PETER'S GLANDS. 



303 



moreover, and forming a stroma or supporting framework 

 throughout its interior, is lymphoid or adenoid tissue (fig. 72), 

 continuous with that which forms a great part of the mucous 

 membrane outside it. The contents of each sac consist of a 

 pale greyish opalescent pulp, formed of albuminous and fatty 

 matter, and a multitude of nucleated corpuscles of various 

 sizes, resembling exactly those found in lymphatic glands. 



The real office of these Peyerian glands or follicles is still 

 unknown. It was formerly believed that each follicle was 

 a kind of secreting-cell, which, when its contents were 

 fully matured, formed a p^ yg * 



communication with the 

 cavity of the intestine by 

 the absorption or bursting 

 of its own cell-wall, and 

 of the portion of mucous 

 membrane over it, and 

 thus discharged its secre- 

 tion into the intestinal 

 canal. A small shallow 

 cavity or space vvas thought 

 to remain, for a time, after 

 this absorption or dehi- 

 scence, but shortly to disappear, together with all trace of 

 the previous gland. 



More recent acquaintance with the real structure of 

 these bodies seems, however, to prove that they are not 

 mere temporary gland-cells which thus discharge their 

 elaborated contents into the intestine and then disappear, 

 but that they are rather to be regarded as structures 



* Fig. 78. Side-view of a portion of intestinal mucous membrane of 

 a cat, showing a Peyer's gland (a) : it is imbedded in the submucous 

 tissue (/), the line of separation between which and the mucous mem- 

 brane passes across the gland : 5, one of the tubular follicles, the orifices 

 of which form the zone of openings around the gland : c, the fossa in 

 the mucous membrane : d, villi : e, follicles of Lieberkiihn (after Bendz). 



