52 BULLETIN 871, U. S. DEPARTMENT OF AGRICULTURE. 
particularly likely to be followed on double-length logs (20, 24, 28 
feet, etc.). But invariably the dry-rot will commence just at the 
top of the fire scar and almost immediately spreads out over the 
entire radius of the heartwood. In other words, in a log with' an 
open fire scar showing on the base but otherwise sound and with 
pockets of dry-rot in the top end, the decay should be considered as 
beginning at about the top of the fire scar and extending from there 
to the upper end of the log in practically the same degree and r il 
extent with relation to the heartwood as is shown on the top end. 
Advance rot (see p. 13) should be treated just the same as mature 
dry-rot. 
In the case of a large swelling on the bole caused by mistletoe it 
is best to have the tree bucked in such a manner as to exclude the 
swelling rather than have such a defect reach the landing as part 
of an otherwise sound log and then be scaled out. 
MARKING. 
Timber sales at present offer the only extensive means of prac- 
ticing intensive silviculture on our National Forests, and the entire 
results are absolutely based on correct marking. Fundamentally, 
the object of marking is to leave the stand in the optimum condition 
for its future welfare and development. This goal should never be 
lost sight of, no matter how clouded the issue may be by a com- 
plexity of immediate and often pressing considerations. To attain 
this end requires a high degree of skill, grounded on a thorough 
understanding of all the factors involved, not the least of which are 
those making for total loss in the species under consideration. 
The fundamental object of marking has been far from completely 
attained if, after cutting, diseased individuals are left standing to 
carry infection to otherwise sound trees of merchantable size, besides 
menacing the future of the advance growth and reproduction. 
Obviously, then, trees with sporophores or shot-hole cups should 
invariably be marked for cutting, for these are positive proofs of 
damaging dry-rot. Such trees are as a rule not only a total loss, 
being unmerchantable from the butt to varying distances of 10 to 
50 feet above the highest sporophore or shot-hole cup, but are the 
most potent factors in spreading infection to other trees, since infec- 
tion can only be brought about by spores coming from sporophores 
on diseased trees. True enough, shot-hole cups in themselves do 
not menace surrounding trees with possible infection, but they do 
indicate that the fungus has reached fruiting maturity and is very 
likely to develop more sporophores, as is attested by the not un- 
common occurrence of two or more shot-hole cups of varying ages 
on the same tree. Furthermore, the fungus mycelium in any in- 
