136 Expejnjneiital Zoology 



These and other experiments with pigeons show that the results 

 are more comphcated than in the case of fowls. It is not possi- 

 ble to bring the results under a single point of view at present. 

 Ewart's experiments^ with pigeons indicate that w^hile certain 

 kinds of crosses may give rise to offspring resembling the Rock 

 Pigeon, yet in other cases a more immediate ancestral color may 

 come out. A dark blue Fantail, having all the characteristic bars 

 of the Rock Pigeon, was bred to a less pure blue Fantail. On 

 two occasions an absolutely pure white Fantail was produced. 

 This result, Ewart thinks, is due to a reversion to a white grand- 

 parent. Ewart also crossed a white Fantail with a white Pouter. 

 The offspring was white in color, but in form resembled the 

 Pouter. A hybrid between an "archangel" and an "owl" was 

 bred to a white Fantail. The two offspring were blue, one of 

 them being almost identical with the wild Rock Pigeon, more es- 

 pecially with the Indian variety. Not only w^as there reversion 

 in color, but in form as well. 



Ewart seems to think that reversion amongst closely inbred 

 races of dogs, horses, and pigeons leads to a sort of rejuvenes- 

 cence of the stock. Those individuals showing the ancestral 

 characters prove to be stronger and more active. 



The reversion to the type of the Rock Pigeon, that seems to play 

 often so conspicuous a role in these experiments with pigeons, 

 recalls the return to the gray color in mice when fancy breeds 

 are crossed, but in the second generation of mice there is a re- 

 turn in some of the forms to the parent types. How far this 

 occurs in pigeons is not clear from the evidence at hand. 



A brief but important note in alternate inheritance in pigeons 

 is given by Staples- Browne. Webfoot sometimes suddenly 

 appears in pigeons. A pigeon of this sort crossed with another 

 having normal feet produced six normal-footed offspring. These 

 individuals (i^i), inbred, produced in one case nine with normal 

 feet and three with webbed feet. Another pair (F^), however, 

 produced seventeen normal birds. Extracted web-footed 

 individuals produced six web-footed. It appears that the latter 

 condition is recessive to normal feet. 



^ The Penycuik Experiments. 



