Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/309

1869.] action, show that the winter at least was such as may now be felt in the woodland region of northern Siberia. The presence of the arctic group of mammals, the Reindeer, Musk-sheep, and the like, implies that the climate under which they lived was severe. But, on the other hand, the presence of the Hippopotamus major in 29 localities, an animal that, so far as we can judge by the habits of the living species, could not have endured the low temperature now necessary for the wellbeing of the Musk-sheep or Reindeer, involves the necessity of supposing the climate to have been temperate or comparatively warm. M. Lartet, in his last Essay on the "Carnassiers et Rhinocères fossiles du Midi de la France", explains the difficulty in the following way:—First of all, he assumes that the arctic herbivores dwelt in France throughout the year side by side with the Hippopotamus; and then he infers that the Postglacial climate was more equable and insular than that of France at the present day. But it is established beyond all cavil that during the time the Postglacial fauna occupied Britain our island formed an integral portion of the continent of Europe—a fact that would at once demolish the idea of the existence of an insular climate during that epoch. The Hippopotamus most probably was, as Sir Charles Lyell suggests, a summer visitant only, and retired southwards in the winter to a more genial clime. I know of no other hypothesis that satisfies all the conditions of the problem.

From that time down to the present day the climate has gradually been modified. As Britain became insular the climate grew more equable, until in the Prehistoric epoch the sole survivors of the northern invaders were the Elk and Reindeer, the latter of which grew more and more scarce until at last it became extinct in the mountains of Caithness towards the end of the twelfth century.

The suggested that a fourth period might be added to the three adopted by the author, viz. the Glacial period, during which it would appear from the paper that some, if not all, of the "postglacial" animals may have lived in Britain.

Mr. remarked that some of the genera referred to both the Postglacial and Preglacial periods (such, for instance, as the Hyæna, Lion, and Hippopotamus) were of southern, and not, like many of the others, of northern and eastern origin. The Lynx also might not improbably be of African descent. It was abundant in the bone- breccia of Gibraltar, as was also the Cervus elaphus and C. dama. Elephas antiquus and Rhinoceros might also be regarded as southern forms; and it was worth consideration whether these portions of the fauna might not be connected with the time when Southern Europe was joined on to Northern Africa.

Mr. stated that at Carrickfergus there was a forest-bed underlying glacial drift, from which possibly the elephant-remains found there had been derived.