THE LAST GREA T BAL TIC GLA CIER 329 



Now, in the first place, the Upper Diluvium of North Ger- 

 many closely resembles, in all essential particulars, the British 

 upper bowlder clay with its associated deposits. Along the 

 southern limits reached by the former we encounter banks and 

 undulating hillocks and sheets of gravel and sand, just as is the 

 case with our upper bowlder clay. Like the latter, also, the 

 upper GescliiebeleJmi is often covered with wide stretches of water- 

 worn materials and sprinkled with erratics. So, again, no ter- 

 minal moraines present themselves as we traverse the country 

 from south to north, until we are suddenly confronted with the 

 great moraines of the Baltic Ridge. Here, then, we cannot but 

 recognize a general resemblance, at least, between the glacial 

 phenomena of Britain and North Germany. In the published 

 works of German geologists I could meet with no evidence 

 to show that the bowlder clay in front of the Baltic Ridge 

 moraines was identical with the bowlder clay behind them. This 

 identity appeared to me to have been taken for granted. At all 

 events, no doubt had been expressed upon the subject, and no 

 attempt made to demonstrate that the two upper bowlder clays 

 are one and the same. Even in the paper to which I am now 

 replying Dr. Keilhack does little more than reiterate his and his 

 colleagues' opinions that the bowlder clays in question are con- 

 temporaneous. Apparently he thinks that their interpretation 

 of the evidence ought to be accepted on the ground of their 

 intimate knowledge of the glacial accumulations of their country. 

 I need hardly say that the accuracy of their observations is not 

 called in question. I doubt if their works have, out of Germany, 

 gained the attention of a more admiring student than myself. 

 Their descriptions, wherever I have been able to test them in 

 the field, have proved, as might have been expected, full and 

 exact. It was not without hesitation, therefore, that I found 

 myself unable to accept their explanation of the evidence. I 

 was consoled, however, by the reflection that they themselves are 

 not agreed as to the precise mode of formation of the Baltic 

 Ridge moraines. When geologists, who claim a long acquaint- 

 ance with the same facts, cannot yet agree amongst themselves 



