INDEX OF SUBJECTS 



327 



Decay, senile, 65. 



Decapoda, segmentation of, 24. 



Decline of growth-rate, 61-71. 



Decomposition, tension, 135. 



Defects, local, due to local injuries, 

 17, 159. 



Degeneration, gray, of medullary 

 groove, 119, 135. 



Dehydration, see Water, withdrawal 

 of. 



Dendritic figure, 130. 



DentaUum, development, 222-224 ; re- 

 moval of polar lobe, 224 ; isolated 

 blastomeres, 225, 226 ; egg-frag- 

 ments, 226. 



Dependent differentiation, see Diffei 1 - 

 entiation. 



Descemet's membrane, 276. 



Desiccation of Hen's egg, 115 ; of 

 Frog's egg, 123. 



Detachment of parts, 8. 



Determinant judgement, 287, 288. 



Deutoplasm, see Yolk. 



Development, denned, 1 ; compo- 

 nent factors of, 2 ; specific, 1, 15, 



17, 280 ; and inheritance, 1 ; 

 rhythm of, 3 ; external conditions 

 of, 18, 20, 152, 155-157 ; a pre- 

 determined process, 19 ; internal 

 conditions of, 20, 158 sqq., 279- 

 286 ; rate of, influenced by tem- 

 perature, 100, 101 ; without potas- 

 sium, 146, 147 ; magnesium, 148 ; 

 and calcium, 150; in partial larvae, 

 200, 204 ; accelerated, see Accelera- 

 tion ; retarded, see Retardation ; 

 arrested, see Arrest ; suspended, see 

 Suspension. 



Deviation, standard, 71. 



Dexiotropic division, see Cell. 



Dextrose. Frog's egg, 121 ; Hen's egg, 

 132. 



Dicephalus tetrabrachius, 175. 



Dicyemidae, 11. 



Differentiation, see also Cytoplasm 

 and Nucleus ; defined, 2 ; histo- 

 logical, 3 ; self-differentiation, 17, 



18, 158, 240, 286 ; increase of, 76, 

 176, 277, 284 ; dependent, 18, 158, 

 162, 277, 286 ; progressive, 247 ; 

 and cell-division, 22, 166, 213, 236, 

 245, 246, 279 ; and growth, 62, 65, 

 279; and increase of cytoplasm, 65 ; 

 cytoplasm in, 19, 208, 212, 2-13, 

 217, 225, 227, 237, 240, 241, 246, 

 261, 266 ; nucleus in, 251 sqq. ; 

 interactions of the parts in, 271- 

 277. 



Dilution of sea- water, as a means of 

 preventing cell-division, 55 ; ex- 



ovates produced by, 118, 189, 190, 

 194 ; causes irregular segmentation, 

 118, 187, 194. 



Dimensions, see Size. 



Diminution of chromosomes, 252, 

 256-258. 



Diphtheria toxine, 132. 



Diplogaster, rotation of fertilization 

 spindle, 34 ; egg- and embryonic 

 axes, 250. 



Diplokaryotic, 267. 



Diprosopus triophthalmus, 175. 



Directive stimuli, 162, 272. 



Discocelis, segmentation of, 25, 30, 47 ; 

 crossed polar furrows, 46 ; fertili- 

 zation and egg-structure, 250. 



Disintegration of epithelium, 119, 

 120, 135. 



Dispermy, in Ascaris, 257; in Echi- 

 noids, 263-265. 



Dispersion of cells, 11. 



Division of nucleus and cell a factor 

 in development, 2 ; of nucleus, see 

 Nucleus ; of cell, see Cell ; of oil- 

 drops, see Oil-drops; of centro- 

 somes, see Centrosomes. 



Doliolidae, buds of, 5. 



Dorsal lip of blastopore, see Blasto- 

 pore. 



Double monsters, see Monsters. 



Dreissensia, 45, 47. 



Drops of fluid, 42, 43 ; of oil, 43, 49 

 sqq. 



Duck embryos, decline of variability 

 in, 71. 



Ducts, see Gland, Segmental ; lumen 

 of, 11. 



Duplicitas anterior, 175. 



Dytiscus, 258. 



Earth-worm, ectoderm of, 3; nephri- 

 dia, 5. 



Echinoderm, blastula, 2, 110, 185; 

 spicules of larva, 2 ; archenteron 

 divides into gut and coelom, 3 ; 

 mesenchyme, 5 ; gastrula, 5 ; seg- 

 mentation of, 22, 21, 26-28, 54, 

 183 ; pressure experiments on eggs, 

 39, 185, 186 ; influence of gravity 

 on eggs, 76 ; artificial parthenoge- 

 nesis, 123 ; effects of sodium, potas- 

 sium, lithium, on larvae, 137-140 ; 

 blastomeres disarranged, 187 ; 

 blastomeres isolated, 190 sqq. ; 

 blastulae and gastrulae cut up, 

 195 ; egg-fragments, 195-197 ; one 

 embryo from two blastulae, 201, 

 202 ; number of cells, rate of de- 

 velopment and, size of partial 

 larvae and their organs, 198-200. 



