INDEX 



317 



Ruff, amorous instincts of, 115 



— display of, 113 



— variability of, 114 



Sabre - toothed tiger, huge 

 canines of, 80 



jaw-fianges of, 80 



Salmon, coloration of. 180 



— courtship of, 1 79 

 Sandpiper, Pectoral, air-sacs in 



display of, 108 

 Scent glands, 67 

 Scorpions, courtship of, 242 

 Secondary Sexual Characters, 



meaning of, 1 3 

 Selection, forms of, 7 

 Selous, Mr. F. C, on habits of 



moose, 59 

 on the mane of the 



lion, 78 

 Sex, beginnings of, 4 



— birth of, 12 

 Sex-antagonism, 9 



Sexual instincts, dominance of, 

 162 



grades of, 183 



importance of, 27 



Sexual selection, definition of, 20 



and human evolution, 38 



in the human race, 32 



instance of working of, 147 



Sexual Selection Theory, modifi- 

 cation of, 154 

 Sharp, Dr. David, on stridulat- 



ing organs, 219 

 Sheep, scent of, 69 

 Skull, human, malformation of, 



35 



Smith Woodward, Dr. A., on 

 factors in evolution, 17 



Smynthurus. remarkable court- 

 ship of, 26 



Snail, hermaphrodite state of, 

 271 



— " love-darts " of, 271 



— significance of coloration of, 

 272 



Somato-plasm, nature of, 1 1 

 South, Mr., on Oak-eggar moth, 



202 

 Spiders, courtship of, 242 et seq. 



— dread sequel to nuptial rites, 

 246 



— drumming of, 237 



— nuptial rites in, 248 



— remarkable coloration of, 239 



— stridulating organs in, 237 

 Starling, Prof., on Hormones, 



14, 16 



State executions v. State pen- 

 sions, 286 



Stickle-back,paternal care in, 181 



— remarkable nest of, 181 

 Stone-flies, degenerate wings in, 



234 



— nuptial rites performed in ice, 



233 

 Stridulating organs of grass 



hoppers, 218 



nature of, 217 



Sun-bittern, display of, 142 

 Syrinx in birds, 123 



Termite, amazing fertihty of 

 queen, 302 



" Territory," importance of, 154 



Thomson, Prof. J. A., on evolu- 

 tion of sex, 12, 309 



Townsend, Mr., on sea- 

 elephants, 87 



Tragopans, display of, 100 



Trimen, Dr., on deceptive 

 coloration in a spider, 240 



Turkey, display of, 99 



