MILK. 197 



down immediately, but retaining their increased size 

 they cause the udder to become hard and much extended 

 in size. This hardness of the udder is often supposed 

 to be caused by some disorder, and much unnecessary 

 trouble is often borrowed on this account. When, how- 

 evei-, the process of lactation is under way, and the 

 glandular follicles begin to break down copiously and 

 the secretion of milk increases, and especially when the 

 colustrum period has passed, the udder becomes less 

 hard and tense, excepting when full of milk, and loose 

 and soft as soon as the milk is drawn. 



The udder of the cow consists of four distinct and 

 separate glands commonly called quarters, each one con- 

 sisting of a mass of lobules, among which are a large 

 number of ducts small at the extremities, but gradually 

 connecting and forming large ducts, which in their turn 

 form sinuses or reservoirs in which the milk gathers as it 

 is secreted. The largest of these reservoirs is immedi- 

 ately above the base of the teats. The teats form the 

 outlets for the principal lactiferous ducts or milk chan- 

 nels, and these connect with an orifice at the extremity 

 of the teat through which the milk is drawn. 



In structure each of the glands of the udder consist of: 

 first, an envelope of yellow elastic fibrous tissue ; second, 

 the glandular tissue formed into lobules ; third, the lac- 

 tiferous ducts or milk channels ; fourth, the milk reser- 

 voirs or the sinuses ; and fifth, the excretory canal or 

 orifice of the teat. 



The elastic envelope is extremely strong and is formed 

 of wide bands detached from the abdominal muscles ; it 

 has numerous prolongations which cross each other in 

 the mass of glandular tissue, forming partitions which 

 divide this into lobes and lobules, which are thus some- 

 what independent of each, other, and are firmly sup- 

 ported without pressing upon each other. This sepa- 

 ration and partial isolation of these parts of the udder 



