Page:Natural History, Reptiles.djvu/138

130 Like most of the tribe, the Viviparous Lizard varies considerably in its colours and markings. The most common variety is of an olive hue, with a line of dark brown down the back, and a band of the same down each side, with rows of black spots between; the under parts are, in the male, bright orange, spotted with black,—in the female pale greyish-green, without spots. Six inches is the average length of the adult male.

There is not perhaps in the whole circle of zoology, a more beautiful example of the gradation between forms whose extremities are widely distinct from each other, than is presented by the gradual and almost imperceptible transition of the Lizards into the Serpents. If we look at a Chameleon, or an Iguana on the one hand, and then at a Rattlesnake or a Cobra di Capello on the other, they seem almost as remotely separated as animals of the same class can be; and yet so minute are the steps by which we are led from one to the other, that it is impossible with any satisfaction to draw a line that shall divide them, other than such as is merely conventional and arbitrary. Pressed by this difficulty, while some zoologists, as Mr. Gray, separate the Lizards from the Serpents by a third order, called Saurophidia, constituted expressly for the reception of these intermediate and transition forms, others, with Merrem have preferred to consider the whole of the scaled reptiles as forming but a single Order.