INTESTINE

The convoluted membranous and muscular tube extending from the pylorus to the anus. It is distinguished into small and large intestines: the former including the duodenum, the jejunum, and the ileum; the latter the ccecum, colon, and rectum. The small intestines have internal membranous folds, called valvulcB conniventes; the large have three parallel muscular bands upon their surface. The intestines admit of separation into three coats: the external, membranous or peritoneal; the middle coat, muscular; and the. inner one, villous. They are attached to the body by the mesentery. The structure of the intestinal canal in different animals is wonderfully adapted to its required functions, dependent upon the nature of their food and other circumstances. Of these peculiarities the principal are adverted to under the titles of the animals in which they occur. [s. 622]