Page:Natural History, Reptiles.djvu/122

114 and the aquatic Monitors, the habits of which differ much from each other. The former have the tail conical and nearly round, and these live in sandy districts or among dry rocks, never frequenting water. They run with rapidity, with a serpentine motion, a mode of progression produced by the long and muscular tail, which helps to push them forward, and aids them in leaping on the prey which they pursue. Some of these were known to the ancients, who regarded them as terrestrial Crocodiles, probably from their size and ferocity.

The aquatic Monitors, which are by far the more numerous, have the tail, which is very muscular and strong, compressed through its whole length; it thus forms a powerful organ of progression in swimming, especially as its upper surface is frequently surmounted with one or two rows of flattened scales forming an elevated crest. These frequent the banks of lakes and rivers, which they traverse by swimming, and into which they are said to drag their living prey, when they have seized it, in the manner of the Crocodiles.

The food of the Varanidæ consists, it appears, of any animals which they have size and strength sufficient to overcome. The terrestrial species hunt after large insects, such as cockroaches, locusts, and beetles; the eggs of ground-building birds, and small vertebrate animals. The aquatic species are still more formidable, for, besides fishes, tortoises, chameleons, and the eggs of birds and of crocodiles, they are said to prey on quadrupeds of considerable size and strength. M. Leschenault de Latour asserts that they associate in bands, and watch at the margins of the rivers to