None
314 APPENDIX B mosomes, and either an accessory odd chromosome (which passes into only one half of the germ cells) or a pair of idio-chromo- somes of unequal size (one of which goes to one half, the other to the other half of the spermatozoa), or both the accessory and the idio-chromosomes (giving four kinds of spermatozoa). The idio- chromosomes are supposed, again, to play a part in sex-deter- mination. Several other observers have found these accessory chromosomes, idio-chromosomes, and pairs of chromosomes of different sizes in various Insects (Boring, Journ. Exp. Zool. iv. 1907; Stevens, ibid. ii. 1905, v. 1908; McClung, Biol. Bull. iii. 1902, ix. 1905; Montgomery, Biol. Bull, vi. 1904; Baum- gartner, Biol. Bul/. viii. 1904-5; Zweiger, Zool. Anz. xxx. 1906 ; Nowlin, Journ. Exp. Zool. iii. 1906); in Spiders (Wallace, Biol. Bull, viii. 1904-5; Berry, Biol. Bull. xi. 1906); and in Myria- pods (Blackman, Biol. Bull. v. 1903; Medes, Biol. Bult. ix. 1905). It is a noteworthy fact that the accessory chromosome retains its individuality in the resting stage (looking like a chromatin nucleolus), while the others break up. The belief in the individu- ality of these others rests therefore on the constancy of the re- _ lative sizes from generation to generation. Further support for the hypothesis may be derived from theo- retical speculations. We know that only z (one-half the normal number) chromosomes are necessary for normal development provided that they comprise a complete set. In sexual repro- duction x maternal unite with ~ paternal. A study of the re- ducing division shows that x whole chromosomes first pair with and are then separated from x whole chromosomes, and that when they differ in size those of the same size pair together, and it looks as though paternal were here separated from maternal, though the distribution of paternal and maternal to the two cells will differ, almost certainly, in different cases. If the particles of which the chromosomes are composed are also to be paired and separated, it would appear to be necessary that their grouping should be constant, in other words that the chromosomes should retain their individuality. (iii) A case of heterogeneous fertilization between eggs of Sea- urchins and the sperm of Antedon has been described above (p. 262). Loeb has recently succeeded in rearing Plutei from the eggs of Strongylocentrotus fertilized by the sperm of a Molluse (Ch/lorostoma). Cytological details are not given (Arch. Ent. Mech. xxvi. 1908). INDEX OF Agassiz: effects of fertilization in Ctenophors, 250. Aristotle: theory of development, 13. — the soul in function and develop- ment, 292 sqq. — mechanism and teleology, 296. Auerbach : segmentation of Ascaris nigrovenosa, 33. ~ von Baer, 16. Balfour : effect of yolk on segmenta- tion, 29, 88. Bataillon: monstrosities osmotic pressure, 120, 135. —- artificial parthenogenesis, 124. Bergh: cell-division in germ-bands of Crustacea, 34. Berthold: surface-tension and cell- division, 41, 42. Bischoff, 16. Blanc: effect of light upon the development of the Chick, 94, 96. Boas: rate of growth in man, 63. — change of variability, 73, 74. — diminution of correlation coeffi- cient, 75. Bonnet : emboitement, 14. — preformation, 15. Bonnevie: diminution of chromo- somes in Ascaris lumbricoides, 258. Born : gravity and development, 18, 83-85. due to — pressure experiments on Frogs’ eggs, 34, 35. Boveri : early development of Strongy- locentrotus, 23, 183-185. — egg of Strongylocentrotus stretched, 9. — suppression of micromeres in Strongylocentrotus, 186. — causes of the pattern of segmenta- tion, 197. — karyokinetic plane, sperm path, * and first furrow in Strongylocentrotus, 185, — potentialities of animal and vege- tative cells, 192. — stratification of cytoplasmic sub- stances, 242, 280. — characters dependent on cyto- plasm in Echinoid larvae, 261, AUTHORS Boveri: diminution of chromosomes in Ascaris megalocephala, 252,255-257. — due to a difference in the cyto- plasm, 257. — hybrid larva from enucleate egg fragment with characters of male parent, 253, 258-260. — irregular distribution of chromo- somes a cause of abnormality, 253, 263-266. — individuality of chromosomes and chromatin, 256, 265. — part played by nucleus in dif- ferentiation, 266, 285. — possible significance of reducing divisions, 266. — number of chromosomes, size of nucleus, and size of cell, 68, 267, 268. — nuclear division not qualitative, 266. Bowditch: rate of growth in man, 63. — change of variability, 73. Brauer : Branchipus, 22, 24. Brooks: Lucifer, 22. de Buffon : Preformation, 15. Bullot: artificial parthenogenesis, 124, Bumpus: change of variability in Littorina, 71, 72. Bunge: respiration of Ascaris, 112. Castle : see Davenport and Castle. Chabry: segmentation furrows and embryonic axes in Ascidians, 229. — development of isolated blasto- meres in Ascidians, 229, 230. Child : critique of Driesch’s vitalism, 292, note. Chun : isolated blastomeres of Cteno- phora, 209. Conklin: maturation, fertilization, and development of Cynthia, 230- 236, — development of isolated blasto- meres in Cynthia, 237. — development of pieces of gastrula in Cynthia, 238. — streaming movements of proto- plasm, 40, 316 INDEX OF Crampton: isolated blastomeres of Ilyanessa, 215, 216. — effect of removal of the polar lobe, 217. Dareste: mechanical agitation of the Hen’s egg, 89. — electricity, 91. Davenport : catalogue of ontogenetic processes, 4 sqq. — definition of growth, 58. — rate of growth, 69. — the rdle of water in growth, 58, 59, 115, 116. — and Castle : acclimatization of eggs of Bufo to heat, 100, Delage : causes of artificial partheno- genesis, 124, — number of chromosomes in arti- ficial parthenogenesis and in mero- gony, 125. De Vries: importance of potassium for turgor of plant-cells, 146. Doncaster: hybrid Echinoid larvae, 261. Driesch: effect of light in develop- ment, 94. — abnormal segmentation in Echinus produced by heat, 105, — Anenteria, produced by heat, 106. — segmentation made irregular by dilution of sea-water, 118. — pressure experiments on Echinoid eggs, 37, 38, 185, 240. — cell-division suppressed by pres- sure and dilute sea-water, 55; and by heat, 105. — nuclear division not qualitative, 186. — blastomeres disarranged, 187, 188. — isolated blastomeres of Echinoids, 190, 191, 193, 194. — potentialities of