Shekhy — Variation of the Constituent Substances of Cows' 1 Milk. 577 



(ii) The -daily variation in . solids-not-fat is approximately equal and 

 practically similar to that in the total milk. 



(iii) The daily variation in fat is not equal to that in the total milk. 



Fat is therefore the great variable among the constituent parts of milk. 

 While alterations in quantity of total milk are accompanied by practically 

 similar alterations in the quantities of water and of solids-not-fat, the same 

 does not hold for the total fat. Generally, however, a marked increase or 

 decrease in milk results in an increase or decrease in fat, but the magnitude 

 of the fluctuation of the latter is seldom equal to that of the former; and 

 frequently an increase in milk is accompanied by a decrease in fat or vice versa. 



MONTH.I 



e 



10 



2 3 4 5 6 7 



Diagram II. 



When the figures representing the percentages of the various constituents 

 for a lactation period are examined, it is seen, as in diagram II, 1 that, 



1 Crowther and Huston, Transactions of the Highland and Agricultural Society of 

 Scotland, vol. xxiii, 1911, p. 97. 



