=Galton, Francis=, theory of heredity (stirp), 2; and Weismann’s, 51, 58-59, 69, 73, 92, 105-106, 108, 115, 129, 130 _et seq._; on gemmules, 60; on inheritance of acquired characters, 62, 69, 107; and stability of the material basis of heredity, 63; on origin of sexual reproduction, 103, 167. =Gärtner=, on Malva, 80; on inheritance of acquired characters in plants, 93. Gemmules, 2; Darwin on the size of, 4; and germ-plasm, 52, 55, 58, 92, 105; and stirp, 58; Galton on, 60. Generative cells of the Hydromedusae, Weismann on, 71, 109; example of continuity of germ-plasm, 72-73. Germ-cells, and body-cells, 29, 75-77; nucleo-plasm of, 30; number of, 43, 45. Germ-plasm, Weismann’s theory of, 5, 105, 173 _et seq._; immortality of, 9, 24; continuity of, 9, 18, 49, 56-67, 69-70, 72, 75, 78, 86-87, 104-105, 109-110, 114, 120, 168; differences in, 12; origin of, 17; independence of, 19; and natural selection, 21; stability of, 22, 49, 57, 66, 86-89, 91-93, 99-100, 104-105, 109, 112-114, 151 _et seq._; lodged in nucleus, 29; and somato-plasm, 29, 81, 110; the modification of, 36; examination of Weismann’s theory of, 48; Weismann’s theory of and Pangenesis, 52; and gemmules, 52, 55, 58, 105-106, 121; multiplication of in the general cellular tissues of plants, 53; De Vries on, 54; Differentiation of, 55; and “formative material,” 56; and stirp, 58-59, 61, 75, 106; and somatic-idioplasm, 69; as a basis of heredity, 70; ancestral germ-plasm, 123. Grafting, and the effect of the somatic-tissues on the germinal elements, 81-82; Darwin on, 83; and bud-variation, 98; Weismann on, 126. H. =Häckel=, theory of heredity, 2. =Hartog, Prof. M.=, on Weismann, 155; on sexual propagation, 166-167. Healing of wounds, 34. =Henslow, Rev. G.=, on regeneration in plants, 53. Heredity, various theories of, 2, 49, 70; statement of Weismann’s theory of, 17; modification of Weismann’s theory of, 28, 46, 52, 65, 68, 75, 163 _et seq._; the nucleus and, 29; “carriers of,” 32, 38, 70, 78, 122; theory of and histology, 38; examination of Weismann’s theory of, 48, 105, 117; comparison of Weismann’s, Darwin’s, and Galton’s theories of, 51, 105-106; criticism of Weismann’s theory of by Strasburger, 51; the material basis of, 61, 63. =Hertwig, O.=, theory of heredity, 2; on polar bodies, 46, 125. =Hildebrand=, or effect of pollen upon somatic tissues (Xenia), 80; on Orchideae, 80. =His=, theory of heredity, 2. =Hoffmann=, on the inheritance of acquired characters, 93-4, 114. Hydromedusae, Weismann on generative cells of, 71, 109; illustrate continuity of germ-plasm, 73-73. I. Identical twins, 41.