animal and vege- tative cells, 193, 194, 201, 242, 243. — fragments of blastulae and gastru- lae in Echinoderms, 194. — potentialities of ectoderm and archenteron, and their limitations, 195. — development of egg fragments of Echinoids, 195, 196. — germinal value, surface-area of larvae, and number of cells, 197- 199, 269. — one larva from two blastulae, 202. — and Morgan : isolated blastomeres of Ctenophora, 210, 211. Se peace of Ctenophora, 30, 1 AUTHORS shi development of Myzostoma, — isolated blastomeres and parts of larvae in Phallusia, 238, 239. — first furrow and sagittal plane in Echinoids, 250. — characters which depend on cyto- plasm in Echinoid larvae, 261, 262. —number of organ-forming sub- stances in cytoplasm, 246, 284, 286. oe of egg-structure, 281, 286, — reason for limitation of potentiali- ties, 192-194, 201, 212, 242, 243, 281, 282, 284, 291. — fate a function of position, 188, 282. — return of displaced mesenchyme cells in Echinus, 274. — stimuli in ontogeny, 20, 277, 282- 284, — part played by nucleus in dif- ferentiation, 266, 284, 285. — equipotential and inequipotential systems, 176, 277, 285. — rhythm of development, 3. — harmony of development, 284. — composition in development, 3, 285. — self-differentiation, 284, — teleology, static, 286, 291, 292, 297. — — dynamic, 291, 292, 297. — vitalism, 20, 289 sqq. Edwards: physiological zero for Hen’s egg, 102. —growth without differentiation, 104. Endres and Walter : post-generation of missing half-embryo, 171. Eycleshymer: first furrow and sagittal plane in Necturus, 168. Fabricius : views on development, 13. Fasola : electric currents, 91. Fehling: growth of the human embryo, 59, 60, 63. Féré : effect of sound-vibrations upon * the Chick, 90. — — of light, 96. — malformations due to high tem- peratures, 105, — need of oxygen for the Chick, 109. — monstrosities produced by various chemical reagents, 132. eee ee INDEX OF Fischel, A. ; hybrid Echinoid larvae, 261. — variability of Duck embryos, 71. Fischel, H. : isolated blastomeres of Ctenophora, 210, 211. — derangement of blastomeres in Ctenophora, 211. Fischer : artificial parthenogenesis, 124, Foot: polar rings in <AUolobophora, 251. Garbowski: function of pigment ring in Strongylocentrotus egg, 192. — first furrow and sagittal plane in Echinoids, 250. — grafting of blastulae fragments of Echinus, 202. Gerassimow: size of nucleus and cells in Spirogyra, 269. Giacomini: need of oxygen for the Chick, effect of low atmospheric pressure, 109, 110. Giardina: differentiation of chroma- tin in female cells of Dytiscus. Godlewski: the respiration of the Frog’s egg, 110, 112, 113. a es panos cross-fertilization, 2. Graf: fusion of blastomeres, 56. Greeley: artificial parthenogenesis produced by cold, 108. — low temperatures and absorption of water, 108. Grobben : Cetochilus, 22. Groom: effect of fertilization in Cirripedes, 250. Gruber: regeneration in Protozoa, 254. Gurwitsch : monstrosities produced in Amphibian embryos by chemical reagents, 120, 123. Hicker : Cyclops, 22. Haeckel : recapitulation, 16. — development of fragments blastulae of Crystallodes, 181, note. Haller : preformation and epigenesis, 15. Harvey : epigenesis, 13. — metamorphosis, 14. Hecker : growth of the human em- bryo, 62, 63. Hensen: growth of guinea-pig em- bryos, 62. Herbst: potassium, sodium, and lithium larvae of Echinoderms, 136-140. — significance of monsters for origin of variations, 141, of AUTHORS 317 Herbst : necessity of elements present in sea-water for normal develop- ment of Echinoid larvae, 141 sqq. — separation of blastomeres of Sea- urchins in calcium-free sea-water, — stimuli in ontogeny, 20, 272, 273, 285. — formation of Arthropod blasto- derm oxygenotactic, 114. — arms of Pluteus due to presence of skeleton, 137, 138, 144, 149, 274, 275, Herlitzka, development of half-blasto- meres of Newt, 175. Hertwig, O.: centrifugalized Frog’s egg, 29, 87 — rules for nuclear and cell division, 31, 32, 85. — — confirmed by pressure experi- ments, 34-36. — gravity and Echinoderm eggs, 78. — insemination of Frog’s egg, 79. — cardinal temperatures for Rana JSusca and esculenta, 97. — monstrosities produced by high and by low temperatures, 99. — temperature and rate of develop- ment, 100. — monstrosities produced in Amphi- bian embryos by sodium chloride, 119, 135. — first furrow and sagittal plane in Frog’s egg, 165. — compressedeggs: disproof of quali- tative nuclear division, 34-36, 168, 169, 240. — development of half-blastomere of Frog’s egg, 169. — mutual interactions of develop- ing parts, 271, 285. Hertwig, O. and R.: — fertilization processes altered by heat and cold, 107. — — by alkaloids, 126 sqq., 263. His: mechanical explanation of development, 3. — germinal localization, 17, 158. — the blastoderm oxygenotropic, 114. Hunter: artificial parthenogenesis by concentrated sea-water, 124, Iijima: spiral asters in Nephelis egg, Jenkinson: pressure experiments on eggs of Antedon, 37, note. — abnormalities of Frog embryos produced by various solutions not due to increased osmotic pressure, 120, 133-135. 318 INDEX OF Jenkinson; plane of symmetry, first furrow and sagittal plane in Frog’s egg, 165-168. Jennings: fertilization spindle in Asplanchna, 34. Kaestner: cardinal temperature points for the Hen’s egg, 102. — malformations due to low tem- peratures, 104, Kant : teleology, 286-289, 292, 297. Kastschenko: injuries to blastoporic lip in Elasmobranchs, 178. Kathariner: gravity and the gray crescent of the Frog’s egg, 86. King : cause of differentiation of lens, 275, 276. Knowlton : see Lillie and Knowlton. Kolliker: 16. Kopsch: first furrow and sagittal plane in Frog’s egg, 165, 168. — effect of injuries to blastoporie lip, 178. Korschelt: fusion of ova in Ophryo- trocha, 202. — nucleus of egg-cell in Dytiscus, 252. Kostanecki and Wierzejski: effect of fertilization in Physa, 250. Kowalewsky : 16. Kraus: the role of water in the growth of plants, 58. Lang : effect of fertilization in Poly- clads, 250. Leibnitz : preformation, 15, Lewis: causes of formation of lens and cornea, 275, 276. Lillie and Knowlton: effect of low temperatures in Amphibia, 100. — temperature and rate of develop- ment, 101. Lillie: effects of salts on ciliary movement, 135. — physiologically balanced solutions, 136. — toxicity and valency, 136. Loeb: suppression of cell-division in Echinoids