614 



GENERATION AND DEVELOPMENT. 



The nipple, which contains the terminations of the lactifer- 

 ous ducts, is composed also of areolar tissue, and contains un- 

 striped muscular fibres. Bloodvessels are also freely supplied 



FIG. 246. 



Dissection of the lower half of the female mamma during the period of lactation 

 (from Luschka). %. In the left-hand side of the dissected part the glandular lobes 

 are exposed and partially unravelled; and on the right-hand side, the glandular 

 substance has been removed to show the reticular loculi of the connective tissue in 

 which the glandular lobules are placed : 1, upper part of the mammilla or nipple ; 

 2, areola ; 3, subcutaneous masses of fat ; 4, reticular loculi of the connective tissue 

 which support the glandular substance and contain the fatty masses ; 5, one of three 

 lactiferous ducts shown passing towards the mammilla where they open ; 6, one of 

 the sinus lactei or reservoirs ; 7, some of the glandular lobules which have been un- 

 ravelled ; 7', others massed together. 



to it, so as to give it a species of erectile structure. On its 

 surface are very sensitive papillae ; and around it is a small 

 area or areola of pink or dark-tinted skin, on which are to be 

 seen small projections formed by minute secreting glands. 



Bloodvessels, nerves, and lymphatics are plentifully supplied 

 to the mammary glands ; the calibre of the bloodvessels, as 

 well as the size of the glands, varying very greatly under cer- 

 tain conditions, especially those of pregnancy and lactation. 



The secretion of milk, which under ordinary healthy cir- 



