There is no animal, however, whose sagacity can foil human ingenuity. The trappers, who hunt the beaver for the sake of his fur, and the peculiar odoriferous secretion called _castor_, are more than a match for all his artifices. Not even in winter-time is he safe from their pursuit. Striking the ice smartly, they judge from the sound whether they are near an aperture; and as soon as they are satisfied, cut away the ice and stop up the opening, so that the beavers, if alarmed, may not escape into the water. They then proceed to the shore, and by repeated soundings trace the course of the beavers' subterranean passage, which is sometimes eight or ten yards long, and by closely watching the different apertures invariably catch the inhabitants. While thus engaged, they must be careful not to spill any blood, as in case of such a mishap the rest of the beavers take alarm, retreat to the water, and cannot be captured. The trappers entertain a superstitious notion, which leads them to remove a kneecap from each beaver and throw it into the fire. The beavers generally quit their huts in the summer-time, though one or two of the houses may be tenanted by a mother and her young family. Those old beavers which are free from domestic ties take to the water, and swim up and down the stream in bachelor-like liberty until the month of August, when they return to a settled life. There are, also, certain individuals called by the trappers "_les paresseux_," or "the idlers," which do not live in houses, and construct no dam, but dwell in subterranean tunnels like those of our common water-rat. They are always males; gay young bachelors, with no incentives, we will suppose, to an industrious career. Neither in the beaver nor in the human world, however, does idleness prosper, for the capture of "les paresseux" is a comparatively easy task. * * * * * South America is the home of those singular Edentate Mammals, with scaly shields, which the natives call _Tatous_, but which are better known to Europeans by the name of _Armadillos_ (_Priodonta gigas_). Cuvier has divided the whole genus into five groups, distinguished from one another by the number and form of their teeth and claws:--"Cachecames," "Apars," "Encouberts," "Cabassous," and "Priodontes." Their general characteristics, however, are the same, and to describe one is virtually to describe all.