INDEX. 



Sprengel on fertilisation in flowers, 



138 

 Starfish, reproduction of parts, 197 

 Starkweather's law of sex, 36, 37 

 Statistics on male and female births, 



Steenstrup on alternation of genera- 

 tions, 200 



Stickleback, habits of, 24 ; secretion 

 of, 250, 251 



Sterility, 298 



Strasburger on fertilisation, 159, 

 160 ; on parthenogenesis, 181 



Summer eggs, 174 



Surinam toad, 63, 252, 253 



Sutton on embryonic hermaphro- 

 ditism, 33, 66 



Syllids, asexual multiplication, 197 



Tadpoles, 41, 248 

 Tapeworm, life-history of, 209, 210 

 Temperance, 297, 298 

 Temperature, influence of, on sex, 



48, 49 

 Thury, theory of sex, 34 

 Tiger-lily, 226 

 Treviranus, 301 ; on influence of 



sperm, 166, 307 

 Tunicates, asexual multiplication, 



198 ; alternation of generations, 



203 

 Twins, 210 ; sex of, 39 



Ulothrix, reproduction in, 127 



Variation, 13, 166, 167, 301, 306 

 Vines on reproduction in plants, 



126, 127 

 Viviparous animals, 248 



Vorticella, reproduction of, 129, 



149, 150 

 Volvox, 58, 128-130 



Wallace, sexual selection, 10-14; 



natural selection, 29, 303, 304 

 Ward, Marshall, on parasitic fungi, 



229 

 Water-fleas, parthenogenesis in, 



Weeping willows, 188 



Weismann on fertilisation, 161, 

 162 ; on polar bodies, 105, 107 ; 

 on use of fertilisation, 164 ; on 

 parthenogenetic ova, 181- 185 ; 

 hydroids, 91, 210, 211 ; alternation 

 of generations, 214; continuity of 

 germ-plasnia, 94, 95, 239-241 ; 

 on organic immortality, 258-261 ; 

 inhericance of acquired characters, 

 51, 304-306 ; variation, 306 



Whelk, cannibalism of young, 249 



Winter eggs, 174 



Wolff, reassertion of epigenesis, 85 



Women, subjection, rights, func- 

 tions of, 267-271 



Worms, hermaphroditism in, 71 ; 

 asexual reproduction, 195-197 ; al- 

 ternation of generations, 209 



Yolk glands, 61 



Yolk-sac, 249 



Yung on sex in tadpoles, 41 



Zacharias on male and female ele- 

 ments, 114; on asexual multipli- 

 cation, 225 



Zona pellucida, 103 



Zona radiata, 103 



r yintcd />y \y ALTKK Scott, Felling, Newcastlc-o)i-TyiLc. 



