BLASTOGENIC VARIATIONS. 141 



rived from the Spot, and was of a paler blue than in the 

 rock-pigeon, as was the stomach. So that two black 

 Barbs, a red Spot, and a white Fantail, as the four 

 purely-bred grandparents, produced a bird exhibiting 

 the general blue colour, together with every character- 

 istic mark, the wild Columba livia" 



Professor J. C. Ewart, in the breeding experiments 

 he has recently been carrying out at Penycuik,* has ob- 

 tained an equally striking case of reversion in the case 

 of the pigeon. He crossed a pure white Fantail cock 

 with the offspring of an Owl and an Archangel. One 

 of the young of this complex pair had the colouration 

 of the Shetland rock-pigeon, whilst the other resembled 

 the Indian rock-pigeon in having a blue croup and the 

 front part of the wings chequered. In this second bird 

 there was complete reversion as to colour, and in the 

 first, wherever measurements were possible, there was 

 practically complete reversion also as to form. The 

 tail feathers were twelve in number and showed but 

 the faintest indications of any colour inheritance from 



*j 



their immediate parents. An additional point of 

 interest lay in the fact that in disposition the bird 

 seemed wilder and more shy than the domestic breeds 

 usually are. 



Many other instances might be quoted from Darwin 

 and others to prove that this tendency to the production 

 of offspring of a blue colour, with the same charac- 

 teristic marks as Columba livia, is present in all the 

 chief domestic races of pigeon. It shows itself more 

 especially when these domestic races are crossed, but 

 may even appear occasionally in the purely bred races, 

 * " The Penycuik Experiments," Edinburgh, 1899. 



