482 Migration of Animals. 



Skertchly's work with Mr. Bristow, we took care to 

 examine into this point. The result was that I satisfied 

 myself of the truth of Mr. Skertchly's observations that 

 the implement-bearing brick-earth in places underlies 

 a boulder-clay, which in his opinion is not of the earliest 

 date, in which case the men who made these tools must 

 have been of inter-Glacial age. If so, why may these 

 men not have been the descendants of men who inhabited 

 the country in pre-Glacial times, and who, when the cold 

 increased, and sheets of glacier-ice advanced far south, 

 retreated into the Devonshire area, as I have hinted in 

 page 470. Perhaps we cannot prove it, but there is 

 nothing improbable in the hypothesis, and I am not the 

 only one who believes it. One thing is certain, that when 

 rude man, along with other mammalia, some of them 

 extinct, first migrated into the British area, he must 

 have done so over land, and no one doubts that in all 

 tertiary and post-tertiary time Britain has been again 

 and again united to the Continent, both before and 

 after the Glacial epoch. For example : 



After the elevation of the country that succeeded 

 its partial depression under the sea during part of the 

 Glacial period, the probabilities are more than strong, 

 that England was united to the Continent, not by a 

 mass of solid rock above the sea level, but by a plain 

 formed by the elevation of the Boulder-beds over part 

 at least of the area now occupied by the German Ocean. 

 Across this plain many animals migrated into our area, 

 some of the species probably for the second time. It is 

 the belief of many geologists, that at the same period 

 Ireland was united to England and Scotland by a 

 similar plain across the area now covered by the Irish 

 Sea, and over this, into Ireland, the Cervus megaceros, 

 formerly called the Irish Elk, the Mammoth, and other 



