Vol. 62.] OE THE SGURR OF EIGG. 69 



better evidence must be adduced against them than had been laid 

 before the Society that evening. 



The Author, in acknowledging Sir Archibald Geikie's criticisms, 

 echoed his regret that a joint visit to the locality had not been 

 found practicable. 



He was not to be understood as denying that the ordinary pro- 

 cesses of erosion went on during the basalt-period. The fluviatile 

 conglomerates intercalated in the succession were evidence of con- 

 temporaneous erosion, although it is probable that these derived 

 much of their material from the volcanic agglomerates rather than 

 from the lavas. 



The intrusive nature of the dolerites had been deduced from the 

 various direct criteria mentioned in the paper, the generalization 

 that the vertical jointing is a characteristic of this intrusive group 

 being a consequent conclusion. 





