Frog

Collier's New Encyclopedia (1921)

in zoology, (1) singular, the English name of the amphibious genus Rana, and particularly of the species Rana temporaria, or common frog. The genus Rana is distinguished from its congeners by having the tongue and tympanum distinct, the skin smooth, and out claws; they are, how. the toes without ever, pointed, and the hinder feet are united almost to the tips by a membrane. The common frog is too well known to require description. It buries itself in the mud at the approach of winter, reappearing in the spring. In the month of March it lays its eggs, which are enveloped in a gelatinous material, in water, where they float. Each female deposits from 600 to 1,200 eggs a year. By April they begin to hatch. The immature frogs which come forth are called tadpoles. They have tails, no legs, breath by gills, and are aquatic. Six or eight weeks later the legs are fully developed, the tail is absorbed, and they quit the water. The common frog is found in most parts of this country, in Europe, in the N. parts of Asia, and in the N. of Africa. Rana esculenta is the eatable frog, common on the European continent. R. pipiens is the bullfrog of North America, and R. clamitans the grunting or Algus frog. (2) Plural frogs; the family Ranidæ of which Rana is the type. They have a thick body, destitute of tail; feet four, long, muscular and adapted for leaping; the larva elongate, fish-like, tailed, and without legs; the gills four on each side. The family does not include the tree frogs, which are ranked as HYLIDE. In farriery, a kind of tender horny substance growing in the middle of a horse's foot.