Lederbaur, 131. Legal restraint of defectives limited, 331. Lens: displaced, 113; cataract, 112. Leprosy, 152. Leptinotarsa, production of variations in, 125. Linden, Countess von, 129. Linin, 31. Little's disease, 215. Locomotor ataxia, 187. Loeb, 62, 203. Longevity, 120. Lord Morton's mare, 10. Lorenz, 113, 114, 115. Low birth-rate, 308. Lowell, Judge John, 312. Luetin test, 188. Lunborg, 243. MacDougal, 125. Margaret, Mother of Criminals, 270. Marriage: barriers to, 331; inter-racial, 296; medical inspection before, 191. Mast, 203. Maternal impressions, 159-160. Maturation: 39, 41, 43, 44; parallel between egg and sperm-cell, 44, 46. Mechanical skill, 120. Mechanism of heredity, 22, 25, 26, 28, 29, 30, 35, 37, 40-54, 94, 95. Melancholia and crime, 279. Memory: 120, 204; not a complete test of normality, 268, 269. Mendel: 68; work on peas, 82. Mendelian factors and chromosomes: 93; inheritance and man, 97; principles, rediscovery of, 68; ratio, cause of, 71. Mendelism, 67, 69. Mental and nervous defects, 228. Mental defective: defined, 255; disproportionate increase in, 232; numbers married, 231, 232; inefficiency of marriage laws concerning, 315. Mental deficiency: not always inherited, 248; tests for, 254, 255. Mental organization of lower vertebrates, 205. Mental process as neural process, 195. Mental unsoundness, 196. Mentality, inheritance of, 19. Mentally disordered, cost of caring for, 257, 258. Mercier, 279. Merriere's disease, 117. Metazoa, 28. Metz, 41. Mice, 78. Michigan, state report on mentally defective, 234. Migraine, 101. Mind, relation to brain, 195. Mitosis: 32, 33; meaning of, 34, 37. Mjöen, 171. Modifiability of behavior, 200, 204, 205, 207, 217, 219, 224, 225, 337. Mongolians, 248. Moral responsibility, 227. Morgan, C. Lloyd, 146, 211. Morgan, T. H., 59, 66. Moron, 244, 268. Morons and crime, 268. Mosaic, heredity a, 13. Motherhood, safeguarding, 165. Motive, training in, 220. Mott, 150. Mulattoes, 92. Multiple sclerosis, 64, 117. Muscular atrophy: 113; Gower's, 65. Musical ability, 120. Mutations: artificial production of, 125; germinal, 125. Mutilations, non-inheritance of, 134. Myopia, 64. Naegeli, 131. Nam family, 271. Natural selection partly done away with in human society, 292. Near-sightedness, 64. Nervous and mental diseases, 153. Nervous organization, inheritable, 242. Nervous response, in lower organisms, 196. Nervous system: mainly inherited, 210, 216; establishment of pathways in, 210; maladjustments of, 231; special developments in man, 213, 214, 215; units of, 208. Nervous systems of anthropoids, 214. Neural pathways, not all established at birth, 217. Neuritis optica, 65. Neurons, 208.