and Fishes, 56, 117. — effect of light in development, 94. —the respiration of Ctenolabrus and Fundulus eggs, 111. —the respiration of the ova of Echinoids, 112. — function of oxygen in regeneration of Tubularia head and other pro- cesses, 114, 273, 274. — effect of hypertonic solutions on Fundulus and Arbacia eggs, 117. — exovates produced by dilute sea- water, 118, 190, 194, 195. AUTHORS Loeb: artificial 121, 124, — effect of potassium cyanide in pro- longing life of ova, 131, 132. — effect of certain salts on Fundulus embryos and on Plutei, 135. — toxicity and antitoxicity functions of valency, 136. — effect of alkalies, 151. — effect of gravity on Antennularia, 272, 278. — heterogeneous cross-fertilization, 262. Lombardini ;: electric currents, 91. Lyon : need of oxygen for the eggs of Arbacia, 112. — action of potassium cyanide, 152. parthenogenesis, Malebranche: preformation, 15, Malpighi: preformation, 14, 15. Marcacci: mechanical agitation of Hen’s eggs, 90. Mark: spiral astersin egg of Limaz, 40. Mathews: artificial parthenogenesis by mechanical agitation, 90. — effects of atropine and pilocarpine on Echinoderm eggs, 131. —toxicity and decomposition tension, 136. —seealso Wilson (E.B.)and Mathews. Mencl: formation of lensin Salmo,276. Metschnikoff: separation of blasto- meres of Oceania, 181. —fusion of blastulae in Mitrocoma, 202. Minot: rate of growth defined, 60. — change of rate of growth of guinea- pigs, 61. — — of rabbits, 62, 63. — — ofchickens, 67. — coefficients of growth, 65. — senescence, 65. — increase of cytoplasm, decrease of mitotic index, 65. — change of variability in guinea- pigs, 71. — genetic restriction, 246, 277. Mitrophanow: malformations due to low and high temperatures, 104. — necessity of oxygen for the Chick, 109. Moore : sodium sulphate an antidote to sodium chloride, 135, 136. Morgan : suppression of cell-division in Arbacia, 56, 118. — gravity and the gray crescent of the Frog’s egg, 86. — monstrosities produced by low temperatures in Rana palustris, 100. — need of oxygen for the Frog’s egg, 110. INDEX OF Morgan ; lithium salts used to produce abnormalities in Frog’s eggs, 120, 135. —attempts to induce parthenogenesis, 124, — number of chromosomes in arti- ficial parthenogenesis, 125. —artificial parthenogenesis produced by cold, 108. — first furrow, plane of symmetry, and sagittal plane in Frog’s egg, 165, 168. — development of half-blastomere of Frog’s egg; post-generation, 170, 171. — development of vegetative cells of Frog’s egg, 173. — potentialities of half-blastomeres in Teleostei, relation of first furrow to sagittal plane, effect of removal of yolk, 178. — effect of injuries to blastoporic lip, 179. — number of cells in partial larvae of Amphioxus, 181. — potentialities of ectoderm Echinoids, 195, — development of egg-fragments of Echinoids, 197. — number of cells in partial larvae of Echinoids, 198. — fusion of blastulae of Sphaerechinus, 201. — and Driesch : isolated blastomeres and egg-fragments of Ctenophora, 210-212. — micromeres of Ctenophore egg, 30. — characters of hybrid LEchinoid larvae, 260. Moscowski: gravity and the gray crescent of the Frog’s egg, 86. Miihlmann: prenatal growth-rate in man, 64. artificial in Nigeli: permutations of original elements in development, 286. Pander: 16. Pearson : variability in man, 73. Pfliiger : isotropy of the cytoplasm, 18, 158 — influence of gravity on develop- ment, 18, 78, 81-83, 158. —rule for direction of nuclear division, 32, 85. Plateau: principle of least surfaces, 41, 43. Platner : 280. Pott : growth of the Chick, 59, 60, 67. AUTHORS 319 Pott and Preyer: respiration of the Chick, 112. — loss of weight of Hen’s egg due to evaporation from albumen, 115. Preyer : rate of growth, 60. Quetelet : change of rate of growth in man (weight), 63. — — (stature), 69. — — (other dimensions), 90. Rauber: effect of reduced atmo- spheric pressure on the Frog’s egg, 110. — effect of pure oxygen on the eggs and tadpoles of the Frog, 113, 114. Reichert: 16. Remak : 16. Robert : mechanics of spiral segmen- tation, 45-47. — rate of growth in man, 68. — change of variability, 73. Rossi: effect of electricity on Amphibian eggs, 91. Roux : aims of experimental embryo- logy, 13. — ‘Mosaik-Theorie’ of self-differen- tiation, 17, 158, 279, 286, 297. — qualitative nuclear division aban- doned, 19, 159, 240. — idioplasm and reserve-idioplasm, 159, 266. —a half-embryo from one of first two blastomeres and post-genera- tion of missing half, 159, 162. — coincidence of first furrow and sagittal plane in Frog’s egg, 17, 159, 165. — the spermatozoon and symmetry of the Frog’s egg and embryo, 80, 165, 247, 248. — meaning of karyokinesis, 252. — dependent differentiation, 17, 158, 277, 286. — functional adaptation, 290. — specific gravity of contents of Frog’s egg, 79. tn gray crescent of Frog’s egg, 80, 165. — influence of gravity on the Frog’s egg, 85-87. — effect of electricity upon the Frog’s egg, &c., 92. — light and development, 93. — segmentation of Rana esculenta, 26. — Frog’s eggs compressed in small tubes, 39, 40. — comparison of systems of oil drops and segmenting ova, 49-53. — cytotropism, 55, 273. 320 INDEX OF Roux : cytotaxis, 55. — vytochorismus, 45. — cytarme, 45, 53. — cytolisthesis, 53. — ‘Framboisia’, 135, Rusconi : electric currents, 91. Sachs: law of direction of cell division, 28. Sala: fertilization processes altered by cold, 108. — fusion of the eggs of Ascaris, 202. Samassa: effect of pure oxygen at i pressures on the Frog’s egg, 14. — effect of lack of oxygen on the Frog's egg, 119. — effect of various gases on the eggs of Ascaris, 112. — development of animal cells of Frog’s egg, 173. — Schaper : development of tadpoles me removal of brain and eyes, 175. — cause of differentiation of lens, 275. Schulze, F. E.: Sponges, 22. Schulze, O.: gray crescent of Frog’s egg, 80, 247 — gravity and the Frog’s egg, 86. — effect of low temperatures on the Frog’s egg, 100. — first furrow and sagittal plane in Frog’s egg, 165. wees monsters from Frog’s egg, Seeliger : hybrid Echinoderm larvae, 260, 269. Selenka: first furrow and sagittal plane in Echinoids, 250. Semper: rate of growth in Limnzea, 67. Smith : Peltogaster, 24. Sollmann : after effects of hypertonic solutions, 124, Spemann : development ofconstricted Newt’s eggs, and embryos, 174, 175. — causes of formation of