anus (anus)

[L., prob. orig. the same as ānus, ann us, a ring: see annulus.] The termination of the digestive tube or alimentary canal; the end of the enteron of any animal; the orifice through which the refuse of digestion is voided. The anus is usually on a part of the body away from the mouth, but it is sometimes coincident with the latter. It is usually a circular orifice, provided with a sphincterial arrangement by which it may be shut; but it is sometimes a cleft or chink, the direction of the axis of which distinguishes zoological groups: thus, it is long i tudinal in turtles, and transverse in lizards and snakes. In many vertebrates and other animals the anus serves for the discharge of the excretion of the kidneys and of the products of the generative organs, as well as of the refuse of digestion. See anal. -anus. [L., a common adj. suffix, whence E. -an: see- an.] A suffix of Latin adjectives and nouns thence derived: common in New Latin names, especially specific names.