None
Inheritance, material basis of, 1, 19, 252; Aristotelian explanation of, 294 ; mechanism of, 1, 19, 280. Injuries, local, the cause of local de- fects, 17, 159. Insects, gut of, 5; pupae, phagocy- tosis in, 5; segmentation of, 24; polar nuclei, 29; eggs of, and grav- ity, 78 ; symmetry of egg and em- bryo, 245. Insemination, first effect of, in Frog, 79. Insufficiency of material, see Poten- tialities, limitation of. Interactions of the parts, 271-277, 284. Internal conditions of development, see Development. Interruptions of continuity, see Cells, movements of. Inyaginations, see Cells, movements of. of growth, see SUBJECTS 331 Investment by cells, see Cells, move-. ments of. Todides, 133. Todine, 141, 145. Ion-proteids, 136. Tons, 135, 136, 140. Iris, 276. Iron, 141. Irregular distribution of chromo- somes, see Chromosomes, Irregularities of segmentation, see Segmentation. Ischnochiton, 25, 46. Isobilateral segmentation, see Seg- mentation. Isopoda, 24. Isotonie solutions, 140, 142, Isotropy of egg, 18, 158, 202, 280; of blastoderm, 179. 120, 123, 124, Jelly of Frog’s spawn, 42, 43, 79. Judgement, Kritik of Teleological, 286-289. Karyokinesis, without calcium, 150 ; significance of, 252. Karyokinetic plane, 185. Kidney, larval, of Lamellibranchs, 5 ; tubules, branching of, 6; anas- tomoses of, 6; tubules (meso- nephric),fusionwithvasa efferentia, 6; tubules in metanephric blas- tema, 11. Labrax, 145. Lacertilia,inner wall of pineal vesicle, Laeotropic division, see Cell-division. Lamellae, systems of, 41 sqq. Lamellibranchs, larval kidney of, 5. Laodice, 181. Lappets of Pilidium, 204, 207. Larva, of Sponges, 6; of Dicyemi- dae, 11; of Coelenterates, 6; characters of, developed early, 3; partial, see Blastomeres, isolated, and Egg-fragments, Latitudinal division, 22, 24, see also Cell-division. Law, Biogenetic, 12, 16; of alterna- tion of direction of cleavage in ‘spiral’ eggs, 25; Sachs’, 25, 40; Weber's, 272. Laws of causation, 13, 285, 298. Leg, rate of growth of, 70. Lens, outer layer of, 7; absent, in cer- tain solutions, 134; causes of for- mation, 275, 276. 332 INDEX OF Lepidonotus, 25, 46. Lepidosteus, 26. Light, general effect on developing organisms, 93; on fern prothallus, 272; on Serpula, Sertularella, 272; effect on direction of embryonic axes, 93; of various colours on eggs of Echinus, Planorbis, 94; Rana, 94, 95 ; Trout, 95 ; Limnaea, 95; Echinoid larvae, 96 ; promotes oxidation, 112. Limax, segmentation of, 25, 26, 30; spiral asters, 40. Limbs, buds of, in Vertebrates, 11. Limitation of potentialities, see Potentialities. Limnaea, 67. Linear cell aggregates, 5. Liriope, 181. Lithium chloride, eggs of Amphibia, 120, 135; salts, on Amphibian eggs, 120, 138, 185; on Echinoid larvae, 137-140, 146. Littorina, 71, 72, 74. Lobe, polar, 214, 228; removal of, 217, 224, 227, Localization of ontogenetic: effects, 289. Loss of potentialities, see Potentia- lities. Lucifer, 22, 47, Macromeres of Echinoids, 22, 30, 185, 192 ; of Ctenophora, 211; of Mollusca, 215, 221. Magnesium in artificial partheno- genesis, 123; Frog embryos, 133, 135; Fundulus, 135, 276; <Arenicola larvae, 135; effect on ciliary and muscular movement, 135; necessity of, 147. Magnetism, 91 sqq. Male element, function of, according to Aristotle, 13. Mammalia, blastocyst, 2, 6, 7, 115; truncus arteriosus, splitting of, 6; trophoblast of placenta, 7; embry- onic plate, 953 segmentation in, 