Of Edentates there are four. The giant armadillo does not range so far, and the delicate little pink fairy armadillo, the truncated Chlamydophorus, is a dweller in the sand-dunes of Mendoza, and has never colonized the grassy pampas. The Tatusia hybrida, called "little mule" from the length of its ears, and the Dasypus tricinctus, which, when disturbed, rolls itself into a ball, the wedge-shaped head and wedge-shaped tail admirably fitting into the deep-cut shell side by side; and the _quirquincho_ (Dasypus minutus), all inhabit the pampa, are diurnal, and feed exclusively on insects, chiefly ants. Wherever the country becomes settled, these three disappear, owing to the dulness of their senses, especially that of sight, and to the diurnal habit, which was an advantage to them, and enabled them to survive when rapacious animals, which are mostly nocturnal, were their only enemies. The fourth, and most important, is the hairy armadillo, with habits which are in strange contrast to those of its perishing congeners, and which seem to mock many hard-and-fast rules concerning animal life. It is omnivorous, and will thrive on anything from grass to flesh, found dead and in all stages of decay, or captured by means of its own strategy. Furthermore, its habits change to suit its conditions: thus, where nocturnal carnivores are its enemies, it is diurnal; but where man appears as a chief persecutor, it becomes nocturnal. It is much hunted for its flesh, dogs being trained for the purpose; yet it actually becomes more abundant as population increases in any district; and, if versatility in habits or adaptiveness can be taken as a measure of intelligence, this poor armadillo, a survival of the past, so old on the earth as to have existed contemporaneously with the giant glyptodon, is the superior of the large-brained cats and canines.