230 GLACIAL GEOLOGY. 



ceiie deposits Las greatly iucreased, and implements and other relics 

 of paleolithic man have been recorded from many new localities 

 thron^hout Europe. But none of this fresh evidence contradicts the 

 conclusions I had i)reviously arrived at; on the contrary, it has greatly 

 strengthened my general argument. - - - 



Thus as years advance the picture of Pleistocene times becomes more 

 and more clearly developed. The conditions under which our old 

 paleolithic predecessors lived — the climatic and geographical changes 

 of which they were the witnesses — are gradually being revealed with 

 a jHCcision that only a few years ago might well have seemed impossi- 

 ble. This of itself is extremely interesting, but I feel sure that I 

 speak the conviction of man\' workers in this field of labor when I say 

 that the clearing up of the history of Pleistocene times is not the only 

 end which they have in view. One can hardly doubt that when the 

 conditions of that period and the causes which gave rise to these liave 

 been more fully and definitely ascertained we shall have advanced 

 some way towards the better understanding of tlie climatic conditions 

 of still earlier periods. - - - It would almost seem as if all one had 

 to do to ascertain the climatic condition of any particular i)eriod was to 

 l)repare a map depicting with some approach to accuracy the former 

 relative position of laud and sea. With such a map could our meteor- 

 ologists infer what the climatic conditions must have been ? Yes, pro- 

 vided we could assure them that in other respects the physical condi- 

 tions did not ditier from the present. Now, there is no })eriod iu 

 the i)ast history of our globe the geological conditions of which :ire 

 better known than the Pleistocene. And yet when we have indicated 

 these upon a map we find that they do not give the results which we 

 might have expected. The climatic conditions which they seem to 

 imply are not such as we know did actually obtain. It is obvious, 

 therefore, that some additional and perhaps exceptional factor was at' 

 work to produce the recognized results. What was this disturbing 

 element, and have we any evidence of its interference with the opera, 

 tion of the normal agents of climatic changes in earlier periods of the 

 worhl's history ? We all know that various answers have been given 

 to such questions. Whether amongst these the correct solution of the 

 enigma is to be found time will show. Meanwhile, as all hypothesis 

 and theory must starve without facts to feed on, it behooves us as 

 working geologists to do our best to add to the supply. The success 

 with which other jnoblems have been attacked by geologists forbids 

 us to doubt that ere long we shall have done inuch to disi)el some of 

 the mystery which still euvelopes the question of geological climates. 