24. Man, see Human being. Massive cell aggregates, 11. Material basis of inheritance, 1, 19, 252; cause, see Cause ; explanations of ontogeny, 12, 20, 286-289, 290, 296, 298. Materialism, 301. Matter and material cause, 13. Matter and mind, 301. Maturation, nuclei of germ-cells in, 252, 254. SUBJECTS Maximum temperature, see Tempera- ture. Mechanical, see Mechanism ; Mechan- ical agitation, 89. Mechanism of inheritance, 1, 280; mechanism, explanation of onto- geny as a, 12, 20, 286-289, 290, 292, 296, 298. Medulla, roof of, 7; solid, in Frog’s embryos grown in certain solu- tions, 133. Medullary folds, 9; not formed at low temperatures, 104 ; divided at high temperatures, 99; remain open in various solutions, 119 sqq.; in Hemiembryo, 160. Medullary plate of Amphioxus, 8. Medusa from isolated blastomere, 181. Megalecithal eggs, 24. Membrane of egg, 45, 46; absence, due to poisons, 128; formed by chloroform, 129; at surface of cells, see Film ; of shell, 104; of Descemet, 276. Mendelian allelomorphs, 266. Mercury, 132. Meridian, streaming, in inverted Frog’s eggs, 84. Meridional division, 22, 32; see also Cell-division. Meridional polarization in Frog’s egg, 83. Meroblastic segmentation, see Seg- mentation. Merogony, 131; male nucleus only in, 254 Mesenchyme, of Echinoderms, 5; of Echinoids, 185, 261, 262, 269; of partial larvae, 193, 194, 198, 237 ; of Ascidia, 235; of Echinoids, displaced, 274. Mesoderm, segmentation of, 11; in Hemiembryo, 160; deficient, after injury to germ-ring, 179; depen- dent on presence of polar lobe, 217. Mesomeres in Echinoids, 27, 185, 192. Mesonephric tubules, see Kidney. Metabolism, nucleus needful for, 252, 254, Metamorphosis (Harvey), 14. Metanephric blastema, see Kidney. Methods of embryology, descriptive, 12; experimental or physiological, 13 Micromeres in Echinoids, 22, 30, 185, 192; suppressed by pressure, 37, 186 ; by heat, 186 ; in ‘spiral’ eggs, 25; suppressed by pressure, 39, 213 ; rotation of, 29, 47 ; of Mollusca ee INDEX OF isolated, 215, 221; of Ctenophora, 39, 209-211. Micropyle, 183. Migration of cells, 4, 5; of spicule cells in Echinoids, 114. Mind and matter, 301. Minimum temperature, see Tempera- ture. Mitosis, quadripolar,tripolar, 263-265. Mitotic index, 65. Mitrocoma, isolated blastomeres, 181 ; fusion of blastulae, 202. Moina, 24. Molecules, meridional rows of, in Frog’s egg, 83. Mollusca, muscles of, 5; segmenta- tions of, 25; eggs of, influence of gravity on, 78; isolated blasto- meres, egg-fragments, 215 sqq. ; symmetry of egg and embryo, 244. Monaster, 267. Monsters, double, in lithium salts, 138; of Frog, 171, 172; of Newt, 174, 175 ; of Amphioxus, 181; of Asterias and Echinus, 194; of Sphaer- echinus, 201. Monstrosity, 1; natural, 18, 159; significance of, 155, 156; produced by shocks, 89 ; perpetual rotation, 90; by sound vibrations, 90; by electric currents and magnetism, 91; by heat and cold, 98 sqq. ; by chemical agents, 120-121, 132; significance for variation, 141. Moral consciousness, 289, 299, 300. Morphaesthetic, 291. Morphine, effect on fertilization, 128- 130; on Hen’s egg, 132. Morphography, 12. Morphology, method of, 12; experi- mental, 1. Mosaik-Theorie, see Theory, mosaic ; segmentation, see Segmentation. Motion imparted by male element, 295, 296. Mouth, growth of, 70. Movements, of cells and cell-aggre- gates, 4sqq., 272 ; in segmentation, see Cell; of organ-forming substances, 207, 208, 226, 