334 



INDEX OF SUBJECTS 



without cell-division, 55, 56, 118 ; 

 indirect division, see Karyokinesis. 



Nucleus, position in cell, 31, 32, 79 ; 

 injured by poisons, 128-130, 135; 

 of yolk, see Yolk-nuclei ; quali- 

 tative division of, 19, 159. 168, 

 186, 213, 240, 265, 279, 280,' 286 ; 

 rapidity of, 65 ; idioplasm in the 

 nucleus, 19, 159; the vehicle of 

 inheritable characters, 253, 258- 

 262 ; in differentiation, 251 sqq. ; 

 essential for life of cell, 251, 252, 

 254 ; of germ-cells alike, 252, 254, 

 256 ; both male and female, not 

 necessary, 254 ; decrease in size of, 

 65 ; variability in size of, 269 ; 

 size of, and number of chromo- 

 somes, 268 ; number of, and number 

 of chromosomes, 268; and cyto- 

 plasm, ratio between, 65, 269 ; 

 volume of, and cell-surface, 269 ; re- 

 sponsive to stimuli, 283 ; reaction 

 of, on cytoplasm, 266, 283, 284. 



Number of cells, see Cell ; of nuclei, 

 see Nucleus. 



Oakland, Mass., school-children, 

 growth of, 63. 



Obelia, 147, 148. 



Obliquity of spindles in ' spiral ' eggs, 

 32 ; of egg axis in Bana esculenta. 



Occasion, 283. 



Oceania, 54. 



Oil-drops, 43 ; systems of. 49 sqq. 



Oils, essential, 132. 



Oniscus, 24. 



Ontogeny and phylogeny, 12 ; causal 

 explanation of, 13, 297, 298. 



Operculum of tadpole, not formed 

 after removal of brain, 176. 



Ophelia, artificial parthenogenesis, 

 124. 



Ophiuroids, segmentation in, 24, 26, 

 28, 47. 



Ophryotroclia, 202. 



Optic cup, and lens, 134, 275, 276 : 

 and cornea, 276, 277. 



Optic vesicles, absent, 110; injured 

 or removed, 275, 276. 



Optimum temperature, see Tempera- 

 ture. 



Orchestia, 24, 26, 28, 47. 



Organ-forming substances, see Sub- 

 stances. 



Organs, elementary, of first, second, 

 &c., orders, 3. 



Orientation, similar, of egg-particles, 

 281, 286. 



Origin and fate of cells, 246 ; know- 

 ledge of, 288, 298. 



Osmotic pressure, as aifecting growth, 

 2, 115, 116 ; as affecting cell- 

 division, 56, 117 ; increased by 

 addition of salt, 116, 117 ; the 

 asserted cause of malformations, 

 120-122; the cause of artificial 

 parthenogenesis, 123, 124 ; decrease 

 of, 118; equilibrium, 118. 



Otolith, 239. 



Oviduct, in Amphibia and Amniota, 9. 



Oxidation, agents of, 131 ; promoted 

 by light, 112; by alkalinity, 151. 



Oxygen, lack of, cell-division sup- 

 pressed, 56, 111, 112 ; effect on 

 pigment of Funduhts, 111, 114 ; 

 quantitative estimation of amount 

 absorbed, 112 ; effect of pure, 112- 

 114 ; need of, 109 sqq., 132. 



Oxygenotactic, Oxygenotropic, 114, 

 273, 274. 



Oxyhaemoglobin, excess of, in Chick, 

 in pure oxygen, 112. 



Papilla, fixing, 229. 



Paraderm, of Amuiota, 8. 



Paraffin oil, 49. 



Parallelism, psycho-physical, 301. 



Paralysis of cytoplasm, 127. 



Pars prima genitalis (Harvey), 14. 



Parthenogenesis, artificial, produced 

 by mechanical agitation, 90, 124 ; 

 by cold, 108, 124 ; by increased 

 osmotic pressure, 123, 124 ; cy- 

 tology of, 124, 125 ; maternal 

 nucleus only in, 254 ; number of 

 chromosomes in, 125. 



Patch, gi'ay, in inverted eggs, 85. 



Patella, isolated blastomeres of, 218- 

 222. 



Pelagic ova, 89. 



Peltogaster, segmentation, 24. 



Penetration by cells, 5. 



Peptones, 132. 



Percentage increments of growth, 

 60 sqq. ; of water, 58-60, 115, 116. 



Periods, spiral, radial, bilateral, of 

 segmentation, sec Segmentation ; 

 variation in, 74. 



Perifatus capensis, 24. 



Perivitelliue cavity, 79, 87 ; fluid, 79. 



Periwinkle, 71, 72, 74. 



Permeability of tissues to salts, &c., 

 119, 121, 124, 145. 



Permutation of original elements, 

 286. 



Petromyzon, notochord in, 8, 133 ; 

 segmentation, 47 ; artificial par- 

 thenogenesis, 124. 



Phagocytosis, 5. 



