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1910] BAILEY—SAP STAIN IN LUMBER 143 
second agency which produces discoloration in sap wood is the activity 
of fungi, which find an abundant food supply in the sap wood, and 
under favorable conditions of heat and moisture (hot, humid weather) 
develop with great rapidity. Thus part at least of the blue colored 
sap stain which occurs so frequently in pine may be produced by the 
dark colored mycelium of a fungus which is found in the food-con- 
taining wood rays and the parenchyma cells surrounding the resin 
canals. In fact, in all samples of blue sap pine which have come under 
my observation the color has been produced by this dark colored 
mycelium. However, it seems very likely that a large part of the 
blue sap stain in pine is produced by chemical reactions, for I am 
informed by lumbermen that sap pine lumber frequently stains 
badly during a few hours. The rapidity with which the discoloration 
is produced indicates the activity of a chemical reaction. 
Although the two agencies producing sap stain are so fundamentally 
different, yet the conditions which favor their activity are very similar. 
As has been indicated above, each agency, in its activity, is closely 
related to the food substances contained in the wood. This is shown 
by the fact that the discolorations, produced by the activity of fungi 
and by chemical reaction, are most conspicuously developed in the 
wood rays and wood parenchyma cells. Both agencies producing 
Sap stain are, in addition, dependent upon certain quantities of oxygen 
(air), heat, and moisture. Thus optimum conditions for sap-staining 
are found in green sap lumber during hot, humid weather, whereas 
unfavorable conditions are found in cold, dry weather and in logs 
immersed in water. It is well known that certain quantities of food, 
oxygen, moisture, and high temperature are necessary for the rapid 
development of fungi, but it seems advantageous to examine with 
greater care a chemical reaction which is dependent upon similar 
conditions. 
Oxidizing enzymes 
It has been known for many years that certain soluble ferments, 
which facilitate the oxidation of organic compounds, are widely dis- 
tributed in plants and animals. These oxidizing enzymes are of funda- 
mental importance in the nutrition and growth of living organisms. 
Furthermore, it has been clearly demonstrated that these enzymes 
