470 



IXDEX. 



Sexes, unequal length of life in the 

 two, 59. 



Sheep, length of life of, 14. 



Sida, spermatozoa of, 178 ; absorp- 

 tion of ova in, 244. 



Siobold, von, on development of 

 Bees, 240. 



Siphonophora, origin of germ- 

 cells of, 205. 



Sirenia, 268. 



Sirex, length of larval life of, 15. 



Smerinthus tiliae, length of life 

 of imago of, 45 ; ocellatus, 407. 



Solenobia triquetrella, length of 

 life of female of, 45 ; death of 

 parthenogenetic forms of, 65, 



301. 

 Soiidago, time of flowering 



changed, 428. 

 Soma, 123, 126, 131, 141, 146, 156, 



157- 



Somatic cells, 28, 29, 75, iii, 147, 

 160. 



Somatogenic characters, 426. 



Somatoplasm, 105, 183. 



Spathegaster, 50. 



Spencer, Herbert, on relation of 

 absorbing surface to size of 

 animal, 7 : on influence of di- 

 minished nutrition, 246 : on cor- 

 relation, 401. 



Spirogyra, on cell-division in, 220. 



Sponges, polar bodies of, 222. 



Spontaneous generation, 34. 



Sprengel, on colours in flowers, 



Squirrel, length of life of, 14. 



Stahl, on protective structures in 

 plants, 266, 



Strasburger, on fertilization of 

 Phanerogams, 181, 350, 366; 

 on cyto-idioplasm, 183 ; on in- 

 fluence of nuclei, 187 ; on iden- 

 tity of daughter nuclei, 190; on 

 nuclei of sexual-cells, 204, 219, 

 252 ; on transmission of germ- 

 plasm, 213; on cell-division in 

 Spirogyra, 222 ; on development 

 of pollen- grains, 227 ; on par- 

 thenogenesis, 242 ; on direction 

 of growth of pollen tube, 252 ; 

 on heredity. 364, 380 ; on polar 

 bodies in plants, 389. 



Strepsiptera, length of life of, 41 ; 



unequal length of life in two 



sexes, 59, 60. 

 Succineae, length of life of, 56. 

 Swans, length of life of, 37. 



Tagetes, production of double 

 flowers of, 421. 



Talents, transmission of, 96 ; na- 

 ture of, 97. 



Tape-worms, 134, 157. 



Termites, duration of life of, 19, 

 40. ^ 



Terns' eggs, 38. 



Thuja, dorso-vcntral structure of 

 shoots of, 404, 408. 



Tillina magna, 119, 150. 



Toad, length of life of, 6. 



Transmission of acquired cha- 

 racters, 73, 8r, 171, 273, 420, 

 424 ; want of evidence of the, 

 81 ; unnecessary for the theory 

 of evolution, 83; unproved, 106, 

 144: amongst Protozoa, 285; 

 supposed botanical proofs of, 



399- 

 Trematodes, parasitic in Mollusca, 



58, 132, 134. 

 Trichodinidae, conjugation of, 



294. 

 Trichoplax adhaerens, 143. 

 Tridacna gigas, length of life of, 



57- 

 Trinchese, on polar bodies, 192, 



228. 

 Tropaeolum, two kinds of leaves 



of, 409. 

 Turkey, the length of life of, 36. 

 Twins, 392. 



Unicellular organisms, immortal- 

 ity of, 26, 28. 

 XJnio, length of life of, 57, 58. 



Valaoritis, on origin of germ-cells, 

 198; on physiological value of, 



251- 

 Vanessa cardui, length of life of, 

 44 ; V. prorsa, 44 ; V. urticae, 

 44 ; V. levana, deposition of eggs 



o<", 95- 

 Variations, alwa\'s present, 103. 



Ventral canal cell, 227. 



