The bones are all strongly bound together by elastic bands, or _ligaments_, and are covered by the great fibrous masses, or _muscles_, which, forming as they do the flesh, take the chief share in giving to each animal its characteristic shape. These muscles are, in most instances, attached to the bones by strong cords or bands resembling the ligaments, and called _tendons_. The bones being, in great measure, articulated or jointed to one another by smooth surfaces, sometimes flat, sometimes round, sometimes pulley-like, act as levers. The muscles are usually attached at one end to a fixed at the other to a movable bone; when they act, by shortening in length and widening in diameter, they make the more movable bone to turn upon the other. In this way they cause the limbs to be straightened or bent, the jaws to be opened or shut, the claws extended or retracted, and perform all the other movements of which the animal is capable. The development of the muscles in the larger Carnivora is wonderfully great. A Lion will kill an Ox with a blow of his paw, and drag it off to his lair as easily as his humble relation, the Cat, disposes of a Rat or Mouse. We now have to consider a most important series of organs--the organs of _alimentation_ or _nutrition_; those, in fact, which serve the purposes of taking in, preparing, and digesting the food. They are the mouth with its tongue, teeth, and salivary glands, the gullet, stomach, and intestines, with the liver, and sweetbread, or pancreas. We are all familiar in ourselves with _four_ kinds of teeth, namely (1), the “incisors,” or cutting teeth, in front; (2), the “canines,” the pointed eye-teeth that come next; (3), the “false grinders,” or “premolars;” and (4), the true grinders, or “molars.” Man has a very even and full-mouthed series; the Carnivora, on the other hand, possess a most irregular series, and in this series there are certain gaps or interspaces. Our own even orderly set is best adapted for a mixed diet, that has for the most part undergone a great amount of change by cooking. But the Carnivora, in their wild state, must eat flesh raw, and for the most part reeking, and this has to be torn from the conquered prey. So that the teeth have to be applicable to the first, or destructive process, and then to the tearing to pieces of the fleshly substance, and the scraping of the bones; they may even have to crush the bones themselves, the more spongy parts serving for food; and, greatest feat of all, to break the hardest long bones for the succulent marrow.