Alimentary Canal′

Syn. Alimentary duct ; Cana′lis Aliment a′′rius , L. In anatomy , the cavity in the bodies of animals into which the food is taken for the purpose of being digested; the whole pa age or conduit extending from the mouth to the anus. In some of the lower animals this is a simple cavity, with only one opening; when the same aperture which admits the food also gives egre to the excrementitious matter. In others it is a true canal, with both a mouth and an outlet. Another step, and we find this canal is divided into a stomach and intestines. In the higher grades, a mouth, pharynx, and œsophagus precede the stomach. Birds have one or two sacculi or crops added to the œsophagus. The stomach of the ruminants consists of four sacs or parts, each of which may be regarded as a separate stomach; that of the bottle-nose whale contains no le than seven of such sacs. The part below the stomach, forming the intestines, is also variously subdivided, complicated, and connected. In man, these subdivisions are termed— DUODENUM , JEJU′NUM , IL′EUM , CÆ′CUM , CO′LON , and REC′TUM ; the lower end or orifice of the last being called the A′NUS . The existence of an alimentary canal is said to be the only true characteristic of an animal. Plants have no common receptacle for their food, nor canal for carrying away effete matter; but every animal, however low in the scale of being, po e es an internal cavity which serves it as a stomach.