lens and. cornea, 275, 276. Sumner : injuries to blastoporie lip of Teleostei, 178, 246. Sutton : individuality ofchromosomes in Brachystola, 256. Swammerdam : preformation, 14, 15. segmentation of Vejdovsk¥ : unequal centrosomes in dividing pole-cells, 31. — polar rings in Rhynchelmis, 251. Vernon: rate of growth in Strongy- locentrotus, 67, 70. AUTHORS Vernon : alteration of variability in Echinoid larvae, 71, 74. — effect of light on Echinoid larvae, 95, 96. — effects of change of temperature on Echinoid larvae, 106, 107, — change of variability produced by heat, 107. — and by chemical agency, 141, 156. — poisonousness of carbon dioxide to Sea-urchin eggs, 112. — characters of hybrid Echinoid larvae, 261. Verworn : behaviour of Protozoa in an electric current, 93. — regeneration in Protozoa, 254, note. Walter, see Endres and Walter. Weber : law of stimuli, 272. Weismann: qualitative division, 19, 297. — cama and reserve-idioplasm, 159. Weldon : growth-rate in Carcinus, 71. em pret of variability in Carcinus, 2 nuclear — — in Clausilia, 73. Wetzel: double monsters Frog’s egg, 172, 245. Whitman: polar rings in Clepsine, 251. Wierzejski, see Wierzejski, 250. Wilson, C. B.: malformations of Amphibian embryos, 120. — acclimatization to salt-solution, 136, Wilson, E. B.: segmentation of Am- phioxus, 26. — segmentation of Renilla, 55, note. — unequal centrosomes in dividing pole-cells, 31. — pressure experiments on eggs of Nereis, 39, 213, 240. — cytology of artificial partheno- genesis, 124, — development of isolated blasto- meres in Amphioxus, 179, 180. — isolated blastomeres of Cerebratulus, and fragments of blastulae, 205, 206. —isolated blastomeres of Patella, 218-222. — of Dentalium, 225, 226. — removal of polar lobe, 224. — effect of fertilization, 222, 223. —development of egg-fragments, 226, 227. from Kostanecki and INDEX OF Wilson (E, B.) and Mathews : sperm- path, egg axis, first furrow, and embryonic axes of Toxopneustes, 185, 249, 250. Windle: effect of magnetism and electricity on development, 91. Wolff: epigenesis, 16. Yatsu : egg-fragments of Cerebratulus, ' effect of light on tadpoles, Zeleny : egg-fragments of Cerebratulus, 07. Zelinka :. fertilization ik Callidina, 34. spindle JENKINSON Y AUTHORS 321 Ziegler: heterodynamic centro- somes, 30. — formation of micromeres in Cteno- phora, 209, note. — pressure experiments on eggs of Echinoids and Ctenophora, 38, 186. — fertilization of Diplogaster, 34. — egg and embryonic axes, 250. Zoja: isolated blastomeres of Hydro- medusae, 181, 182. —animal and vegetative cells of Strongylocentrotus, 193. Zur Strassen: segmentation Ascaris, 31. — fusion of the eggs of Ascaris. of INDEX OF SUBJECTS Abnormality, 1; produced by cen- trifugalizing, 88; by shocks, 89; by. perpetual rotation, 90; by sound vibrations, 90; by electric currents and magnetism, 91; by heat and cold, 98 sqq. ; by desicca- tion, 115; by sodium chloride and other substances, 199 sqq., 132; significance offorstudy ofvariation, 155, 156; produced by irregular distribution of chromosomes, 263- 266. Absorption of water, see Water. Absorption, by cells, 5. Abstraction of water, withdrawal of. Acanthocystis, 48. Acceleration of development by weak electric currents, 91; in violet light, 94, 95; at high tempera- tures, 97, 105; in pure oxygen, 110; by pilocarpine, 151; by sodium hydrate, 151. Acclimatization, 290; to heat, 100; to hypertonic solutions, 117; to salt, 136. Acids, 122. Acrosome, 123. Adaptation, 290. Aggregates of cells, 5 sqq. Aggregation of cells, 5. Agitation, mechanical, 89. Albumen, asa medium, 45, 53; drops of, 54; of Hen’s egg, 115. Alcohol, 182. Aleyonaria, 55. Alkalinity, need of, 150, 151. Alkaloids, in Amphibian eggs, 120, 123 ; on Sea-urchin eggs, 126 sqq. ; on Hen’s egg, 132. Allantois, fused with somatopleure, 9; sticks to yolk sac in eggs that are not turned, 89. Allelomorphs, 266. Allolobophora, 251. Alteration of potentiality, see Potenti- ality. Alteration in shape of cells, 5, 29, 48. Alternation in direction of division in ‘spiral’ cleavage, 25, 28. Amblystoma, absorption of water by see Water, tadpole, 58; effects of cold, 100; effect of solutions, 120; acclima- tized to salt, 136; formation of lens, 275. American Periwinkles, 71. Ammonia, on Hen’s egg, 132; effect on nuclei, 135. Amnion, not formed at low tempera- tures, 104; folds of, 9; abnormal, 110. Amniota, archenteron of, 8 ; oviduct of, 9. Amoeboid processes in blastomeres, 53; movements of polar lobe, 227. Amphiaster, see Spindle. Amphibia, oviduct in, 9; absorption of water by tadpoles, 58, 115; influence of electric current on, 91; effect of various solutions on, 119-123, 133-135; effects of heat and cold on, 97-101 ; acclimatized to heat, 100 ; tosalts, 136 ; isolated blastomeres of, 159 sqq. Amphikaryotic, 267. Amphioxus, club-shaped gland, 6; medullary plate, 8, 133 ; segmenta- tion of, 22, 26, 28, 47; in certain solutions, 140; potassium neces- sary to adult, 147; isolated blasto- meres of, 179, 180; double embryos, 180. Amphitrite, segmentation of, 26; parallel polar furrows, 46; artifi- cial parthenogenesis, 124. Anachronism of first furrow in Frog, 161, 165. Analytical theory of Driesch, 280- 286. eee of cell-aggregates, 6, Anencephaly, 119. Anenteria, 106. Angles between contact surfaces in systems of lamellae, 43; in seg- menting ova, 47, 53; between egg axis and first furrow in forcibly inverted Frog’s eggs, 82; between plane of symmetry, first furrow, and sagittal plane, 165-167. Animal cells, see Cells. Animal pole, near anterior end of INDEX OF embryo, 165 ; apical organ formed at, 244, Anion, 136. Annelids, germ-bands of, 5 ; nephri- dia and coelom, 6; nerve-ganglia of, 11; segmentation of, 25, .48 ; symmetry of egg and that of embryo, 241. Antecedent conditions, 283. Anledon, pressure, 37 ; heterogeneous eross-fertilization, 262, Antennularia, 272, 273. Antidotes to poisons, 135, 136. Antitoxicity, 136. d Apical body, 123. Apical organ of Echinoids, 144; of Pilidium, 204-206 ; of Ctenophora, 211; of Patella, 218; of Dentalium, 224-225 ; of Molluses and Annelids, 244, Aplysia, 46, 47. Aplysia depilans, 30 ; Arachnids, 2 Arbacia, suppression of cell-division, 56, 117 ; artificial parthenogenesis, 108 ; need of oxygen, 112; effect of atropine, 131; of sodium hydrate, 151; hybridization experiments, 261. Archenteron, of Echinoderms, 3, 