16 THE ‘‘BLUING’’ AND THE ‘‘RED ROT” OF THE PINE. 
In spite of numerous investigations, the causes of the green color 
and its relation to the wood remained comparatively obscure until 
recently, when Vuillemin published an extended account” showing 
that one-form of the green color was due to the growth in the wood 
of one of the Discomycetes, /7elotium xruginosum. Vuillemin men- 
tions a number of other fungi which have been described as causing 
the green color, among others, Propolidium atrocyaneum Rehm, on 
wood of the poplar; Wevia xruginosa Rehm, on the tansy; .and 
Fusarium xeruginosum Delacroix, on potato tubers. 
Without going into details, Vuillemin established the fact that the 
green coloring matter, called xylindeine, is formed by the hyphe of 
Helotium xruginosum, and that the presence of these green-colored 
hyphe gives the green color to the wood. The wood fiber itself 
remains colorless. The xylindeine is soluble in alkalis and can readily 
be extracted. The wood fiber is not destroyed, but remains intact.. 
The name ‘‘green decay” is therefore incorrectly applied, for the 
green wood is in no sense decayed. ‘This is an interesting fact, for it 
will be remembered that the same has been said of the ‘* blue” wood. 
A more detailed comparison of the relation of this green coloring mat- 
ter and the fungus forming it to the coloring matter in the ‘*blue” 
wood will be published in another paper. » 
The blue stain of coniferous woods is a familiar defect in the United 
States, particularly in the South, where freshly sawed lumber, 
especially shingles and lath, is affected during the moist warm weather 
of April, May, and June. The blued lumber is considered as a low- 
grade material, and many precautions are taken by Southern manufac- 
turers to prevent loss. A full account of this trouble and a discussion 
as to its cause and methods for its prevention are now in preparation. 
In Europe the blue color of pine wood was first noted by Hartig,’ 
who refers briefly to the fact that a fungus (Ceratostoma piliferum 
(Fr.) Fuckel), is the cause of bluing in coniferous wood, especially of 
pine trees which have been weakened by caterpillars, and of firewood. 
He states that the hyphe of this fungus, which are brown, grow rap- 
idly inward into the trunk through the medullary rays and that they 
avoid the heartwood, probably because of its small water content. 
The blue color of coniferous wood in this country is probably caused 
by the same fungus referred to by Hartig, although it seems necessary 
to refer to it under a different name (Ceratostomella. pilifera (FY.) 
Winter). 
@Vuillemin, Paul. Le Bois Verdi. (Bull. dela Soc. d. Sciences de Nancy, Ser. LI, 
15: 90-145; 1898. 1 pl.) References to earlier works on the green color are given 
in this paper. 
> Hartig, Robert. Lehrbuch der Pflanzenkrankheiten, 1900, pp. 75 and 106. (See 
also earlier editions of the Lehrbuch fiir Baumkrankheiten; see also Frank, A. B., 
Krankheiten der Pflanzen, 1: 107, 1895. ) 
