212 Mr. H. Watney on the Minute [Jan. 27, 



Groups of young cells are found. These groups (" epithelial buds ") 

 are due to germination. 



2. The membrana propria covering the villi is composed of large 

 cells. In vertical sections the cells are seen to be round or oval, and lie 

 close below the above-mentioned dark line. "When the membrane is 

 separated from the rest of the tissue, it is seen to be composed of these 

 cells arranged as an endothelium. The membrana has holes or gaps in 

 it ; and in teased preparations the superficial capillaries are always 

 attached to it, as the large cells partially surround the vessels. Villi 

 which are denuded of their epithelium are bordered by these large cells, 

 and not by the dark line, as the reticulum (which forms the dark line) 

 breaks off with the epithelial cells. 



In oblique sections of the villi the reticulum is seen to surround the 

 cells forming the membrana. 



3. The membrana of Lieberkiihn's crypts, when isolated from the 

 surrounding structures and viewed from above, is found to be a homo- 

 geneous membrane with nuclei imbedded in it. In oblique sections of the 

 membrane in situ it is seen to be composed of cells, and the reticulum is 

 found to surround the cells composing it. 



4. The muscle-endings in the mucosa. — In cross sections of the 

 muscle-fibres of the muscularis mucosae, a reticulum is seen to surround 

 the individual muscle-fibres ; this reticulum is continuous with that of 

 the mucosa. 



The author next describes the manner in which the muscle-fibres 

 terminate in the rabbit's colon. The individual fibres are attached to the 

 large cells forming the membrana propria by means of the reticulum. 



This reticulum must therefore be regarded not only as a network of 

 threads, but as forming in places membranous investments. 



5. The muscle-fibres in the villi have an adventitia formed by the 

 reticulum of the villus ; if the muscle-fibres end near the membrana, the 

 adventitia may be attached to the endothelial cells forming the mem- 

 brane. 



6. The blood-vessels are found to have an adventitia formed by the 

 reticulum. In the veins the reticulum surrounds the endothelial cells 

 and even passes betiveen them. In the arteries the reticulum surrounds 

 the muscle-fibres ; and where the latter are few and scattered, the reti- 

 culum forms a very definite adventitia to the vessel. 



7. The chyle-vessels are also found to have an adventitia formed by 

 the reticulum ; i. e. in longitudinal sections of the vessel threads are 

 seen attaching the vessel to the reticulum. The reticulum can be seen 

 to penetrate between the endothelial cells in the same manner as in the 

 veins. 



8. The tissue of the mucosa is shown to be composed everywhere of 

 a reticulum and of cells held in its meshes. The author finds that while 

 there is no difference, or only slight differences, between the reticulum 



