MILK. 165 



Thus if the milk abstracted at one time, and which has 

 been long secreted, be divided into three parts, each being 

 received successively into a distinct vessel, the first milk will 

 seem to be poor and watery, the second more rich, and the 

 third the most so of the entire. The first portion is to be 

 regarded as that which has been longest formed, and the 

 third as the most recently secreted. 



The knowledge of the above fact leads to one practical re- 

 sult in the case in which the milk is too rich for the digestive 

 powers of the child ; thus by allowing such milk to remain 

 for a longer period than usual in the breast, a fluid of lighter 

 quality and less abounding with nutritive principles will be 

 obtained. 



A second effect of prolonged retention or engorgement of 

 the milk in the breast is to occasion the aggregation of the 

 globules into masses. (See Plate XI V.^. 6.) 



Pus and Blood in the Milk. 



Having now described those constituents by the combina- 

 tion of which milk is formed, as well as the several conditions 

 in which these may be encountered, we may next refer to 

 those structures which occasionally occur in milk as the result 

 of disease. 



Thus the corpuscles of both pus and the blood are some- 

 times encountered in the milk, those of the former fluid 

 occurring much more frequently than those of the latter. 



The puriform matter which issues from the breast in cases 

 of abscess of that gland is made up of a mixture of pus and 

 milk globules, with occasionally blood discs. (See Plate XV. 



fig- i.) 



But both pus and blood corpuscles, the latter very rarely, 

 may be contained in the milk which issues from the breast 

 through its natural channels. 



I was so fortunate as to meet with an excellent example 

 of blood in the milk, the occurrence of which is so rare that 

 Donne, at the period of the publication of the " Cours de 

 Microscopic," and with all his researches on the milk, had 



