338 



INDEX OF SUBJECTS 



Serranus, 178. 



Sertularel'a, 272. 



Sertularia, 272. 



Sexual reproduction, 1 ; Aristotelian 

 view of, 13, 294-296. 



Shaking eggs, a means of disarrang- 

 ing blastomeres, 188 ; or separating 

 them, 190 ; prevents division of 

 centrosome, 265, 267. 



Shape of cells, 29; altered by spindle, 

 48. 



Shocks given to eggs, 89. 



Silicon, 141. 



Silk- worms, exposed to influence of 

 magnetism, 91. 



Sipunculoids, 22. 



Sipunculus, 9. 



Siphonophora, 181. 



Size, increase of, see Growth; of 

 organisms, 65 ; of cells, deter- 

 mined by yolk, 29, 48 ; in partial 

 larvae, 199 ; of bubbles, 43, 46 ; of 

 nucleus, see Nucleus ; of partial 

 larvae and their organs : in the 

 Newt, 173 ; in Fishes, 178; in Am- 

 phioxus, 181 ; in Echinoids, 198, 

 199 ; in Nemertines, 206. 



Skeletal cells, and notochord, 5. 



Skeleton, of Chick, malformations of, 

 90 ; of Pluteus, in potassium, 137 ; 

 and lithium salts, 138; without 

 sulphate, 144 ; without potassium, 

 146 ; without magnesium, 147 ; 

 without calcium, 149 ; without car- 

 bonate, 150 ; in bromides, 145 ; in 

 neutral media, 151 ; number of 

 arms depends on number of spi- 

 cules, 138, 144, 150, 195, 275 ; de- 

 pendent of nucleus, 261 ; of hy- 

 brids, 259-262. 



Soap films, 41, 42 ; bubbles, 43-47. 



Sodium, chloride, used to suppress 

 cell-division, 56, 117 ; to produce 

 abnormalities, 119, 120, 133-135; 

 larvae of Echinoids, 137; bromide, 

 120, 134 ; sulphate, 135 ; nitrate, 

 135 ; butyrate, 140 ; formate, 145 ; 

 hydrate, 151, 262 ; acclimatization 

 to, 136 ; effect on ciliary and 

 muscular movement, 135 ; neces- 

 sity of, 145. 



Solenoid, Tesla's, 91. 



Solutions, chemically equivalent, 

 140 ; equimolecular, 140 ; hyper- 

 tonic, 116, 117, 120-122, 123, 124; 

 hypotonic, 118; isotonic, 120, 123, 

 124, 140, 142. 



Somatic cells of Ascaris, 252, 253. 



Somatoploure, fused with allantois, 

 and trophoblast, 9. 



Somites, fusion of, 11. 



Soul, Aristotelian doctrine of, 292- 

 297; nutritive, 13, 293; percep- 

 tive, 13, 293 ; reasoning, 294 ; and 

 body, 292. 



Sound-vibrations, effect of, 90. 



Specific gravity of yolk, 78, 79. 



Spermatozoon, entrance of, and di- 

 rection of first furrow, 40, 185, 

 247, 248 ; entrance of, and gray 

 crescent, 80, 165, 247, 248; en- 

 trance of, and alteration of egg- 

 structure, 80, 165, 222, 232, 247- 

 251 ; sperm-sphere and aster, 123 ; 

 nature of stimulus imparted by, 

 124 ; effect of alkaloids on, 129 ; 

 without potassium, 146 ; without 

 magnesium, 147. 



Sphaerechinus, effect of heat on, 105, 

 106, 187 ; potassium and lithium 

 larvae, 137-140 ; necessity of cer- 

 tain elements for, 142 sqq. ; pres- 

 sure experiments, 186 ; isolated 

 blastomeres, 191 ; blastomeres dis- 

 arranged, 187 ; pieces of blastulae 

 and gastrulae, 194, 195 ; size of 

 partial larvae and their organs, 

 198, 200; one embryo from two 

 blastulae, 201, 202 ; hybridization 

 experiments, 258-262. 



Spina bifida, in centrifugalized 

 eggs, 88 ; as a result of heat, 99 ; 

 of cold, 100 ; of lack of oxygen, 

 110. 



Spindle, nuclear, direction of elonga- 

 tion of, 31, 32, 34, 39, 48, 248; 

 oblique in ' spiral ' eggs, 32 ; rigi- 

 dity of, 48 ; in artificial partheno- 

 genesis, 124, 195; in karyokinetic 

 plane, 185. 



Spiral segmentation, see Segmenta- 

 tion ; asters, see Asters. 



Spirogyra, 269. 



Spleen of Vertebrates, 5. 



Splitting of cell-aggregates, 6, 9, 11. 



Sponges, larval skeleton, 2, 3 ; gem- 

 mule of, 5, 11 ; segmentation of, 

 22, 47 ; larva of, 6 ; unipolar im- 

 migration in, 11. 



Spongitta, 47. 



Sports, 141. 



Stages, series of, in development, see 

 Rhythm. 



Standard deviation, 71. 



Static teleology, 291, 292. 



Stature, human, change in rate of 

 increase, 68-70 ; variability of, 74 ; 

 correlations with other magni- 

 tudes, 75. 



Stereoblastulae, 128. 



