ice until it assumed the form of bergs, and then be'deposited. 

 Many pieces of rock would, in all probability, be detached from 

 the glacier bed on what is now the lower ground. They too would 

 be deposited in the mud issuing from beneath the glacier. 



It was previously mentioned that the rocks in the lower ground 

 dip seaward. Their broken ends thus oppose the mountains 

 whence came the glaciers, so that a glacier, moving outward over 

 the lower ground, would, in certain parts of its course, as for 

 instance where the ends of strata cropped out in the side of a 

 valley, have the best possible chance of tearing up rock fragments 

 from its bed. Again, rocks from totally different localities might 

 be borne on icebergs, which in time, through the influence of 

 currents, might be so mingled as to drop their stony contents at or 

 near the same place. 



Thus we get an explanation of all the main facts presented by 

 the Lower Boulder Clay. The mingling of the boulders and the 

 local derivation of the clay are both satisfactorily accounted for. 

 Those curious facts mentioned by Mr. James Geikie as occurring 

 in other localities are also explained. I refer to streams of boulders 

 embedded in the lower clay, and but little removed from their 

 parent rock, as if they had just been torn up from the glacier bed 

 and dragged away in a string by the ice. Other phenomena, such 

 as the occurrence in the clay of flag-like fragments of rock standing 

 on end also receive an explanation. It is only the lower part of 

 the clay that would be formed under the glacier, that is as a 

 moraine profonde ; the upper part of the clay would be deposited 

 outside the glacier altogether, and rock fragments falling there 

 might be expected to be imbedded vertically as well as horizontally, 

 but such a thing could not occur in a moraine profonde. 



It has been asserted by some that the tough character of the 

 lower clay is due to the kneading it received under the glaciers ; 

 but that is not so, for I have seen clay as tough as any boulder- 

 clay in lough-holes twenty fathoms below the upper surface of the 

 solid rock, probably having been washed down joints from the 

 overlying glacial deposits. Again, the matrix of boulder-clay, after 

 it has been taken up by water and thrown down in another place, 



