are thus pierced in every direction. We even see 

 enormous stones bored quite through, from side to 

 side, by these destroyers. It was for a long time be- 



Fioj. 44. — Gneiss bored by the Pbolndes Dnctyltis. 



Heved that they effected their lodgment while the 

 ror»k was in a soft state, and that it afterwards grew 

 harfl around them, and enclosed them as in a living 

 tomb, owinpr to the petrifying virtue of the water. 