185; in lithium larvae, 137; of Amniota, 8; in Hemigastrula, 159; everted, see Exogastrula; in double monsters of Frog, 172; tip of, removed, 195; of partial larvae, 198, 205, 221. Architecture of nucleus in Mosaic Theory, 19. Area vasculosa, 110. Ayrenicola, segmentation of, 26, 30, 47; effect of ions on larvae, 135. Arm, rate of growth of, 70; varia- bility, 74; of Pluteus, see Pluteus. Arrangement of systems of drops or bubbles, 43, 44. Arrest of development at low tem- peratures, 97, 99, 102, 104. Arrhenokaryotic, 267. Arthropods, blastoderm of, 5, 114; muscles of, 5; somites of, 11; nerve-ganglia of, 11 ; segmentation of, 24. Artificial parthenogenesis, see Par- thenogenesis, Ascaris lumbricoides, 258, Ascaris megalocephala, segmentation of, 27, 28, 34, 47; cell-movement, 29; _ simultaneous division of related cells, 31 ; eggs poisoned by oxygen, 112 ; fusion of eggs to form double - monsters, 202; symmetry of egg limacina, 30, 45. SUBJECTS 323 and embryo, 245; diminution of chromosomes, 252, 253, 256-258 ; individuality of chromosomes, 256; dispermy, 257. Ascaris nigrovenosa, 33, 34. Ascidians, segmentation of, 24, 26, 47, 54, 229, 235 ; effect of solutions, 140; isolated blastomeres, 230, 237; symmetry of egg and that of embryo, 229, 235, 245. Ascidiella, egg- and embryonic axes, isolated blastomeres, 229, 230. Asplanchna, unequal asters, 30; fertilization spindle, 34, 48. Asters, spiral, 40; unequal, 30; in- duced by salts, 124, 125; altered by alkaloids, 128-130. Asterias, flattening of blastomeres, 45 ; artificial parthenogenesis, 108 ; effect of atropine, 131; exogas- trulae, 140; necessity of sulphate, 144; necessity of potassium, 146 ; blastomeres without magnesium fall apart, 148; blastula cut up, 194; tip of archenteron removed, 195; coelom-sacs removed, 195; ochracea, heterogeneous cross-fertili- zation, 262. Asteroids, segmentation of, 24, 26, 28, 47, 54 Atmospheric pressure as affecting growth, 2; reduced, 109, 110; increased, 114, Atrium, 229. Atropine, 131. Attachment of cells to other bodies, 5, Auditory vesicle of Vertebrates, 6. Axes of embryo, see Embryonic axes. Axial organs, correlations between, 75. Axis cylinder, 273. Axis of egg, see Egg axis. Axolotl, 119. Bacterial toxines, 132. Barium, 150. Bases, 122. Batrachus, 178. Beginnings, knowledge of, 289, 298. Belgians, growth of, 63. Benzole, 42. Berée, pressure experiment, 39; iso- lated blastomeres and egg-frag- ments, 209-211. Bilateral segmentation, see Segmen- tation. Bilateral symmetry, see Symmetry, Bile-capillaries, 6. Bipinnaria, necessity of sulphate, 144, Y 2 324 INDEX OF Birds’ eggs, effect of electric current on 91. Blastema, metanephric, see Kidney. Blastocoel, see Segmentation cavity. Blastocyst of Mammalia, 2, 6, 7, 115. Blastoderm, of Arthropods, 5, 114, 273 ; of Cephalopods, 6 ; of Sauro- psida, 6; growth of, without for- mation of primitive streak, 104 ; growth of oxygenotropic, 114, 278 ; isotropic, in Teleostei, 179. ~ Blastomeres, separate, in Tricladsand Salps, 5; in Oceania, 181; grouping of, in Salps, 11 ; size of, 29 ; separa- tion of, 45; before division, 45; in calcium-free sea-water, 45, 150; without magnesium, 148; flattened against one. another, 45, 53; movements of, 29, 42, 53. — ‘isolated’ development of, in the Frog, 159-161, 169-171,173 ; in the Newt, 173; in Fishes, 178 ; in Am- phioxus, 179, 180; in Coelenterata, 181, 182; in Echinoderms, 190 sqq.; in Nemertines, 204,205 ; in Cteno- phora, 209-211; in Mollusca, 215 sqq.; in Ascidia, 229, 230, 237, 239; reason for differences in behaviour of, 241-244, Blastopore, dorsal lip of, in Frog, 80; in forcibly inverted eggs, 82, 84; rim of, thickened by heat, 99 ; fails to close, 99, 119 sqq., 133; in half-blastomere of Frog, 170; in double monsters of Frog, 172; injury to lip of, in Fishes, 178; in Ascidia, 235; in Molluses and Annelids, 244. Blastula, of Echinoderms, 2, 6, 115, 185 ; in lithium salts, 137 ; opaque, without potassium, 146; opaque, in neutral media, 150; crumpled, without carbonate, 148; of Coe- lenterates, 6; of Sponges, 6; pieces of, in Siphonophora, 181 ; in Echinoids, 194 ; in Nemertines, 206; long-ciliated, from animal cells of Echinoids, 192; united to form one embryo, 201, 202. Bleu de Lyon, 94, 96. tes , the first to be formed (Harvey), Blood-vessels, growth of, 5; branch- ing of, 6 ; lumen of, 11; distended at low temperatures, 104 ; muscles of, 273. Blue light, 94-96. Bolina, 210. Bombinator igneus, Pfliiger’s experi- ments on eggs, 82, 83. SUBJECTS Bone, 2 ; and tendon, 5. Bonnetty machine, 91. Bostonschool-children, growth of, 63. Boys, see Human being. Brachystola, 256. Brain remains open solutions, 119 sqq. Branchipus, 22, 24, 47. British Periwinkles, 71, Bromides, 123, 132, 133, 134. Bromine, 141, 145. Budding, a form of development, 1 ; nucleus in, 284, 285. Buds of Doliolidae, 5; of plants, 11; of Vertebrate limbs, 11. Bufo, absorption of water by tadpoles, 58; acclimatization to heat, 100; rate of growth affected by tempera- ture, 102 ; effect of solutions, 120. Butyrate of sodium, 140. in certain Caesium, 146. Caffein, 120. Calcium, effect of absence of, 45, 148 ; effect on cilia and muscles, 135, 150; acetate, 49; phosphate, 58, 149; chloride, 123, 133; nitrate, 135; hydrogen phosphate, 148, 150; carbonate, 148, 150; sea- water without, for isolating blasto- meres, 45, 150, 190. Callidina, 34. Cane-sugar, effect of, on Frog’s eggs, 120, 121, 133, 135, 1386; artificial parthenogenesis, 123. Capillaries, 5; anastomoses of, 6; absence of, without oxygen, 110. Capillarity, in cell-division, 41 sqq., 145. Capitella, 26. Carbon dioxide, fatal to Frog's eggs, 110; to Teleostean ova, 111; to Echinoid eggs, 112 ; not fatal to Ascaris eggs, 112; quantitative determination of, 112 ; excess pro- duced by Chick in pure oxygen, 112; neutralized by hydroxyl, 151. Carbonate, necessity of, 148-150. Carbon-ion, see Carbonate. Carcinus moenas, growth-rate, 71; decrease of variability, 72, 74. Cardinal temperature points, see Temperature. Cartilage, 2. Catamenia, 294. Cation, 136, 145. Causal, see Cause ; causal harmony, 284, 285, 292. Cause, explanation in terms of cause and effect, 12, 20, 286-289, 290, 292, INDEX OF 296, 297, 298 ; formal, 13, 293, 296 ; efficient, 13, 296, 297, 299; final, 20, 296, 297, 299; material, 294, 296, 299. Cavities, development of, 11. Cavity perivitelline, 