Travellers unacquainted with the reptiles which haunt the wilds of America, on first seeing a whip-snake rapidly approaching, will, with sensations of alarm, urge on their steeds to escape--for it appears fully capable of springing up and inflicting mortal injury; but, from having no fangs, it is unable to harm any one. From the delicacy of its colour, the elegance of its form, and the rapidity and gracefulness of its movements, it cannot fail to be admired. FROGS:--THE BULL FROG. We shall find no small number of the frog race throughout America. Worthy of being the president of his nation is that enormous batrachian, the bull frog, both from his size, the power of his notes, and his hardihood and endurance. If we visit at night the neighbourhood of some pool or marsh, we shall soon learn to know the sound of his voice, especially when perhaps he and five hundred of his family are, with their heads half out of the water, amusing themselves in the performance of a concert, each striving to outdo his neighbour in the loudness of his tones. He is a first-rate swimmer; and when driven out of the hole in which he passes the warm hours of the day, he plunges into the water, and skims along the surface some distance before he dives below it. Only on such occasions, or when, perhaps, a dark thunder-cloud shrouds the sky, does he appear in the daytime, and give utterance to his notes. He feeds on snails and water creatures; sometimes on crayfish and other crustaceans; and occasionally, if a duckling or young chicken come in his way, he will not scruple to take them into his capacious maw. His ordinary size is from six to seven inches; but specimens have been met with which have measured nineteen--and even twenty--inches, from the nose to the extremity of their feet. He has a smooth black skin above, with a greenish hue on the head, and lower part of the body greyish-white--the throat being white, dotted with green. He can take enormous leaps; and is so admirable a swimmer, that specimens have been known to exist in the water without once landing for several years. THE SOLITARY FROG. Inland, where no water is to lie found, we shall meet with a creature of an olive colour--the back covered with tubercles--and with a blunt nose. It might easily be mistaken for a toad, though it is a veritable frog. Even in winter, before the snow has disappeared, we may see the hardy little creature making its way over the frozen surface of the ground. At the breeding season, however, it returns, like other frogs, to the water. It resides for the chief part of the year in sandy districts, in which it forms burrows, about six inches in depth, by means of a flat, sharp-edged spur, with which it is furnished. Into these burrows it makes its way backwards, very much as a crab crawls into its hole when seeking shelter from danger. There it sits, with its head poked out, watching for passing prey. THE SAVANNAH CRICKET FROG.