TT epee eee OR Te ye ORE en are eS ee) Oe ee ey eT 
sz eng aaer sr ay ete zs 
Progress of Geology. 11 
igneous, and that in the intermediate times fire and water divi- 
ded the empire between them. In a word, he concludes with 
> t , and 
Ps thee of the past condition of the earth cannot be measured 
y its existing condition.” 
members of the Silurian rocks into the inferior strata of the Old 
Red group, has been well shown by Mr. Lightbody, and the fos- 
sils of its |, 
in Scotland, Mr. Geikie and others have shown the upward 
crustacea in the lower or gray beds, south of the Tay. I may 
here note, that the point whic 
- 
flags with their numerous ichthyolites seems to be admitted b 
these ichthyolites as belonging to the lower member of the group, 
and had good grounds for his views, since at his native place, 
