ORGANS OF THE BODY. 



489 



Fig. 480. Openings of the glaiids 

 of Lieberkiihn in the mouse. At 

 (a) an empty opening, in the 

 other cases each is tilled with 

 columnar cells, placed with 

 their long axis towards the 

 centre. 



The contents of these crypts, unlike those ofBruHnei** glands, consist of 

 delicate columnar nucleated cells, with widened 

 base, which rest on the membrana propria. 

 These, together with the open axial canal, may 

 be seen in every transverse section (fig. 470, 

 (I). According to Schulze, between these cells 

 other goblet cells may present themselves, a 

 point worthy of note. 



In suitable preparations (fig. 480) the orifices 

 of the glands are to be seen at varying dis- 

 tances from one another, lined with columnar 

 epithelium, which passes in through the en- 

 trance of the tube. At those points at which 

 the villi are very crowded, the orifices of these 

 glands of Liebekuhn surround their basesin ring?. 



256. 



We now turn, finally, to the lymphoid follicles of the small intestine. 

 These occur with greater frequency here than in the stomach, which fact 

 is explained by the greater similarity of their 

 tissue to that of the mucosa of the small in- 

 testine. As has been already mentioned, 

 they are in the first place met with scattered 

 over the whole length of the small intestine 

 as glandulcu solitaries. These are roundish, 

 opaque, white bodies of very unequal size, 

 ranging from 0'2 to 0*4 and 2'2 mm. In 

 some subjects they are very scantily repre- 

 sented, or even entirely absent, while in other cases they appear in mul- 

 titudes. In situation and structure they correspond with the agminated 

 glands into which they may merge without any sharp boundary. At parts 

 of their periphery they are continuous with tl e circumjacent connective- 

 tissue. 



By the agmination of these follicles it is that Peyer's patches or plaques 

 are formed (figs. 481, 482), _^ A 



which occur in man, as in 

 all mammalia, in the greatest 

 abundance, but in very 

 various degrees of develop- 

 ment. In some cases they 

 are made up of from 3 to 7 

 follicles only, but more fre- 

 quently of from 20 to 30. 

 Again, when large, they may 

 contain up t,o 50 or 60 of 

 the latter. 



Peyer's patches are found 

 principally in the small 

 intestines, and always at the 

 free side, or that opposite to the mesenteric attachment of the viscus. They 

 appear, as a rule, first at the end of the jejunum, and become more 

 frequent in the ileum. 



But although this is the usual mode of distribution, it is not without 



Fig. 481. One of Peyer's glands from 

 the rabbit. 



Fig. 482. Vertical section through one of Fryer's glands 

 from the rnbbit. , villi: ft, bodies of gla.ids rounded off 

 above ; c, others, apparently open above. 



