INDEX 



481 



Teleology: the problem of, 30; in inter- 

 pretation of reduction in planarians, 

 44; in interpretation of budding in 

 plants, 231; in interpretation of re- 

 lation between agamic and gametic 

 reproduction in plants, 367, 369. 



Temperature coefficient: of rate of 

 chemical reaction, 68; of length of life 

 of Planaria dorotocephala in cyanides 

 and narcotics, 68; of length of life of 

 sea-urchin eggs, 308; of rate of develop- 

 ment, 308. 



Teratomorphic form, in Planaria doroto- 

 cephala, III, 223. 



Teratophthabnic form, in Planaria doro- 

 tocephala, III. 



Torreya taxifolia, archegonium and egg 

 of, 33?- . 



Transmission: in relation to colloids, 26; 

 in relation to axial gradients, 209; 

 decrement in, 209, 217, 227; as means 

 of physiological correlation, 217; limit 

 of, 217, 219, 231; in nerves, 218, 230; 

 quantitative effect of, 225; efficiency 

 of, 227. See also Conducting paths; 

 Conductivity. 



Trematode, parthenogenesis in larvae 

 of digenetic, 395. 



Tubularia: simple individual of, 210; 

 reconstitution of, 210; limit of domi- 

 nance in agamic reproduction of, 220; 

 limit of dominance in reconstitution 

 of, 221. 



Ulothrix, spore formation in, 247. 

 Urocentrum turbo, rejuvenescence of, 

 in agamic reproduction, 141, 142. 



Vacuole, in infusoria, 137. 

 Vacuolization, in plant cells during 



differentiation, 245, 284. 

 Vaucheria: spore formation in, 247: 



conditions of spore formation in, 250; 



conditions of gamete formation in, 



365. 

 Volume and surface. See Surface. 

 Volvox, gametes of, 316. 



Water: in relation to colloids, 24; in 

 relation to growth, 36; production of, 

 in metabolism 37; in relation to senes- 

 cence, 184, 279, 283. 



Winter egg, 390, 404. 



Zamia: spermatozoid of, 334; egg of, 339. 



Zooid: formation of, in Planaria doroto- 

 cephala, 123; formation of, in Steno- 

 stomum, 133; as member of animal 

 colony, 237. 



Zoospore, 247, 252. 



Zygogenesis, 343, 389; gradations be- 

 tween, and parthenogenesis, 410. 



Zygogenic egg: oogenesis of, compared 

 with that of parthenogenic egg, 343; 

 in daphnid Crustacea, 390. 



Zygospore, in algae and fungi, 316. 



