PRELUDE TO DESCRIPTIVE GEOLOGY. 545 



out considerable steps of classification and gene- 

 ralization. When, in our own time, geologists were 

 become weary of controversies respecting theory, 

 they applied themselves with extraordinary zeal to 

 the construction of stratigraphical maps of various 

 countries ; flattering themselves that in this way 

 they were merely recording incontestable facts and 

 differences. Nor do I mean to intimate that their 

 facts were doubtful, or their distinctions arbitrary. 

 But still they were facts interpreted, associated, and 

 represented, by means of the classifications and 

 general laws which earlier geologists had estab- 

 lished ; and thus even Descriptive Geology has been 

 brought into existence as a science by the forma- 

 tion of systems and the discovery of principles. 

 At this we cannot be surprized, when we recollect 

 the many steps which the formation of Classifica- 

 tory Botany required. We must now notice some 

 of the principal discoveries which tended to the 

 formation of Systematic Descriptive Geology. 



VOL. III. N N 



