Desert animals are generally the Colors of the desert. Thus, for instance, the lion, the antelope, and the wild donkey are all sand-colored. "Indeed," says Canon Tristan, "in the desert, where neither trees, brushwood, nor even undulation of the surface afford the slightest protection to its foes, a modification of Colors assimilated to that of the surrounding country is absolutely necessary. Hence, without exception, the upper plumage of every bird, and also the fur of all the smaller mammals and the skin of all the snakes and lizards, is of one uniform sand Colors."