79 ; and sagittal plane in Frog, 165-168 ; segmenta- tion, see Segmentation cavity. Cell-plate, 41. Cells, animal and vegetative, differ- ences in potentiality, 191, 204- 206, 242. — division of (see also Segmenta- tion), a factor in development, 2, 22 sq.; not necessarily a pro- cess of differentiation, 22, 166, 245, 246, 279; meridional, 22, 32; in compressed eggs, 34, 36; equatorial, 22; latitudinal, 22, 32; in compressed egg, 34, 36; dexio- tropic, 26, 28; laeotropic, 26, 28; alternation of direction of, 25, 28; direction of, 29, 54; depends on that of nucleus, 31, 48, 55; pressure experiments on, 34-39; and yolk, 24, 29, 48; and surface-tension, 41 sqq.; influence of gravity on, 78 ; influence of electricity on, 93 ; unequal, 29, 30, 168; rate of, 29, 261; suppressed, 55, 56, 106, 117; simultaneous division of the ovum into several cells, 55, 56, 118, 128, 130, 264, 265; in plant-cells, 41; qualitatively unlike, 158, 286; power of, restored in fertilization, 252. — follicle, of Tunicata, 5; and cell aggregates, movements of (Daven- port), 4 sqq.; movements of, in seg- mentation, 29, 42, 222; number of, in partial embryos or larvae: in the Newt, 173; in Amphioxus, 181; in Coelenterata, 182; in Echinoids, 197, 269; in Nemertines, 206; separation of, 45, 105, 145. Cellulation, 162. Cellulose, 58. Centrifugalized eggs, 29, 87, 88. Centrosomes, heterodynamic, 30; in artificial parthenogenesis, 124, 125; direction of division, 40; division prevented, 265, 267. Cephalopods, blastoderm of, 6; segmentation of, 27; symmetry of egg and axes of embryo, 245. Cerebratulus, isolated blastomeres and egg-fragments, 204-208, Cestoda, 28. Cetochilus, 22. Chaetopods, artificial partheno- SUBJECTS 325 genesis, 124; pressure experiments, 39, 213. Chaetopterus, 214. Chemical agents, effect of various, 126 sqq.; need of, 142-152. Chemically equivalent solutions, 140. Chemotactic, 55, 273. Chest-girth, change in rate of in- crease of, 70. Chick, Harvey, 14; Malpighi, 15; de Buffon, 15 ; percentage of water in, 59, 60; decline of growth- rate, 67; effect of electric current, 91; influence of light of various colours, 96; respiration of, 109, 110, 113; effects of heat and cold, 102-105 ; effects of poisons, 132. Chloral hydrate, effect on fertiliza- tion, 128-130. Chlorates, 145. Chlorides, 123, 133; see also Sodium chloride, and Chlorine. Chlorine, necessity of, 145. Chloroform, 42; and vitelline mem- brane, 129. Chondrin, 58. Chorion, of Teleostei, 35. Choroid, 273 ; choroid fissure, 273. Chorophilus, 120; acclimatized to salt, 136. | Chromatin, the vehicle of inheri- tance, 252; individuality of, 256, 265, 266. Chrcmosomes, number of, varied artificially, 267; in merogony, 267 ; in artificial parthenogenesis, 125, 267; and cell-volume, 268; and size of nucleus, 268; and number of cells, 268; irregular distribution of, in poisoned eggs, 128-130 ;' in dispermic eggs, 253, 265; individuality of, 252, 256; diminution of, 252, 256-258. Cilia, apical tuft of, in Plutei, with- out sulphate, 144; in Pilidium, 204-206. — movement of, 135; independent of sulphates, 144; without magne- sium, 147; in neutral media, 151. Ciliated ring of Pluteus, without sulphate, 144; without calcium- earbonate, 148; of Mollusca and Polychaeta, 213, 220. Cirrhipedes, segmentation of, 22, 24 ; fertilization and egg-structure, 250, Clausilia, decrease of variability, 74. Cleavage, see Segmentation. Clepsine, germ-bands of, 6; rings, 251. polar- - Clove-oil, 54. 526 ~ INDEX OF Clymenella, 46. Clytia, 181. Cocain,. effect on fertilization, 128- 130. Coefficient of growth, 65; of varia- bility, 71, 72, 73; of correlation, 75 Coelenterata, skeleton in, 2; uni- polar immigration in, 11; segmen- tation of, 22, 28, 47, 54; develop- ment, of isolated blastomeres, 181. Coelom, of Echinoderms, 3; of Annelids, 6; epithelium of, and gonads, 7; lumen of, 11; sacs removed, 195. Cohesion of blastomeres, 45, 148, 150. Cold, effects of, on segmentation and development, 99 sqq.; on fertiliza- tion, 107, 108; arrest of develop- ment due to, 97, 99, 102, 104; together with potassium cyanide, 132 ; produces artificial partheno- genesis, 108, 124; segmentation of an isolated blastomere becomes total, 216. Combination of original elements, 286. Composition, organs formed by, 3, 277, 285. Concentration of material of blasto- poric lip in axis of embryo, 178; of sea- water, 124. Conerescence of lips of blastopore, 178; of layers, see Cells, movements of. Conditions cof development, see De- velopment. Cone of entrance, 128. Connective tissue, 273. Consciousness, of the process, in development, 20, 291, 297. Constriction, see Cells, movements of. Contact stimuli, 137, 272, 275-277. Contractility of cytoplasm, 130, 131. Contraction of muscles, inhibited by magnesium, 135, 148; sodium necessary for, 135, 145; potassium necessary for, 147. Co-ordination, 284. Copper sulphate, 96. Cornea, causes of formation, 275, 276, Corpus luteum, 5. Corpuscles, concentric, of thymus, 11. Correlation, 75; decrease in, 75, 277; between symmetry plane, first furrow and sagittal plane, 167. Cosmie process, 298. Costae of Ctenophora, 211, 212. SUBJECTS ’ Cotylorhiza, necessity of potassium, 146. Crab, see Carcinus. Crangon, 24. Crepidula, segmentation of, 26, 30; asters and protoplasmicmovement, 40; flattening of blastomeres, 45 ; parallel polar furrows, 46. Crescent, gray, see Gray crescent.. Crinoids, 22. Cross-fertilization, see Hybrid. Cross furrow, see Polar furrow. Crustacea, segmentation of, 22, 24,47; eggs of, and gravity, 78; structure of egg, and embryonic axes, 245, Crystallodes, 181. Ctenolabrus, cell-division suppressed, 56, 111; first furrow and sagittal plane, 178; need of oxygen for, 111, 262. Ctenophora, segmentation of, 26, 208 ; micromeres, 30; pressure, 39; influence of gravity on eggs, 78; micromeres displaced, 211; isolated blastomeres, 209, 210; egg-frag- ments, 212; effect of fertilization, 250. Cyclas, 26. Cyclops, 22. Cynthia, development, 230; isolated blastomeres, 237; symmetry of egg, 232, 250. os Cytarme, 45, 53. Cytasters, 125. Cytochorismus, 45. Cytolisthesis, 53. Cytoplasm, organ-forming substances in the, 19, 208, 212, 213, 217, 224, 225, 228, 233, 236, 240, 241, 246, 280, 286. — nucleus and, 31, 131; ratio be- tween, 65, 269; inter actions of, 266, 283, 284. — increase of, in differentiation, 65, 66 ; ascent of, in