THE DAIRY. 517 



animals in improving the stock of common farms ; and it is fast 

 coming to be understood that, while for ordinary purposes there is 

 not, perhaps, a great advantage in favor of pure breeding, there is 

 a decided advantage in the infusion of a large proportion of the 

 blood of some v/ell-defined race, into the mixed breeds kept for 

 various dairy purposes; and while it is not seldom that we find a 

 common or "native" cow that, both in the production of milk, and 

 cheese, and of butter, is in all respects as good as ordinary speci- 

 mens of the pure breeds, it is a general truth that the larger the 

 proportion of a thoroughbred strain that we are able to introduce 

 into our common herds, the better will be the general results, and, 

 what is incidentally of great advantage, the more uniform will be 

 their character, and the more will they come under the influence 

 of a regularly established and methodical system of treatment. 



It is a well-established principle in cross-breeding, not only 

 with cows, but with all domestic animals, from horses to poultry, 

 that the purity of blood should be on the side of the sire ; and 

 by a proper observance of this principle we may, within two or 

 three generations, bring the general characteristics of our herds to 

 a tolerably close conformity with the thoroughbred standard. The 

 physiological reason for this influence is supposed to be, that, by a 

 long course of careful breeding, certain desirable qualities have be- 

 come so established in the race, — such a "fixity of type" has been 

 created, — that the pure blood, crossed with animals of less marked 

 peculiarities, has, so to speak, a greater impetus, and exercises 

 a more powerful influence over the progeny. A dozen native 

 cows of varying form, color, and quality, crossed with a pure 

 Devon bull, would produce calves possessing very generally the 

 characteristics of the Devon race ; and after the second or third 

 generation reversals to the common type would be comparatively 

 rare. 



Therefore, if it is determined by a farmer that any one of the pure 

 races of dairy animals possesses for his purposes decided advan- 

 tages, it is within his power, simply by the use of vigorous males 

 of that race, to establish throughout his herd, within a very few 

 years, most, if not all, of the desirable dairy qualities of the pure 



