28 BULLETIX 301, U. S. DEPARTMENT OF AGRICULTURE. 
are probably individual, occurring in about the same proportion 
everywhere, and while of secondary importance, in the long run 
they are sure to be favorable to success in fox farming. Already 
prolific pairs bring much higher prices than those which have thrown 
small litters or have not been tested. Inasmuch as one of the main 
causes of loss among young cubs is the timidity and nervousness of 
vixens, the development of more docile strains will result in corre- 
sponding increase in the birth rate. Some male foxes are much better 
mates and sires than others. In selecting breeders the temperament 
of males as well as of vixens should be considered. The physical 
development and potency of males are also essential factors. Young 
males that are not strong, or not well developed when six months old 
are not likely to be of use in the breeding yards the first year, and 
should not be selected for sires. 
Food is recognized as a very important element in the development 
of good animals. The finest specimens of domestic cattle are those 
which have been fed most wisely. As regards foxes, much remains 
to be learned concerning the effects of different rations upon such 
matters as potency, character of fur, and rate and limits of growth. 
It should be a part of every breeders plan to discover what he can 
about the relative values of foods and methods of handling as influenc- 
ing the process of selective breeding. Ultimate success or failure in fox 
farming depends largely upon the aspirations of those engaged in it. 
If breeders earnestly, consistently, and indefatigably endeavor to 
improve their stock and to produce pelts that are larger, softer, and 
more uniformly colored than the usual run, there can be no question 
as to the result. There will never come a time when an extra fine 
silver fox pelt will not command a good price, or when a breed pro- 
ducing such pelts will not be in demand. 
ACCESSORIES. 
Contentment and vigor of the animals within a ranch is of the 
utmost importance. Whatever contributes toward increasing these 
qualities should be incorporated if possible. It is well to test young 
foxes with such toys as a ball, a tin can, or a piece of woolen cloth, 
with a view to amusing them and exciting a spirit of playfulness. 
A variety of objects in which they can hide and upon which they can 
mount for a survey of their surroundings, as hollow logs, stumps, 
brush piles, or open barrels, is desirable. 
While the suggestions given under this heading apply primarily to 
those having large capital invested in fox farming, they will also be 
found helpful to those operating on a small scale. The present value 
of silver foxes is so great that every precaution is taken to prevent 
accidents, sickness, or other misfortunes. Watchmen are kept on 
