526 SOILS. 



grafting stock which would resist the tendency to chlorosis 

 which renders many of the American phylloxera-resistant 

 vines useless to the viticulturists of France. Viala did not 

 find such grape-vines until he reached the cretaceous (chalk) 

 area of Texas, where the native vines had long ago adapted 

 themselves to marly soils; and these vines have solved the 

 problem for French viticulture. 



And England, France, Belgium and most of western 

 Europe are rich countries, largely owing to their abundant 

 limestone formations; and it may be questioned whether, had 

 this been otherwise, Europe would so long have remained the 

 center of civilization ; for starving populations are not a good 

 substratum for high mental culture and progress. It may 

 equally be asked whether the invariably calcareous character 

 of arid soils, as heretofore shown, has not, together with 

 their general high quality, been largely a determining factor 

 in the location and persistence of so many ancient civilizations 

 in arid lands; as outlined in chapter 21, page 417. In this con- 

 nection, the proper distinction between calcareous and non- 

 calcareous soils passes from the domain of natural science to 

 that of the history of human civilization. 