227; protoplasmic, 40, 41. Mucin, 58, 79. Muscles, in Arthropods, 5; of Ascidia, 235, 237; in Mollusca, 5; of gut, 5; of blood-vessels, 273 ; striated, 55; abnormal, in rotated Hen’s eggs, 90; contractions of, see Con- traction. Mutations, 141, Myotomes, 11. SUBJECTS 333 Myriapods, 24. Mysis, 24. Myzostoma, 214, 228. Nature, 301. Neck, rate of growth, 70. Necturus, 168. Nematocysts in Planula, 3. Nemertines, segmentation in, 25; isolated blastomeres and egg-frag- ments, 204-208, Neo-vitalism, 20; see also Vitalism. Nephelis, 40. Nephridia of Earthworm, 3, 5; of Annelids, fusion with coelom, 6. Nereis, segmentation in, 25, 47; un- equal asters, 30; egg compressed, 39, 213; crossed polar furrows, 46 ; change of shape of cells, 48; arti- ficial parthenogenesis, 124, Nerves, growth of, 5; branching of, 6; anastomoses of roots, 6; plexuses of, 6; fusion with end-organ, 6 ; crest, 11; ganglia, fusion of, 11; fibres, 273; physiology of, 290. Nervous system of Earthworm, 3; of Teleostei, 6, 11, 183; of Inverte- brates, 11; of Ascidia, 235, 237. Neural, see Nerve. Newt, development of half-blasto- meres, 173; double monsters, 174, 175. Nickel nitrate, 94. Nicotine, and eggs of Bufo, 120; effect on fertilization, 126, 130; on Hen’s egg, 182. Nitrates, 123. Nitric oxide, eggs of Ascaris in, 112. Nitrogen, eggs in, 110, 112. Non-electrolytes, poisonous effects of, 136 ; see also Cane-sugar, Dextrose, Urea. Normal temperature, see Temperature. Notochord, vacuoles of, 2; early differentiation of, 3; application of skeletal cells to, 5, 11; formation of in Urodela, &c., 8; from archen- teron,.11; divided at high tem- peratures, 99; in cane-sugar, 133 ; whole, in Hemi-embryo, 160; of Ascidia, 235, 237. Notochordal tissue, in neural tube and archenteron, 134. Nucleus, division of, a factor in de- velopment, 2, 22 sqq. ; division of, direction determines that of cell, 31, 55; rules of Hertwig for, 31, 32; rule of Pfliiger for, 32 ; polar divisions of Insects, 29; polar divi- sions with equal asters, 31; division 334 INDEX OF 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, 288; reaction of, on cytoplasm, 266, 283, 284. Number of cells, see Cell; of nuclei, see Nucleus. Oakland, Mass., growth of, 63. Obelia, 147, 148. Obliquity of spindles in ‘ spiral’ eggs, 82; of-egg axis in Rana 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. school-children, Ophelia, artificial parthenogenesis, 124, Ophiuroids, segmentation in, 24, 26, 28, 47. Ophryotrocha, 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. SUBJECTS Osmotic pressure, as affecting 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 Fundulus, 111, 114; quantitative estimation of amount absorbed, 112; effect of pure, 112- 114; need of, 109 sqq., 132. Oxygenotactic, Oxygenotropic, 114, 278, 274. Oxyhaemoglobin, excess of, in Chick, in pure oxygen, 112. Papilla, fixing, 229. Paraderm, of Amniota, 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; ey- tology of, 124, 125; maternal nucleus only in, 254; number of chromosomes in, 125. : Patch, gray, 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, see Segmentation ; variation in, 74. Peripatus capensis, 24. Perivitelline 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, 138; segmentation, 47; artificial par- thenogenesis, 124.. Phagocytusis, 5. _— INDEX OF Phallusia, 288. Pharmacology, 136. Phascolosoma, 25. Phosphorus, effect on Chick, 132; necessity of, 