DRY-ROT OF INCENSE CEDAE. 49 
through dead or broken tops are so insignificant that they may be 
entirely disregarded. (4) Severe wounding is not a prerequisite for 
severe cull cases or extensive decay at any stage in the life of incense 
cedar. 
APPLICATION OF RESULTS. 
RELATIVE IMPORTANCE OF DRY-ROT. 
In the foregoing discussion the one big factor which stands out 
almost to the exclusion of all others is the dry-rot. Mechanical 
injuries of certain types play some role, not only in destroying 
merchantable timber values but in lessening the annual increment. 
However, it is chiefly the fact that wounds are the means for the 
entrance of dry-rot which makes them of any but insignificant 
importance. 
Factors reducing the annual increment of the host, namely, Gym- 
nosporangium blasdaleanum, Phoradendron juniperinum libocedri, Stig- 
matea sequoiae, and HerpotricJiia nigra are of minor importance. In 
fact, only the first two named, being decidedly ubiquitous, are 
worthy of the least consideration; but the resulting loss is so slight 
and intangible that under present conditions it may well be disre- 
garded except incidentally. The rare trifling lo£s in merchantable 
timber from burls of the mistletoe can not be of consequence. 
Fungi such as Polystictus abietinus, P. versicolor, Polyporus volva- 
tus, and others (see p. 4), only attacking dead wood and never 
found on living trees, are to be regarded as beneficial, since they 
hasten the decomposition of ground litter, thus increasing the humus 
in the soil and removing a serious fire menace. 
Loss resulting in the heartwood of living trees from the so-called 
secondary rots is very slight in the aggregate. It is rare that such 
decays are at all far-reaching, and, furthermore, it is possible that 
certain of them may be abnormal forms of the dry-rot. 
To repeat, then, the one big consideration from a pathological 
viewpoint which must hold above all in the silvicultural treatment 
and utilization of incense cedar is the dry-rot, together with the 
interrelated mechanical injuries. 
CONTROL OF DRY-ROT. 
Very little can be hoped for in the line of any serious consideration 
or attempt at direct control of dry-rot on private holdings for years 
to come. The private owner is averse to any increase in expenditures 
which does not show prospects of immediate gain. On certain private 
holdings where the incense cedar was heavily affected by dry-rot, all 
the trees have been left standing, only the more valuable species 
being removed, leaving the diseased individuals to continue spreading 
the decay to uninfected members of the present and future genera- 
tions. 
