370 



INDEX 



ganisms, 266-268; germ cell forma- 

 tion, 273-276; sea urchin, 266-272; 

 fish, 273, 276-278; dogs, 278-279; 

 fowl, 279; hybrid vigor, 281, 291- 



293 

 Hydra, 309 



Identical twins, 198-204 

 Inactivation of genes, 356-359 

 Inbreeding, 312-314, 345 

 Incompatibility, of germ cells and 

 chromosomes, 266-276; of struc- 

 tures and functions, 276-280 

 Inequalities among genes, 289 

 Inferiority, origin, 293, 297-299 

 Infra-Bar, 248 



Inheritance, through X-chromosomes, 

 22-34; sex-linked, 83-103; in man, 

 98, 103; autosomal, 104-122; typi- 

 cal Mendelian, 104; Mendelian, 

 no; tables of results, 113, 117; 

 through Y-chromosome, 122-129; 

 three main types, 129, 206; role of 

 cytoplasm, 169; rules and ratios, 

 206-231; change of method result- 

 ing from chromosome breakage, 

 219; blending, 233; interactions 

 with environment, 232-265 

 Injurious effect of mutations, 355 

 Intelligence quotient, 257-263 

 Interchange of blocks of genes, 326 

 Intermediate characters, 223 

 Intersex, 64 



Inversions,_326, 328, 330-333 

 Irregularities in chromosomes, 315- 



338 

 Ives, P. T., 350, 365 



Jimson weed, 319-322 

 Johnston, O., 354, 365 

 Jollos, v., 348, 349, 350, 358, 364 



Kammerer, P., 251, 265 

 Killough, D. T., 360, 365 

 Komai, T., 257, 265 

 Krafka, J., 249, 265 

 Kupelwieser, H., 267, 268, 281 



Landauer, W., 129 

 Lang, A., 278, 282 

 Lange, J., 202, 205 

 Law, Mendel's, no 

 Lebistes, 126, 129 



Left-handedness, in twins, 201, 255 

 Lethals, 100, 175-176; lethal muta- 

 tions, 356 

 Li, Ju Chi, 36 



Light, reaction to, 100 



Lillie, F. R., 73, 82 



Linear arrangement of genes, 146-160 



Linkage, 165-168; linkage groups, 

 168-177; number, 171, 173; relation 

 to chromosomes, 171-174; ratios, 

 212-217; result of breakage, 333 



Locus of gene, 160 



Loeb, J., 266, 281 



Lophius, sex ratio, 76 



Lygaeus, chromosomes, 19 



MacDowell, E. C, 229 



Maize, chromosome maps, 162; link- 

 age groups, 174; characters influ- 

 enced by genes and environment, 

 245-247; unstable mutations, 353 



Man, chromosomes, 57; sex ratio, 76; 

 sex-linked characters, 98; heredity 

 in, 103 ; inheritance through Y, 128; 

 linkage groups, 174; characters af- 

 fected by genes, 197-204, 252, 253; 

 identical twins, 199 ; mental char- 

 acteristics, 201-204, 254-265; moral 

 characteristics, 202; race crossing, 

 280; constitution of population, 

 298; production of superior and in- 

 ferior individuals, 292-299; family 

 relationships, 299-301 



Maps of chromosomes, 160-162 



Materials of heredity, 3, 5-34, 37; 

 discovery, 6; in germ cells, 45; re- 

 lation to cytoplasm, 164 



Maturation, 47, 53 



Meiosis, 47 



Melandrium, 128 



Mendel, G., 106, 109, 129; law of, no 



Mendelian heredity, 109, 114 



Mendelian inheritance, 104, 106, 109, 

 129; tables of results, 113, 117, 122 



Mendelian ratios or rules, 109, 113, 

 117, 122, 206-231 



Mendelism, 122 



Menidia, 44, 273 



Mental age, 257 



Mental characteristics, 197, 254-265 



Metz, C. W., 337 



Mirror-imaging, in twins, 256 



Mitosis, 9, 41 



Modifying factors, 186 



Moenkhaus, W. J., 44, 273, 281 



Mohr, O. L., 355 



Moisture, effect on inherited charac- 

 ter, 243 



Mollusk-sea urchin hybrids, 267 



Monozygotic twins, 198 



Moral characteristics, 202 



