INDEX OF SUBJECTS 



339 



Sternum, girth round, rate of growth, 



70. 



Stimuli, 12, 20, 272-277, 283-285; 

 of spermatozoon in fertilization, 

 123, 252 ; exerted by spicules of 

 Pluteus, 137, 275 ; directive, in 

 post-generation, 1C2. 



Stolon, see Hydroids. 



Stomodaeum, 9 ; formed in Anen- 

 teria, 106 ; in Exogastrulae, 137 ; 

 absent without potassium, 146 ; 

 formed from isolated ectoderm, 

 195; of Ctenophora, 210, 211. 



Stratification of organ-forming sub- 

 stances, 242, 280. 



Strongylocentrotus liridus, segmentation 

 of, 23 ; egg stretched, 39 ; decline of 

 growth-rate, 67 ; growth-rate of 

 arms of Pluteus, 70 ; decline of 

 variability in, 71 ; eggs exposed to 

 heat, 107 ; to action of alkaloids, 

 126 sqq. ; normal development, 

 183-185 ; micromeres suppressed, 

 186 ; hybridization experiments, 

 261, 262 ; purpuratus, heterogene- 

 ous cross-fertilization, 262. 



Strontium, 156 ; bromide, 132, 133. 



Structure, increase of, 2, 279 ; of egg, 

 see Egg-axis, Symmetry of egg. 



Strychnine, eggs of Bufo, 120 ; effect 

 on fertilization, 128-130 ; on Chick, 

 132. 



Substances, organ-forming in cyto- 

 plasm, 19, 207, 208, 217, 224, 225, 

 228, 233, 236, 240, 241, 246, 280, 

 286 ; specific action of substances 

 present in sea- water, 152. 



Succession, in the formation of parts, 

 13. 



Suckers, 239. 



Sulphates, 123 ; of quinine, 128-130 ; 

 of magnesium, 135 ; of sodium, 

 135; necessity of, 143, 144. 



Sulph-ion, see Sulphate. 



Sulphuric acid, 145. 



Superficial cell-aggregates, see Cell. 



Surface, area of, in partial larvae, 

 198, 269 ; area of nuclei and num- 

 ber of chromosomes, 268. 



Surface-tension, 41 sqq., 55, 56. 



Surfaces of contact between blasto- 

 meres, in radial segmentation, 22 ; 

 in spiral segmentation, 45-47 ; be- 

 tween isolated cells, 54 ; between 

 soap-bubbles, 43 ; between oil- 

 drops, 49 sqq. 



Suspension of development, at low 

 temperatures, 97, 99, 102, 104. 



Swelling after shrinkage in hyper- 

 tonic solutions, 124. 



Sycandra, 22. 



Symmetry, bilateral, of egg cytoplasm, 

 33, 80, 163, 232, 247, 280, 281; 

 radial, of egg, 79, 163, 204, 222, 

 232, 280; bilateral, and sagittal 

 plane, 80, 229, 235, 244 ; produced 

 by gravity, 82, 84, 87; radial, of 

 Plutei without sulphate, 144 ; bi- 

 lateral and first furrow, 167, 229, 

 235. 



System, equipotential, 176, 277 ; in- 

 equipotential, 176, 277. 



Systems of lamellae, see Lamellae ; of 

 drops, see Drops. 



Tadpole, tail of, phagocytosis in, 5 ; 

 absorption of water, 58, 59 ; rate 

 of growth in, 67 ; influence of 

 light on, 94 ; effect of pure oxygen, 

 113, 114 ; effect of increased at- 

 mospheric pressure on, 114; brain 

 and eyes removed, 175, 275 ; forma- 

 tion of lens and cornea, 275-277. 



Tail of Tadpole, phagocytosis in, 5 ; 

 doubled at high temperatures, 99. 



Taxis, Tactic, see Stimuli and Re- 

 sponses. 



Teleology, of Kant, 286-289 ; dynamic, 

 291,296; of Aristotle, 297. 



Teleostei, nervous system of, 6, 133 ; 

 segmentation, 26, 35 ; injuries to 

 germ-ring, 178 ; effect of fertiliza- 

 tion, 251. 



Tellurium, 144. 



Teloblast, continued division in same 

 direction, 29 ; continued unequal 

 division, 30 ; unequal asters in, 31. 



Telolecithal eggs, 24, 30. 



Temperature, as affecting growth, 2, 

 59 ; cardinal points, for Frog's egg. 

 97 ; for Hen's egg, 102 ; for Plutei, 

 107 ; alteration of variability with, 

 107 ; high, see Heat ; low, see Cold. 



Tendon, 5. 



Tension, see Surface-tension, Decom- 

 position-tension. 



Tentacles, branching of, 6. 



Teratology, 119, 155, 156. 



Teredo, 2fi. 



Tetrahedral arrangement of ccjlls, 

 24, 25, 26, 28, 29, 47; of soap- 

 bubbles, 43. 



Tetrasters, 107; produced by alka- 

 loids, 128. 



Thalamencephalon, roof of, 7. 



Thelykaryotic, 267. 



Theory, ' Mosaic ', or self-differentia- 

 tion, 17, 19, 158; analytical, of 

 Driesch, 280-286. 