141. Physa, crossed polar furrows, 46; effect of fertilization, 250. Physico-chemical responses tostimuli, 285 Physiological zero, see Temperature, minimum. Physiologically balanced solutions, 136. Physiology of development, 138; physiological laws, 13, 298. Pigment, change of position in iso- lated ‘blastomeres of Frog, 53; of Frog’s egg, 79; disappearance of, in Frog’s egg, 80, 163; in Fundulus, in darkness, 94; with- out oxygen, 111, 114; distributed through cell-body (gray degenera- tion), 135; of secondary mesen- chyme in Pluteus, 144; without magnesium, 148; without calcium, 150; in neutral media, 151; of Strongylocentrotus, 183-185 ; function in gastrulation, 184, 192; of Den- talium, 222; of Cynthia, 230 sqq., 250. Pilidium, 205-207. Pilocarpine, 131. Pineal vesicles, inner wall of, split in Lacertilia, 9. Pisces, egg-axis and embryonic axes, 178; half-blastomeres, 178; in- juries to lip of blastopore, 178. Placenta, of Mammals, 7. Placental Mammals, segmentation, 24, Planorbis, segmentation in, 25; crossed polar furrows, 46; light of various colours, 94. Plant, division of cells, 41 ; absorp- tion of water by, 58. Planula, nematocysts in, 3; from blastula by unequal growth, 6; from isolated blastomeres, 181 ; giant, from fused blastulae, 202. Plate, medullary, see Medullary ; ae white, in inverted eggs, Platyhelmia, excretory tubules of, 6; segmentation, 54. Pluteus, in light of various colours, 96; ciliary movement of, 135; effect of potassium, sodium, lithium, 137; necessity of various elements for, 142 sqq.; partial, 194-196, 199, 200; hybrid, 258- SUBJECTS 262; arms of, dependent on skeleton, 138, 144, 150, 195, 275; growth rate of arms, 70, 71. Podarke, crossed polar furrows, 46. Pole cells, see Teloblast. Polar areas, in Frog’s eggs exposed to electric currents, and in other structures, 92, 93; bodies, asters of same size in, 31; in Ascaris ni- grovenosa, 33; in Callidina, 34; division, violate Hertwig’s rule, 34 ; furrows, see Furrows ; lobe, see Lobe; nuclei, see Nucleus ; rings, 251. Polarity of Echinoid egg, 183; see also Egg-axis, Polarization, meridional, in Frog's egg, 83; of egg-particles, 281, 286. Polyaster, 128. Polyclads, 25. Polychaeta, influence of gravity on eggs, 78; pressure experiments, 39, 213. Polyspermy, pathological, 107; due to poisons, 128; irregular distribu- tion of chromosomes in, 253, 264, 265. Polyzoa, 22. Position, changes of position in development, 3; Davenport’s cata- logue of, 4 sqq.; fate a function of, 188, 282. Post-generation of missing half-em- bryo in Frog, 161, 162; denied by Hertwig and Morgan, 170, 171; confirmed by Endres, 171. Post-trochal region, 224. Potassium bichromate, 94; bromide, 123, 132; nitrate, 123; sulphate, 123 ; iodide, 132; chloride, 123, 133; cyanide, prolongs life, 131, 132; larvae of Echinoids, 137, 146 ; necessity of, 146. Potentialities, altered by chemical reagents, 140; limitation of, 175, 176, 180, 181, 191, 194, 201, 204, 242-244, 246, 277, 281, 284, 286; due to lack of material, 182, 194, 201, 225, 242, 281, 291; due to lack of specific material, 180, 201, 217, 225, 242, 243, 281, 291. Practical concept of freedom, 289. Predetermination of embryonic axes, see Embryonic axes; physico- chemical, 285. Prediction, the function of science, 299. : Preformation of organ-forming sub- stances, 207, 227, 241, 286, 335 336 Preformation hypothesis, see Evolu- tion. Prelocalization, 207, 222, 227, 