520 SPECIAL HISTOLOGY. 



varies from 1-4 of a line; their breadth is 0-028-0-036 of a line ; that 

 of their aperture, •02-0-03 of a line. They are composed of a delicate 

 homogeneous membrane projyria and of a cylindrical epithelium, which, 

 even during chylification, never, like that of the intestine, contains fat ; 

 their cavity is filled, during life, by a clear, fluid secretion, the so-called 

 intestinal juice, which, however, becomes rapidly changed after death, or 

 on the addition of water, so that the glands appear to be filled with cells, 

 or with a granular mass. 



The vessels of Brunner's glands have the same arrangement as those 

 of the salivary, whilst around Lieberklihn's ca'ca they follow exactly 

 the type of those of the stomach. A fine network of capillaries of 

 0"003 of a line, passes up round the ca^ca and, upon the surface of the 

 mucous membrane, enters an elegant polygonal reticulation of some- 

 what wider (0-01 of a line) vessels, which communicates on one side with 

 the vessels of the villi, on the other is directly continuous with veins, 

 which, after communicating with those of the villi, run directly out of 

 the mucous membrane. Hence, in this case also, the veins are con- 

 nected only with the superficial network round the glandular apertures 

 and with that in the villi, but not with that which surrounds the glands, 

 so that, as in the stomach, the vessels which supply the secretion im- 

 mediately succeed the arteries, and precede those to which the absor- 

 bent 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 inflammations, typhus, 

 peritonitis, Bohm found a white viscid secretion in many Lieberklihnian 

 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, accord- 

 ing to Bohm, this epithelium, as well as that of the whole intestine, is 

 thrown ofi". 



§ 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 Peyers patches [glandiila' agminata^). 

 They are rounded, flattened organs, invariably situated along that sur- 



