Having a good digestion, the Mandrill has a tolerably large liver, but it is separated into several lobes, or pieces, which are more in number than those of the other genera; but as it is partly insectivorous in its diet, there is no necessity for a very full-sized large intestine, and this is not furnished with the appendix noticed in the man-shaped Apes. Finally, as regards the skull, it may be said, that that of a large adult Mandrill is the strongest created; so huge are the jaws, face, teeth, and crest-ridges, that one wonders where its brain can be put in life. The true brain-case is indeed small, and is encroached upon inside by the back of the orbits, whence the eye looks out under the “beetle-brows.” The forehead bone is triangular-looking, and there is no ascending of the forehead, the bone being, as it were, crushed flat, so as to make a triangular space with the brows in front. Ridges exist on the sides of this space, and pass backwards to the occiput, where they meet side crests from the ear-bones. The occiput is stuck up in a singular manner, and the surface of the bone is strongly marked by the muscles which draw the head backwards. Of course the singular part of the skull is the huge ribbed prominence of the upper jaw-bone on the side of the nose, and the great upper canine teeth. THE DRILL.[69] Very little is known about the habits of another Baboon which is found on the coast of Guinea, and which is called the Drill. But it has been described, drawn, and stuffed frequently, and has been called Wood Baboon, the Cinereous Baboon, and the Yellow Baboon. The natives evidently confound it with the young Mandrill; and as it is good-tempered when young they capture specimens for European menageries, where they are commonly to be seen. It appears to be a modified Mandrill, like it in temper, and in its disagreeable adult qualities; it has not, however, the grand coloration of the face, although the prominences of the cheek-bones are present. The Drill is smaller than the Mandrill, and has a short stumpy tail, occasionally two inches in length, covered with bristly hair, and ending in a brush. The colour of the hair is greener than that of the Mandrill, and underneath it is whiter and more silvery, whilst there is much light-brown hair on the upper parts of the limbs. It has whiskers, which are brushed back, and a small orange-coloured beard; moreover, the general tint of the skin beneath the hair is dark-blue, and the dinginess is relieved by scarlet callosities.