inverted eggs, 84 ; receptive to stimuli, 283; para- lysed by poisons, 127; contrac- tility of, 130, 131; determines diminution of chromosomes, 257. Cytotaxis, 55. Cytotropism, 55, 273. Daphnella, 24. Daphnia, 24. Darkness, Fundulus embryos, 94; tad- poles of Frog, 95.; eggs of Limnaea, 95 ; Echinoid larvae, 96. Death-rate, selective, 74 ; in various lights, 94-96 ; in desiccators, 115; of heterogeneous hybrids, 262. Oo INDEX OF 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, Dentalium, development, 222-224 ; re- moval of polar lobe, 224; isolated blastomeres, 225, 226; egg-frag- ments, 226. Dependent differentiation, see Differ- 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, defined, 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, sce Suspension. Deviation, standard, 71. Dexiotropie 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, 213, 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- SUBJECTS 327 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, 24, 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. 328 INDEX OF Echinoids, egg, segmentation of, 22, 27 ; position of nucleus in egg, 31; normal development of, 183-185; pressure experiments on, 37, 38, 185, 186 ; blastomeres disarranged, 187, 194; isolated blastomeres, 190 sqq. ; egg-fragments, 195-197; fragments of blastulae and gastru- lae, 199, 195; one embryo from two blastulae, 201, 202; larvae, in- fluence of light on, 95, 96; require oxygen, 112; spicule cells in, 114; influence of potassium, sodium, and lithium, 137-140; partial larvae, size of, rate of development of, number of cells of, 198-200; hy- brids, 258-262. Echinus, pressure experiments, 37, 38, 185, 186; suppression of cell- division, 55; influence of light, 94 ; ciliary movement in larva, 135; potassium, sodium, and li- thium larvae, 137; necessity of certain elements for, 142 sqq.; blastomeres disarranged, 187, 188, 194; blastomeres isolated, 190 sqq.; segmentation of egg-frag- ments, 195-197; blastula cut up, 194; grafting of blastula frag- ments, 202 ; size of partial larvae, 199, 201; hybridization experi- ments, 258-262; number of chromosomes varied, 267. Ectoderm, of Earthworm, 3; growth of, in Amphioxus and Vertebrates, over medullary plate, 9; of Sipun- culus, 9 ; of lithium larvae, reduced, 139, 140; of Echinoid, gastrula, separated,195; of partial larvae,198. Ectoproctous Polyzoa, segmentation of, 22. Efficient cause, see Cause. Egg axis, how determined, 79, 163, 183, 204, 208, 232, 249, 250, 280; and gravity, 78; and embryonic axes, 81, 165, 166, 174, 204, 209, 229, 233, 236, 244, 281; and seg- mentation furrows, 81, 85, 229, 235 ; secondary, in inverted eggs, 85 Egg-fragments, enucleate, fertilized, see Merogony ; segmentation of, see Segmentation. Elasmobranchs, lower layer cells, 5; segmental duct, splitting of, 6; yolk-nuclei, 88; injuries to germ- ring, 178. Elastic plates and tubes, layers of Chick compared to, by His, 3. Electricity, 91 sqq. SUBJECTS Elementary organs, sce Organs. Emboitement, 14. Embryology, experimental, 1, 13; descriptive, 12; comparative, 12, 16; aims of, 13, 156, 157, 297, 298. Embryonic axes, and gravity, 78; and symmetry of egg, 81, 165, 166, 174, 204, 209, 229, 233, 236, 244, 266, 281; influence of light on, 93. Embryonic plate, of Mammals, 9. Embryos, double, 201, 202 ; partial, see Blastomeres, isolated, and Egg- fragments. End, knowledge of the, 286, 289, 296, 297, 299. Endoderm of Echinoid larvae, sepa- rated, 195. End-organ and nerve, see Nerve. Energy, life not a form of, 291. English, growth of, 63. Entelechy, 291, 297. Environment, physical and chemical, adaptation of developing organism to, 157. _Epidermis of Earthworm, 3. Epigenesis (Harvey), 13, 15; (Wolff), 16; not a theory, 17, 19. Epithelium, degeneration of, 120. Equatorial division, 24. Equilibrium, osmotic, 118. Equimolecular solutions, 140. Equipotential, 176, 277. Essential oils, 132. Ether, 132. Ethical, 289. Eucharis, 209. Evaginations, see Cells, movements of. Eversion of gut, see Exogastrula. Evil, problem of, 299. Evolution, theory of (of the indivi- dual), 14; modern form of, 19, 158 ; (of the race), 16, Excretory, see Kidney. Exocoetus, 178. Exogastrula, in lithium salts, 137; without sulphate, 143; of Ascidia, 237. Ex-ovates, of Arbacia, 118. Experimental method inembryology, 1, 13, 297, 298. External conditions of development, see Development. Eyes, width of face between, growth of, 70. Fat, 58. Fate a function of position, 188. Ferments, in nucleus, 283. Fertilization in Ascaris nigrovenosa, 33; altered by heat, 107, 108; INDEX OF altered by alkaloids, 126 sqq.; in- dependent of sulphates, 144; without potassium, 146; without magnesium, 147; in neutral media, 151; alteration of egg structure in, 80, 163, 222, 232, 247- 251; two processes involved in, 252. Film, at surface of blastomeres, 45, 54, 150; of drops of fluid, 42, 45, 54. Final cause, see Cause. First furrow, coincidence of, with sagittal plane, see Furrow, first. Fissure, choroid, 273. Flattening of blastomeres against one another, 45, 53. Flexure, cranial, 110. Folds, medullary, see Medullary. Follicle cells, in Tuniecata, 5. Follicles, of hair, 7. Food, growth dependent on, 2, 58, 59. Foot, rate of growth, 70. Form, production of, 1; necessary for, 252, 254. Formal cause, see Cause. Formate of sodium, 145. Formative stimuli, 273. Fovea germinativa, 79. Fragments of egg, see Egg-fragments ; of blastulae, and gastrulae, s¢e Blastulae, Gastrulae. Framboisia, 135. Freedom, 289, 299. Fresh water, Funduluseggs in, 117,136. Frog, ovarian and uterine egg, 79; effect of fertilization, 163; eggs forcibly inverted, 18, 78, 158; in- fluence of gravity upon, 18, 78 sqq. ; eggs placed on vertical wheel, 85 ; eggs kept in constant motion, 86 ; egg centrifugalized, 29, 87, 88; pressure experiments, 34-37, 40, 168; absorption of water by tadpoles, 58; eggs exposed to electric cur- rents, 92, 93; eggs, influence of light on, 94 ; eggs, influence of heat on, 97-99; of cold on, 99-100; eggs, respiration of, 110-112; effect ofsodium chloride on eggs, 119, 120, 276 ; of other substances, 120, 121 ; acclimatized to sodium chloride, 136 ; firstfurrow and sagittal plane, _17, 159, 165-168; half-embryo from half-blastomere, 18, 159 sqq., 169-171; double monsters, 171, 172; development of animal and vegetative blastomeres, 173 ; forma- » oflens,275,276 ; of cornea, 276, if Frontal breadth in Carcinus, growth of, 71; variability of, 72. nucleus SUBJECTS Fuchsin, 94. Functional adaptation, 290. Fundulus embryos, in light and dark- ness, 94 ; need of oxygen for, 111, 114, 274; in fresh water, 117; effect of ions on, 135, 136; in sodium chloride, 117; in magne- sium chloride, 276; first furrow and sagittal plane, 178; injuries to blastopore, 178. Furrow, first, and sagittal plane in Frog, 17, 159, 165-168 ; in Necturus, 168 ; in Newt, 175; in Fishes, 178 ; in Ascidia, 229, 233, 2385; in Echinoids, 250 ; and plane of sym- metry, 167, 233; and horizontal plane in Newt, 175; first and en- — trance point of spermatozoon, 40 ; in Frog, 247, 248; in Toxopneustes, 250. Furrows, polar, parallel, and crossed, 25, 26, 46,47; in Rana, 53 ; in sys- tems of oil drops, 50. Fusion of cell-aggregates, see Cells, movements of; of larvae to form double monsters, 137, 201 ; or one larva, 202. 