528 T. C. CHAMBERLIN 



rate. While our results must be corrected for the difference 

 between present rates of denudation and the mean secular rate — 

 and this correction is quite certainly large, involving other factors 

 than the cultural one — comparisons with other modes of attack 

 must be made previous to such corrections if these have not simi- 

 larly entered into the results of these other studies. 



This general concurrence in results seems to imply that the 

 continents have made peripheral growths of the same order as 

 their other forms of growth. This in turn implies that the conti- 

 nental borders have had a permanency and stability of the same 

 order as the continents themselves. 



