BALSAM FIE, 
31 
Since the fruiting bodies of the fungi, or, as the lumbermen call 
them, "punks" or "conks," appear on the fir after the tree is con- 
siderably rotten, it is exceedingly hard to tell merely by the appear- 
ance of the tree whether it is sound or not. Being short-lived, 
balsam fir at the age of 80 to 100 years is already old, and especially 
susceptible to rot of any kind. Therefore one seldom finds an old 
balsam that is perfectly sound. 
"glassy" fir. 
During the winter months balsam fir logs often have on cross 
section a "glassy" or "icy" appearance, which some lumbermen 
consider an indication of defect. When cut by the crosscut saw, 
the wood shows irregular areas which are perfectly smooth and shiny 
as if planed. A microscopical examination of the wood, 1 however, 
did not reveal any signs of decay in the smooth areas, and the struc- 
ture could not be distinguished from that of the ordinary rough areas. 
During winter the water present in the wood of balsam fir is 
mostly frozen, and the shiny, smooth spots are therefore not due to 
any disease, but to the frozen condition of the wood. That this is so 
is further shown by the fact that the same section of wood when cut 
in an unfrozen condition appears rough over its entire area. The ice 
formed in the wood acts as reenforcing material and prevents the 
usual tearing of the wood fiber. 
FLRE. 
Balsam fir is very sensitive to fire. Its superficial roots are easily 
affected by surface fires, and the flames reach its cambium through 
the thin, tender bark, killing the tree. In a balsam injured by fire 
the lower foliage first turns brown, and finally the top. The dying in 
some cases is very slow, but is none the less certain. 
WIND. 
Balsam fir does not suffer from windshake, but it is easily uprooted 
and broken by wind because of its shallow root system and slender, 
brittle bole. 
THE WOOD. 
GENERAL STRUCTURE. 
The wood of the balsam fir in external appearance is strikingly 
like that of eastern spruce, and it is often necessary to go to the 
gross and minute characters of its anatomical structure in order 
to distinguish it. Balsam fir is ordinarily close-grained and, like 
1 Glassy Fir. by Hermann von Schrenk. Sixteenth Annual Report of the Missouri TJotanical Garden, 
pp. 117-120. St. Louis, Mo., 1905. 
