pups. This would be an average yield of only 1-25 per pen. Since 

 the number at a birth is seldom less than 3, and is often from 5 to 7,. 

 it is obvious that such a figure indicates either a large percentage 

 of infertile matings, or very considerable losses among the growing 

 pups. The exact importance of the first factor cannot at present be 

 even roughly estimated, but as regards the second it would appear 

 to be established, upon the independent testimony of many exper- 

 ienced breeders, that' from 40 to 60 per cent of the foxes actually 

 born never reach maturity.- Thie losses thus indicated are largely 

 avoidable, for there are individual ranches where the yield is very 

 much higher than the estimated average. In many it is over 

 2-S, and it appears that it may sometimes even exceed 4. What 

 can be accomplished by some ranches ought not to be impossible 

 to any. It wojuld be hard to say what may be the practical limit 

 of improvement, but if the actual yield be taken as 1-5, and the 

 generally attainable set no higher than 3, it would seem not 

 unreasonable to hope that the revenues of the industry mighty 

 by scientific management, at least be doubled. 



II. Factors Responsible for the Low Rate of Increase. 



The factors responsible for the low average rate of increase 

 are evidently very numerous, and are not always readily deter- 

 minable; but most of them appear to be classifiable under one or 

 other of the following heads: 



1. Infectious Diseases. 



2. Parasites. 



3. Food Poisoning. 



4. Imperfect Nutrition. 



1. infectious diseases. 



Several randies are known to have been visited by distemper 

 within the last few years, and it is suspected that others have 

 suffered without permitting their misfortune to become public. 

 While the loss thus caused to the industry as a whole represents 

 probably but a small fraction of the total' revenue, a single outbreak 

 may spell at least' temporary disaster for the individual. 



It hardly needs to be said that the problem presented by 

 distemper is mainly one of prevention. From this point of view 

 the existing practice of many ranches is certainly capable of 



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