242 THE STORY OF THE EARTH AND MAN. 



seen we do not need this limestone to convince us of 

 the continent-building powers of the oceanic protozoa; 

 but the distribution of these limestones, and the ele- 

 vation which they attain, furnish the most striking 

 proofs that we can imagine of the changes which the 

 earth's crust has undergone in times geologically 

 modern, and also of the extreme newness of man and 

 his works. Large portions of those countries which 

 constitute the earliest seats of man in Southern Europe, 

 Northern Africa, and Western and Southern Asia, 

 are built upon the old nummulitic sea-bottom. The 

 Egyptians and many other ancient nations quarried it 

 for their oldest buildings. In some of these regions it 

 attains a thickness of several thousand feet, eviden- 

 cing a lapse of time in its accumulation equal to that 

 implied in the chalk itself. In the Swiss Alps it 

 reaches a height above the sea of 10,000 feet, and it 

 enters largely into the structure of the Carpathians 

 and Pyrenees. In Thibet it has been observed at an 

 elevation of 16,500 feet above the sea. Thus we learn 

 that at a time no more geologically remote than the 

 Eocene Tertiary, lands now of this great elevation 

 were in the bottom of the deep sea; and this not 

 merely for a little time, but during a time sufficient 

 for the slow accumulation of hundreds of feet of rock, 

 made up of the shells of successive generations of 

 animals. If geology presented to us no other revela- 

 tion than this one fact, it would alone constitute one 

 of the most stupendous pictures in physical geography 

 which could be presented to the imagination. I beg 



