346 INDEX OF SUBJECTS 
Spermatogenesis, 42, 256 ff. 
Spermatogonia, 127. 
Spermatozoon, 19-22, 48. 
Sphérule, 276. 
Spireme, 14, 15. 
Spongilla, 73. 
Spongioplasm, 4, 5. 
Sporulation, 17. 
Squash bug, 256. 
Starfish, 6. 
Statoblast, 18. 
Statocyte, 70, 71, 73. 
Stem-cell, 175. 
Stone-fly, hermaphroditic, 194. 
Synapsis, 44, 122, 250 ff., 305. 
Synaptene, 251, 252. 
Synizesis, 43, 237, 251, 252. 
Tenia, 136, 137. 
Telophase, 15, 16. 
Telosynapsis, 254. 
Testis, 41. 
Tethya, 70, 76, 79. 
Tetrad, 44, 45. 
Tipulides, 107. 
Toad, hermaphroditic, 207-208. 
Tokocyte, 71, 73, 79. 
Trophochromatin, 28. 
Unit character, 304. 
Uterine spindle, 157. 
Vacuole, 5, 8. 
Vegetative pole, 20. 
Vertebrate, 32, 95-105, 212. 
Vitelline membrane, 113, 114. 
Vitellophag, 114. 
X-chromosome, 255 ff., 264, 299. 
Y-chromosome, 259 ff., 264. 
Yolk, in germ cells, 101, 224. 
Yolk nucleus, 19, 226, 285. 
Zygosome, 251. 
Zygote, 1, 48. 
