rEYER'S GLANDS. 



301 



met with in two conditions, viz., either scattered singly, 

 in which case they are termed glandules solitaries, or aggre- 

 gated in groups varying from one to three inches in length 

 and about half-an-inch in width, chiefly of an oval form, 

 their long axis parallel with that of the intestine. In this 

 state, they are named ylandula agminate, the groups being 

 commonly called Peyer's patches (fig. 75). The latter are 

 placed almost always opposite the attachment of the 

 mesentery. In structure, and probably in function, there 

 is no essential difference between the solitary glands and 



Fig. 75.* 



the individual bodies of which each group or patch is 

 made up ; but the surface of the solitary glands (fig. 76) is 

 beset with villi, from which those forming the agminate 

 patches (fig. 77) are usually free. In the condition in 

 which they have been most commonly examined, each 

 gland apppears as a circular opaque-white sacculus, from 

 half a line to a line in diameter, and, according to the 

 degree in which it is developed, either sunk beneath, or 

 more or less prominently raised on, the surface of a 

 depression or fossa in the mucous membrane. Each gland 



* Fig. 75. Agminate follicles, or Peyer's patcJi, in a state of disten- 

 sion : magnified about 5 diameters (after Boelmi). 



