26 



COMMISSION OF CONSERVATION 



R.B. 



Producing half red and half 

 black gametes 



R.B. 



R.B. 



R.B. 



Producing half red and half 

 black gametes 



+ R.B. 



Producing half red and half 

 black gametes 



R.B. B.B. 



I- B.B. 



Producing only black 

 gametes 



R.B. 



R.B. 



B.B. 



B.B. 



It will be noticed that wheii the black colour (B.B) appears the 

 animal is always pure, while, R.R. is pure red and R.B. is also red 

 with darker points. 



It is well to bring out clearly the average results to be expected, 

 as considerable speculation is indulged in as to whether or not certain 

 foxes when bred to a silver wUl produce some silver pups. As much 

 as $500.00 each has been paid for red pups that have one silver parent, 

 because it is expected that, if the pup is mated to a silver, the result- 

 ing litter will be composed of silver and red foxes in about equal numbers. 

 The hopes are realized in most instances; but many chances of securing 

 silver pups are lost because the breeder gets only red pups the first 

 generation and becomes discouraged. 



There, is a wide-spread belief that the silver descend- 

 Foxes'f^om Reds ^^*^ °^ ^®*^ foxes are rusty black in colour and are 



not as pure a type as those bred pure for generations 

 in the fox ranches. Professor W. E. Castle, of Harvard University, 

 says that only experiments will prove what quality will be obtained 

 in the sUver young of a red parent.* The results noted in this investi- 



* Professor Castle, replying to an inquiry, says: 



" The several facts stated in your letter of November 14th, 1912, which I assume 

 you have sufficiently verified, show clearly that black (or silver) coat character 

 in foxes is a Mendelian recessive in relation to the common red coat and may be 

 recovered in the second generation from a cross with red. Whether it would be 

 improved or deteriorated as a consequence, experiment alone could show. I should 

 think that the 'patch' or 'cross' foxes occasionally obtained in the F, generation 

 might be well worth experimenting with, as indicating in that particular strain a 

 tendency for the dominance to be reversed. If this tendency could be strengthened 

 by judicious selection, a more potent strain of silvers might result. If, by this 

 means, a strain potent enough to dominate F, could be secured, it is evident that 

 silver foxes could be produced much more readily." 



