WOODPECKERS IX RELATION TO TREES. 
the wood must be sound, and 
ishes. Many of the .species 
resulting defects in the wood 
W 
t. 
for the latter two uses have few blem- 
are attacked by sapsuckers, and the 
are serious. Defects have been found 
in the beech, chestnut, and chinquapin, 
and in all they are detrimental to the 
appearance of the wood, and in small 
pieces they diminish the strength. Or- 
namental curled grain is sometimes 
produced in beech, but black cavities 
and extensive brown stain also are 
formed, which counterbalance the good 
effect of the desirable grain. In chin- 
quapin and chestnut (fig. 22 and PL 
IX, fig. 8) large open checks result 
from sapsucker work, which seriously 
blemish and weaken the wood. 
In oak, sapsucker blemishes or bird 
Fig. 20.— Effects of sapsucker work on wood . 1 „ «. «1,«»« *. ;^,^ ; l i„„, „U.«i*» 
of big sheiibark \ iiicoria inciniosa). pecks are almost mvanably open knotty 
stains and gnarly growth. (From iiop- checks, sometimes small but usually 
half an inch square or larger. The 
checks and the immediately adjoining wood are usually heavily 
stained and the checks are sometimes partly filled or surrounded by 
loose soft or rotten wood. The wood over the defects is more 
or less stained and dis- 
torted. Checking 
through the blemishes 
commonly occurs, and 
the weakening of the 
wood is further shown by 
the tendency of wind- 
shakes to occur along the 
line of sapsucker inju- 
ries. Defects have been 
observed in the wood of 
19 oaks, in 17 of which 
they are serious enough 
to cause marked loss in 
value of woods so prized 
for furniture, in t erio r 
finish, and other orna- 
mental uses, «'>nd in 2 of 
which, black oak dig. 23) and cow oak (lig. 24), they are so huge 
a- lo spoil the wood for any but the coarsest construction. The 
large, open, knotty checks so characteristic of sapsucker work 
Fro. 
1.— Effects of sapsucker work on wood of hornbeam 
(Curpiiiits arolininiKi). Small checks and stains. 
