THE PHYSIOLOGY OF LACTATION 



45 



civilized people of the West, and we are so completely accustomed 

 to this fact that in our minds "milk" always means cow's milk. 

 Cow's milk, therefore, commands our attention more than other 

 milk, and it is mutually agreed that when "milk" is spoken of 

 cow's milk is meant. 



Fig. 11.- 



-Showing a section through the teat and one quarter of the udder of a 

 cow. (After Moore and Ward.) 



The cow's udder is situated on the abdomen between the hind 

 legs. It is separated into four quarters which are divided by 

 layers of fibrous tissue. Each pair — the one on the right side and 

 the one on the left — represents one gland, and while there is no 

 connection between the glands, there is some connection between 

 the two quarters of the same gland. It is possible, therefore, to 

 obtain some milk from one quarter by milking the other one on 



