Subject Index 



589 



Moths, inheritance of sex in, 70, 

 481, 483, 484, 485 

 isolating mechanisms, 523 

 Mouse, body size in, 355, 356 

 coat color of, 278, 323, 336, 355 

 color genes and body size, 356 

 harelip, 35 



isolating mechanisms in, 522 

 pink eye, 356 

 short ear, 356 

 short tail, 36, 37 

 Mule, 388 



Multiple alleles, 27, 28, 90, 92, 103, 

 m, 105, 162, 271 ff., 278, 

 283 fif., 498-501 

 Multiple factors, 346, 353, 357 

 Multivalents and autopoh'ploidy, 



466 

 Mutable genes, 236, 237, 238, 239, 



240, 241 



effect of other genes on, 241, 269 

 Mutations, 225 ff. 

 accumulation of in populations, 



519, 532, 536 

 bud, 234, 235 

 detection of, 249, 250, 251, 252- 



257 

 effect of time of origin, 234 

 effect on viability, 231, 232 

 gene, 227, 230, 235 

 effect of environment on, 240, 



241, 243, 258, 260, 263 

 induction of, 243, 244, 245, 246, 



247, 248, 249-257 

 harmful nature of, 231, 235. 386 

 induced in Drosophila, 243, 244, 



245, 246, 251, 252, 253, 254, 



255, 256, 257 

 induced in Habrobracon, 246, 247, 



253 

 induced in plants, 243, 244, 247, 



248 

 lethal, 231, 250-257, 258, 259, 260, 



261 

 nature of effects of, 230, 231 

 recessive nature of, 232, 233 

 reverse, 239, 245 

 somatic, 233, 235, 374 



Mutations {continued) 



sterility, 232 



time of occurrence, 234, 238 

 Mutation rate, 236 ff., 240 



Natural polyploids, 471 



Natural selection, 235, 236, 264, 386 



Nectarine, 235 



Nemesia strumosa, 35, 113, 116, 117, 



120, 121, 275, 276, 430 

 Neurospora, 314 

 Neutral gene, 342, 346, 371 

 Neutrons, 260, 261 

 Newt, see Triton and Triturus 

 Nicotiana, corolla length in, 275, 



349, 350, 351 

 endosperm in hybrids of, 443, 444 

 flower color in, 275, 353 

 haploids, 437 

 pollen color in, 275 

 self-fertility in, 277 

 self-sterility in, 273, 274, 275 

 Nicotiana alata, 349, 350, 351, 359 

 Nicotiana Langsdorfjii, 349, 350, 351, 



352, 359, 449, 450, 451 

 Nicotiana Sanderae, 108, 112, 113, 



352 

 Nicotiana sylvestris, 459 

 Nicotiana sylvestris X N- tomentosa, 



477 

 Nicotiana sylvestris X N- tomento- 



siformis, 477 

 Nicotiana tabacum, 459 

 Nicotiana tomentosijormis, 459 

 Nightshade chimeras, 478 

 Nonchromosomal inheritance, 540- 



542 

 Nonconjugation, 424 

 Nondisjunction, 423 fif., 498 



somatic, 429, 430 

 Nucleus, 3, 4 



Nuclear membrane, 3 ff., 4> 58 ff. 

 Nuclear sap, 6, 9 

 Nuclear stains, 220, 221 

 Nucleic acid, 76, 77, 220, 221, 222, 



267, 306 

 Nucleolus, 4, 6, 7, 12, 58. 62, 63, 125 

 Nucleolus-organizing region, 216 



