CANAL

A cavity in the interior of an animal body in which the nutriment is taken to be digested, before it is conveyed by the nutritive ve els to Ihe system; it affords the best organical characteristic of an animal, but Ota various modifications of structure. Sometimes it is a simple cavity with one opening; sometimes a true canal, with an outlet or anus, distinct from the inlet or mouth; this canal may be divided into stomach and intestine, as in the oyster; or a mouth, pharynx, and oesophagus may pre [s. 45]