376 



INDEX 



synapsis, 135, 294 



Synapta, cleavage (regular), 227, 



228,229 

 syndesis, 135 

 Syngamus, 107 

 syngamy, 12, 13, 165 

 synizesis, 135 



Tadorna, spermatozoon, 99 



tail, of spermatozoon, 98 



Teleost, gastrulation, 343, 346, ff., 

 347 



telolecithal ova, 93, 226 



telophase, 54 



telosynapsis, 136 



Tennent, 304 



Tennent and Hogue, 207 



terminal filament, of spermatozoon, 

 100 



test cells, of Tunicates, 120, 120 



testis, 109; structure, 121 



tetrads, 136, ff., 139, 146 



Tetramitus, conjugation, 193; divi- 

 sion, 69 



Torpedo, blastoderm, 355; poly- 

 spermy, 170 



Toxopneustes, entrance of sperma- 

 tozoon into ovum, 168; fertiliza- 

 tion, 173 ; paths of pronuclei, 186 



Trachelomonas, cell division, 59, 64 



Trichomastix, autogamy, 191 



Trichosomum, 107 



tridermic embryo, 333 



Triton, blastula, 331 ; gastrulation, 



trophochromatin, 58, 158 

 " trophospongien," 40, 41 

 Tyndall, 1 



Unequal division, in cleavage, 231 

 Unio, blastomeres, 256 ; cleavage 



(radial), 235; mitosis, 50 

 Urodeles, spermatogenesis, 124 

 Urospora, gametes, 198 



Vacuoles, 39 



variation, relation to fertilization, 

 213; relative amount in gameti- 



cally and agametically produced 

 individuals, 214 



vasa deferentia, 129 



vasa efferentia, 129 



vegetal pole, 92 



Vernon, 304 



Vesperugo, spermatozoon, 99 



Virchow, 20, 42 



vitelline membrane, 95 



viviparous, 104 



Volvox, gametes, 198 ; reproduction, 

 9-11, 11, 199, 200 



Vorticella, fertilization (conjuga- 

 tion), 196 



DeVries, 265 



Wallace, 313 



Weismann, 14, 203, 213, 265, 292 



Whitman, 162, 264, 352 



Whitney, 269 



Wilson, 76, 101, 136, 168, 185, 231, 



247, 257, 263, 269, 271, 280, 281, 



287, 298, 311, 313, 314 

 Winiwarter, 133, 135 

 Wolff, 22, 355 

 Woodruff, 211 



X-chromosomes, 307; in maturation, 

 diagram, 309; in relation to sex, 

 diagram, 310; variations in, 311, 

 312 



Yatsu, 183, 207, 287 



Y-chromosomes, 311, 312 



yolk, arrangement in ova, 93; lobe, 

 of Dentalium, 271; nucleus, 89; 

 pyramids, 242 ; relation to develop- 

 mental period, 108; sac, 350; 

 stalk, 351 



Zeleny, 287 



Ziegler, 81 



Zoja, 280 



zona radiata, 95 



zoospores, 4 



Zur Strassen, 253, 255, 282 



zygonema, 135 



zygote, 11 



