DOUGLAS FIR PITCH MOTH, al 
laths, or firewood. Therefore to illustrate them adequately 1t would 
be necessary to spht tree trunks, often for the length of several logs, 
to show a side view of an entire seam, and even if this were accom- 
plished successfully the result would be merely something like a 
board which had been spht and had been loosely stuck together 
again. With the exception of figure 2, showing the evolution of 
Fig, 5.—Wound caused by the Douglas fir pitch moth. Photographed 
soon after emergence of moth. Natural size. (Original.) 
the pitch seam, the photographs used to illustrate the injury to 
Douglas fir by pitch-moth infestation are from material from which 
the insect emerged so recently that the cause of the wounds is 
obvious. Such injury within the tissues of a coniferous tree is never 
eliminated in the course of years, but rather becomes accentuated 
when the split of the tissues is later extended for the length of many 
feet by mechanical strain. 
