320 EDSON S. BAST IN 



analyses. Certain field evidence is unfavorable to the theory that 

 these are eutectics. 



The broader field relations suggest that the large areas character- 

 ized by particular abundance of pegmatite intrusions constitute in 

 reality the roofs overlying granite batholiths. Where more extensive 

 erosion has exposed the flanks of such batholiths pegmatite masses 

 in the bordering schists are not abundant. 



