THE DEVELOPMENT OF ANIMALS 77 



furnished are supplemented by such food ats green corn or 

 rape, and (.2), by changing from a ration essentially car- 

 bonaceous to one nitrogenou5 in character, or sufficiently 

 so to furnish food approximately in balance, such a change 

 may be made by substituting clover or alfalfa hay for corn 

 stover, or meal composed largely of wheat bran or gluten 

 meal for corn meal. 



Quality in milk is also affected by the food, first, with 

 reference to the constituents which it contains, and second, 

 with reference to its flavor. The first influence is so slow 

 in its action as to be virtually imperceptible under normal 

 conditions. To illustrate: Feed, under normal conditions, 

 a Jersey cow whose milk is very rich in butter fat, food that 

 will test practically the same, but it will be reduced in quan- 

 tity. Reverse the process of feeding and it will still test 

 practically the same, but will increase in quantity up to a 

 certain limit. The quality of milk, therefore, viewed from 

 the standpoint of direct influence of food upon its essential 

 constituents, is not perceptibly influenced thereby. The 

 percentage of butter fat and other constituents will be 

 just the same, except the total quantity of these will be in- 

 creased or decreased with such increase or decrease in the 

 total milk product from a cow, within a given time, as may 

 be brought about by the character of the food fed. 



The quality in milk, viewed from the standpoint of its 

 analysis, is almost entirely a matter of transmission, and 

 it is probably more a breed peculiarity than a matter of 

 individual inheritance and yet the importance of individual 

 inheritance is not to be under-estimated. The Channel 

 island breeds are characterized by the production of milk 

 only moderate in quantity, but rich in butter fat. The 

 Holsteins on the other hand are characterized by the pro- 

 duction of a large quantity of milk, and relatively low in 

 butter fat. But these differences in the character of the 

 milk are not due to inheritance and selection alone. They 

 are due also to the action of food producing change so 

 slowly as to be imperceptible, except when measured by 



