440 



AN INTRODUCTION TO MODERN GENETICS 



Polydactyly 203 

 polymorphism 162 

 polyploids 64 



analysis 257 



animals 254 



association 70 



auto- and alio- 67 



fertility 70, 72 



induced 255 



pairing 69, 71 



secondary 74, 261 



species 254 

 polysomics 66 

 population size 295 

 position effects 371, 373, 399 

 potato 250, 322, 323 

 precocity theory 115, 231 

 preformation 370 

 presence and absence 368 

 Primula kewensis 72, 256, 322 



sinensis 71, 72, 107, 159 

 prochromosomes 39 

 progeny performance tests 312 

 protective coloration 300 

 proteins 365, 392, 393 

 Protozoa 59 

 pseudo-chiasmata 1 16 

 pseudo-dominance 83 

 pesudogamy 60 

 pure lines 314 



quantitative characters 160 



rabbits 175, 200, 270, 318 

 races, crossing 346 



human 340 



local 2i6j 225, 271, 279 



plants 274 



senescence 245 

 radiation, and mutation 383 



ultra-violet 384, 386, 392, 395 

 radish-cabbage hybrid 63, 170, 256 

 random extinction 293, 295 

 random mating 327 

 ratios, dihybrid 161 

 rats, learning 305 



inbreeding 319 



selection 313 

 realizers 191, 215, 223, 235 

 rearrangements, formation 94, 390 



induced 389 



small 267, 375j 39© 

 recapitulation 242, 246, 296 



recombination 48, 230 

 reduction of organs 297 

 reproduction, of gene 399 



types of 58 

 reproductive rate 287, 351 

 ring, formation iii, 268 



bivalents 109 



chromosomes 86 

 rodents, colours 179, 270 

 roses 59, 261 

 rust 322 



segmental interchange 109, 267 seq. 

 segregation, chromatid 71, 103 



in polyploids 68 seq. 



intrisomics 84 

 selection, maize 310, 317 



mass 310 



natural q.v. 



in pure lines 315 



rats 313 

 selective advantage 287, 301 

 sex determination, see particular 

 groups 



environmental 224, 226 



progamic 230 

 sex chromosomes 75 seq. 

 sex differential 77, 222, 223, 235 

 sex-limited inheritance 79, 331 

 sex-linkage 79, 331 



partial 80, 332 

 sex substances 227, 218 

 sexuality, gamophase 212 



gamete 208, 226 



meaning 207, 234, 236 



multipolar 214, 235 



relative 210 



theory 232 



zygophase 215 

 sheep 319 

 shift 72 

 sizes 377, 399 

 Solanum 64, 84, 87, 255 

 Spartina Townsendii 261 

 species, artificial 254 seq., 262, 268 



centres of origin 250 



differences 263 seq. 



divergence 284 



evolutionary types 253 



initiation 282 



polyploid 254 seq. 



sudden origin 248 



variable 263 



