ELABORATION OF NUTRIENT MATERIALS PEYER's GLANDS. 211 



the glands are made up of an adenoid or cytogenous tissue, the meshes of 

 which contain lymph-corpuscles, and fatty and albuminous molecules of 

 various size; altogether presenting an appearance of heing the seat of 

 rapid changes of progressive metamorphosis. Each follicle is surrounded 

 by a large lymphatic sinus, 1 beneath which is a close vascular network ; and 

 according to the observations of Frey, which have been confirmed by K<il- 

 liker,' 2 capillary vessels pass freely into the midst of its contents, and then 

 return loops, as shown in Fig. 89. The researches of Teichmaun 3 show 



FIG. 89. 



Horizontal Section through the middle plane of three Peyerian Glands in the Rabbit, showing the 

 distribution of the bloodvessels in the interior. 



that these bodies are never penetrated by any lacteal vessels, though their 

 presence in the mucous membrane occasions considerable disturbance in the 

 usual arrangement of the lacteal system. The figures on page 189-190 

 show clearly the relations which they hold to the surrounding vessels, to- 

 gether with the general structure of the small (Fig. 76) and large intestine 



1 Klein, in Handbook for the Physiological Laboratory, 1873. p. 125. 



2 Mikroskopische Anatomie, Band ii, 171. 



3 Teichmann's investigations were chiefly made by means of injections ; but His, 

 who examined thin sections of the intestinal mucous membrane after merely washing 

 them with water and a camel-hair brush (Untersuch. iiber den Ban der Peyerischen 

 Driisen, Leipzig, 1868, p. 7), maintains the elaborate system of vessels described by 

 Teichmann to be only splits or fissures in the membrane between the follicles, trav- 

 ersed by fibrous cords and bands, and containing bloodvessels. At the same time 

 ho agrees with the view that they serve as channels for the conduction of the chyle. 

 He considers that the proper substance of the parietes of the follicles is continuous 

 with that of the villi and subjacent portion of the mucous membrane; both consist- 

 ing of a matrix of areolar tissue with nucleated cells imbedded in it, and of capilla- 

 ries, the latter being sparingly distributed to the follicles, causing them to appear 

 like clear spaces in fine sections. He applies the term adenoid tissue to the matrix of 

 the follicles, and to the surrounding tissue of the intestinal mucous membrane. The 

 Licberkiihnian Glands are imbedded in this adenoid substance, and immediately 

 external to them is the muscular layer (Brvicke) of the mucous membrane. He 

 believes lastly, that the cells imbedded in the adenoid substance become blood-cor- 

 puscles. 



