EXPLANATION OF THE PLATES. 



PLATE LII. 



Fig. 1. Villi, showing the layer of epithelial cells with which 

 they are generally covered, especially during the 

 intervals of digestion. Magnified 100 diameters. 



Fig. 2. Ditto, uncovered by the layer of epithelium figured 

 in the previous drawing, and showing the lacteals, 

 as well as the granular cells, which the villi always 

 contain, whether in an active or passive condition. 



Fig. 3. Peyer's Glands in the cat. Magnified 20 diameters. 

 The vessels in the villi, between the glands, are in- 

 jected ; but those of the glands themselves are not 

 so, and this accounts for their being uncoloured. 



Fig. 4. Vertical section of the mucous membrane of the 

 ileum of the cat, showing the flask-like form of 

 Peyer's Glands. No essential difference exists be- 

 tween these glands, as they occur in most of the 

 Mammalia, and in the human subject. This and 

 the previous drawing were prepared from two very 

 perfect preparations, kindly lent me by Mr. Quekett. 



Fig. 5. Follicles of Lieburkuhn in the duodenum. Magnified 

 60 diameters. 



Fig 6. Solitary glands of the small intestines uninjected, of 

 their natural size, and as they occurred in a case of 

 muco-enterite. 



