340 



INDEX OF SUBJECTS 



Thickenings of cell-aggregates, see 

 Cells, movements of. 



Thigh, rate of growth, 70. 



Thigmotropism, 272, 275-277. 



Thinnings of cell-aggregates, see Cells, 

 movements of. 



Thio-sulphate, 144. 



Thymus, concentric corpuscles of, 

 11. 



Toad, 82, 102. 



Totipotent, parts, 76 ; see a/so Whole 

 nuclei, 266, 283, 284, 285. 



Toxicity, 122, 135, 136. 



Toxines, bacterial, 132. 



Toxopneustes, 185, 250. 



Transportation, by cells, see Cells, 

 movements of. 



Trematoda, segmentation, 28. 



Triasters, 107 ; produced by alka- 

 loids, 128. 



Triclads, blastomeres of, 5, 54, 273; 

 segmentation, 28, 55. 



Tripolar mitosis, 265. 



Trochoblasts, 213, 220. 



Trochophore, 224, 225. 



Trochus, 26, 30, 45-47. 



Trophoblast of Mammalia, 7 ; fusion 

 of, with embryonic plate, 9 ; fused 

 with somatopleure, 9 ; coenocytic 

 and syncytial, 55. 



Trophochromatin, 258. 



Tropism, Tropic, see Stimuli and 

 Responses. 



Trout eggs placed between poles of 

 a magnet, 91 ; between electrodes, 

 91 ; in light of various colours, 95. 



Truncus arteriosus of Mammals, split- 

 ting of, 6. 



Tubercle toxine, 132. 



Tubularia, 114, 144. 



Tunicata, follicle cells of, 5. 



Turbellaria, yolk-glands, 5. 



Turgor of plant-cells, 246. 



Umbrella, segmentation, 26, 30 ; flat- 

 tening of blastomeres, 45 ; parallel 

 polar furrows, 46. 



Understanding. 301. 



Unequal division, see Cell-division ; 

 of oil-drops, 52 ; numbers of chro- 

 mosomes, see Chromosomes. 



Unto, segmentation, 25, 30, 47 ; un- 

 equal asters, 30 ; flattening of blas- 

 tomeres, 45 ; crossed polar furrows, 

 46. 



Unipolar, see Immigration. 



Units, representative of inheritable 

 qualities, 19, 159, 246, 246, 279, 

 280. 



Urea, Frog's egg, 121 ; notochordal 



tissue, 134; nuclei, 135. 

 Urodela, notochord in, 8, 133. 



Vacuolation of cells of SpaerecMnus, 

 146, 261. 



Valency, 136. 



Variability, decline of, during growth, 

 71-74 ; increased at time of puberty, 

 73 ; causes of decline, 74 ; in- 

 creased by an adverse change of 

 conditions, 74, 141, 156; in period, 

 74. 



Variation, see Variability. 



Vasa efferentia, union of, with meso- 

 nephric tubules, 6. 



Vegetative cells, see Cells. 



Vegetative pole, blastopore at, 244. 



Veliger, 217. 



Ventricosity, of shell of Littorina, 71. 



Vertebral column, rate of growth, 70. 



Vertebrates, spleen of, 5 ; bone and 

 tendon, 5 ; vitreous body, 5 ; vasa 

 efferentia, 6 ; nerve- crest, 11 ; seg- 

 mental duct, 5 ; lens, 7 ; auditory 

 vesicle, 6 ; limb-buds, 11 ; me- 

 dulla, 7; artificial parthenogenesis, 

 124; thalamencephalon, 7; seg- 

 mentation, 22, 24, 47. 



Viole de Parme, 94. 



Violet light, 94-96. 



Vital constant, 291. 



Vitalism, 291 sqq. 



Vitellophags, 4, 273 ; vitelline mem- 

 brane, see Membrane. 



Vitreous body of Vertebrate eye, 6. 



Volume of partial larvae, 199 ; of 

 cells, and number of chromosomes, 

 268 ; of nucleus, and cell-surface, 

 269. 



Waist, rate of growth, 70. 



Water, absorption of, in growth, 2, 

 58, 59, 115, 116; in hypotonic 

 solutions, 118; decrease of, in later 

 stages, 58 ; evaporation of, from 

 albumen, 115; not absorbed by egg 

 of Frog, 123. 



withdrawal of, 119 ; in fertiliza- 

 tion, 123 ; and artificial partheno- 

 genesis, 123, 124 ; aggregated about 

 apical body and middle-piece of 

 spermatozoon, 123. 



- fresh, 117, 136 ; distilled, 136. 



Weight, increase of, as a measure of 

 growth, 58 sqq. ; correlations with 

 other magnitudes, 75; loss of, in 

 Hen's egg, 115. 



White plate, in inverted Frog's eggs, 

 85, 87. 



dal 



