22 COMMISSION OF CONSERVATION 



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



Reanng Silver 



Foxes from Reds ants 01 red loxes 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 experiment will prove what quality will be obtained in the 

 silver young of a red parent.* The results noted in this investigation 

 indicate that some of the best skins ever produced are those of silvers 

 having a red parent. There was difficulty in obtaining information on 

 this important point as breeders were extremely reticent in giving in- 

 formation concerning their experiences in cross-breeding with reds, 

 because of a great prejudice against such breeding on Prince Edward 

 Island. The prejudice, no doubt, resoilts from an ignorance of Mende- 

 lian principles in segregating types. 



It is interesting to note that Eev. G-eorge Clark, of St. Catharines, 

 Ont., has in his possession a black dog fox obtained from near York 

 Factory, Hudson Bay, which, he asserts, has sired none but silver pups, 

 when mated with any vixen. Of course, the five or six litters sired by 

 one dog does not provide sufficient data from which to form a general 

 conclusion. It may be that many of the thousand or more red foxes kept 

 in captivity will yet be crossed so as to produce a proportion of silver 

 stock. As the red foxes were generally purchased from districts which 

 produce very ordinary pelts, it is quite probable that, in many cases, the 

 resulting silver will not be of good quality. The climatic conditions of 

 Canada, however, which are very favourable to the production of good 

 pelts, may improve exotic sub-species. 



Breeders are generally better pleased if cross foxes are 

 as Breeders produced the first generation, but, as a rule, if cross foxes 



are bred out, the tendency to produce an occasional red 

 pup will never be wholly eliminated. Having cross foxes in the ancestry 

 of silver foxes means that a proportion of red gametes are thrown and 



* Professor Castle, replying to an inquiry, says: 



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

 assuma 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, ex- 

 periment 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." 



