Flow of substances and regeneration in _Bryophyllum_, 161 ff.
Fluctuating variations, 6, 297 ff., 346 ff.
Food, influence on polymorphism in wasps, 222 ff.
Food castration, 224; influence on sexual cycle in rotifers, 224; on metamorphosis in tadpoles, 155
_Fundulus heteroclitus_, 51, 116, 147, 300, 301, 302, 307 ff., 321 ff., 328 ff., 335, 337, 357 ff.
Genus and species, chemical basis of, 40 ff.
Grafting, heteroplastic, in animals, 46; in plants, 47
Gravitation, influence on organ formation in _Antennularia_, 194 ff.; on the egg of the frog, 141
Growth, termination of, 184; influence of cell size, 187
Harmonious character of organism, 5, 6, 318 ff., 341 ff.
Heliotropism, 11 ff., 257 ff., 318; heredity of, 250 ff.; change of, 279, 280 ff.; and adaptation, 318
Hemoglobins, crystallographic measurements of, 64 ff.
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
Hermaphroditism, 89 ff., 212 ff., 216, 219 ff. _See also_ Inhibition _and_ Regeneration.
Heterogeneous hybrids, purely maternal, 49, 50
Heterogeneous transplantation, Murphy's experiments on, 44 ff.; limitation of, 46
Hormones, 145, 155, 181, 219; and Mendelian heredity, 245 ff., 348; and adaptation, 342. _See also_ Organ-forming substances.
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.
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.
Lack of oxygen, influence on disintegration of tissue, 355 ff.
Light, influence on organ formation, in cave animals, 319 ff.; in _Proteus_, 325; in _Eudendrium_, 326. _See also_ Heliotropism.
Lillie, F. R., 80, 82 ff., 87 ff., 93, 134, 191, 218, 292