124 LACTIFEROUS GLANDS. 



mina, which are the orifices of the excretory ducts of a little 

 gland forming the tubercle. The areola consists of a spongy 

 tissue beneath which there is no fat; it is susceptible of disten- 

 tion during lactation, or from particular excitement. 



The greater number of anatomists have considered these tu- 

 bercles as intended only for the secretion of an unctuous fluid 

 which lubricates the areola and nipple, and protects them from 

 excoriation by the sucking of the infant. It is said, however,* 

 that when some time has elapsed after a repast, or when there 

 has been a long interval to the nursing of the child, milk flows 

 from them abundantly; but that in inverse circumstances a 

 transparent, limpid fluid is distilled in small drops : all of which 

 would tend to prove that they are of the same nature with the 

 'mammae themselves, being only smaller. In addition to them, 

 it is said, that the areola and the nipple are furnished with a 

 great number of sebaceous glands, which do not elevate them- 

 selves above the surface, and which may be found on and near 

 the tubercles. 



The Papilla, 



Is the truncated cone in the centre of the mamma, of the same 

 colour with the areola, and surrounded by it. The lactiferous 

 tubes terminate on its extremity. It is collapsed and in a very 

 pliable state for the most part, but when excited it swells, be- 

 comes more prominent, and of a deeper colour. Its skin is 

 rough, and provided with numerous and very small papillae. 

 Its internal structure consists of the extremities of the lactiferous 

 tubes united by condensed cellular membrane. 



The mamma is supplied with blood from the external thoracic, 

 intercostal, and the internal mammary arteries. Its veins attend 

 their respective arteries. The nerves come from the axillary 

 plexus and from the intercostals. The lymphatics run into the 

 internal mammary, intercostal, and axillary trunks. 



* J. F. Meckel 



