Page:Jardine Naturalist's library Entomology.djvu/141

Rh of the intestine," says Burmeister, speaking of that part which corresponds to what we have called after the French physiologists, the small intestine, "is to be determined from its divisional distance from the stomach, it must be considered as the true ilium, which is however contradicted by its function, which, like that of the cæcum of the glires of the mammalia, subjects the food to a second digestion and extraction before it is rejected. We are convinced of this by the comparison of its state in the stomach, and in this portion of the canal, for we find it here much more pappy than there, but not so viscous as in the colon." The Cæcum (Pl. II. fig. 2 g.) is that portion of the canal, behind the small gut, where the unassimilated parts of the alimentary substances, now completely deprived of their nutricious particles, begin to acquire a hard consistency, previous to their expulsion by the rectum. It is generally a direct continuation of the small intestine, but it is divided from it by a valve, which completely shuts up the opening. In some cases, however, the intestine is united to its side, and it forms a large ovoid vessel, as in Dytiscus Rœselii, and allied species. The external surface is frequently covered with papillæ, and the internal, particularly near the mouth of the small gut, with glandular warts, which are supposed to secrete a fluid to assist in the expulsion of the fecal matter. This segment of the canal is usually short, but it varies too much to admit