ii6 
Journal of Agricultural Research 
. Vol. I, No. a 
much-branched fungus hyphae 5 to 10/z in diameter. These hyphae 
are especially abundant in the spring wood. In this stage the rotten 
wood easily pulls loose in thin flakes, the line of cleavage being between 
the medullary rays. Many white and yellowish white unabsorbed 
cellulose wood fibers are found in the rot at this stage. 
The third and final stage of the rot is found in the center of the tree 
and is of a reddish brown color, there being a rather sharp line of demarca¬ 
tion between this and the light-tan color of the second stage. In this last 
stage there are found remnants of the vessels, a few unabsorbed fiber 
tracheids, wood fibers, and partially decomposed medullary rays inter¬ 
mixed with the colorless hyphae of the fungus. Not enough hyphae are 
present, however, to bind the rotted wood into a tough mass. The 
wood at this stage at first is rather brittle when dry and can be partially 
crushed into fragments between the fingers, but finally it crumbles into a 
brownish dirtlike mass, which remains in a cavity thus formed inside the 
tree, unless removed by squirrels, etc. On the split surface of the rotting 
wood which was exposed directly to the air and rain water a dark, reddish 
brown mycelial layer of a gelatinous nature was found. This gelatinous 
mass might, of course, be a foreign growth and not a part of the myce¬ 
lium of the fungus Polyporus piloiae. The reddish cast is due to the 
formation of reddish brown bodies on or among the hyphae; sometimes 
several of them form a conidialike chain. 
In general, the delignification seems to begin in the layer of wood fibers 
forming the boundary line between the summer growth and the spring 
layer of wood formed the following year and spreads most rapidly in the 
spring wood, leaving more or less intact the largest vessels and the cells 
immediately adjacent. At this stage many of the medullary rays contain 
a chestnut-brown, humuslike substance. 
A Pocketed or Piped Rot in the Texan Oak 
The rotted wood from which the following description was made was 
obtained from an old log of Texan oak (Quercus texana), just beneath a 
very large sporophore of Polyporus piloiae. 
The rot in this host is much like that described for the scarlet oak, 
consisting of long strands of white to creamy white, cellulose fibers inter¬ 
spersed with the partially changed spring wood and medullary rays. 
There is a zone of one-fourth to one-half inch of discolored wood be¬ 
tween the sound wood and the zone where the delignification is evident. 
A Pocketed or Piped Rot in Chinquapin 
This description of the pocketed or piped rot was made from material 
obtained from a fallen log of chinquapin (1 Castanea pumila) on which a 
sporophore of Polyporus piloiae was found. The rot was seen a number 
of times in fallen chinquapin trees in the Ozark National Forest. In 
