CHYLIFEROUS APPARATUS. 



639 



Fig. 251. 



Fig. 252. 



Section 

 Villus. 



of Intestinal 

 (Gerlach.) 



a. Artery, b. Vein. c. 

 Lymphatic. Magnified 

 250 diameters. 



Intestinal Villus with the 

 commencement of a 

 Lacteal. (Krause.) 



All these are mere speculations, too often entirely gratuitous ; and 

 the view, that they never open by free orifices on the surface of the 

 intestine, as was formerly imagined, is entirely in accordance with the 

 results of modern histological inquiries. 



The marginal illustration, Fig. 252, from Krause exhibits the appear- 

 ance presented by the incipient 

 chyliferous vessels in the villi 

 of the jejunum of a young man, 

 who had v been hanged soon 

 after taking a full meal of fa- 

 rinaceous food. The chylife- 

 rous vessel issuing from each 

 villus appeared to arise by seve- 

 ral small branches, in some of 

 which free extremities could 

 be traced, whilst others anas- 

 tomosed with each other. The 

 arrangement of the different 

 anatomical constituents is well 

 seen in Fig. 251, which re- 

 presents an injected intestinal 

 villus of a cat, which was killed 

 during digestion. When they 

 become perceptible to the eye, 

 they are observed as in Fig. 

 249, communicating frequently with each other; and forming a minute 

 network, first between the muscular and mucous membranes, and after- 

 wards between the muscular and peritoneal, until they terminate in 

 larger trunks, a, a, a, a. When they attain the point at which the 

 peritoneal coat quits the intestine, they also leave it; creep for an inch 

 or two in the substance of the mesentery; and enter a first row of 

 mesenteric glands. From these they issue, of a greater size and in less 

 number; proceed still farther along the mesentery, and reach a second 

 row, into which they enter. From these, again, they issue, larger and 

 less numerous; anastomosing with each other; and proceeding towards 

 the lumbar portion of the spine, where they terminate in a common 

 reservoir, the reservoir of Pecquet, receptaculum seu cisterna cliyli, 

 (Figs. 250 and 253) which is the commencement of the thoracic duct. 

 This reservoir is situate about the third lumbar vertebra; behind the 

 right pillar of the diaphragm, and the right renal vessels. The chy- 

 liferous vessels generally follow the course of the arteries; but some- 

 times proceed in the spaces between them. They exist in the lower 

 part of the duodenum, throughout the whole of the jejunum, and in the 

 upper part of the ileum. M. Voisin 1 affirms, that all, or at least the 

 major part, of them pass through the substance of the liver, before 

 they empty their contents into the thoracic duct. After proceeding a 

 certain distance, they anastomose, he says, with each other, enlarge in 

 size, and are collected together so as to form a kind of plexus below the 



1 Nouvel Apergu sur la Physiologic du Foie, &c., Paris, 1833. 



