Ameba, 23, 24. Ancestors, number of, 4. Ancestry: a network, 3; dual, 6; in royalty, 5; pride of, as a eugenic agent, 309. Backward child, 256. Backwardness, importance of early determination, 256, 257. Bardeen, 126. Barker, 229. Barr, 246, 247, 248. Barrington, 179. Bateson, 77, 82. Bees, inheritance in, 136, 137. Behavior: lower animals, 197; modifiability of, 200, 204-207, 217, 219, 224, 225, 337; not wholly established by heredity, 217, 227; rational, 205, 206; various forms of, possible, 207, 219. Bell, 152. Bezzola, 170. Billings, 249. Binet-Simon test, 255. Biometry, 16. Birthmarks, 159, 160. Birth-rate: significance of, 302; too low in desirable stocks, 302, 304, 305, 307. Blastomeres, 55. Blastophthoria, 163. Blended inheritance, 87, 92, 93. Blends, mistakes for, 91. Blindness, infantile, 183. Blistering, 113. Body: how built up from germ, 36; duality of, 50. Brachydactylism, 107. Brain: in higher animals, 213; mechanism, maladjustments of, 230. Branthwaite, 180, 292. Breeding, experiments, method of, 14, 15. Brewer, 142. Brieux, 101. Bronner, 266. Brown Sequard, 132, 133. Cabot, 183. Cacogenic strains, 310. Cajal, 209. Cancer, 117, 154. Capsella, 131. Castle, 134. Cataract, presenile, 112. Cattle: horn characters, 79; roan, 81. Cell: a unit of structure, 20; diagram of, 21; structure of, 20, 30. Cell-division: 31; indirect (mitosis), 32; meaning of indirect, 34. Cell-theory, 22. Cellular basis of heredity, 22. Ceni, 174. Centrosome, 31. Cerebral cortex, not functionally homogeneous, 211. Character: defined, 12; dominant, 74; recessive, 74. Characters: contrasted, 69; determiners of, 13, 14; independence of, 69; inheritable and non-inheritable, 121, 122; more than two pairs of, 87; new combinations of, 82, 83, 84; separable, 69; symbols for, 78; two pairs of, 82. Chauvin, 132. Chemotropism, 198. Childbirths, intervals between, 165. Children of the future: ours to determine quality of, 338, 339; and home, 338. Cholera, 152. Chorea: 117; Huntington's, 113-115, 243, 325. Chromatin, 31. Chromosome, 32. Chromosomes: individuality of, 39, 48; determiners in, 94; in germ and body cells, 40; Mendelian factors and, 93; number and appearance, 34, 41; pairs of, 40, 93, 94; significance of, in heredity, 35, 49, 50, 51, 53, 54. Chromotropism, 198. Church, 242. Cleavage, 36. Cleft-palate, 178. Cole, 166. College graduates and birth-rate, 304. Coloboma, 113. Color-blindness, 60-62. Conceptual thought, origin of, 206. Conduct: importance to young of practise, 221, 223; hereditary predisposition and, 218, 337; responsibility for, 195. Congenital traits, 123. Conjugation, 25. Consciousness, 206.