Notices of Memoirs — J. Geikie, Antiquity of Man. 177 



clearly proved by the river gravels that palaeolithic man entered 

 Britain ages before the valleys in the south of England were hol- 

 lowed out to their present depth — that during his long occupation 

 the rivers succeeded in cutting out the valleys to their present depth 

 and breadth — and that not until this was effected did palseolithic 

 man disappear and neolithic man take his place. No neolithic re- 

 mains occurred in the ancient river gravels. The evidence of these 

 gravels thus bore out that which was furnished by the caves and by 

 a comparison of the two sets of stone implements themselves, and all 

 combined to show that a decided and well-marked break separated 

 the palaeolithic from the neolithic period. What, then, was the 

 nature of this break? What caused palceolithic man and the old 

 pachyderms to disappear at once and altogether before neolithic man 

 and an almost totally different group of animals entered the country ? 

 To answer this question it was necessary to consider the deposits be- 

 longing to that wonderful period which was known as the Ice Age, 

 or Glacial Epoch. By means of maps and diagrams the lecturer 

 then pointed out the salient features of the evidence under this head. 

 He described a number of sections representing glacial deposits in 

 Scotland, Switzerland, and North America, and explained how these 

 showed that the Glacial epoch was not one long uninterrupted age 

 of ice, but rather a succession of cold and mild periods. There was 

 distinct evidence to prove that the great ice-sheet which buried 

 Scotland to a depth of not less than three thousand feet, and which 

 filled up all our shallow seas and even overflowed the outer Hebrides, 

 sometimes melted away from our seas and low grounds and retired 

 to the deep glens of the highlands, and then rivers flowed in our 

 valleys and many lakes appeared, and the country was clothed and 

 peopled with plants and animals. Similar phenomena were found to 

 characterize the glacial deposits of Switzerland and America. The 

 Scottish interglacial deposits had yielded remains of the mammoth, 

 the Irish deer, the horse, the great ox, and smaller animals such as 

 frogs and water-rats, and fragments of various kinds of trees, besides 

 organisms peculiar to fresh-water. The Swiss accumulations con- 

 tained beds of lignite with which were associated the great ox, 

 the rhinoceros, the elephant, and other animals. 



In America ancient forests were found lying between glacial 

 deposits, the trees being still indigenous to that country, and remains 

 of the old pachyderms had been met with in a similar jDosition. In 

 Scandinavia there was evidence to show that the glacial epoch was 

 interrupted by at least two mild interglacial periods. The evidence 

 derived from all these regions also clearly pi-oved that since the last 

 cold j)eriod of the glacial epoch there had been no warm or genial 

 conditions, but only a gi"adual amelioration of climate down to the 

 present time. The lecturer then went on to point out what bearing 

 these facts had upon the question of man's antiquity in Britain. 

 The evidence furnished by the palaeolithic deposits showed that 

 during their accumulation man experienced two kinds of climate, 

 one of which was cold and almost arctic in character, the other mild 

 and genial. Now, as no mild or genial climate had supervened in 



Vol. X. — NO. cvi. 12 



