38 THE UNIVERSE. 



Strabo it was maintained that these were the remains of 

 seeds used as food by the ancient workmen, who had aban- 

 doned them, and which had fossilized by the action of time. 

 But the Greek geographer refuted this vulgar tradition, 

 and in his description of Egypt he classes the nummulites 

 among the petrifactions, calling to mind that in his own 



, ; *fe"~ 



*JvV\ 



18. Gigantic Tridacna, used in the Moluccas as a Bathing-Tub. 



country, Pontus, there were hills full of tuff stones similar 

 to lentils. 



Having spoken of microscopic shells, we now proceed to 

 speak of some colossal ones. 



One of these in particular has acquired a certain celebrity 

 on account of its size and the peculiar use to which it has 



