SUCCESSION AMONG ROCKS. 297 



sidered as a mere continuation of the English one in 

 the conterminous district. 



It is nearly useless to inquire whether the superior 

 strata of England have never been deposited above 

 the coal series of Scotland which most resemble those 

 of the former country, or whether they have once 

 existed and been worn away. This is not, at any 

 rate, the place for such an inquiry. If it is true of 

 the middle deposit, as, to a certain extent, is not 

 improbable, it may equally be so with regard to the 

 northern and western ; though, in this last case, the 

 proper coal series is wanting, and not only this, but 

 very often, the rocks beneath it ; while the causes of 

 waste, supposing this to have been the fact, have ope- 

 rated to a different effect in the two cases. 



