20 BULLETIN 1037, U. S. DEPARTMENT OF AGRICULTURE. 
against sap-stained or moldy stock that is to be covered, provided 
there is no incipient decay associated with it. 
The reduction in the value of stained lumber sometimes amounts 
to $2 or more per 1,000 feet, board measure, and perhaps one-fourth 
of the annual mill cut of the United States is attacked. In one year 
it was estimated that the total losses from sap-stain amounted to be- 
tween 8 and 9 million dollars (Weiss, 56; Weiss and Barnum, 57; see 
also Pratt, 34). The amount in any locality, however, depends upon 
the climate, the season, and several other factors. 
Weather conditions have a marked influence upon the amount of 
damage to freshly cut timber in the woods or to green stock in storage 
and in transit. During warm and moist weather such stock will 
sometimes stain badly and in a short time, unless it is properly safe- 
guarded. This, of course, is due to the fact that the warm and humid 
conditions stimulate the development of the fungi. It follows, then, 
that the greater losses from sap-stain, sap-rot, or mold should be ex- 
pected during the warmer months, and especially during those 
months in which both high temperatures and high humidity nor- 
mally prevail. As a matter of fact, this is the case. In the months 
of April, May, June, July, and sometimes August and even Septem- 
ber, depending upon climatic conditions, the greatest damage occurs. 
In the South, owing to the prevailing high temperatures and relative 
humidities, the losses are often extremely severe. The greatest losses 
occur in low-grade coniferous lumber, especially the southern pines, 
owing partly to the high percentage of sapwood and partly to the 
fact that the low-grade lumber is seldom kiln dried, but is stacked 
in the yard to air season. Under such circumstances, unless unusual 
precautions are observed, it is very liable to the attacks of the sap- 
stain fungi. 
From replies to the questionnaires sent out by the wood-stock com- 
mittee to contractors and producers of wood stock regarding sap- 
stain and mold in vehicle stock and from the data derived from the 
personal investigations of the writer, it was learned that these losses 
are dependent largely upon the manner in which the stock is piled in 
the cars and sheds during transit or storage. The losses average less 
than 10 per cent, but may reach from 25 to 75 per cent. The writer 
was informed that because of such damage to green spokes during 
the summer of 1918, sometimes as many as 50 per cent in a carload 
lot were culled. When turned spokes were selling at $150 per 1.000 
feet b. m., the loss on a carload containing perhaps 12,000 escort 
spokes, 2^ by 2| by 27 inches, was evidently considerable, perhaps 
amounting to hundreds of dollars. One firm reported that it had 
knowledge of entire carloads being destroyed. In some instances 
cars had gone astray and had finally reached their proper destina- 
