The herpetology of mountain regions is very limited, for the number of species diminishes rapidly as we ascend in altitude or latitude. The reptilian life of any district, however, is highly interesting, as it is more natural and well defined than that of other vertebrates, because reptiles have a limited range … and are less likely to be forced out of their original habitats or introduced by man. It has been supposed that in order of altitudinal range, lizards go highest, snakes next, and batrachians and chelonians last. There are no chelonians in the valley as far as we know; but we found frogs as high up as Antisana Hacienda, and no lizards there. Gibbon found no snakes at La Paz.