REPRODUCTIVE ORGANS IN THE FEMALE. 335 



basement membrane and a membrana propria, the 

 latter containing basket cells whose processes mingle 

 with the glandular epithelium. 



The interstitial tissue just external to the alveoli 

 is composed of connective-tissue cells that stain 

 heavily with nuclear dyes, while in the intervening 

 spaces between the alveoli, connective-tissue fibers 

 and fat cells are abundant. A supply of plain muscle 

 fibers intervene and surround the ducts in the nip- 

 .ple. The fibers placed longitudinally function in 

 the erection of the nipple, while the circular ones 

 constrict the ducts. 



The nipple does not Epithelial Connective-tissue 



develop until after 

 birth. Its normal po- 

 sition is in the fourth in* 

 tercostal space, about 

 four inches from the 

 sternum. It is clothed 



With Stratified pig- Fig. 240. Section through two alveoli 



mented epithelium and 

 devoid of hair follicles 



and sweat glands. The skin immediately around 

 the nipple is also pigmented, forming an areola with 

 numerous small papillae, giving a rough or wrinkled 

 appearance. Besides large sweat glands, twelve or 

 more large sebaceous glands, called glands of Mont- 

 gomery, are present in this area. These glands open 

 at the apices of the small papillae just mentioned, 

 and are usually considered as accessory milk glands. 

 Vessels and Nerves. The arteries that supply the 

 breasts are the long thoracic, the internal mammary, 



