THE ARRIVAL OF MAN IN EUROPE 



cal conditions are such as to enable a great 

 accumulation of ice to begin. We are not, there- 

 fore, obliged, on Mr. Croll's view, to suppose 

 that every epoch of high eccentricity has inau- 

 gurated a glacial period ; and we see, in particu- 

 lar, why such a result was not likely to follow 

 2,650,000 years ago or 800,000 years ago, sup- 

 posing the latter date to have occurred before 

 the beginning of the Pliocene age ; and thus the 

 only serious objection to Mr. Croll's theory is 

 effectually disposed of. 



We have every reason to believe, then, that 

 the great Glacial period of the Pleistocene age 

 began 240,000 years ago, and came to an end 

 80,000 years ago. But at the beginning of this 

 period men were living in the valley of the 

 Thames ; at the end of it the men of the River- 

 drift had probably become extinct, and their 

 place in Europe had been taken and held for ages 

 by the boreal Cave-men, who now in turn were 

 about starting on their long retreat to the arctic 

 regions. How long a time may have elapsed be- 

 fore the swarthy Iberian settled in Europe, with 

 his dogs and cattle, we have no means of decid- 

 ing ; nor can we say when the blue-eyed Aryan 

 began his invasions, though we know that this 

 last event must have been very recent, not 

 very long before the dawn of history. Nor can 

 we tell how long there had been human beings on 

 the earth before the Glacial epoch began. But, 

 6* 



