﻿PLATE 
  I. 
  

  

  F. 
  J. 
  H. 
  Merrill, 
  Photo. 
  

  

  Precambrian 
  granite, 
  Breakneck 
  Mt., 
  N. 
  Y. 
  

   Photomicrograph 
  in 
  polarized 
  light, 
  enlargenent 
  22 
  diameters. 
  

  

  