90 MR. R. STAPLES-BRO^A NE ON [Feb. 18, 



variety of pigeon. lu the Black Xun the cere or eye-wattle is 

 blackish as are also the beak and claws, l^o details of the 

 ancestry of the $ Nun were obtained. The variety breeds true to 

 the markings and no self-coloured birds or whites are produced. 



Cross-bred Birds. 



Although this experiment was taken as far as the F. 2 genera- 

 tion, no blue birds were produced. The numbers, however, ai-e 

 small, and it is possible that in further matings they might have 

 appeared. Blacks were raised in F. 2, but for want of sjoace were 

 not tested. Three birds also appeared in F. 2 which resembled 

 the Nun in markings, these are alluded to in Table Y. as " white 

 with a few black feathers." These birds wei-e not bred from. The 

 remaining birds were classed in three divisions as, " blacks with a 

 few white feathers," " mottled, with black in excess," and " mottled, 

 with white in excess." This classification, although useful for 

 purposes of description, is purely arbitrary, and no suggestion is 

 made that the birds differed gametically. It was very noticeable 

 that in the mottled birds the markings of the Nun were present, 

 and in addition black mottling occurred on those parts of the 

 plumage which are white in the Nun. Full descriptions of the 

 cross-bred birds are given in the details of the exj)eriments. 

 There appears to be no correlation between the presence of a shell 

 and the Nun markings. 



Details of the Matings. 

 F. 1 Generation. 



Exp. 34. — Nun $ (no number) x Black Barb c? (no number). 



These birds were mated together for two years and twelve 

 young were produced. All were black with white feathers and in 

 all the black was in excess of the white. Two distinct types of 

 birds, however, were produced. One class consisted of black birds 

 with a few white feathers which appeared usually on the rump, 

 vent, and thighs, and on the neck or breast sometimes in the 

 position of the junction of the white of the breast with the black 

 of the "bib," as described in the Nun pigeon. Seven of the F. 1 

 birds were of this tj^pe. In the other class, of which there were 

 five, the birds presented a more mottled appearance, black how- 

 ever being in excess. The head, bib, and tail Avere always black. 

 The flight-feathers black with the exception of one or two, the 

 rump frequently white. The back and wing-coverts black mottled 

 with some white, the breast and abdomen white mottled with some 

 black feathers. 



F. 2 Generation. 



Exp. 35.~F. 1 Black with few white feathers $ 8 x F. 1 Black 



with few white feathers S 54. 

 Both these birds were raised in Exp. 34 and were of the first 



