INDEX OF SUBJECTS 



337 



magnesium, 148 ; and calcium, 

 150 ; with decrease of germinal 

 value, 200, 204. 



Rhumkorff coil, 91. 



Bhynchelmis, 251. 



Rhythm of development, 3. 



Rind at surface of blastomeres, 54. 



Ringer's solution, 120. 



Rotation, perpetual, of Hen's eggs, 90 ; 

 of pronuclei in Ascaris nigrorenosa, 

 34 ; in Diplogaster, 34 ; not in 

 Callidina, 34 ; of tirst two blasto- 

 meres in Callidina, 34 ; of micro- 

 meres on macromeres, 47. 



Rotation structure, of ova, 79. 



Rotifera, 26. 



Rubidium, 146. 



Rule, of Balfour, 29, 88 ; exceptions 

 to, 30 ; of Hertwig, 31, 32, 85 ; 

 confirmed in Ascaris nigrovenosa, 

 34 ; and in Diplogasler, 34 ; by 

 pressure experiments, 34 sqq. ; 

 violated, bypolar divisions, &c., 34 ; 

 of Pfliiger, 32, 85. 



Sagittal plane and first furrow in 

 Frog, 17, 159, 165-168 ; in Cteno- 

 phora, 209; in Newt, 175; in 

 Ascidia, 229,235; and plane of sym- 

 metry, 80, 165, 229, 235 ; deter- 

 mined by gravity, 82, 84 ; and 

 streaming meridian, 84. 



Sulmo lens, 276 ; see also Trout. 



Salps, blastomeres of. 5, 28, 54 ; 

 rearrangement of cells, 11. 



Salt-solution as a medium, 45, 53 ; 

 see also Sodium chloride. 



Salts of various kinds, malformations 

 in, 119 sqq., 132, 276; artificial 

 parthenogenesis, 123, 124. 



Salvelinxs, 178. 



Sauropsida, blastoderm of, 6. 



Science, the scope and functions of, 

 297 sqq. 



Sciences, relation of, to one another, 

 299, 300. 



Scleroblasts of Sponges, 3. 



Sclerotome, 11. 



Sea-urchin, see Echinoids, Pluteus, 

 Echinus, Sphaerechinus, Strongylo- 

 centrotus, Arbatia. 



Sea-water, calcium-free, used to 

 separate blastomeres, 45, 190. 



Sea-water, composition of, 141 ; 

 artificial, 142. 



Secondary qualities, 300. 



Secretion of substances in growth, 

 258. 



Segmental duct, growth of, 5 ; 

 splitting of, 6. 



JENKINSON 



Segmentation of the ovum, a factor 

 in development, 2, 279 ; the be- 

 ginning of development, 22 ; and 

 differentiation, see Cell-division, 

 Differentiation; a mosaic, 17, 19, 

 158, 213, 236. 245, 246 ; types of, 22 

 sqq. ; radial, 22, 49, 53 ; spiral, 25, 

 30, 45-47, 52, 204 ; bilateral, 26, 49, 

 52, 229, 235 ; isobilateral, 26, 208 ; 

 irregular, 28, 54, 55 ; periods of 

 spiral, radial, bilateral, 26 ; types 

 pass into one another, 28 ; mero- 

 blastic, in Vertebrata, 24 ; in 

 Arthropods, 24 ; in Cephalopods, 

 27 ; in centrifugalized Frog's egg, 

 29, 88 ; as a result of heat, 97 ; in 

 salts, solutions of, 119 ; causes of 

 pattern of, 29 sqq., 197, 246, 266 ; 

 and egg-axis, 81 ; in compressed 

 eggs, 34-40 ; influence of gravity 

 on, 78 sqq. ; effect of electricity on, 

 92 ; of heat, 97, 105 ; of cold, 100 ; 

 of altered osmotic pressure, 117, 

 118 ; of chemical poisons, 119, 121, 

 128-130; of lack of oxygen, 111, 

 112; without sulphate, 143 ; with- 

 out chlorine, 145; without sodium, 

 145 ; without potassium, 145 ; 

 without magnesium, 145 ; in neu- 

 tral media, 151 ; without calcium, 

 150 ; irregularities of, produced by 

 heat, 105, 187 ; by shaking, 188 ; 

 altered osmotic pressure, 117, 118; 

 by dilution of sea-water, 187 ; 

 alkaloids, 128-130; by calcium- 

 free sea-water, 45, 188, 190 ; by 

 double fertilization, 264, 265 ; of 

 isolated blastomeres, total. 173, 178, 

 180, 181, 230; partial, 190, 204, 205, 

 210, 211, 215 sqq.. 229, 237 ; of egg- 

 fragments, 195-197,207, 212,226,227. 

 Segmentation cavity, 11 ; absent in 

 Stereoblastulae, 128; reduced with- 

 out potassium, 146 ; in Hemi- 

 blastula, 159. 

 Segmentation of mesoderm, 11 ; of 



neural crest, 11. 

 Selective death-rate, 74. 

 Selenium, 144. 



Self-differentiation, see Differentia- 

 tion. 



Senescence, 65. 

 Senile decay, 65. 

 Sense-organ of Ctenophora, 211 ; see 



also Apical organ. 



Separation of blastomeres, see Blasto- 

 meres. 



Septa, of corpus luteum, 5. 

 Serosa, of Sipunculus, 9. 

 Serpula, 272. 



