SECT. 155.] AFFINITIES OF PEYEIl's GLANDS. 337 



border, and support villi, upon the most prominent part of their"?;, 

 intestinal surface. 



I consider it as quite established that the follicles of the Peyerian patches 

 have no openings, but will, however, notice the following points : — 1. In 

 animals examined immediately after death, the capsules are invariably found 

 closed, as may be very readily seen on the well-developed patches of the pig, 

 sheep, cat, dog, etc, which I may recommend in general for the investigation 

 of these organs, because the patches in man are so frequently altered. 2. An 

 appearance of openings may arise from the depressions of the mucous mem- 

 brane over the individual follicles, especially when the prominent part of the 

 wall of the follicle is not much distended. 3. In man, the closed follicles are 

 subject to manifold diseased conditions, and they are frequently found 

 ruptured and altered, so that often nothing remains of the patches but a 

 reticulated, indistinctly pitted surface ; moreover, they may, as Virchow first 

 showed, burst after death, when they are allowed to lie in water in a warm 

 place, on which account, perhaps, many of the apertures found in dead 

 bodies must be regarded as having been produced by putrefaction. 



The connection of the Peyerian follicles with chyle-vessels, asserted by 

 "Brucke, from which these organs have been viewed as lymphatic glands, 

 deserves, at any rate, to be duly considered ; still I must here, as with 

 reference to many other subjects, take upon myself the somewhat un- 

 grateful task of warning against too hasty conclusions. An unprejudiced 

 consideration of the facts at present known does not warrant the conclusion, 

 that the direct transition of the follicles into chyle-vessels, as Briickc main- 

 tained at first, has been proved (see my Micr. Anat., II. 2, p. 188), nor that, 

 as Briicke now assumes, there exist in the interior of the follicles interstitial 

 chyle-spaces, which lie between their vessels, and lead externally to true 

 lymphatic vessels upon the follicles. That there is a difference between the 

 Peyerian patches and the lymphatic glands cannot be denied. In the latter, 

 the alveoli communicate directly with one another ; whilst in the former, the 

 follicles are almost always completely closed vesicles (communications of in- 

 dividual follicles, as were observed by Herile and Briicke, are certainly very 

 rare ; I likewise never saw them destitute of a wall at any side) ; further, the 

 lymphatic glands have afferent and efferent chyle-vessels, whilst on the patches 

 of Peyer, only the latter are known ; lastly, the alveoli of the glands, as I must 

 remark, in contradiction to Briicke, are also found filled with chyle, whilst 

 in the follicles, no one has, hitherto, seen anything of the kind. Never- 

 theless, I will not altogether dispute Briickc s view of the signification of the 

 patches of Peyer ; and I would call upon observers to investigate whether 

 lymphatic vessels exist in the interior of the follicles, and whether, as I 

 have seen in one case (Zcitschr.f. wiss. Zool.), the chyle-vessels coming from 

 the patches are richer in chyle-cells than those proceeding from other places 

 of the intestine, which, if confirmed, would, in my opinion, be sufficient in 

 warranting us to regard these organs as formative centres of the lymph- 

 corpuscles. 



