DRY-ROT OF INCENSE CEDAR. 27 
the same tree, each one, however, the result of a separate and distinct 
inoculation. As soon as an infection causes a measurable amount of 
cull it becomes a cull case and is so termed. Hence, every infection 
is not a cull case, but every cull case is an infection. Only loss of 
merchantable timber through dry-rot is considered; cull from 
wounds, knots, limbs, insect borings, or crook is disregarded, since 
these have no bearing on the loss from dry-rot except when the 
decay is directly traceable to a wound. In such cases loss from the 
wound is included with the volume of rot. 
For figuring from the field notes and measurements the cull caused 
by dry-rot, the amount and degree of damage with relation to the 
resulting loss in merchantable lumber was carefully taken into 
account, just as it is in scaling. For example, a cull case might 
have considerable linear extent but consist only of a few scattered 
pockets hi a straight line, resulting in little or no loss hi merchantable 
volume. The same number of dry-rot pockets, shorter hi linear 
extent but radially scattered throughout the heartwood, probably 
would cause considerable cull. Again, a. number of pockets close to 
the sapwood, mostly slabbing out when the log is sawed, would have 
far less weight than the same pockets in the center heartwood. 
Meinecke's method (16, p. 37) of considering the entire bole of the 
tree over the linear extent of decay as cull, while justifiable with the 
commercially inferior white fir, could not be applied to the distinctly 
more valuable hicense cedar. Here the lateral extent of the decay 
also had to be taken into account. This could be readily determined 
from the field notes and diagrams. For example, if the decay occu- 
pied one-fourth of the area as seen on cross sections and had a linear 
extent of 10 feet, the volume outside the bark of this 10-foot frustum 
(the tree being considered as a cone, see p. 26) was first secured 
and then one-fourth of it was considered as the volume of the decayed 
portion of the tree. Below one-fourth the decay was usually treated 
as negligible except when it had a linear extent of several feet. The 
volume was then computed as before. 
Separate tables containing the above figures were worked up for 
the four areas, the trees being arranged progressively by ages, begin- 
ning with the youngest. It does not seem necessary to present these 
tables, since they were merely preliminary. 
In considering the trees on the intermediate area it was found that 
the first infection which resulted in cull occurred in a tree 98 years 
old. However, infection can take place at a much earlier age than 
this. For example, in a tree 104 years old there was a light cull case 
traced to a healed lightning wound. The tree was injured at the 
age of 50 years and the Wound completely healed when the tree was 
63 years old; hence, the tree could not have been older than 63 years 
at the time of infection. Again, in a tree 146 years old there was a 
