absent, since they have been successfully ousted by the more highly organised groups of Eutheria. But at that period, when the higher Eutheria were in the ascendant, Australia and the islands to the north became cut off from Asia, and thus became freed from inroads of Eutheria, which were partly prevented by the physical barrier of the sea from effecting a settlement, and partly perhaps prevented owing to the ground being already taken up by the Marsupials. Likeness of habit gave the older inhabitants victory in the struggle for existence. The general statements that have been here made are in accord with current opinion upon the factors of geographical distribution. But the past range of animals appears to be less consonant with the received views. In the Tertiary {83} period, groups of animals had often a far wider range than at present. To-day the Rhinoceroses are limited to Asia and Africa, and to quite limited parts of the former continent. In the past, these animals were abundant in Europe and North America. Wild Horses now have a range which is not widely different from that of the Rhinoceroses, save that they extend into the more northern regions of Asia. Their remains are abundant both in North and South America. The Hippopotamus, now confined to Africa, once ranged over Europe, Madagascar, and India. There were plenty of American and European Lemurs. Elephants were nearly world-wide in their range; and, in short, restricted distribution seems to be on the whole a characteristic of animals of the present day. These statements, however, though perfectly true, must not lead to erroneous inferences. It is rather impressed upon the reader, in books which contain sections dealing with geographical distribution, that animals on the whole occupy more restricted areas at present than in the past. There are, however, plenty of examples of groups of extinct creatures which had, so far as we know, quite a restricted range. Thus the Toxodonts were purely South American, as were the Glyptodonts and some other forms. And, on the other hand, the Cervidae of to-day are as widely, if not more widely, distributed than at any other time. The Hares and Rabbits are now nearly universal in range; the Cats almost so. We meet with Bovidae, even excluding the Sheep and Goats, in all the four quarters of the globe, excluding only South America and, of course, Australia. The Camelidae are still common to both the Old and the New Worlds.