1908,] INHERITANCE OF COLOUR IN PIGEONS. 81 



Series B. 



The Crossbreds mated to Whites. 

 F. 1 X lohite. 



Exp. 12.— F. 1 Black w. f. $ 63 x "White Fantail S 32. 



The 5 63 was raised in Exp. 1 and is the same bird used in 

 Exps. 3, 5, and 39. In this experiment only two young were 

 raised, both black with white feathers. One (46) had only a few 

 white feathers on the rump, vent, and thiafhs ; the other (47) had 

 in addition to this a few on the head and neck and a few wing- 

 and tail-feathers white. Had this experiment been continued 

 whites would undoubtedly have appeared. 



Blues of F. 2, F. 3, and F. 4 mated to whites. 



Experiments 13 to 23 (see Table II.) show the results of mating 

 the blue birds raised in the foregoing experiments to whites. 

 Some of the whites used were pure Fantails, but the resiilts were 

 apparently the same when " extracted " whites were used (Exps. 

 19, 20, 21, 22). 



Exps. 13, 14, and 15 show the result of mating homozygous 

 blues with whites — 24 young were raised in these three experi- 

 ments, all blue with some white feathers. 



Exps. 16-23 show the results of mating blues containing white 

 to whites. In all 41 young were raised, of which 13 were blue 

 with white feathers and 28 were white. The expected results 

 from these matings were blues (with white feathers) and whites 

 in equal numbers. The irregular numbers are discussed in detail 

 immediately after the descriptions of the experiments fi'om which 

 they were obtained. 



Details of Exps. 13 — 23. 



Exp. 13.— White Fantail 2 25 x F. 2 Blue (with 2 white 

 feathers) c? 19. 



The S has already been described among the blue birds of the 

 F. 2 generation as being of a darker colour than usual, and having 

 two white feathers which were subsequently moulted out. Twelve 

 offspring were reared all blue with some white feathers. The 

 blue colour varied slightly, in some it was of a darker shade than 

 in the father, and in all was darker than in birds raised in the 

 other experiments. The amount of white also varied from a bird 

 having only a few white feathers on the rump, vent, and thighs, 

 to one having white on the head, neck, breast, rump, abdomen, 

 vent, and thighs, as well as several wing-feathers, 10 tail-feathers, 

 and some under tail-coverts. The average amount of white was 

 about midway between these two extremes. 



Exp. 14.— F. 3 Blue $ 98 x White Fantail S 46. 



Exp. 15.— F. 2 Blue 2 120 x White Fantail S 26. 



The two $ birds were raised in Exp. 9. No white feathers 

 were seen. Twelve offspring were raised all blue with white 

 feathers. The blue colour was uniform throughout. In some 

 cases the sooty colour of the wing- coverts was to a slight extent 



Proc. Zool. Soc— 1908, No. VI. 6 



