Why do Amphibia resemble Mammalia, and differ from Fishes?
Because their temperature is greatly influenced by that of surrounding objects. In this, and warm-blooded animals, as mammalia and birds, whose temperature is high, and not greatly influenced by the changes in the heat of external objects, the temperature is regulated by the vital powers of the animals; and limits are assigned, beyond which it is dangerous to pass. The range of warm-blooded animals is confined; that of cold-blooded animals extensive.
