R. Staples-Browne 149 



Series C. (v. Table III.) 



Exp. 56. Silver, no white $ 43 x Wliite Fantail ^ 23. 

 Exp. 57. „ „ „ X Extracted white ^^ 37. 



Exp. 58. „ „ „ X Extracted white </ 50. 



In the above three matings the same silver % , raised in Exp. 47, 

 was paired to three white birds, the origins of which have already been 

 stated. lu all 11 young were produced. This F^ generation consisted 

 entirely of blue birds chequered with black and having some white 

 feathers. The birds were practically indistinguishable from those pro- 

 duced by the mating of a typical C. livia with a White Fantail in 

 Exp. 52, and corresponded closely to them as regards amount, variation, 

 and distribution of the white feathers. 



In this experiment not only is the factor for chequering introduced 

 by the white, but also the additional factor which when present with 

 silver produces blue. 



Special interest attaches itself to Exp. 58, owing to the fact that 

 the white ^ had given a very aberrant result when previously mated to 

 blues carrying white. These matings have been described in my previous 

 paper on the inheritance of colour in domestic pigeons^ If reference is 

 made to Exps. 19, 20, and 22 it will be noticed that, instead of the 

 expected equality of blue and white birds, young were obtained in 

 proportion of 9 whites to 3 coloured. The suggestion was there made 

 that the inheritance of white might in some cases be sex-limited, and 

 comparable with cinnamon in Canaries and white in some species of 

 Doves. Had this been the case with the pigeon in question we should 

 have expected a certain number of white $ s in the F^ generation from 

 such a mating as the present one. Here, however, the seven birds 

 produced are all coloured. This experiment very strongly suggests that 

 another explanation must be looked for regarding the unconformable 

 numbers produced in the Barb-Fantail raating.s. 



Exp. 59. Silver, no white $ 43 x Blue chequer, some white ^ 116. 



The silver $ is the same bird that was used in the last three 

 experiments. The blue chequer J", raised in Exp. 57, is of the F^ 

 generation. This mating is therefore mother and son. The ^ had 

 white feathers on the head, rump, vent and thighs, one flight feather 



' P. Z. S. 1908, pp. 81—84. 



