II PROGRESS OF PALEONTOLOGY 37 



cause. It is needless to inquire how far these 

 statements are strictly accurate ; they are 

 sufficiently so to justify Buffon's conclusions that 

 the dry land was once beneath the sea ; that the 

 formation of the fossiliferous rocks must have 

 occupied a vastly greater lapse of time than that 

 traditionally ascribed to the age of the earth; 

 that fossil remains indicate different climatal 

 conditions to have obtained in former times, and 

 especially that the polar regions were once 

 warmer ; that many species of animals and plants 

 have become extinct ; and that geological change 

 has had something to do with geographical dis- 

 tribution. 



But these propositions almost constitute the 

 frame-work of palaeontology. In order to com- 

 plete it but one addition was needed, and that 

 was made, in the last years of the eighteenth 

 century, by William Smith, whose work comes so 

 near our own times that many living men may 

 have been personally acquainted with him. This 

 modest land-surveyor, whose business took him 

 into many parts of England, profited by the 

 peculiarly favourable conditions offered by the 

 arrangement of our secondary strata to make a 

 careful examination and comparison of their 

 fossil contents at different points of the large area 

 over which they extend. The result of his 

 accurate and widely-extended observations was to 

 establish the important truth that each stratum 



