GLASSY FIR. 



BY HERMANN VON SCHRENK. 



During the past winter some specimens of wood of the 



(Abies balsa me a) 



Mi 



Botanical Garden, which showed peculiar smooth spots at 

 various points on cross sections. Two views of pieces 

 of wood of this character are shown on plate 20. It 

 will be noted that the sections there shown present a 

 rough appearance, usually found when pieces of wood are 

 cut with a cross-cut saw. 

 areas, however, which are p< 



There are certain irregular 

 rfectly smooth and shin v. as 



if they had been planed. Some of these areas extend out 

 from the heart to the sap wood, while some of them form 

 irregular circumscribed spots, one of which shows promi- 

 nently on the lower figure of the plate. In all of the speci- 

 mens sent in, the sap wood had the same appearance as the 

 irregular smooth spots. A careful examination made with 

 a hand lens showed no signs of decay in these smooth areas, 

 nor could they be distinguished in any way from balsam 

 fir wood, after it has been planed with a sharp plane. 



The specimens were sent from the forests in southwest- 

 ern Maine, in the region of the Androscoggin River. A 



balsam 



am 



"glassy 



»> 



or 



. < 



icy 



5> 



appearance. It was claimed by some 



glassy appearance indicated 



From information obtained it is apparent that this glassy 

 appearance shows itself in the balsam fir quite regularly 

 during the winter months. It occurs both in old and young 

 trees and apparently, as far as outward appearances go, in 

 perfectly sound wood. 



A microscopical examination was made of the glassy 

 areas, and the sections so made were compared with sim- 



(117) 



I 



