New York Agricultural Experiment Station. 157 



Mabel S. F. (No. 17) on the other hand, had aborted two calves, 

 the last of these abortions having taken place on October 28, 1910. 

 She was very nearly dry. She gave only a small quantity of milk 

 and at times the smears which were made from her milk were found 

 to be more or less soluble in alcohol so that it was difficult to make 

 good preparations. This indicated some condition of her milk which 

 was different from normal. The abnormality was not correlated 

 in any way with fluctuations in the cell count. 



Millie of Geneva (No. 19) had suffered from " spider in the teat " 

 during the lactation period previous to the one in which these tests 

 were made. The left hind quarter was seriously affected but finally 

 returned to its normal condition except that the duct of this teat 

 was more or less obstructed. She calved normally on September 

 18, 1910. 



Graph II shows the fluctuations in cell counts of these cows much 

 more clearly than the figures in the table. The upper part of this 

 Graph shows the record of the two normal cows and the lower part 

 the record of the two abnormal cows. The striking daily varia- 

 tions shown in these curves are seen to occur in all cases. The two 

 normal cows maintain a lower average cell count than the two 

 abnormal cows when the whole period is taken into consideration; 

 but, if the last week of the period is considered by itself, this would 

 not be the case, for Mabel S. F. shows a decidedly lower count 

 than she had shown previously although she was approaching the 

 end of her lactation period. At the same time, the cell count for 

 Gerty F. 1 shows a decided increase in the cell content of her milk 

 so that she had as high a cell count as any of the four cows during 

 the last few days of the test. All of the cows show counts higher than 

 500,000 cells per cubic centimeter at some time during the period, 

 although Hammond F. 1 usually shows counts of less than 250,000 

 cells per cubic centimeter. 



There is a certain constancy in the number of cells discharged, 

 which is maintained for days or weeks at a time but the indica- 

 tions are that more extended records would show that great fluctua- 

 tions occur even in the case of the normal cows. 



There is no evidence of the cyclic variations noted by Breed and 

 Stidger in the case of two of the cows which they studied nor do 

 the curves show any common characteristics so far as has been 

 noted. The fact that the one hand-milked cow had a higher 



