Influence of Food on Kind of Milk 317 



of total solids, the question is, Can the richness of 

 milk be modified by changes in the ration ? For in- 

 stance, is the milk from a very generous food supply 

 richer than that from a moderate or scanty ration, 

 or will a highly nitrogenous ration cause a secretion of 

 milk with a higher percentage of solids than a ration 

 poor in protein ? It would probably be generally con- 

 ceded that if variations in milk are caused in these 

 ways, they are small as compared to those due to 

 breed characteristics or to individuality. Can we bring 

 about variations sufficiently large to be important ? 

 This question has been much discussed and much in- 

 vestigated from the work of Kiihn in 1868 down to 

 the present day. Mau}^ experiments have been con- 

 ducted for long periods and short periods in which 

 very moderate rations have been compared with very 

 large ones, highly nitrogenous foods with those of a 

 low protein content, dry with green or succulent ma- 

 terials, and grains of the same class with one another, 

 and, in a great majority of cases, the verdict has been 

 that "no consistent relation appears to exist between 

 the quantity or character of the ration and the com- 

 position of the milk." The writer has examined the 

 results of nearly all the important experiments of this 

 character of which he could find a record, and in but 

 few cases could he discover that there was a material 

 increase or decrease in the proportion of milk solids 

 which bore a logical relation to variations in the ration. 

 In some cases, a temporary change appeared in the 

 milk immediately after a violent change in the ration, 

 but in most instances of this kind, there was very 



