
PTT.T F.TTX BTL U. S. PEPABTXEXT OF AGRICULTURE. 
any definite information, but certainly the chemical and physical 
condition of the substratum must hare a strong bearing on this 
phenomenon. Hartig (9, pp. 115-116; believes hi the case of Poly- 
posis [Fames igniarius that the width of the annual rings of .the 
wood is not without influence on the rapidity of decay. Munch 20. 
p. 156 states that the more rapidly grown coniferous wood, conse- 
quently that with the broader annual tings, is more speedily decayed 
by Fames annosus than slower grown wood with narrower rings, even 
extending this to broad and narrow rings in the same individual. 
Later :22. p. 403-406 . he shows that suppressed individuals of beech 
artificially infected with Stereum pfrrrpureuwt. S. rugosum, Paly% 
{Fames) igniarius* and P. [F.] famentari/us were more seriously de- 
cayed than do min ant thrifty trees, yet it is just such suppressed trees 
which must have the narrowest annual rings. Finally (23, p. 521 . 
the same investigator finds no relation whatsoever between the 
breadth of the annual lings and the rapidity of decay in the wood of 
oak attacked by Poly poms (Fomes^ igniarius. 
PUIIPLE COLOEATIOX 
Accompanying the dry-rot is a purplish coloration of the heartwood 
which is very characteristic. The writer does not find this mentioned 
in any description of the dry-rot so far available, but it is well known 
to the lumberman. This color varies from a light salmon-red or pink 
to a pronounced purplish red in trees with heavy decay, where it may 
stand out strongly in cross section as a ring surrounding the decayed 
area or present a mottled appearance c" r er the entire heartwood. 
Where the coloration is faint it is sometimes impossible to detect it 
in cross section, but if the tree is split longitudinally the color is 
readily apparent, although it often fades out entirely after several 
days' exposure to light and air. It usually co mm ences at ground 
level and extends upward, but may start at varying heights. 
Microscopical studies of this colored wood did not show any devia- 
tion from sound wood. Xo hyphae were found except at points im- 
mediately adjacent to pockets of dry-rot. Xo chemical or physical 
examination was possible. 
In all. 634 trees were dissected in which the purple coloration was 
present. The notes from Cow Creek did not include data on this 
coloration. The youngest tree in which the coloration was present 
had an age of 72 years, while the youngest tree cut was 52 years old. 
Xo attempt can be made to set a mini m uni age limit for trees with 
purple coloration, since not nianv trees were cut below the age of 
70 years. 
Of the 634 trees tmder consideration, the purple was present in 54 
in which no dry-rot was found. In these the coloration, varying 
through all shades from a very faint salmon pink to pronounced red- 
