THE CELLULAR CONTENT OF MILK 135 



whether the bulk of the cells are derived from the epithelium of 

 the gland or whether they must be regarded as white corpuscles, 

 which have exuded from the tissues and from the blood 

 stream. 



Czerny (1890) investigated the colostrum corpuscles of human 

 milk and believed that the cells were in reality leucocytes, whose 

 function was to remove such fat globules as had not been passed 

 out in the milk, and to transfer them from the mammary gland 

 to the nearest lymph gland. He did not regard them as excretory 

 material. Czerny injected milk into the dorsal lymph sac of a 

 frog and found that the fat globules were taken up by the leucocytes 

 and carried away. Further experiments carried out on women, 

 and also on a cat and on a rabbit, strengthened his belief in the 

 carrying power of these leucocytes. He believed that when the 

 gland function becomes upset, leucocytes pass through in increas- 

 ing amounts. He found in a cat investigated, that the lymph 

 glands nearest to the mammary gland were full of the same type 

 of leucocyte as those found in the milk, and, in fact, could not 

 be distinguished microscopically from the colostrum corpuscles. 

 Czerny appears to regard these cells as normal leucocytes, of the 

 large uninuclear variety. 



Winkler divided the cells present in milk into several groups. 

 He believed that the majority of them were derived from the 

 epithelium of the gland. Such cells often appeared to be multi- 

 nucleated, but were, he believed, not blood corpuscles. These 

 views are also held by Hewlett, Villar and Re vis, who examined 

 the varieties of cells present in a large number of milk samples. 

 These investigators divided the cells into the following classes: 

 (i) Large uninucleated cells, (2) multinucleated cells, (3) small 

 uninucleated cells these classes forming the main mass of cells 

 present ; in addition they described small numbers of eosinophile 

 cells, some larger cells with vacuolated protoplasm, and other 

 cells whose characteristics were indeterminate. These authors 

 regard the vacuolated cells, which were of large size, as ' probably 

 fat -bearing ' cells. No phagocytosis was observed. No amoeboid 

 movement in any of the cells was noticed. It seems possible that 

 these vacuolated cells of Hewlett may correspond to the cells 

 described by Czerny, although Hewlett does not himself make any 

 statement upon this subject. See Plate I. facing next page. 



Berka examined cells in human milk, and considers that the 

 cells are lymphocytes of the large uninuclear variety. He be- 

 lieves that as these cells begin to disintegrate the nucleus takes 

 on a polymorphic appearance, thus resembling the usual poly- 

 morphic leucocyte. He states that these cells are amoeboid, and 

 considers therefore that they are not of epithelial origin. More- 

 over, in examining sections of the active gland, mitoses t are 

 not seen in the cells lying in the secretion which would, he 

 thinks, be the case if the cells found in milk were derived mainly 



