NORMAI. VARIATION IN FAT CONTENT OF MIXED MILK. 305 



of any Other milking of the day. The total day's milk is. as 

 would be expected, relatively somewhat less variable in fat per- 

 centage than the milk from any single milking. 



II. In absolute amount of fat, the evening milk is rela- 

 tively much more variable than the morning's milk. The mid- 

 day milk occupies an intermediate position in this respect. This 

 result would appear to indicate that during the night, when the 

 cows are at rest, fat production in the udder is a more uniform 

 process from cow to cow and from day to day, than during the 

 day time when the cows are in some degree active. 



While the foregoing constants and their discussion were ob- 

 tained primarily for their significance in connection with further 

 scientific studies, it is clear that they have some points of practi- 

 cal interest to the farmer selling milk to the creamery, to the 

 creameryman buying milk, and to the dairy inspector enforcing 

 a minimum fat content milk law. 



