THE INTESTINES. 101 



supply the secretion immediately succeed the arteries, and 

 precede those to which the absorbent function is more 

 especially assigned (comp. Frei, cited below). 



[Whence the small round cells, with a single nucleus, which 

 are to be met with in the intestinal mucus, proceed, is doubtful. 

 I have not found them in the glands and I can only refer 

 them to the epithelium, whence I am inclined to suppose that 

 these cells, which are usually few, arise upon the surface of the 

 mucous membrane like the mucous corpuscles of the oral cavity. 



In various, particularly intestinal, disorders, in inflamma- 

 tions, typhus, peritonitis, Bohm found a white viscid secretion 

 in many Lieberkuhnian glands (Gland, int., p. 34), which, as 

 subsequent observations of the same author (Darmschleimhaut 

 in der Cholera, p. 63) would indicate, was merely an epithelium 

 detached from the walls of the cavity, and which had become 

 aggregated into a compact plug. In cholera, according to 

 Bohm, this epithelium, as well as that of the whole intestine, 

 i3 thrown off.] 



§ 155. 



Closed follicles of the small intestines. — Vesicles of a peculiar 

 kind are found scattered, singly or in groups, over the walls of 

 the small intestine, of whose anatomical and physiological 

 import we have, as yet, attained no very clear idea and which 

 may therefore, for the present, be most fittingly described under 

 a general denomination. 



The most important of these are Peyer's patches (glandula 

 agminatce). They are rounded flattened organs, invariably 

 situated along that surface of the intestine which is opposite 

 to the mesentery ; they are most distinct upon the inner 

 surface, where they appear as rather depressed, smooth spots, 

 without any very sharp definition, but they are also recognis- 

 able from the exterior, by the slight elevation to which they 

 give rise ; by transmitted light they look like more opaque 

 portions of the membrane. These patches are usually most 

 abundant in the ileum, but they are not uncommonly to be met 

 with in the lower part of the jejunum : — occasionally they exist 

 in its upper portion close to the duodenum and even in the 

 inferior horizontal portion of the duodenum itself. Ordinarily 



