Tree-Kangaroos

Abstract

THE birth of a tree-kangaroo at the Gardens of the Zoological Society of London is an event well worth recording. Another was born at about this time last year. One would have supposed that the drastic change from the tropical forests of New Guinea and North Australia to a relatively small cage in London would have inhibited the reproductive activities. Even without this added interest, the presence of this strange creature in the Gardens is something more than welcome to all who are concerned with the problems presented by anomalous changes of habit and habitat in the animal kingdom. The typical kangaroo is, in itself, a sufficiently remarkable animaL For here we seem to have a convincing example of ‘neo-Lamarckian’ changes of form. Though how the initial stage of the leaping habit began we are scarcely likely to discover. It is not merely that the hind-legs and tail have grown inordinately large, but we have also to take into account the quite unusual nature of the reduction of the toes; for instead of disappearing on each side of a median axis, the reduction of the second and third toes has taken place on the inner side of the foot, where the claws only are visible in the living animal.