DRY-ROT OF INCENSE CEDAR. 
39 
centage with open fire scars) shows that of the total number of trees 
analyzed on the intermediate area, 38.3 per cent had open fire scars, 
while on the optimum area the percentage is only 23.5. In other 
w T ords, these percentages of the total number of trees cut on the 
areas under consideration w T ere still exposed to infection by wood- 
destroying fungi through fire scars alone. The last column indicates 
that 72.2 per cent of the trees on the intermediate area and 49.3 per 
cent of those on the optimum area have had open fire scars at some 
period of their life history, thus exposing them to inoculation by 
fungous spores. 
Table VI.— Incense-cedar trees found in the combined areas having fire scars. 
Number 
of trees 
(basis). 
Trees with fire scars (per cent). 
Locality. 
Open. 
Internal. 
Miscella- 
neous. 1 
Total. 
Intermediate area 
509 
566 
38.3 
23.5 
33.2 
25.4 
0.8 
.4 
72.2 
Optimum area 
49.3 
Combined 
1,075 
30.5 
29.1 
.5 
60.1 
1 Includes wounds probably but not certainly caused by fire. 
The internal scars on the intermediate area exceeded those on the 
optimum area by less than 8 per cent, but there were 15 per cent more- 
open scars. This points to the fact that the intermediate area has 
been visited by more serious fires than the other, since, as has already 
L en pointed out, large catfaces are normally the result of repeated 
fires. 
The combined figures for all the areas show that a total of 30.5 
per cent of the trees had open fire scars, while 60 per cent suffered 
fire injury at some time. The column headed "Miscellaneous" in- 
cludes trees with scars not identified beyond all doubt as having been 
caused by fire. These are so few that the}- need not enter into the 
interpretation of the figures. 
FROST. 
Frost causes some injury in incense cedar but is not nearly as serious 
in this respect as fire. Frost cracks as a rule extend for some dis- 
tance up the tree and go deeply into the heartwood. A common place 
for the cracks to commence is just at the apex of an open fire scar, 
apparently a point of weakness in the tissues of the wood. Often 
they are somewhat spirally twisted around the trunk, distinctly 
reminding one of typical lightning scars. While frost cracks present 
only a very narrow opening for the entrance of fungous spores, yet 
in length those cracks or clefts are often quite extensive. In many 
cases the wood around a frost crack is badly discolored, causing 
considerable loss in the merchantable contents of the tree. 
