As there is a greater power given in drawing up the tongue in the first stage of swallowing, there must be something extra to pull it down again in the second stage, for in this the back of the throat, the gullet, and the back of the tongue are all brought from above to a lower level. This is arranged by a modification of a muscle, which in man and the Chimpanzee, for instance, stretches from the top of the bladebone, across the lower part of the neck, to the bone at the base of the tongue (the _omo-hyoid_ muscle). It has also two bellies in man, or, in other words, the muscular fibres are attached to the bladebone and to the hyoid bone, and there is an intermediate tendon; moreover, this passes through a pulley, so that the obliquely-placed muscle in the lower part of the neck acts straight upon the tongue, and pulls it down in a right line. In the Macaques, this muscle has no central tendon, and the muscular fibres pass all the distance from the bladebone to the os hyoides at the base of the tongue. [Illustration: 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.