B/.TRACHIANS. 07 



form there the branchia?. These latter are numerous small tufts attached 

 to four cartilaginous arches, placed on each side of the neck, adhering to 

 the hyoid bone, and enveloped in a membranous tunic, which is covered 

 by the general skin. The water which enters the mouth, passing through 

 the intervals of the cartilaginous arches, makes its exit, sometimes by two 

 openings, and at others by one, situated either in the middle or left side 

 of the external skin, according to the species. The hind feet of the Tad- 

 pole are very gradually and visibly developed; the fore feet are also deve- 

 loped, but under the skin, through which they subsequently penetrate. 

 The tail is gradually absorbed. The beak falls and discloses the true 

 jaws, which at first were soft, and concealed beneath the skin; and the 

 branchia? are annihilated, leaving to the lungs alone the function of re- 

 spiration in which they participated with those lungs. The eye which at 

 first could only be discerned through a transparent spot in the skin of the 

 Tadpole, is now visible with its three lids. The intestines, which, in the 

 beginning were very long, slender, and spirally arranged, become short- 

 ened, and acquire the enlargements requisite for the stomach and colon ; 

 for the Tadpole feeds solely on aquatic plants, and the adult animal upon 

 insects and other animal matters. Tadpoles reproduce their limbs almost 

 like Salamanders. 



The period at which each of these changes takes place varies with the 

 species. 



In cold and temperate climates, the perfect animal passes the winter 

 under ground, or in mud under water, without eating or breathing, though 

 if we prevent it from respiring during the summer for a few minutes by 

 keeping its mouth open, it dies. 



Rana, Laur. 

 Frogs, properly so called, have a long tapering body; the hind feet ex- 

 tremely long, strong, and more or less perfectly palmated ; the skin smooth ; 

 upper jaw furnished all round with a row of small fine teeth and an inter- 

 rupted transverse range of them in the middle of the palate. On each 

 side of the head of the male and below the ear is a thin membrane, which 

 becomes distended with air when he croaks. These animals leap and 

 swim well. 



R. esculenta, L. ; Rcesel. Ran. pi. xiii, xiv. (The Green Frog). 

 A fine green spotted with black; three yellow streaks on the back; 

 belly yellowish. A common species in Europe in all stagnant wa- 

 ters, and very annoying by its ceaseless nocturnal clamour. Its 

 flesh is a wholesome and agreeable food (a). The female exudes 

 her ova in bundles in the marshes, &c. 



R. temporaria, L. ; Rcesel. Ran. pi. i, ii, iii. (The Common 

 Frog). Reddish-brown spotted with black; a black band com- 

 mencing at the eye and reaching across the ear. This species is the 

 first that appears in the spring; it visits the land less frequently than 

 the preceding, and is not so noisy. Its Tadpole is not so large at 

 the epoch of its metamorphosis. The South of France produces a 

 Frog, 



@5ir (n) At least for the French; hut these reptiles are never used for food in 

 England. — Eng. Ed. 



r 2 



