136 MILK AND ITS HYGIENIC RELATIONS 



from the epithelium of the gland. He agrees with Czerny that 

 these cells are capable of taking up fat globules which have not 

 been excreted and of conveying them to the nearest lymph gland. 

 He believes that in other animals the colostral cells are probably 

 polymorphic leucocytes. 



Gratz and Maray considered that the cells from the milk of 

 cows were mostly of the type of polymorphic leucocytes, though 

 colostrum corpuscles, presumably derived from the gland epithelium, 

 were also present. The number of polymorphic cells increased in 

 conditions of mastitis. 



Thomas examined the cells present in milk and believed that 

 they consisted of polymorphic leucocytes and of large mono- 

 nuclear cells which had phagocytic powers. Granular cells 

 were also present which resembled epithelial cells in their 

 appearance. 



Without going further into the question of the origin of these 

 cells, it may be reasonably concluded that a proportion of the cells 

 found in milk is likely to be derived from the gland tissue. All 

 active tissues of a glandular character tend to throw off a certain 

 number of cells as a result of their activity, these cells presumably 

 being dead or dying when cast off. Further, it is only reasonable 

 to suppose that a number of leucocytes will be present in normal 

 milk. The mammary gland has a large blood supply, and it has 

 already been shown that a comparatively free filtration of salts 

 and other substances takes place from the blood vessels to the 

 lumen of the gland. Moreover, a high degree of cellular activity, 

 which must be a normal condition of the active gland throughout 

 the whole period of lactation, suggests in itself that there will be 

 present in the whole gland tissue considerable numbers of white 

 corpuscles of various forms. 



Savage examined the cells in the milk from the several quarters 

 of some cows which had one quarter affected by inflammatory 

 conditions. The most prominent variety of cells seems co have 

 been the large uninucleated type, although sometimes there 

 appears to have been excess of the multinucleated cells. Savage 

 calls these cells 'leucocytes,' i.e. he considers they are derived from 

 the blood. Hewlett and his co-workers think that in cases of a high 

 cell count, even where tnere may be some inflammation, there is 

 an increase in the multinuclear cells, but they do not consider that 

 such cells are ' pus ' cells in the usual meaning of the term. 



The increased number of cells found in colostrum does not 

 afford any difficulty. It is known that before the gland function 

 is actively developed in the production of milk, the lumen of the 

 tubules is crowded with cells. These cells must evidently first be 

 cleared out of the gland with the early colostrum secreted. 



Practically, the point at issue from the public health aspect is 

 at what stage the number of cells found in the milk, and the variety 

 of such cells, must be regarded as passing from the normal cell con- 



