•0 



TECHNICAL TKOPEUTIES OF WOOD. 



another ; these cases arc described under Forest Protection. Small 

 defects due to local loss of bark, which have afterwards healed over, 

 are termed rind-galls (fig. 15), — Tn.] 



(f ) Internal Bark. — Wlicnevcr two or more terminal shoots oi 

 a tree have grown close together during its youth and become 

 enclosed in one stem, the timber is useless except for firewood. 

 This defect, as exemplified in fig. 16, occasionally occurs in 



Fig. 17. 



Fio. 16. 



spruce-trees planted or sown on very rich soil : forking also 

 results from injuries by frost, snow, game, &:c. 



[In tropical countries, internal bark is formed naturally in certain 

 trees and climbers, such as Dalberr/ia ^xt?a"c«/a^T and Jhtiihhiia 

 Vahlii.—Tn.] 



(g) Damage by Mistletoe. — Mistletoe often causes the wood of 

 silver-fir and other trees to be riddled with holes (fig. 17). This 

 is chiefly in the upper part of the tree, and thus the length of 

 many otherwise promising logs must be reduced, as this riddled 

 wood can be used only as fuel, and even then is difficult to 

 split. [Vi^Jc ]\ranual of Forestry, Vol. IV., p. aOG.— Tr.] 



(h) Damage by Resin-tapping. — Resin-tapping may also cause 

 stems to assume a curious fluted shape. When spruce and black 



