1004 



THE MAMMARY GLANDS. 



The mucous membrane is continuous with the common integument at the 

 orifices of the ducts ; its epithelium is scaly or tesselated, and in the 

 smallest ducts and their ultimate vesicles consists of cells having a diameter 

 very little exceeding that of their nuclei. 



Fig. 697. 



Fig. 697. MAGNIFIED VIEWS OP THE GLANDULAR SUBSTANCE OP THE MAMMA DURINQ 

 THE PERIOD OP LACTATION (from Henle). 



A, section of a small lobule of the gland, magnified 60 diameters; 1, stroma of connec- 

 tive tissue supporting the glandular tissue ; 2, terminal ramuscule of one of the gland- 

 tubes ; 3, glandular vesicles. 



B, four glandular vesicles magnified 200 diameters, showing the lining ^epithelial cells 

 and some milk-globules within them. 



Blood-vessels and Nerves. The arteries which supply the mammary glands are 

 the long thoracic and some other branches of the axillary artery, the internal mam- 

 mary, and the subjacent intercostals. The veins have the same denomination. 

 Haller described a sort of anastomotic venous circle surrounding the base of the 

 nipple as the circidus venosus. The nerves proceed from the anterior and middle 

 intercostal cutaneous branches. 



In the male, the mammary gland and all its parts exist, but quite in a 

 rudimentary state, the gland itself measuring only about six or seven lines 

 across, and two lines thick, instead of four inches and a half wide and one 

 and a half thick, as in the female. Occasionally the male mamma, espe- 

 cially in young subjects, enlarges and pours out a thin watery fluid ; and, 

 in some rare cases, it has secreted milk. 



Varieties. Two or even three nipples have been found on one gland. An addi- 

 tional mamma is sometimes met with, and even four or five have been observed to 

 co-exist ; the supernumerary glands being most frequently near the ordinary pair, 

 but sometimes in a distant part of the body, as the axilla, thigh, or back. 



