Cellular Content of Milk. 



25 



took a stand against this view of Winkler, as he had observed them 

 in the milk of entirely healthy animals, but not until the present 

 time has he been able to offer an explanation of the nature of these 

 bodies, designated as "skinlets" or " shell." They represent 

 desquamated cells of the stratum mortificatum of the pavement 

 epithelial layers singly or in groups. Although usually no parti- 

 cular structure is manifested yet in single instances typical flat, 

 round nuclei can be seen. 



If the teats of a slaughtered cow are taken and the cistern and 

 milk duct are carefully cut open, and from the surface of the milk 

 duct a small quantity of the 



cellular layer is scraped Fig. 10. 



off, an examination by the 

 usual method discloses the 

 typical "shells." 



2. If cells from the 

 cistern are prepared and 

 examined, elongated or 

 oval, or quadrangular cells 

 with oval nuclei, frequent- 

 ly elongated at the base, 

 will be found, singly or in 

 groups. Single fat drop- 

 1 e t s may frequently be 

 seen in the plasma sur- 

 rounding these cells. Sim- 

 ilar cells may also be found 

 in normal milk. They are 

 usually single, although 

 sometimes united in 

 groups arranged like flow- 

 ers. In stimulation, which 

 brings on a desquamation 

 from the mucous mem- 

 brane of the cisterns, or 

 from the parenchyma in 

 catarrhal conditions of the 

 milk passages, they of 

 course appear in masses. 



Such reactions occur in the cistern for instance as a result of 

 the so-called kneading. 



3. Cells from the secreting milk ducts and the alveoli, ap- 

 pearing large or small according to the quantity of fat globules 

 collected in them, often become tremendously distended and bloated 

 (foam cells). Their structure is mostly honeycombed or mulber- 

 ry-shaped when they contain fat ; without fat the cell is surrounded 

 with only a narrow^border of protoplasm. The nucleus is usually 

 in good condition. 



Film of sediment from milk of a fresh milking cow. 



Cells from the stratified layer of pavement epithelia 



of the teat canal. Thionin. 1 X 1000. 



