Note 39 — STEPPES AND DESERTS.

p. 20.—“Awakened from a torpid state by the first fall of rain.”

Extreme dryness produces in plants and animals the same phenomena as does the withdrawal of the stimulus of heat. Many tropical trees and plants shed their leaves during the dry season. The crocodiles and other amphibious animals hide themselves in the mud, where they lie apparently dead, like animals in a state of hybernation or plunged into winter sleep by cold. (See my Relation historique, T. ii. pp. 192 and 626.)