for miles across the land from one river-bed into another. On the same spot where, erewhile, the thirsty horse anxiously snuffed the air to discover by its moisture the presence of some pool, the animal is now obliged to lead an amphibious life. The mares retreat with their foals to the higher banks, which rise like islands above the waters, and as from day to day the land contracts within narrower limits, the want of forage obliges them to swim about in quest of the grasses that raise their heads above the fermenting waters. Many foals are drowned; many are surprised by the crocodiles, that fell them by a stroke of their jagged tail, and then crush them between their jaws. Horses and oxen are not seldom met with, which, having fortunately escaped these huge saurians, bear on their limbs the marks of their sharp teeth. ‘This sight,’ says Humboldt, ‘involuntarily reminds the observer of the great pliability with which nature has endowed several plants and animals. Along with the fruits of Ceres, the horse and the ox have followed man over the whole earth, from the Granges to the La Plata, and from the coast of Africa to the mountain-plain of Antisana, which is more elevated than the lofty peak of Teneriffe. Here the northern birch-tree, there the date-palm, protects the tired ox from the heat of the mid-day sun. The same species of animal which contends in eastern Europe with bears and wolves, is attacked in another zone by the tiger and the crocodile.’ [Illustration: ELECTRICAL EEL. (GYMNOTUS ELECTRICUS.)]