THE "BLUE" FUNGUS. . 15 



in the State of Nebraska outside of the arid belts and in the Black 

 Hills, the wood will last from four to six years when placed in the 

 ground in the form of a cross-tie, for instance. Dead trees may stand 

 in the forest for many years without decaying, especially when killed 

 by fire, but ordinarily when the bark remains on the trees they begin 

 to decay after the third year. 



From observations made on the "black-top" trees now standing in 

 the forest it would seem that the lasting power of the "blue" wood 

 would be very small. It is perhaps not fair to compare these trees 

 with sound ones, for their bark is full of holes, giving fungus spores 

 every opportunity to enter, as described below. When placed in the 

 ground this wood rots very fast, if one can draw conclusions from the 

 dead tops lying around in the forest. There is every reason why it 

 should rot rapidly. The hyphge of the "blue" fungus have opened pas- 

 sageways for the rapid entrance of water and for other fungi in almost 

 every medullary ray. Dried wood will probably last a long while, 

 especially if properly piled, so as to allow the air to circulate between 

 the separate pieces. When sawed and split for cord-wood, the "blue" 

 wood should keep just as long as the green wood. The tendency to rapid 

 decay can be largely done away with by treating the wood with some 

 preservative. Ties were cut during the past spring from green timber 

 and from dead trees. These were shipped to Somerville, Tex., where 

 they were impregnated with zinc chloride. These ties were laid in 

 the tracks of the Santa Fe Railroad and are now under observation. 

 A second lot of ties has been cut during the past summer from green 

 trees and from "sorrel tops," "red tops," and "black tops." These 

 will be treated within a short time and laid in the track of a Mexican 

 railway so as to determine the relative resistance of the various grades 

 of "blue" timber in a tropical climate as compared with the green tim- 

 ber. On the particular road chosen for this experiment the life of very 

 resistant timbers is short. 



THE "BLUE" FUNGUS. 



The blue color of the wood is due to the growth of a fungus in 

 the wood cells. The staining of wood due to fungi has been known 

 for many years, especially the form known as 4 ' green wood " (bois 

 verdi). In Europe this green coloration attracted the attention of 

 foresters and investigators as early as the middle of the last century, 

 and a number of descriptions and discussions appeared from time to 

 time (particularly in France), in which an attempt was made to account 

 for this phenomenon. A green dye was extracted from this wood, 

 which at one time was thought to be valuable because of its absolute 

 permanency. Various dicotyledonous woods showed the green color; 

 among others, beech, oak, and horse-chestnut. 



