140 NOTE OX ITACOLUWITE OR FLEXIBLE SANDSTONE. 



The instances I have cited may now be summed up. 

 The Kaliana rock shows (?) interlocking structure of quartz 

 with removal of matrix ; the Charli rock shows cavities with 

 possible interlocked structure of matrix. The rocks described 

 by Mr. Card show cavities with possible interlocking of main 

 material of rock (dolomite). 



It would appear from these results that interlocking is often 

 doubtful, and in the main subsidiary ; that flexibility depends 

 on (1) the nature of the matrix ; (2) the removal of such 

 matrix in suitable proportion, as set forth by Mr. Oldham, 

 so as to allow of free movement of the other constituents of 

 the rock. 



