LARGE-HEADED QUADRUPEDS.

The great teeth of such quadrupeds as the Hippopotamus require proportioned jaws, and, consequently, the bones of the head are of great strength and weight. Thence arises a necessity for the head being supported by a particular ligamentous apparatus, which in the bull is vulgarly called the paxwax (the ligamentum muchæ). This ligament extends from the prominent spines of the vertebrae betwixt the shoulders, to the occiput or back of the head, so as to suspend the head, and of course without muscular exertion or waste of vital energy. This ligament, however, differs from the common ligaments which knit the bones together, in being elastic; without which property it would check the motions of the head. On this subject of the wonderful provisions evinced in the bones of the head and neck of the larger animals, we were much interested in what was lately delivered by Sir C. Bell, the anatomical Professor in the Royal College of Surgeons. On exhibiting the skull of the elephant, and leading his audience to remark the weight of the grinding teeth, the length of the tusks, and the size and strength of the jaws, he observed it was impossible that such an enormous engine of mastication could be suspended at the end of a long neck. Jockies, he said, attended very particularly to a light head and a short neck in a horse; a heavy head and a long neck brought too great a weight to bear upon the fore-feet. If such slight differences in the shape were observed to produce defects in the horse, the consequent imperfection would be incalculably greater in the elephant. But in this animal, nature, instead of projecting the head on such a neck as would enable the mouth to reach the ground, diminishes the depth of the vertebrae of the neck in a very remarkable manner, so as in fact to fix the head to the body without the intervention of a neck. But how was the animal to feed? since the want of a neck and the projection of the tusks made grazing in the usual way impossible. This implied the necessity of a trunk, which is equivalent to a hand, and enables the animal to feed itself without projecting the head to the ground. By these and similar illustrations, the Professor proved design in the structure of the skeleton; and contrasted the heads of the horse, the elephant, and the giraffe.