Phillipsburg Herald

A Beaver's Teeth.

As in every 'gnawer,' the beaver's skull is armed with two long chisel-like teeth in each jaw. These teeth are exceedingly powerful, and are to a beaver what an ax is to a woodsman. One such tooth taken from the lower jaw of a medium-sized skull (they can be removed without difficulty, unlike the most of ours) is bent into nearly a semi-circle, and measures five inches along its outer curve. Only one inch of this length projects from the skull. The corresponding one from the upper jaw is bent into more than a complete half-circle, and measures upon its outer face four inches, of which less than an inch protrudes from its bone casing. In width each tooth is five-eighths of an inch. Examination of one of them reveals the secret of how a beaver can perform such feats as chopping down a birch-tree sixteen inches in diameter, not to speak of softer woods, like the basswood, of much greater size. The tooth is composed of two materials. Along the outer face or front of the tooth is a thin plate of exceedingly hard enamel; on the inner, forming the body of the tooth, is a substance called dentine. The dentine, being softer, wears away with use; the thin enamel remains comparatively unworn, so that the tooth assumes the shape of a keen chisel that never grows dull. The tooth is hollow at the base for half its length, and is filled with a nourishing substance which keeps it constantly growing. Thus, not only is the natural wearing away provided against, but a certain amount of wear becomes an actual necessity. With such instruments, the beaver is admirably fitted for obtaining its natural food, the bark of shrubs and trees.—St. Nicholas.