BATESON AND PUNNETT 



51 



s., thus dispensing with the concep- 

 tions of compound allelomorphs and 

 synthesis. 



During the past two years we have 

 tested a considerable number of r.p. 

 combs, with the result that each of the 

 4 types has been met with over and 

 over again. Speaking generally, this 

 form of comb exhibits much variation 

 in size, shape, and amount of the spe- 

 cial feathering on its posterior surface, 

 though hitherto we have been unable 

 to establish any connection between 

 such variations and the gametic output 

 of individuals in which they occur. 

 We may now consider in rather more 

 detail the matings in which the various 

 types of r.p. combs are concerned. 



Pi/re r.p. (zygotic constitution R.P. 

 R.P.).— This type has occurred in 2 

 Malay bantam hens (Experiments 242, 

 268, 284) and in a black-red Malay 6 

 (Experiment 351) all purchased. It has 

 also occurred in Fo from an original 

 cross of r. X p. (Experiments 255, 256, 

 333, 383). Further, we have one case 

 (Experiment 366) where it was formed 

 from 2 r.p. birds which were produced 

 by the mating of r.p. /p. with single. 

 Since every bird with an r.p. comb 

 must give off some gametes at any rate 

 containing both R. and P., we mav% of 

 course, expect some pure r.p. birds to 

 be produced by the mating of any 2 

 birds with this forrh of comb. In all 



the above experiments r.p. combs alone 

 resulted from the union of the pure 

 r.p. bird with a single. 



Co7ubs r.p. X p- (zygotic constitu- 

 tion R.P. P. no R.).— {'Cf. Experiments 

 196 to 197, 239, 271, 278, 287, 305, 314, 

 328, 336, 355, 357 to 358, 385, 387 to 

 388, 390, 391.) 



The birds tested in Experiments 196 

 to 197, 239, and 287 were Malays with 

 natural r.p. combs. The rest were pro- 

 duced artificially in Fo from original 

 matings r. X p., r-s. X p-s., or r.p. X s. 

 On mating with singles this type of r.p. 

 comb gave in all 285 r.p. and 296 peas, 

 the expectation, of course, being equal- 

 ity. 



Coiubs r.p. X f- (zygotic constitu- 

 tion R.P.R. no P.).— ('Cf. Experiments 

 233, 283, 297, 316, 338 to 339, 360, 371 

 to 372.) 



The bird tested in Experiment 283 

 was a 6 Malay bantam, whilst those in 

 Experiments 233 and 316 were Malay 

 9 s. The rest were artificially pro- 

 duced. Altogether 289 birds were 

 produced, of which 149 had r.p. and 

 140 rose-combs, expectation as in the 

 last case being equality. 



Combs giving all 4 with Si?igle 

 (zygotic constitution R. no P. P. no 

 R).~(Cf. Experiments 208, 212 to 

 214, 217 to 218, 232, 234, 236, 238, 240 

 to 241, 243, 249, 251 to 252, 260 to 262, 

 272, 275, 277, 298, 300, 302 to 303, 306 



