144 Report of the Department of Bacteriology of the 



centimeter, a figure which is much higher than that given for cow- 

 milk. The cell counts were made by Mr. Stidger. 



* Pounds of milk given at the milking from which test was made. 



t Pounds milk given in 24 hours. 



X Milked once a day. 



§ Quoted from Breed and Stidger (p. 381). See footnote 1. 



II. CELL CONTENT OF MILK IN RELATION TO THE 



PERIOD OF LACTATION. 



The only satisfactory kind of data to show the relationship which 

 may exist between the period of lactation and the number of cells 

 discharged during different portions of the lactation period would 

 be daily records of the number and kinds of cells discharged during 

 the complete lactation periods of a sufficiently large number of normal 

 animals to eliminate chance variations. Unfortunately the present 

 investigations have been carried out under such circumstances that 

 it has been impossible to keep such records. 



During the investigations the milk of several animals has been 

 examined daily for several weeks or for longer periods at occasional 

 intervals. These show some of the conditions which prevail and 

 so are given in the following pages. 



A. CELL CONTENT OF THE MILK OF FRESH COWS. 



The milk of two fresh cows was studied, both of whom were more 

 or less abnormal and might therefore be expected to give high cell 



