Vol. 60.] IMPLEMENTIFEROUS SECTIONS AT WOLVERCOTE. 127 



yielding clay on the sides also, caused them there to take up a 

 horizontal position, along the line of least resistance. 



Again, the material is not only free from any bedding, but 

 lumps of sand are stuck in beside masses of Thames gravel in 

 a manner which suggests that they were frozen or half-frozen 

 when they were shoved in ; otherwise it is hard to account for 

 the oblong lumps of sand. 



Another circumstance was to my mind decisive, both as to the 

 age of the Drift in relation to the gravel-bed, and the nature 

 of the cause to which the Drift is due. It is this : the Oxford 

 Clay beneath the Drift is weathered to the depth of about 10 or 

 12 feet : it seems to have been shaken, and penetrated so far by 

 surface-water. This line of weathering is constant, beneath the 

 Drift ; and when it approaches the gravel-bed, it goes under it 

 for a certain distance until it is cut off by the descending depth 

 of the river-gravel. Beneath the deeper pan of the old river- 

 valley the blue clay is quite unweathcred. Three facts are here 

 proved : (1) The weathered band of clay was older than the ancient 

 river, because the river destroyed it; (2) the force of the river 

 did not weather the clay beneath; (3) the force of the Drift did 

 weather the clay, and must consequently have been a heavy and 

 a powerful force. A rolling drift of ice, snow, stones, and mud 

 would be heavy and powerful, and might, I think, act so as both to 

 shake the clay beneath and to shove portions of its own gathering 

 mass into the softened clay beneath its passage. This, at least, is 

 the only explanation of the section that I can suggest as satis- 

 factory. I consider it to be an ice-drift, and to mark an important 

 epoch in the Glacial Age. 



At a distance of about half a mile, at a place called Peartree 

 Hill, and on an elevation similar to that of Wolvercote, there is 

 another section of the Drift (see fig. 2, p. 128). Its features are 

 quite similar to those which I have described ; it also contains 

 implements, and the clay beneath it is also weathered and shaken 

 in the same manner as the clay at Wolvercote. There is at Pear- 

 tree Hill no trace of any river- action : there is solely the Drift. 



From the Drift at Wolvercote no fossil has been obtained, except 

 the implements, which constitute at least a trace of life. From 

 Peartree Hill I have obtained from a workman (and the staining 

 corresponds with the gravel) the canine tooth of a wolf — an un- 

 satisfactory fossil, as it gives no indication of the age of the gravel. 



The implements obtained from the two beds are in two wavs 

 distinct. Those found in the river-bed are very large, of beautiful 

 shapes, of chalk-quarried flint, and very little stained. Those from 

 the Drift are small, of very ordinary shape, formed of flint taken 

 mostly, if not altogether, from the Drift. To the simplicity or 

 rudeness of form I do not attach much importance : partly, because 

 few implements only have been found, not a sufficient number on 

 which to base a general judgment; partly also, because very 

 simple forms are found in use throughout all Palaeolithic time ; 

 partly, because very beautiful forms of implements occur in other 



