8 BULLETIN 1163, U. S. DEPARTMENT OF AGRICULTURE. 
Table 4. —Infection court of conk-rot in Douglas fir. 
Infections. 
Percentage of total. 
Average volume. 
Infection court. 
Number, 
basis. 
Volume. 
) 
Number. 
Board 
• feet. 
Cubic 
feet. 
Board 
feet. 
Cubic 
feet. 
Knots . 
98 
83.0 
99.62 
99.48 
796 
77.0 
Fire scars.. . 
10 
8.5 
.04 
.03 
3 
.2 
Falling-tree wounds. 
3 
2.5 
0 
.05 
0 
1.4 
T,io''htning scars . . 
4 
3.4 
.34 
.43 
68 
8.2 
Dead tops.. 
Unknown scars . 
1 
2 
.9 
1.7 
0 
0 
0 
0 
0 
0 
0 
0 
t 
Table 5. —Infection court of trunk-rot in Douglas fir. 
Infections. 
Percentage of total. 
Infection court. 
Number, 
basis. 
Volume. 
Number. 
Board 
feet. 
Cubic 
feet. 
Board 
feet. 
Cubic 
feet. 
TCnots ... 
7 
46.7 
44.6 
46.1 
353 
28.4 
Fire scars. . 
2 
13.3 
0 
0 
0 
0 
Falling-tree scars . 
4 
26.7 
30.0 
26.9 
415 
29.0 
Tiight.ninp' scars . 
2 
13.3 
25.4 
26.9 
705 
58.0 
Table 6 brings out the relation between fire and red-brown butt-rot. 
The major portion of the infections entered through fire scars, and 
the resulting volume of decay was proportionately much higher. This 
imtt-rot also attacks the roots and can probably be spread by the con¬ 
tact of a diseased root with a sound one. About^ll per cent of the 
volume of rot is apparently traceable to this method of infection. 
Besides these two the other infection courts are of no importance. 
Table 6.— Infection court of butt-rot in Douglas fir. 
Infection court. 
Infections. 
Number, 
basis. 
Percentage of total. 
Average volume. 
Number. 
Volume. 
Board 
feet. 
Cubic 
feet. 
Board 
feet. 
Cubic 
feet. 
Knots. 
1 
1.4 
1.4 
0.5 
60 
2.0 
Fire scars. 
41 
58.6 
78.2 
79.1 
83 
8.0 
Falling-tree scars... 
4 
5.7 
3.7 
5 0 
40 
5.2 
Lightning scars. 
4 
o. 7 
2.5 
1.8 
28 
1.8 
Boots. 
16 
22.9 
10.8 
11.5 
29 
3.C 
Unknown scars. 
4 
5.7 
3.4 
2.1 
38 
2.2 
