10 BULLETIN 722, U. S. DEPARTMENT OF AGRICULTURE. 
acterized in hemlock and grand fir by its uniformity in occupying 
the heartwood (figs. 4 and 8). In alpine fir the rot in cross section 
takes on a somewhat stellar development, due principally to the 
concentration of the hyphe along certain of the medullary rays. . 
In badly decayed living trees it is invariably the case that the rot 
not only occupies the entire heartwood of the trunk but the heartwood 
of the branches as well (fig. 9), extending in some of the larger ones 
a distance of several feet, causing the formation of sporophores at 
some distance from the trunk. 
The advance rot of Echinodontium tinctorium is very difficult of 
detection and unless accompanied by small brownish discclorations 
or by reddish or 
brownishstreakscan 
not be detected with- 
out a very close ex- 
amination. In the 
early stages of the 
decay the wood as- 
sumes a faint yel- 
lowish, spongy tex- 
ture. Sometimes this 
stage is intensified 
by the presence of 
small, hardly dis- 
cernible brownish 
areas, which later de- 
velop into the typi- 
calrot. The exten- 
sion of the advance 
Fic. 7.—Section of hemlock, showing a branchstub asa meansoffirst rot beyond the typi- 
infection of heart-rot. The decay has commenced spreading into lrot vari t] 
the heartwood from the end of the branch tissue. cairo SaEIeS greatly 
according to the con- 
ditions. Some accurate data are at hand to determine the average 
height of the advance rot beyond the typical rot. Such data will 
be found very useful to scalers in determining the amount of cull to 
deduct from the gross scale in order to cut out all the advance rot 
which might later develop into the crumbly decay complained of by 
dealers in hemlock lumber. Meinecke? states that in the white fir 
(Abies concolor) of this region the advance rot produced by £.tinctorium 
extends about 2 to 6 feet beyond the typical rot. From the data 
collected on more than 200 hemlocks of all ages and sizes an exten- 
sion of 1 to 5 feet has been found to be general. A single figure 
1 Weir, JoR. Destructive effects of Trametes piniand Echinodontium tinectorum. Jn Phytopathol- 
ogy, V. 3, no. 2, p. 142. 1913. 
2 Meinecke, E. P. Forest-tree diseases common in California and Nevada, p. 52. 1914. Published by 
U.S. Department of Agriculture, Forest Service. 
a. 
