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.
The mode of feeding and the form and number of the teeth of necessity correspond: tearing and gnawing are processes that need teeth like knives and scissors, while grinding or chewing require teeth like millstones. Both these kinds exist in the Bear. In the Dog the crushing teeth become less in size and importance; in the Lion they are suppressed, and all the teeth have a cutting character, their number being at the same time much reduced.
The teeth are often all that remains of certain extinct creatures; they are, therefore, a most important part of the anatomy of an animal, as well as being of great service in the matter of classification or grouping. They are the hardest of all the organs; their relation to the food of the species, and their necessary correlation to the digestive organs, makes them serve as a key to the rest of the creature’s structure, which structure is in absolute harmony with its habits and daily life.
STOMACH OF LION.
The tongue is covered with horny projections, or papillæ, and in the Cat tribe serves as a rasp to rub and scrape off the smaller fragments of flesh from the bones. The stomach is always simple, that is, consists of a bagpipe-like cavity not divided into compartments, as in the Ruminants and some other animals. A great difference from herbivorous animals is also seen in the length of the intestine. As the food is of a highly nourishing nature it requires less time for its digestion, and a smaller surface for its absorption into the blood, and the intestine is therefore remarkably short—not more than three times the length of the body in the Lion and Wild Cat, instead of being fifteen to thirty times the length, as in some vegetable feeders. The Carnivora have, therefore, the manifest advantage of a more compact and smaller “barrel” than the Herbivora, and, in consequence, have less weight to carry, and are slim and slender-waisted.
As might naturally be expected, the organs by which the blood, loaded with nourishment from the digestive canal, is carried to all parts of the body, are well developed. The heart, if not “as hard as the nether millstone,” is yet compact and strong in the highest degree: the circulation is vigorous, and the result is seen in great courage and astonishing powers of endurance.
