LACTIFEROUS DUCTS. 495 



Haller appears to have entertained the remarkable senti- 

 ment, that some of the ducts originate in the adipose matter 

 about the gland, as well as in the glandular substance.* > 



The papilla, or nipple, in which these ducts terminate, is in 

 the centre of the mamma : it consists of a firm elastic substance, 

 and is nearly cylindrical in form. It is rendered tumid by 

 irritation, and by certain emotions. 



This power of erectibility of the nipple is due to the presence 

 of some contractile tissue in its composition analogous to the 

 dartus structure of the scrotum. There is now believed to be no 

 erectile tissue in its composition. 



The lactiferous ducts terminate upon its extremity. When 

 it is elongated they can freely discharge their contents ; but 

 when it contracts, this discharge is impeded. The skin imme- 

 diately around the nipple is of a bright red color in virgins of 

 mature age. In pregnant women it is sometimes almost black ; 

 and in women who have borne children it is often brownish. 

 It abounds with sebaceous glands, which form small eminences 

 on its surface. 



During gestation these follicles or glands are much increased 

 in size, so as to become in consequence of this enlargement, one 

 of the most certain signs of pregnancy. During suckling they 

 are still farther enlarged, so as to appear like small pimples 

 projecting from the skin, and serve by the increased secretion 

 they throw out, to defend the nipple and areola, from the 

 excoriating action of the saliva of the child. 



This gland exists in males, although it is very small. In 

 boys, soon after birth, it has often been known to tumefy, and 

 become very painful, in consequence of the secretion and accu- 

 mulation of a whitish fluid, which can be discharged by pres- 

 sure. It also sometimes swells and is painful, in males at the 

 age of puberty. 



* Elementa Physiologiae, Tom. 7, Pars II. page 7. In the adipose matter 

 about the gland, the lactiferous tubes (ducti gdlactophori) appear to communi- 

 cate with the absorbent vessels. In injecting the gland with mercury, I have 

 frequently found the metal to pass off from the ducts along the absorbent 

 vessels. p. 



