accurate data upon the composition of vixen's milk, not only in 

 regard to organic but also inorganic constituents. The immediate 

 need of such data should not be forgotten in any experimeijital 

 work which may be planned in the future. 



The dietary imperfections, to the probable existence of which 

 attention has been drawn, are likely to be most conspicuous during 

 the winter season. The reason for thinking so is thatonilk-is never 

 included in the diet until after the pups are born in the early 

 spring. This situation is the more unfortunate since a diet of 

 meat and cereals alone furnishes a particularly poor provision for 

 the requirements of pregnancy and lactation. If the practical 

 difficulties that have hitherto excluded milk from the diet of the 

 pregnant female cannot be overcome, other sources of calcium 

 and of the fat-soluble accessory become an absolute necessity. 

 Eggs (with the shell) would provide both, bone-meal might be 

 useful in supplying the former, and the latter could be derived 

 from the liberal use of liver, tripe and other glandular materials. 

 Many of the most successful ranchers have been led by experience 

 to include one or more of these articles of diet in their winter 

 regime. In others the situation is perhaps saved to some extent 

 by the use of cod-liver oil biscuits. 



Reference has been made to the possibility of a deficiency of 

 calcium in the diet of the foxes. The other inorganic constituents 

 of the food also demand attention. Many caretakers appear to 

 be very much afraid of giving their foxes too much common salt, 

 and it would not be surprising if this fear led occasionally to a 

 deficiency of sodium. It might be a good plan to leave the solution 

 af this question to the fox itself, by placing in each pen a lu^'mp of 

 rock salt. 



A human subject restricted to the articles which have been 

 actually used in feeding foxes would stand a considerable chance 

 of being attacked by scurvy. The only foodstuffs in the list 

 already given, which contain the "anti-scorbutic" vitamine, are 

 milk, which is not particularly rich in it, and probably apples. 

 Scurvy is a disease from which flesh-eating animals are not positively 

 known to suffer; it is none the less possible and indeed likely that 

 they require for the maintenance of perfect nutrition a supply 

 of the antiscorbutic element present in green vegetables, fruits, 

 and many tubers. If such a requirement does actually exist, it is 



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