164 CRITIQUES AND ADDRESSES. [vn. 



have discussed elsewhere, and probably, though by no 

 means necessarily, in one locality. Whether he arose 

 singly, or a number of examples appeared contempo- 

 raneously, is also an open question for the believer in the 

 production of species by the gradual modification of pre- 

 existing ones. At what epoch of the world's history this 

 took place, again, we have no evidence whatever. It 

 may have been in the older tertiary, or earlier, but what 

 is most important to remember is, that the discoveries 

 of late years have proved that man inhabited Western 

 Europe, at any rate, before the occurrence of those great 

 physical changes which have given Europe its present 

 aspect. And as the same evidence shows that man was 

 the contemporary of animals which are now extinct, it is 

 not too much to assume that his existence dates back at 

 least as far as that of our present Fauna and Flora, or 

 before the epoch of the drift. 



But if this be true, it is somewhat startling to reflect 

 upon the prodigious changes which have taken place in 

 the physical geography of this planet since man has been 

 an occupant of it. 



During that period the greater part of the British 

 islands, of Central Europe, of Northern Asia, have been 

 submerged beneath the sea and raised up again. So has 

 the great desert of Sahara, which occupies the major part 

 of Northern Africa. The Caspian and the Aral seas have 

 been one, and their united waters have probably com- 

 municated with both the Arctic and the Mediterranean 

 oceans. The greater part of North America has been 

 under water, and has emerged. It is highly probable 

 that a large part of the Malayan Archipelago has 

 sunk, and its primitive continuity with Asia has been 

 destroyed. Over the great Polynesian area subsidence 

 has taken place to the extent of many thousands of 

 f ee t subsidence of so vast a character, in fact, that 