829 Galvanotaxis, 272. Galvanotropism, 272. Gammarus, 24. Ganglia, see Nerve. Ganoids, 26. Gastrula, of Echinoderms, 5; opaque in neutral media, 151 ; of animal and vegetative cells, 191- 194; pieces of, in Echinoids, 194 ; of Ascidia divided, 238. Gastrula wall of lithium larvae, 138-140. Gastrulation, need of sodium for, 145 ; of isolated blastomeres, 191-194, Gemmule of Sponges, 5, 11. Genetic -restriction, 246, 277; sce also Potentialities, limitation of. Geophilus, 4. Geotropism, 272. Germ-bands, 5; of Clepsine, 6; from teloblasts, 29; of Crustacea, 34. Germ-cells, liberation of, 11; the vehicles of inheritance, 1, 252; of Ascaris, 253. Germ-layers, 2. Germ-ring, injuries to, 178. Germinal localization, His’s prin- ciple of, 17. Germinal value, and loss of potenti- ality, 181; and number of cells, 182, 197, 206, 269; and size of 330 INDEX OF larvae, 198, 199, 269; and rate of development, 200, 204, Geryonia, 181, Gill slits, abnormal, 104. Girls, see Human being. Glands, growth of necks of, 5, 273; branching of, 6; club-shaped, of *Amphioxus, 6. Globules, of Wolff, 16. Glycerine, 132. Gonads, from coelomic epithelium, 6. Grafting of pieces of blastulae, 202. Gravity, influence on segmentation of Frog’s egg, 18, 78, 158; in- fluence on development in general, 78; Pfliiger’s views, 83; directive influence of, experimentally elimi- nated, 85; replaceable by a centri- fugal force, 87; effect on Antennu- laria, 272, 273; on Sertwaria, 272. Gray crescent of Frog’s egg, 80; said to be due to gravity, 87; caused by spermatozoon, 247, 248. Gray degeneration, see Degeneration. Gray patch in inverted eggs, 85, 87. Green light, 94-96. Growth, a factor in development, 1, 279; conditions of, 1, 58, 59; local inequalities of, 2,3, 11; in length, 5; of spherical and plane surfaces, 6; defined, 58; without differen- tiation, 104; dependent on ab- sorption of water, 58, 59, 68, 115, 116,146; and other substances, 58 ; change of rate, 61-71; change of variability during, 71-75 ; change in correlations during, 75, 76; rate of, defined, 60 ; variable, 74; influenced by temperature, 101. Guinea-pig, change of rate of growth, post-natal, 61, 62, 65; pre-natal, 62; decline of variability in, 71. Gut, muscles of, 5 ; of Echinoderms, 3; imaginal, of Insecta, 5; of Pluteus, in potassium, 137 ; with- out sulphate, 143; without mag- nesium, 147; without potassium, 146. Haemoglobin, not formed in absence of oxygen, 110. Haemorrhage, due to cooling, 104. Hair, follicles, 7. Half-embryo, depends on position of egg, 170, 171. Hand, rate of growth, 70; varia- bility, 74. Harmony, causal, 284, 285, 292; of composition, 285, Head, length, rate of growth,. 70; SUBJECTS variability, 74; correlations with other parts, 75; breadth, rate of growth, 70; variability, 74; corre- lations with other parts, 75. Heart, the first organ to be formed, according to Aristotle, 13, 294; -beat of Chick at low temperatures, 104; halves of, remain apart, 104 ; distended, 104; beat of Fundulus in hypertonic solution, 117. Heat, 97 sqq., as affecting growth, 59; effect of, on Frogs’ eggs and em- bryos, 97-99; acclimatization to, 100; effect on Sphaerechinus ova, 105, 106, 187; on fertilization, 107, 108 ; stimuli, 272. Heliotropism, 272. Hemiblastula, 159 ; superior, 161. Hemicrania, 119. Hemi-embryo lateralis, anterior, 161. Hemigastrula, 159. Hemikaryotic, 267. Hemimorula, 159. Hemitheria anteriora, 18. Hen’s egg, axis vertical, 78; need for being turned, 89; exposed to shocks, 89; perpetually rotated, 90; exposed to sound-vibrations, 90; placed between poles of a mag- net, 91; influence of light on, 93, 94; loss of weight of, 115; effect of poisons on, 132. Heterocentron, 58. Heterodynamic centrosomes, 30. Heterogeneity of ovum, 2, 157; and homogeneity, 298. Heterogeneous hybridization, 262, Hips, rate of growth, 70. Holoentoblastia, 139. Holothurians, segmentation of, 22. Homologies, sought for in descrip- tive embryology, 12. Human being, decline of growth-rate after birth, 63, 64, 65; before birth (sce Human embryo) ; rise of growth-rate at puberty, 65 ; decline of variability, 73; increase at pu- berty, 73; decline of correlations, 75 159, 171; Human embryo, percentage of water in, 59, 60; decline of growth-rate, in weight, 63; in stature, 68; of organs, 70. Humid atmosphere, necessary for Hen’s egg, 115. Hybrid Pluteus from enucleate egg- fragment, 253, 258-260; Plutei, various, 262; heterogeneous, 262. Hydractinia, 47. ee INDEX OF Hydranth, see Hydroids. Hydrochlorate of morphine, 128-130. Hydrogen, effect of, 109-111, 132. Hydroids, growth of stolons and hy- dranths, 5; attachment of, 272; from isolated blastomeres, 181. Hydroxyl, 150, 151. Hyoid of tadpoles, enlarged, 114. Hypertonic solutions, see Osmotic pressure. Hypotonic solutions, pressure. see Osmotic Idiochromatin, 258. Idioplasm, 159. Idioplasma, in the nucleus, 19. Ilyanassa, segmentation, 26, 214, 215; isolated blastomeres, 215-217 ; re- moval of polar lobe, 217. Immigration, see Cells, movements of, Immunity, 290. Inerease of mass, 58, 115; of self- differentiation, 75, 176, 277, 284; of structure, 2, 279. Increments, percentage of growth, 60, Index, mitotic, 65 ; of development, 103 Individuality of chromosomes and chromatin, 252, 256, 265, 266. Induction, 282, 283, Inequalities, local, Growth. Inequipotential, 176, 277. Inheritable qualities, represented by units in the germ, 19, 159, 246, 247, 279, 280. 