When Jumbo—who was an African elephant—and one of the Asiatic elephants stood side by side, the difference was very marked. The summit of the head of the Indian species forms a pyramid, while the front, or forehead, is concave. In Jumbo the front of the head was somewhat convex, the eye was larger; and when we compare the feet, we find that while the African elephant has, as a rule, four nails on each foot, the Asiatic has four on each hind-foot, and five on each fore-foot. The number of nails often varies with individuals. The Indian natives esteem those animals most which possess five on each fore-foot, and four on each hind-foot, or eighteen, odd numbers being considered unlucky. The author of “Oriental Field Sports” says that he has observed elephants with fifteen nails, which no native would purchase; and he heard of one with twenty, and saw one with eighteen. These differences are external, as all elephants possess five toes upon each foot internally. The two species also differ as to their teeth. The incisor teeth of elephants are greatly developed, forming the tusks, and only occur in the upper jaw of living forms. They often attain enormous size, weighing from one hundred and fifty to three hundred pounds. The tusks of the Asiatic elephants born in this country were visible at birth. Concerning them in general, Sanderson states that they are not renewed, but are permanent; his information being based upon the personal observations of many years. Corse, who made observations in the last century, and published them in the “Philosophical Transactions,” 1799, states that the elephants observed by him had milk, or deciduous tusks as well as permanent ones; that the milk-tusks appeared at about six months of age and fell out between the first and second years. He found in the young skull the place of the capsule of the permanent tusks, which appear a couple of months after the loss of the milk-tusks. Huxley says, “In recent elephants, only the two incisors are preceded by milk-teeth;” and this may be the generally accepted belief. The tusks have no roots like the teeth of some animals, but fit firmly into what are called premaxillary sockets: and if we should examine this buried or hidden portion, we should find that it was partly hollow, so to speak; the ivory at the root being very thin, and surrounding a pulp where the ivory is being secreted. The length of this soft pulp varies according to the age of the animal: thus, in young elephants, only a small portion of the tusk outside of the gum is solid ivory; all the rest being hollow, or containing the pulp. As the animal grows, this cavity decreases in length, until in extremely old elephants it disappears entirely and the tusk is solid ivory.