241. Pressure, atmospheric, see Atmo- spheric ; osmotic, see Osmotic ; ex- periments on eggs of Frog, 34-37, 40-168 ; on eggs of Echinoderms, 37, 38, 185, 186; on eggs of Nereis, 39, 213; on eggs of Berie, 39; as a means of preventing cell-division, 55, 56. Primary qualities, 300. Primitive streak absent, 104. Principle of germinal localization, 17. Principle of least surfaces, 41-44 ; - in spiral segmentation, 45-47; disobeyed in radial and bilateral types, 49. Proctodaeum, 9. Pronuclei, causes of union of, 130; both male and female, not needed, 254. Proportionality, 293, 295; of parts in partial larvae, 198-201, 290; in one larva from two blastulae, 202. Prototroch, 213, 224. Protozoa, alteration of shape during division, 48; senile decay, 65; enucleate fragments of, 254; in electric current, 93. Pseudo-gastrula, 237, Pseudo-triaster, -tetraster, 108, 129. Psychoid, 291, 297. Puberty, increase in growth-rate at, 65 ; increase in variability at, 73 ; increase in value of correlation coefficient at, 75, 76. Purposiveness, 286-289, 296, 299. Purposes, see Purposiveness. Pyrosoma, 24, Quadripolar mitosis, 263-265, 267. Qualities, inheritable, see Inheritable. Qualities, primary and secondary, 300. Qualitative division of nucleus, see Nucleus, Quartettes of micromeres in ‘ spiral’ eggs, 25, 30, 213; isolated, 215, 221. — effect on‘ fertilization, 128- 30. : Rabbit, decline of growth-rate, post- natal, 62, 65; prenatal, 63. Radial segmentation, see Segmenta- tion; radial symmetry, see Sym- metry. Rana esculenta, bilateral segmenta- tion, 26, 28; obliquity of egg-axis, INDEX OF SUBJECTS 81, 163; cardinal temperature points, 100; effects of salt, 118; brain and eyes of tadpole removed, 175; fusca, segmentation, 28, 47, 53; cardinal temperature points, 97; influence of heat and cold, 97-100; effect of salts and other substances, 119-123; artificial parthenogenesis, 124; symmetry of egg, 81, 163, 247, 248; formation of lens, 275; palustris, symmetry of egg, 81, 247; influence of cold, 100; temporaria, symmetry of egg, 81, 163, 247, 248; virescens, influence of cold, 100. Rate of cell-division, see Cell-division ; of Development, see Development ; of growth, see Growth. Ratio between nucleus and cyto- plasm, 65, 268, 269. Rearrangement of cells, 11. Recapitulation theory, 12, 16. Red light, 94-96. Redistribution of yolk‘and proto- plasm in inverted eggs, 84; of organ-forming substances, 207, 208, 226, 227. Reducing agents, 131. Reflective judgement, 287, 288. Reflex movements of tadpoles de- prived of brains, 176. Regeneration, 290; a form of. de- velopment, 1; of head of Tubularia, 114, 144; and Reserve Idioplasson, 159; of missing half-larva in Cteno- phora, 210; in Ascidia, 239; necessity of nucleus for, 254; of lens, 276; nucleus in, 284, 285. Regulation, 290. Renilla, 55. Reproduction, sexual, 1 ; Aristotelian view of, 13, 294-296. -Reserve-idioplasm, 159, 161, 266. Resistance to injury, capacity for, alters, 104. > Respiration of Chick, 109, 113; of Frog’s egg, 110, 111, 112 ; of Teleo- stean ova, 111; of Echinoid ova, 112. Responses to stimuli, 12, 20, 114, 272-277, 283-285. Restriction, genetic, 246, 277 ; see also Potentialities, limitation of. Retardationof development, by sound vibrations, 90; by light of certain colours, 94-96; at low tempera- tures, 97,99, 100; without oxygen, 110, 111; by desiccation, 115; by increased osmotic pressure, 117 ; in absence of potassium, 146 ; and INDEX OF SUBJECTS 337 magnesium, 148; and calcium, 150; with decrease of germinal value, 200, 204. Rhumkorff coil, 91. Rhynchelmis, 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 nigrovenosa, 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, 80; of Hertwig, 31, 32, 85; confirmed in Ascaris nigrovenosa, 84; and in Diplogaster, 34; by pressure experiments, 34 sqq.; violated, by polar 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. Salmo 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. Salvelinus, 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, Arbacia. 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 Z 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, 2138, 236, 245, 246 ; types of, 22 sqq. ; radial, ‘92, 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; asa 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 caleium- 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; sce also Apical organ. Separation of blastomeres, sce Blasto- meres. Septa, of corpus luteum, 5. Serosa, of Sipunculus, 9. Serpula, 272. 338 INDEX OF 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, 183-135; larvae of Echinoids, 137; bromide, 120, 134; sulphate, 135 ; nitrate, 1353 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. Somatorpleure, fused with allantois, and trophoblast, 9. SUBJECTS Somites, fusion of, 11. Soul, Aristotelian doctrine of, 292- 297; nutritive, 138, 293; percep- tive, 13, 298 ; 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. Spongilla, 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. INDEX OF Sternum, girth round, rate of growth, 70 Stimuli, 12, 20, 272-277, 283-285 ; of spermatozoon in fertilization, 123, 252; exerted by spicules of Pluteus, 137, 275; directive, in post-generation, 162, Stolon, see Hydroids. Stomodaeum, 9; formed in Anen- teria, 106; in Exogastrulae, 137 ; absent without potassium, 146; formed from isolated ectoderm, 195; of Ctenophora, 210, 211. Stratification of organ-forming sub- stances, 242, 280. Strongylocentrotus lividus, segmentation of, 23 ; egg stretched, 39; decline of growth-rate, 67; growth-rate of arms of Pluteus, 70; decline of variability in, 71; eggs exposed to heat, 107; to action of alkaloids, 126 sqq.; normal development, 183-185 ; micromeres suppressed, 186; hybridization experiments, 261, 262; purpuratus, heterogene- ous cross-fertilization, 262. Strontium, 156; bromide, 132, 133. Structure, increase of, 2, 279; of egg, see Egg-axis, Symmetry of egg. Strychnine, eggs of Bufo, 120; effect on fertilization, 128-130; on Chick, 132. Substances, organ-forming in cyto- plasm, 19, 207, 208, 217, 224, 225, 228, 238, 236, 240, 241, 246, 280, 286; specific action of substances present in sea-water, 152. Succession, in the formation of parts, 13. Suckers, 239. Sulphates, 123; of quinine, 128-130 ; of magnesium, 135; of sodium, 135; necessity of, 143, 144. Sulph-ion, see Sulphate. Sulphuric acid, 145. Superficial cell-aggregates, sce Cell. Surface, area of, in partial larvae, 198, 269; area of nuclei and num- ber of chromosomes, 268. Surface-tension, 41 sqq., 55, 56. Surfaces of contact between blasto- ‘meres, in radial segmentation, 22 ; in spiral segmentation, 45-47 ; be- tween isolated cells, 54; between soap-bubbles, 43; between oil- drops, 49 sqq. Suspension of development, at low temperatures, 97, 99, 102, 104. Swelling after shrinkage in hyper- tonic solutions, 