COMMON MACAQUE.
In addition to these modifications where muscle replaces tendon, there are those of several other muscles which act on the tongue, the larynx, and on the upper and lower parts of the windpipe, their conjoined action being to approximate all these parts. These muscles, which are separate in man, are united in one in the Macaques.
The head of these Monkeys, hanging as it does when they go on all-fours, requires extra support, and one of the muscles of the back, which from its square shape is called the rhomb-shaped muscle, is especially attached to the occiput, and helps to hold the head up. Another assistant in the movement on all-fours is a muscle which pulls the bladebone forwards when the animal is walking. It springs from the outer processes of the upper bones of the neck (transverse process of the upper cervical vertebræ), and is attached to the spine of the bladebone. This muscle is seen in the great beasts of prey also, and in the Semnopitheci and Guenons. A similar “wild-beast” peculiarity exists in the arrangement of the muscles of the hand; the muscle which extends the little finger and opens it is divided, and has greater connections with the fourth finger than in man. The long muscle which extends the thumb, and the short one which draws it from the fingers, are not separate in the Macaques, but the muscle has two tendons, and thus foreshadows the arrangement which in man and the higher Apes gives such perfection of movement to the thumb.
The Macaques have their ears rather pointed at the tip, and not rounded, and the general shape of their bodies is not lanky like that of the active long-legged Guenons and Semnopitheci. They are less gracefully made, and the dog-like appearance, so palpable in the Baboon, is recognised in their fore parts and head. Moreover, the colours are not usually pretty and variegated, as in many of the kinds of the genera already described, but are dun and sad in tint. Their tail varies according to the species in length, and a rough method of classification may be made which divides them into those with long, those with moderate, and those with short and almost no tails.
TOQUE.
The large Common Macaque (M. cynomolgus), and the Round-faced, or Formosan Monkeys (M. cyclopis), and the Bonnet Monkey, represent the long-tailed kinds; the Bhunder (M. rhesus), has a tail of middle length; and the short-tailed group about to be mentioned consists of the Moor, the Pig-tailed, and the Belanger Monkey. The tail-less one includes the Magot. Finally, the Silenus Ape, usually miscalled Wanderoo, is so baboonish that, although it has a long tail, it cannot be placed with the Common Macaque in the beginning of the chapter, but must come at the end, so as to lead to the true Dog-headed Apes, or Baboons, which will be described further on.
If the remarks in [page 106] about the fourth division of the Cercopitheci are now read carefully, it will be understood how these Monkeys, the Macaques and the Baboons, form a group of creatures which is only really separable into kinds or species, but that the genera are very artificial.