182 



SEVENTEENTH LECTURE. 



Let us now examine the organ at the height of its activity 



in the body of the nursing woman 

 (Fig. 161). 



The gland vesicles, rounded or 

 elongated (o. 1 128 to o. 1872 mm.), 

 are formed by a membrana propria 

 with fiat stellate cells. They have 

 a simple lining of low cylinder cells 

 (of 0. 01 13 mm.). Those finest se- 

 cretory canals between the cells, 

 which we have already mentioned 

 at p. 134, have also been demon- 

 strated here by means of injections. 

 The excretory canal-work also 

 has a cylindrical epithelium. How 

 far the fatty secretion of our organ, 

 the milk, depends upon the destruc- 

 tion of the gland cell, or whether the latter structure does not 

 simply express the produced or received fat substance from 

 the membraneless, contractile cell-body — are questions which 

 require more accurate investigation. 



In advanced life, the female mammary gland loses its 

 secretory apparatus. It becomes reduced to the old canal- 

 system of a long passed period of childhood (Langer). 



The colostrum (already mentioned at Fig. 124) contains, in 

 addition to albuminous fat vesicles surrounded by a very thin 

 envelope, gland cells and cell fragments, 0.01 5 1 to 0.0564 mm. 

 in size. The ordinary milk of a later period contains only 

 the former elements, the so-called milk globules. The size of 

 the latter varies from about 0.0023 to 0.009 mm - 



Fig. 161. — Gland-vesicles of a nurs- 

 ing woman, with cells and capillaries. 



