Cats have a particularly flexible skeleton of more than two hundred and thirty bones, in which the forelegs can turn in almost any direction without strain, the head can turn almost completely through one hundred and eighty degrees and the spine is very mobile, especially the tail which can bend in any way it wishes. The skeleton is linked by more than five hundred well-developed muscles, which are especially strong in the lumbar region and the legs, to give them a powerful spring, and in the neck shoulders, to enable them to strike their prey. The cerebellum, that part of the brain which coordinates muscular movement and controls balance and direction, is also highly developed, giving the cat very fast reactions and enabling very rapid movement of its' lithe and agile body. The cat thus has the power and the fluidity of movement it needs to be a successful predator, but its chest cavity is small for its size,and consequently it has a small heart and lungs, which means that it is easily tired. In fact a cat's life consists of bursts of great activity interspersed with comparatively long periods of rest and recuperation. The space saved by the small chest is taken up by large digestive organs to allow for the alternating periods of gorging and fasting which make up the life of a carnivore in the wild. Like man, the cat has a collar-bone; it is the only domestic animal to have one-though it is small and does not hamper freedom of movement. Its limbs and digits, however have developed in a quite different way.
Its legs have similar components to those of human limbs, but its wrists and ankles appear to be halfway up the leg-only when a cat is sitting does its hind "foot" rest on the ground in human fashion. Its elbows and knees appear much closer to the body. The leg joints are arranged at closed angles which, coupled with their muscle power,gives them the ability to make great jumps. The cat walks upon its toes, of which there are normally five on each forefoot and four on each hind-foot, although extra toes are not uncommon. The soft fleshy pad of paws absorb any sudden shocks and protect the cat's weight-bearing bones. With their downy covering, and the tufts of fur between the pads, the paws make a cat's stealthy tread very quiet indeed-but by no means inaudible to other cats. Naturally outdoor cats wear off the down on their paws, which become tough and leathery, but do not lose their sensitivity, which is acute, or more so,than that of out fingertips. Although the cat's digits have not developed into the versatile fingers of the human hand, its front paws are used for an enormous range of activities. They will hold things down and lift things up, cupped they become a scoop, clasped together they will lift things between them, they can be dipped into cream at the bottom of a jug where no tongue can reach, they can test temperature and texture, pull, pummel, swat, fondle and clout, as well as act as a sponge for washing places where the tongue cannot stretch. Although a cat will normally carry things in its mouth, it will often first pick them up with its front paws which are much more flexible than most people imagine. The rear paws do not have such flexibility, but they are larger and stronger, and are used in fighting as well as providing the pushing power for running and jumping.
