310 INTRODUCTORY REMARKS, &C. 



interesting variety of position and of relations, which may 

 be supposed to point, not only to a connexion once more 

 intimate among them, but to an equally intimate, though 

 more distant union between these islands and the main- 

 land also. ' From the variety of character and position 

 presented by these strata in different places, there will 

 also be found to result some important geological conse- 

 quences which would scarcely appear from considering 

 them separately. 



They present a further common bond of union in the 

 Trap rocks, which, with scarcely any exception, are found 

 in the whole. That deposit will also be seen to constitute 

 a portion of an extensive range which is associated with 

 the whole extent of the secondary strata ; covering a 

 great part of these on the mainland, and reaching, even 

 from the Mull of Cantyre and the western coast of Ayr, 

 to the eastern sea. 



