168 DISCUSSIONS IN CLIMATOLOGY. 



which, like that of the Eocene, has as yet presented 

 no indication of the intrusion of anything to interfere 

 with its uniformly sub-tropical character." 



In reply to all this, it may be stated that the simple 

 absence of any trace of glaciation in the Tertiary 

 deposits of the South of England certainly cannot be 

 regarded as conclusive against the existence of an 

 epoch of glaciation during that period. Not many 

 years ago geologists denied that there was any 

 evidence to be found of glaciation in the South of 

 England, and at the present time there are hundreds 

 of geologists who will not admit that that part was 

 ever overridden by land-ice. If it is so difficult 

 to find in that quarter evidence of the last 

 glacial epoch, severe as that glacial epoch was, we 

 need not wonder that no trace of glaciation so 

 remote as that of the Eocene period is now to be seen. 

 Besides all this, there is in the South of England the 

 land-surface on which the glaciation, if any, took place, 

 whereas not a vestige of the old land-surfaces of the 

 Eocene period now remains. It therefore seems to me 

 that the mere fact of nothing as yet having been 

 found in the Tertiary deposits of the South of 

 England, indicating one or more cold periods, is no 

 proof that there may not possibly have been such 

 periods, and even of considerable severity. The same 

 remarks hold equally true in regard to the deposits on 

 the continent referred to by Mr. Wood. 



It will be urged in reply that there is one kind of 

 evidence which ought to be found, as it could not 

 possibly have been obliterated by the destruction of 

 the Tertiary land-surfaces — that is, the presence of 

 erratic blocks and foreign rock-fragments imbedded in 

 the strata. Mr. Wallace states that in the many 

 thousand feet in thickness of alternate clays, sands, 



