24 



MILK SECRETION 



that is, there is enough connection between the two to allow 

 a portion of the milk to be drawn from the rear quarter through 

 the front teat on the same side, and vice versa. 



The milk-glands proper are located near the abdomen and 

 extend a trifle downwards into the udder. The remainder of the 



GLAND-LOBULE 

 ALVEOLI 



FIG. 2. Schematic figure showing cross-section of cow's udder; and also 

 enlargement of epithelial cells in alveoli when cow is giving milk (i). Each 

 alveolus is surrounded with a membrane called tunica propria. Cell nuclei 

 not shown. When cow is in milk they are also enlarged. When not the 

 epithelial cells are llat and the nuclei small and spindle shaped (2). 



udder is filled with ducts, fibrous and connective tissue, muscle, 

 nerves, and blood-vessels, the whole udder assuming a sort of 

 spongy and open condition. 



The teat is simply a cylindrical-shaped body, with a hollow 

 tube extending down through the center of it. At the bottom 



