James Oeikie — On Changes of Climate. 169 



wherL Arctic conditions supervened in Britain, must have shifted to 

 more southern regions of Europe, where no doubt it was charac- 

 terized by the presence of an abundant mammalian fauna), to prey 

 upon the few reindeer and smaller animals that were likely to be 

 found so far north as the frozen barrens of England ? Yet we know 

 that the hyaena at least was a regular denizen of our caves, and found 

 matters so comfortable that, accoi'ding to Mr. Dawkins, its large size, 

 as compared with that of the living animal, was probably due to 

 '* the abundance of food which it obtained." 



These and other considerations, into which I cannot enter here, 

 have led me to conclude that this hypothesis of seasonal migrations 

 is untenable. With glacial conditions in Scotland and the hilly 

 grounds of England and Ireland, neither temperate flora nor fauna 

 could have existed in our country. There could be nothing in such 

 an Arctic England, therefore, to tempt the herbivora away from the 

 rich feeding-grounds of the then temperate zone, and just as little 

 to wile the carnivora so far from their wonted haunts. And to 

 suppose the hippopotamus, the elephant, and the rhinoceros capable 

 of migrating for enormous distances, and to such a country too, is to 

 suppose that these animals differed entirely from their present 

 representatives. 



The only other hypothesis which appears possible as an explana- 

 tion of the occurrence of Arctic and Southern forms in our super- 

 ficial deposits is that which assumes certain fluctuations of climate 

 to have taken place during the accumulation of the mammal- 

 bearing drifts.^ But here a great difficulty meets us on the very 

 threshold. If the presence of the hippopotamus, the elephant, and 

 the rhinoceros, compels us to assume that at the time these animals 

 lived in England the winters must have been mild and genial, we 

 are at a loss to conceive how such great changes of climate could 

 have occurred within Post-glacial times. There are few points we 

 can be more sure of than this, that since the close of the Glacial 

 epoch, — since the deposition of the clays with Arctic shells and the 

 " Saxicava Sands," — there have been no great oscillations, but only 

 a gradual amelioration of climate. It is quite impossible to believe 

 that any warm period could have intervened between the last Arctic 

 and present temperate conditions, without leaving some notable 

 evidence in the superficial deposits of Scotland, Scandinavia, and 

 North America — these being the countries in which the passage 

 from the later glacial beds to recent accumulations can be most dis- 

 tinctly traced. This fact would, indeed, afford an insurmountable 

 objection to the hypothesis I am now about to consider, if it were 

 necessary to suppose that the great oscillations of climate referred 

 to supervened during Post-glacial times. For this supposition, how- 

 ever, there appears to be not only no sufiicient reason, but the 

 evidence, as well positive as negative, seems all against it. 



' As I am writing for geologists, it is hardly necessary that I should remind 

 them that this is the view Sir Charles Lyell inclines to hold (Principles, vol. i., 

 p. 192). Sir John Lubbock, in his well-known work, is of the same opinion (Prehist. 

 Times, p. 301). 



