THE CELLULAR CONTENT OF MILK 



139 



Thoma-Zeiss apparatus. The leucocyte count was found to be 

 extremely variable, extending from 40,000 to over 1,000,000 per c.c. 

 Savage also investigated the cell content of milk at different stages 

 of milking in the fore-milk,middle milk,and stoppings respectively. 

 He found that the middle milk usually showed the lowest count. 



Russell and Hoffmann (1907) used the Doane-Buckley method 

 for counting the cells, but they showed that better results were 

 obtained when the milk was previously heated to 70 C. before 

 centrifuging. Even then, however, great variations in the cell 

 content were obtained, and they did not feel able to fix any standard 

 within which the cell content could be considered to be normal. 

 They considered, however, that a high cell content was suggestive 

 of some trouble of the udder, although this trouble might no longer 

 be active. The figures found by them varied to between 4000 

 and 1,000,000 cells per c.c. 



Campbell (1909) used the Doane-Buckley method, but after 

 centrifuging removed the supernatant liquid only to the fifth or 

 sixth mark. The tube was then filled up to the 10 c.c. mark with 

 distilled water and recentrifuged. This was repeated until the 

 upper surface of the liquid was transparent, when the supernatant 

 fluid was removed down to the I c.c. mark. This remaining c.c. 

 of sediment was thoroughly mixed, and the cells contained in it 

 counted by means of a blood-counting apparatus. Campbell states 

 that washing the cells several times before staining removed the fat 

 globules more satisfactorily, and that no precipitate was obtained 

 from the stain. 



Campbell also compared the results obtained by using the 

 methods of Stokes, Stewart, Doane and Buckley, and Trommsdorff 

 on the same samples of milk. The investigations carried out by 

 Campbell in regard to the difference in the counts obtained when 

 the milk was previously heated (as recommended by Russell and 

 Hoffmann), and when the heating was omitted, are most striking. 

 He has also investigated the cellular content of the fore-milk, 

 middle milk, and strippings, with heat and without heat, and some 

 characteristic findings are given in the following table : 



