346 HEROES OF SCIENCE. 



attention to the subject of the antiquity of man and 

 to the possible origin of species. He wrote to a 

 friend in his usual half-jesting manner : " I have 

 been much occupied with another geological subject 

 besides that which your niece, Ellen Twisleton, 

 irreverently calls the proving her to be first cousin 

 to a turnip (a violet she should have said) ; I mean 

 the antiquity of man as implied by the flint hatchets 

 of Amiens, undoubtedly contemporaneous with the 

 mammoth, and also the human skeletons of certain 

 caves near Liege, which I believe to be of cor- 

 responding age. I regard the pyramids as things 

 of yesterday in comparison of those relics." Lyell 

 struggled long in his mind against the theory of 

 the great age of man on the earth, and converted 

 himself to the belief in it, and in 1861 he wrote, 

 after examining the associated remains of human 

 art and extinct animals, such as the mammoth and 

 hairy rhinoceros in England, that "the late dis- 

 coveries at Heme Bay and Reculver convince me 

 that man inhabited England when the Thames was 

 a tributary of the Rhine." He published a work 

 on the antiquity of man, and then began to interest 

 himself about the great age when ice reigned 

 supreme over much of the northern hemisphere. 

 Writing to his nephew he states : " On a hill called 

 Moel Tryfaen (in North Wales), at a height of 

 thirteen hundred feet above the sea, I found twenty 

 species of fossil shells, all of living species, in sand 

 and gravel fifty feet thick. You would have known 

 most of them familiarly." Some of these shells 



