3io DIGESTION. 



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 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 secretion into the intes- 

 tinal canal. A small shallow cavity or space was thought 

 to remain, for a time, after this absorption or dehiscence, 



Fig. 78.* 



but shortly to disappear, together with all trace of the 

 previous gland. 



More recent acquaintance with the real structure of 



* Fig. 78. Transverse section of injected Peyer's glands (from Kol- 

 liker). The drawing was taken from a preparation made by Frey: it 

 represents the fine capillary looped network spreading from the sur- 

 rounding blood-vessels into the interior of three of Peyer's capsules from 

 the intestine of the rabbit. 



