In size the reindeer resembles the English stag, but his form is less graceful and more compressed. He stands about four feet six inches in height. Long, slender, branching horns embellish his head. The upper part of his body is of a brown colour, the under part is white; but as the animal advances in years his entire coat changes to a grayish-white, and, in not a few cases, is pure white. The nether part of the neck, or dewlap, droops like a pendent beard. The hoofs are large, long, and black; and so are the secondary hoofs on the hind feet. The latter, when the animal is running, make by their collision a curious clattering sound, which may be heard at a considerable distance. The reindeer anciently invaded Europe and Asia to a comparatively low latitude; and Julius Cæsar includes it among the animals of the great Hercynian forest. Even in our own time large herds traverse the wooded heights of the southern prolongation of the Ouralian range. Between the Volga and the Don they descend to the 46th parallel; and they extend their wanderings as far as the very foot of the Caucasus, on the banks of the Kouma. Still, the proper habitat of the reindeer is that region of ice and snow bounded by the Arctic Circle,--or, more exactly, by the isothermal line of 0° C. Both the wild and the tame species change their feeding-grounds with the seasons. In winter they come down into the plains and valleys; in summer they retire to the mountains, where the wild herds gain the most elevated terraces, in order to escape the pertinacious attacks of their insect-enemies. It is a fact worthy of note that every species of animal is infested by a parasitical insect. The œstre so terrifies the reindeer that the mere appearance of one in the air will infuriate a troop of a thousand animals. In the moulting season these insects deposit their eggs in the skin of the unfortunate animal, and there the larvæ lodge and multiply _ad infinitum_, incessantly renewing centres of suppuration.