THE FATS. 293 



adhere externally to the epithelium of the intestinal mucous mem- 

 brane. The occurrence of these external globules on the epithelium 

 is a perfectly natural phenomenon, and there is no difficulty in dis- 

 tinguishing them from fat-globules within the epithelium and from 

 other cells. Now if we consider the epithelial cells themselves, 

 whether they are still adherent to the villi, or have peeled off in large 

 thimble-like shreds, we very frequently find fat-globules in them, 

 which, however, are not to be observed, or are few in number, after 

 the use of food free from fat. During digestion the cylinder epithe- 

 lium is often somewhat distorted in form, and presents a distended 

 appearance ; the broad margin of the base of the conical cylinder 

 epithelium is raised up into an extremely thin and hyaline, strongly 

 convex, or perfectly hemispherical cover. Below the epithelium 

 we perceive the lacteals commencing in small club-like dilatations, 

 and surrounded by a layer of vesicular or cellular bodies, which 

 appear as if they were imbedded in an undefined fibrous mass, the 

 true parenchyma of the villi ; more externally, near the peripheral 

 investment of the villi with cylinder epithelium, there are not only 

 the contractile fibre-cells which were first seen by Briicke, but also 

 the small trunks of the blood-vessels which communicate with one 

 another by a very fine network of capillaries. According to 

 E. H. Weber,* there is, however, a layer of roundish cells, in addi- 

 tion to the blood-vessels and lacteals, between the epithelium and 

 the true parenchyma of the villi ; in the fasting state these cells 

 present a collapsed appearance, but during digestion they become 

 filled and much distended. It is, moreover, worthy of remark, that 

 very often (but not always) some few of these vesicles are filled 

 with a dark granular matter, while the great majority, amongst 

 which they are interspersed, are distended with a light fluid exactly 

 resembling oily fat ; we very often see a large vesicle (dark in 

 transmitted, but white in incident light), and by its side another 

 vesicle equally distended with a strongly refracting fluid; in addition 

 to the very distended cells of these two kinds, which are for the 

 most part situated on the apices of the villi, we always remark 

 gradual transitions to minute granules, some of which are light 

 and others dark, as far as the immediate neighbourhood of the 

 finest ramifications of the lacteals in the villi. Funke has given 

 accurate delineations of Weber's preparations, in his Atlas 

 (P. 8, F. 1, 2, and 3). While Weber regards these light and dark 

 vesicles as a layer of true cells between the epithelium and the 

 parenchyma of the villus, and is consequently of opinion that the 

 * M tiller's Arch. 1847, S. 309. 



