Lesley.] 392 [May, 



a fixed and unalterable state of things in the relation of land to sea. 

 Thus similar changes go on now ; why should we imagine it other- 

 wise in ancient times ? Until we can prove it to have been other- 

 wise, we have no right to apply with rigor the epithet antediluvian 

 to these remains of man. 



I may add, that on my way to Neuchatel to visit my friend Prof. 

 Desor, and while I was being entertained in the most delightful 

 manner by M. Troyon, with an inspection of the many rare piloti 

 relics in his museum at Lausanne, I learned that Desor was in Africa 

 with two other members of a commission of the French Government, 

 studying the age of the Sahara. Sketches of their results have been 

 published by him since their return, by which we learn that they 

 have fully confirmed the opinions of previous explorers, that the 

 north of Africa has risen very recently from beneath sea level, prob- 

 ably in the human age. Or, perhaps we should say, as Herr Traut- 

 schold would have it (Zeitsch. der Geol. Gesell. 1S63, p. 411), the 

 ocean bed has deepened itself since man was created, so as to drain 

 the whole Sahara and Libyan desert land. The commission found 

 the Cardlum exJuh not only embedded within the rock of the desert, 

 but at a fixed horizon over some hundred miles of their route, and 

 this shell fish was the chief food of the savages of the stone age. 



The obliteration of so much sea surface, whether rapidly or slowly 

 effected, must have produced one of the greatest alterations in the 

 physical condition of the surface of the earth, on that side of it. 

 While the Mediterranean waters covered Northern Africa (with the 

 exception of the Atlas Mountains, the Abyssinian highlands, and 

 other unknown mountain ranges under or beyond the equator), more 

 humid winds must have fertilized Arabia, Persia, and Bokhara, and 

 ameliorated the rigors of Thibet and China, if it could not quite 

 prevent the formation of the Desert of Tobi. On the other hand, 

 rains must have swollen the Caspian and Aral seas to such a height, 

 that they then made but one, overflowing the lower steppes and con- 

 founding themselves with the Azof and Black Sea shores, and with 

 the Northern Ocean. 



If, then, mankind appeared on earth previous to the drying up of 

 the Sahara, he had three widely separated continents to appear upon : 

 Southern Africa, Eastern and Southern Asia, and Western Europe. 

 If the change from that condition of things to a condition of things 

 analogous to that we see now, was accomplished with suflScient ra- 

 pidity to permit of the formation of a tradition, such tradition could 

 hardly assume any other shape than that of the Noachian deluge. 



