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the case. Moreover, it is difficult to conceive how water could have 

 collected the bones of a multitude of individuals of the same race, 

 distributed over a wide extent of country, into a few favoured 

 localities. The bones of all other animals inhabiting the same 

 country, and remaining on its surface, would have been exposed to 

 the same action, and should have been deposited in the same tomb. 

 If these animals all perished at the same time in each locality, some 

 common cause must have produced the catastrophe. 



Although the existing evidence may be insufficient to lead us to 

 the true solution of this interesting question, yet it may be useful to 

 throw out hypotheses, which, by accounting for some of the facts, 

 shall direct the attention of future observers to the examination of 

 such special points as may either partially support or directly dis- 

 prove these conjectures. 



With this view I shall offer two conjectures, one dependent on the 

 subsidence of the land, the other upon the rising of the waters. 



Conjecture I. By the subsidence of the land. 



Let us imagine that the basin of the bottom of the Mediterranean 

 had at a former period been on a level with, or just above the 

 African continent. Sicily and the various islands would then have 

 stood above it as mountain chains. 



One portion of the drainage of this land may have been effected 

 by a vast river passing into the Atlantic through the opening now 

 known as the Straits of Gibraltar. 



In this state of things extensive freshwater lakes arid other large 

 rivers may have contributed to support large herds of Hippo- 

 potami. 



In such circumstances the gradual subsidence of this land would 

 check the outflow of its rivers, and occasion extensive marshes and 

 lakes, a state of things favourable to the increase of the Hippo- 

 potami. As the subsidence proceeded, those animals which dwelt 

 on the banks of the lakes and rivers would be driven inland. The 

 waters of the Atlantic, entering through the channel of the former 

 river, would convert the low ground and the marshes into sea, and 

 thus gradually isolate the sinking land from the African coast. 



When this state of the country had caused the Hippopotami to 

 multiply rapidly, an increased rapidity in the sinking of its lands 

 through the waters, might drive those animals rapidly to the higher 



