﻿502 Canadian Record of Science. 



In the case of the granite masses which are found at a 

 number of points throughout the Eastern Townships, the 

 same association of these with strata of widely different 

 horizons is seen ; since in some places the granites are 

 surrounded by pre-Cambrian rocks, while in other cases 

 the slates of the Cambrian and of the Cambro-Silurian are 

 in contact. iSTear the line of junction these slates are 

 frequently converted into schists and contain crystals of 

 staurolite and chiastolite. That there was a period of 

 great disturbance subsequent to the Silurian time is 

 evident from the fact that at several points in this area 

 the Silurian and Devonian strata are folded up, overturned 

 and altered ; so that these newer sediments are now 

 beneath those of Cambro-Silurian age, while the corals 

 which are found in the Devonian slates are drawn out 

 into flat masses, and the slates themselves are sometimes 

 altered to schists, which in hand specimens can with 

 difficulty be distinguished from those of the pre-Cambrian 

 areas. 



Some Common Birds in their Relation to 

 Agriculture.^ 



By F. E. L. Beal, B.S. 

 Continued from No. 6, page 309. 



THE REDWINGED BLACKBIRD. 



(A gelaius phceniceus. ) 



The redwinged, or swamp, blackbird is found all over 

 the United States and the region immediately to the 

 north. While common in most of its range, its distribu- 

 tion is more or less local, mainly on account of its 

 partiality for swamps. Its nest is built near standing 



1 Reprinted from Farmers' Bulletin No. 54, U.S. Department of Agriculture, 1897. 



