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22   COMMISSION OF CONSERVATION

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

Rearing Silver   ants of red foxes are rusty black in colour and are
Foxes from Reds

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 prole 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, results from an ignorance of Mendelian principles in segregating types.

It is interesting to note that Rev. George 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

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

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 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 Fl 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 Fl could be secured, it is evident that silver foxes could be produced much more readily."


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