REGISTRATION BY DYKES 85 



versa, the dykes which are revealed to us in ancient 

 volcanic regions may be supposed to present us with 

 a register of the eruptions of past times. Further, the 

 formation of the fissures would be attended by earth- 

 quake shocks, and they would result from a readjustment 

 of the earth's crust to unequally distributed stress. In 

 connexion with the last great eruptions in the West 

 Indies, such a readjustment evidently affected a large 

 part of the globe, and was signalised by earthquakes 

 in numerous localities. 



