THE PKOBLBM OF THE LIZARD ROCKS. 495 



I have not discussed the origin of the serpentine, but have 

 simply taken it as an existing rock interstratified with other 

 rocks and acted upon by dynamic forces. In thus venturing 

 to differ from so many eminent investigators, I cannot do better, 

 in conclusion, than quote the sentiments so happily expressed by 

 Professor Bonney in the most recent discussion of all upon the 

 Lizard question, which has appeared while my paper was going 

 through the press.* Professor Bonney said that " on so difficult 

 a subject all well considered hypotheses must tend to the dis- 

 covery of truth." 



* Notes on the hornblende schists and banded crystalline rocks of the Lizard 

 by Major General C. A. McMahon, F.G.S., and discussion thereon, Q.J.G.S.,to1. 

 xlv., p. 544. 



