Some idea of the time which has elapsed since primitive man inhabited this rude dwelling may be formed from these excavations. Two feet below the surface lay the Romano-British layer, and we know therefore that about 1,600 years was required for the earth to accumulate to that depth. The Neolithic layer was six feet below this; hence 4,800 years would be necessary to form this depth of earth. So we may conclude that at least 6,400 years ago Neolithic man used the cave. A long time previous to this lived the creatures of the lower cave earth, the bison, elephant, and the hyena with the solitary human bone, which belonged to the sharp-shinned race (Platycnemic) of beings, the earliest dwellers in our country. It is doubtful whether Palaeolithic man has left any descendants. The Esquimaux appear to somewhat resemble them. Professor Boyd Dawkins, in his remarkable book, _Cave Hunting_, traces this relationship in the character of implements, methods of obtaining food and cooking it, modes of preparing skins for clothing, and particularly in the remarkable skill of depicting figures on bone which both races display. In carving figures on bone and teeth early man in Britain was certainly more skilful than his successor; but he was a very inferior type of the human race, yet his intelligence and mode of life have been deemed not lower than those of the Australian aborigines. The animals which roamed through the country in this Pleistocene period were the elk and reindeer, which link us on to the older and colder period when Arctic conditions prevailed; the Irish deer, a creature of great size whose head weighed about eighty pounds; bison, elephant, rhinoceros, hippopotamus, lion, wolf, otter, bear, horse, red deer, roe, urus or gigantic ox, the short-horned ox (_bos longifrons_), boar, badger and many others which survive to the present day, and have therefore a very long line of ancestors. The successor of the old stone implement maker was Neolithic man, to whom we have already had occasion to refer. Some lengthy period of geological change separates him from his predecessor of the Old Stone Age. Specimens of his handiwork show that he was a much more civilised person than his predecessor, and presented a much higher type of humanity. He had a peculiarly shaped head, the back part of the skull being strangely prolonged; and from this feature he is called _dolichocephalic_. He was small in stature, about 5 feet 6 inches in height, having a dark complexion, and his descendants are the Iberian or Basque races in the Western Pyrenees and may still be traced in parts of Ireland and Wales. The long barrows or mounds, the length of which is greater than the breadth, contain his remains, and we find traces of his existence in all the western countries of Europe.