CHAPTER XVI. 



THE COW'S UDDER AND MILK SECRE- 

 TION. 



The mammary glands are peculiar to all of 

 the mammalian animals, the highest class of ani- 

 mals and the class to which our domestic ani- 

 mals belong. The mammary gland of the 

 cow is commonly spoken of as the udder and 

 originally only supplied milk for her young, 

 but since the cow has been domesticated she 

 produces milk for human consumption, one of 

 the most important articles of food. 



The udder of the cow is a compound gland 

 divided into two symmetrical halves and each 

 half is again divided into equal parts, thus 

 making four quarters of the cow's udder. From 

 each quarter is suspended a teat which has 

 an opening at the lower end from which the 

 milk may be drawn. Occasionally there is a 

 pair of rudimentary teats, which are of no con- 

 sequence and do not give any milk. At the 

 base of each teat is a cavity, known as the 

 galactophorous sinus, in which the milk is 



111 



Digitized by Microsoft® 



