v. Dungern, 80

Duration of life, 360 ff.

Durham, 249

Dutrochet, 154

Dzierzon, 208

Ectoderm formation, 130 ff.

Egg, as the future embryo, 8, 9, 70, 126, 151; artificial parthenogenesis of, 95 ff.; organisms from, 128 ff.; determining unity of organism, 151-152; chromosomes in, 198 ff.

Egg structure, 129 ff.; influence of centrifugal force on, 135; and regulation, 139, 140, 141; and fluidity of protoplasm, 141

Ehrlich, 45, 322, 332 ff., 341; side-chain theory of, 88, 188

Eigenmann, 320, 323 ff.

Electromotive forces, origin in living organs, 140

Engelmann, 357

Engler, 24

Entelechy, 4, 170, 182

Environment, influence of, 286 ff.; temperature, 288 ff., 344 ff.; salinity, 306; adaptation to, 319

Enzyme action, 23 ff., 297, 302

Ernst, A., 21

Eternity of life, 34 ff., 360

_Eudendrium_, 260, 261, 269, 277, 278, 326

_Eudorina_, 277

_Euglena_, 264, 269, 272, 277

Euler, H., 21

Evolution, 346 ff.; and mutation, 348

Ewald, W. F., 261 ff., 269, 280, 301

Farmer, J. B., 347

Fermi, 350, 354

Fertilization, heterogeneous, 48 ff., 51, 73 ff.; specificity in, 71 ff.; and oxidation, 117 ff.; and permeability, 119 ff.

“Fertilizin,” 84, 87 ff., 93

Fischel, 187

Fischer, 303 ff.

Fish, 55

Fitness of environment, 317

Fitzgerald, J. G., 63

Flow of substances and regeneration in _Bryophyllum_, 161 ff.

Fluctuating variations, 6, 297 ff., 346 ff.

Folin, 22

Food, influence on polymorphism in wasps, 222 ff.

Food castration, 224; influence on sexual cycle in rotifers, 224; on metamorphosis in tadpoles, 155

Ford, 63

Forssmann, 63

Frédéricq, 351

Free-martin, cause of sterility, 218-219

Friedenthal, H., 53 ff., 60

Frisch, K., 278, 279

Fröschel, P., 263

Fuchs, H. M., 90

_Fucus_, 123

_Fundulus heteroclitus_, 51, 116, 147, 300, 301, 302, 307 ff., 321 ff., 328 ff., 335, 337, 357 ff.

Galileo, 346

Galvanotropism, 11, 270 ff., 319

Gay, F. P., 62 ff.

Generation, spontaneous, 14 ff., 34

Genes, 4 ff., 152, 319

Genus and species, chemical basis of, 40 ff.

Geppert, 358

Germination in seeds, 35 ff.

Giard, 180, 216 ff.

Godlewski, E., 48, 75, 78, 120, 126, 169

Godlewski, E., Sr., 18

Goebel, K., 154, 161

Goldfarb, A. J., 326

Goldschmidt, R., 220 ff.

Goodale, H. D., 218

Gortner, R., 249

Graber, V., 256, 276

Grafting, heteroplastic, in animals, 46; in plants, 47

Gravitation, influence on organ formation in _Antennularia_, 194 ff.; on the egg of the frog, 141

Gray, J., 122

Gregory, 243

Groom, T. T., 280

Growth, termination of, 184; influence of cell size, 187

Gudernatsch, J. F., 155, 255, 342

Guyer, 124

Gynandromorphism, 209

Haeckel, 346

Half-embryos and whole embryos, 141, 142

Hammond, J. H., Jr., 269

Harden, 16

Hardesty, 358

Harmonious character of organism, 5, 6, 318 ff., 341 ff.

Harrison, 31

Hartley, 111

Healing of wound, 187

Hektoen, 66

Heliotropism, 11 ff., 257 ff., 318; heredity of, 250 ff.; change of, 279, 280 ff.; and adaptation, 318

Helmholtz, 34

Hemoglobins, crystallographic measurements of, 64 ff.

Henderson, L., 317

Henking, 198 ff.

Herbst, C., 97, 147, 193, 306, 310

Heredity, of genus and species, 40 ff., 70, 151, 152; Mendelian, 70, 151 ff., 229 ff., 348; of sex, 198; sex-linked, 203 ff., 238 ff.; and evolution, 348

Herlant, M., 78 ff., 115 ff.

Hermaphroditism, 89 ff., 212 ff., 216, 219 ff. _See also_ Inhibition _and_ Regeneration.

Hertwig, O., 97, 123, 292

Hertwig, R., 95, 97

Hess, C., 278

Heterogeneous hybrids, purely maternal, 49, 50

Heterogeneous transplantation, Murphy’s experiments on, 44 ff.; limitation of, 46

Heteromorphosis, 155, 193-196

Hill, C., 25

_Hippiscus_, 199

Holmes, S. J., 269

Hoppe-Seyler, 351

Hormones, 145, 155, 181, 219; and Mendelian heredity, 245 ff., 348; and adaptation, 342. _See also_ Organ-forming substances.

Huxley, 346

Hybridization, heterogeneous, in sea urchins, 48 ff., 73 ff.; in fishes, 51; in plants (Mendel’s), 230 ff.

Hydrolytic enzymes, action of, 24; reversible action of, 24 ff.

Hypertonic solution, 99, 111 ff.

Imitation of cell structures by colloids, 39

Immortality, of cancer cells, 30; of somatic cells, 30 ff.; of life in general, 34 ff.

Inheritance, of colour-blindness, 203, 204, 205; of eye pigment in _Drosophila_, 204 ff.; of pigments, 248 ff.; of acquired characters, 337 ff.

Inhibition of regeneration in _Bryophyllum_, 162 ff.

Inhibition of sexual characters of opposite sex, in pheasants, 218; lack of in hermaphrodites, 219; in _Bonellia_, 226

Instincts, 10 ff., 253 ff.; sexual, 198 ff.

Intersexualism, 221

Intestine, formation of, 130 ff.

Isoagglutinins, 66 ff., 92

Isolation of blastomeres, 136 ff.

Jacoby, 352

Janda, V., 219 ff.

Jansky, 67

Janssens, 242

Jennings, H. S., 264 ff.

Jensen, 45

Joest, 46

Johannsen, W., 42, 333

Jones, 352

Jost, 90

Kammerer, P., 325, 337 ff.

Kanitz, A., 290, 292, 296

Kastle, J. H., 26 ff.

Kellogg, V. L., 279

Kelvin, 34

King, W. O. R., 50, 247

Klug, 351

v. Knaffl, E., 106

Knowlton, E. P., 292

Kofoid, C. A., 143