An Instance of Adaptation among the Deer

Abstract

MY friend Major C. S. Cumberland has just brought from Manipur the head and hind-foot of a deer, the latter of which affords an interesting instance of adaptation to environment. The deer in question is the Manipuri representative of the thamin (Cervus eldi) of Burma, an animal inhabiting open tree jungle. The Manipur valley is, however, a huge swamp, and the thamin of that locality have developed a peculiar modification in the foot which enables them to walk with ease in such ground. In the Burmese thamin the under surface of the hind pasterns is covered with hair in the ordinary manner, and the animal walks entirely on the main hoofs, keeping the pasterns much elevated. In the Manipuri thamin, on the other hand, the under surface of the pasterns is covered with a hard, horny, bare skin, which immediately above each hoof has almost the consistency of horn, and is practically continuous with the hoof itself. Moreover, so far as can be determined from comparison with a mounted specimen of the Burmese form, the pasterns are very considerably longer than in the latter. In walking, according to the account given by Major Cumberland, the foot is much bent, so that the animal walks on nearly the whole of the under surface of the pasterns, and thus gains a firm support on the yielding morass.