A single genus seems able to adapt itself to the climate and conditions of the Temperate Zone, and still reigns in the Mediterranean region--in Africa, to the north of the Atlas; in Spain, on the rock and in the neighbourhood of Gibraltar--this is the genus Baboon (the _Pithecus_ of the classical writers), included in the family Macaucos. It differs from other genera of the same family in being tailless. This organ is rudimentary in some species of Macaucos, properly so called--as in the Red-faced Macauco of Japan; in others, its length never exceeds that of the animal's body. It is the same with the genus Mangabey. Among the Cynocephali, the tail is usually short. These apes are remarkable, as their name indicates, for their prominent muzzle, which resembles that of a dog; and, moreover, for the naked callosities, more or less extensive and of a bluish or vivid red colour, which exist on the upper part of their thighs, immediately beneath the tail. The Macaucos and the Cynocephali are, in general, of tall stature. When standing upright, they will be about two and a half to three feet in height, but this posture is not natural to them, and they rarely adopt it unless constrained. For their hinder limbs being of nearly the same length as the fore, the quadrupedal mode of progression is easy and habitual, either when they move on the ground or traverse the horizontal branches of the trees among which they live. These apes are endowed with surprising strength, and several, especially among the Cynocephali, render themselves formidable by their ferocity and their aggressive audacity. In captivity they show, while young, a mildness of disposition which, joined to their keen intelligence, would seem to render them capable of being greatly improved by careful training. But these good inclinations do not long endure: arrived at the adult age, the Macaucos and Cynocephali soon allow all their malignity, mischievousness, brutality, and vicious instincts to peep out, and as they grow older become completely intractable.