HELENA, 10. 



Streptolabis hispoides, 93. 



STRUGGLE for existence, 28, 33. 



SURVIVAL of the fittest, law of, 

 stated, 33 ; its action in deter- 

 mining colour, 67. 



SWAINSON'S circular and quinarian 

 theory, 45. 



SYLVIAD.E, sexual colouring and 

 nidification of, 245. 



SYNAPTA, 258. 



TACHORNIS pJuenicobea, 228. 

 Tachyris hombronii, 172; it home, 



172 ; lycaste, 172 ; lyncida, 172 ; 



nephele, 172; nero, 172; zarinda, 



172. 

 TANAGRID/E, sexual colouring and 



nidification of, 245. 

 TAPIR, 299. 

 TELEPHORI, similar colouring of 



two sexes, 114. 



TEMPERATE and cold climates fa- 

 vourable to civilization, 318. 

 THECODONTIA, 299. 

 TIIEUATES, mimicked by Hetero- 



mera, 95. 

 Thyca descombesi, 172 ; Jiyparete, 



172; rosenbergii, 172; zebudn, 



172. 



TIGER, adaptive colouring of, 52. 

 TIMES newspaper on Natural Selec- 

 tion, 296. 

 TOOLS, importance of, to man, 



314. 

 TREE FROGS, probable mimicry by, 



103. 



TRICONDYLA, 97. 

 TRIMEX, Mr., on rank of the Papi- 



lionidw, 136. 

 TRISTRAM, Kev. II., on colours of 



desert animals, 50, 