124. SUBJECTS 339 Sycandra, 22. Symmetry, bilateral, of egg cytoplasm, 33, 80, 163, 232, 247, 280, 281; radial, of egg, 79, 163, 204, 222, 232, 280; bilateral, and sagittal plane, 80, 229, 235, 244; produced by gravity, 82, 84, 87; radial, of Plutei without sulphate, 144; bi- lateral and first furrow, 167, 229, 235. System, equipotential, 176, 277; in- equipotential, 176, 277. Systems of lamellae, see Lamellae ; of drops, see Drops. Tadpole, tail of, phagocytosis in, 5; absorption of water, 58, 59; rate of growth in, 67; influence of light on, 94; effect of pure oxygen, 113, 114; effect of increased at- mospherie pressure on, 114; brain and eyes removed, 175, 275 ; forma- tion of lens and cornea, 275-277. Tail of Tadpole, phagocytosis in, 5; doubled at high temperatures, 99. Taxis, Tactic, see Stimuli and Re- sponses.. Teleology, of Kant, 286-289 ; dynamic, 291, 296; of Aristotle, 297. Teleostei, nervous system of, 6, 138 ; segmentation, 26, 35; injuries to germ-ring, 178; effect of fertiliza- tion, 251. Tellurium, 144, Teloblast, continued division in same direction, 29; continued unequal division, 30; unequal asters in, 31. Telolecithal eggs, 24, 30. Temperature, as affecting growth, 2, 59; cardinal points, for Frog’s egg, 97; for Hen’s egg, 102; for Plutei, 107; alteration of variability with, 107; high, see Heat; low, see Cold. Tendon, 5 Tension, see Surface-tension, Decom- position-tension. Tentacles, branching of, 6. Teratology, 119, 155, 156. Teredo, 26. Tetrahedral arrangement of cells, 24, 25, 26, 28, 29, 47; of soap- bubbles, 43. Tetrasters, 107; produced by alka- loids, 128. Thalamencephalon, roof of, 7. Thelykaryotic, 267. Theory, ‘ Mosaic’, or self-differentia- tion, 17, 19, 158 ; : analyrieah) of Driesch, 280-286. 340 INDEX OF Thickenings of cell-aggregates, see _ Cells, movements of, Thigh, rate of growth, 70, Thigmotropism, 272, 275-277. Thinnings of cell-aggregates, sce Cells, movements of. Thio-sulphate, 144. a ian. concentric corpuscles of, Toad, 82, 102. Totipotent, parts, 76; see also Whole nuclei, 266, 283, 284, 285. Toxicity, 122, 135, 136. Toxines, bacterial, 132. Toxopneustes, 185, 250. Transportation, by cells, see Cells, movements of. , Trematoda, segmentation, 28. Triasters, 107; produced by alka- loids, 128. Triclads, blastomeres of, 5, 54, 273; segmentation, 28, 55. Tripolar mitosis, 265. Trochoblasts, 213, 220. Trochophore, 224, 225. Trochus, 26, 30, 45-47. Trophoblast of Mammalia, 7; fusion of, with embryonic plate, 9; fused . with somatopleure, 9; coenocytic and. syncytial, 55. Trophochromatin, 258. Tropism, Tropic, see Stimuli and Responses. Trout eggs placed between poles of a magnet, 91; between electrodes, 91; in light of various colours, 95. Truncus arteriosus of Mammals, split- ting of, 6. Tubercle toxine, 132. Tubularia, 114, 144. Tunicata, follicle cells of, 5. Turbellaria, yolk-glands, 5. Turgor of plant-cells, 246. Umbrella, segmentation, 26, 30; flat- tening of blastomeres, 45; parallel polar furrows, 46. Understanding, 301. Unequal division, see Cell-division ; of oil-drops, 52 ; numbers of chro- mosomes, see Chromosomes. Unio, segmentation, 25, 30, 47; un- equal asters, 30; flattening of blas- tomeres, 45; crossed polar furrows, 46. Unipolar, see Immigration. Units, representative of inheritable qualities, 19, 159, 246, 246, 279, 280. SUBJECTS Urea, Frog’s egg, 121; notochordal tissue, 1384; nuclei, 135, Urodela, notochord in, 8, 