. Quain's elements of anatomy . the intestine (lacteals) may be conveniently distinguishedas those of the mucous membrane, and those of the muscular coat. Those ofth3 mucous membrane form a copious plexus (fig. 531) which receives thecentral vessels of the villi and pervades both the mucous and submucous layers—in the latter being of considerable size, and foi-ming, as before mentioned, aclose plexus or a sinus around the base of each lymphoid follicle. Another set oflymphatics lies under the peritoneal coat, and is especially developed along anarrow strip at the attachment of the mesentery. I
. Quain's elements of anatomy . the intestine (lacteals) may be conveniently distinguishedas those of the mucous membrane, and those of the muscular coat. Those ofth3 mucous membrane form a copious plexus (fig. 531) which receives thecentral vessels of the villi and pervades both the mucous and submucous layers—in the latter being of considerable size, and foi-ming, as before mentioned, aclose plexus or a sinus around the base of each lymphoid follicle. Another set oflymphatics lies under the peritoneal coat, and is especially developed along anarrow strip at the attachment of the mesentery. In the muscular coat, the mainjdIcxus is situated between the circular and longitudinal layers of fibres (fig. 532,1);and there are likewise close plexuses threading the whole thickness of the muscu-lar wall. These lymphatics of the muscular coat are in complete continuity withthose of the mucous membrane, and pass into larger vessels at the mesentericborder,which again run into the lacteal vessels of the mesentery. Fig. Fig. 531.—Vertical section op a portion of a patch of Peters glands, withTHE lacteal vessels INJECTED (after Frey). 32 diameters: The specimen is from the lower part of the ileum : a, villi, with their lacteals leftwhite ; &, some of the tubular glands; c, the muscular layer of the mucous membrane ;d, cupola or projecting part of the nodule ; e, their central part ; f, the reticulatedlacteal vessels occujjying the lymphoid tissue between the nodules, joined above bythe lacteals from the villi and mucous surface, and passing below into g, the reticulatedlacteals under tlie follicles, which again pass into the large, efferent lacteals, j; i, partof the muscular coat. Tlie iiervcx of the small intestine are chiefly derived from the superiormesenteric plexus. This plexus is formed by nervous branches, from the coeliacplexus, the semilunar ganglion, and from the vagus nerve. The plexus andplexif orm branches into which it divides cling at first very closely
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