lar below its possible maximum. The fundamental problem of 

 the fox farmer, as of every breeder of animals, is one of nutrition ; 

 and it is the failure fully to solve this problem that occasions at 

 present the most serious losses to the industry. 



If a fox, or any other animal, is to be maintained through 

 life in perfect nutritive condition, its diet must conform to each 

 and all of the following requirements. (1) It must furnish protein 

 (flesh-building food) in such quantity and also of ^uch quality as 

 will make good the wear and- tear of the body tissues, and provide, 

 in young annuals, material for growth. (2) It must have an 

 adequate fuel value or energy content (commonly measured in 

 heat units or calories), a requirement best met by supplementing 

 the necessary protein with carbohydrates (starchy foods) and fats. 

 (3) It must contain proper amounts of certain indispensable ' 

 mineral elements, such as phosphorus, calcium (lime), iron, and 

 the like. (4) It must include a sufficient supply of the so-called 

 vitamines, essential accessories of unknown nature, the absence 

 of which leads to various types of disordered nutrition, and of 

 which there are believed to exist at least three, (the "fat-soluble 

 the "water-soluble", and the "antiscorbutic"). 



To what degree these requirements are met, or fallen short of, 

 in one fox ranch or another, it is not at present possible to decide. 

 It is of course easy enough to obtain a list of the articles that make 

 up the foxes' menu; but to ascertain, item by item,, the actual 

 food consumption of the individual animal, (which is what really 

 counts), is quite another matter. Such information, as it has 

 hitherto been possible to collect, touches merely the qualitative 

 aspect of the problem. Any attempt, therefore, here i made to 

 correlate the nutritional disorders reported with specific defects 

 of diet is to be regarded as purely preliminary in character. 



The most striking feature of feeding practice, as it has come 

 under my observation, is its lack of uniformity. Each ranch 

 seems to have worked out more or less independently an individual 

 plan, and, so long as this operates with even moderate success, 

 it fears to risk a change. Failure and success alike have been 

 largely the result of chance. The diets in use have in short been 

 developed largely at haphazard, and, generally speaking, with 

 few guiding principles other than the supposed habits of the wild 

 fox. It is assumed, rightly or wrongly, that the latter lives almost 



6 