133, Vacuolation of cells of Spaerechinus, 146, 261. Valency, 136. Variability, decline of, during growth, 71-74; increased at time of puberty, 73; causes of decline, 74; in- creased by an adverse change of conditions, 74, 141, 156; in period, 74. Variation, see Variability. Vasa efferentia, union of, with meso- nephric tubules, 6. Vegetative cells, see Cells. Vegetative pole, blastopore at, 244. Veliger, 217. Ventricosity, of shell of Littorina, 71. Vertebral column, rate of growth, 70. Vertebrates, spleen of, 5; bone and tendon, 5; vitreous body, 5; vasa efferentia, 6; nerve-crest, 11; seg- mental duct, 5; lens, 7; auditory vesicle, 6; limb-buds, 11; me- dulla, 7; artificial parthenogenesis, 124; thalamencephalon, 7; seg- mentation, 22, 24, 47. Viole de Parme, 94, Violet light, 94-96. Vital constant, 291. Vitalism, 291 sqq. Vitellophags, 4, 273 ; vitelline mem- brane, see Membrane. Vitreous body of Vertebrate eye, 6. Volume of partial larvae, 199; of cells, and number of chromosomes, 268; of nucleus, and cell-surface, 269. Waist, rate of growth, 70. Water, absorption of, in growth, 2, 58, 59, 115, 116; in hypotonic solutions, 118; decrease of, in later stages, 58; evaporation of, from albumen, 115; not absorbed by egg of Frog, 123. — withdrawal of, 119; in fertiliza- tion, 123; and artificial partheno- genesis, 123,124; aggregated about apical body and middle-piece of spermatozoon, 123. — fresh, 117, 136; distilled, 136. Weight, increase of, as a measure of growth, 58 sqq.; correlations with other magnitudes, 75; loss of, in Hen’s egg, 115. White plate, in inverted Frog’s eggs, 85, 87. ee INDEX OF SUBJECTS 341 Whole larvae from blastomeres or 29, 48; specific gravity of, 78; egg-fragments, in the Newt, 173; descent of, in inverted eggs, 84; in Teleostei, 178; in Amphioxus, in centrifugalized eggs, 88; in- 180; in Coelenterates, 181; in jured by heat, 97; by cold, 98; by Echinoderms, 193, 197; in Nemer- salts, 119, 135; effect of removal tines, 204, 207. in Teleostei, 178; of Cynthia, 230 ; Withdrawal of water, see Water. -cells of Triclads and Salps, 5; Woman, see Human being. -gland of Turbellaria, 5 ; -lobe, see Worcester, Mass., school-children, Lobe, polar ; -nuclei in centrifuga- growth of, 63. lized Frog’s egg, 30, 88; in eggs grown in salt, 119; -plug persistent as a result of heat, 99; of cold, 100 ; Xylol, 54. in,solutions of salts, &c., 119 sqq. ; -sac ruptured in eggs that are not Yellow light, 94-96. turned, 89; of Fundulus, pigment Yolk, 2; influence of, in cleavage, 24, of, 94, 111, 114, 274. ADDENDA ET CORRIGENDA P. 5, 5 lines from bottom, for unicellular read multicellular. P, 28, line 10, after irregular, insert and in Triclads. P.57. To Literature add J. Sacus. Die Anordnung der Zellen in jiingsten Pflanzentheilen, A7b. Bot. Inst. Wiirzburg, ii, 1882. P. 114. To Literature add G. Buner. Weitere Untersuchungen tiber die Athmung der Wiirmer, Zeitschr. physiol. Chem. xiv, 1890. P. 140, line 22, for prospective potentialities read prospective signifi- cances. P. 225, 2 lines from bottom, for is now placed in read has now moved into, P. 271. To Literature add W. S. Surron. On the morphology of the chromosome group in Brachystola magna, Biol. Bull. iv, 1902. P. 278. To Literature add J. W. Jenkinson. On the effect of certain solutions upon the development of the Frog's egg, Arch. Ent. Mech. xxi, 1906. 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