The Milk Glands and their Functions. 



89 



blood; when that secretion takes place is yet a moot 

 point, the opinion held by the best authorities is, that 

 the secretion of the greater part of the milk goes on dur- 

 ing the act of milking. It is now held that the nervous 

 system has largely to do with the production of milk, a 

 reasonable conclusion when we remember that the act- 

 ivity of a gland depends largely on its blood supply, 

 that supply being controlled by the nerves, whose action 

 is to contract or widen the blood vessels. 



Eoehrig de- 

 scribes a nerve 

 which leaves the 

 spinal cord and 

 goes to the udder, 

 filaments from its 

 branches go to 

 the teats, the cis- 

 terns and the 

 alveoli. When 

 the teats a're 

 worked with the 

 hands the nerves 

 surrounding them 

 are irritated, and through them the secreting glands are 

 stimulated, causing their contraction and the discharge 

 of their contents. 



The veins along the belly leave the front of the udder 

 and go forward in a more or less winding manner, branch 

 more or less often, and eventually disappear through 

 holes in the abdominal floor, termed milk-wells, then 

 pass along on the inside of the upper side of the breast 



A FUXNELrSHAPED UDDKR. 



