Nov. 10, 1913 
Heart-Rots of Hardwood Trees 
119 
was mainly due to the fact that practically all of the trees came from a 
coppice growth, and if the original stump was diseased, the later generation 
of trees springing from its base were also infected through their union 
with the old diseased stump. Officials of the Unadilla Railroad claim 
that chestnut ties having only a small amount of this rot in their centers 
last only three to five years when placed in their roadbed. 
This rot in the chestnut is apparently identical with the piped rot of 
chestnut described by Von Schrenk and Spaulding. 1 Their description 
of the piped rot of the oak in the same publication apparently includes 
two distinct rots; viz, this rot caused by Polyporus pilotae and the 
common heart-rot of the oak caused by Polyporus dryophilus 2 which is 
also a piped rot in one of its stages and will be described in a later 
publication. 
Resui/ts op Investigations op the Pocketed or Piped Rot 
The most common and constant characters of this rot, taking all the 
hosts into consideration, are the presence of long, continuous strands of 
cellulose, the delignified wood fibers and fiber tracheids, and the white- 
lined pockets so common in the living oak and chestnut in the early 
stages of the rot. In the white oak the changing of the wood fibers into 
cellulose is not so complete as in the other hosts, so that the wood is not 
broken down as much. In both white oak and chestnut there are holes 
which run tangential to the tree through the spring wood or radially from 
one annual ring to another. This condition is especially noticeable in 
the older stages of the rot in the butt of the trees and in the vicinity of 
freshly formed sporophores of the fungus. 
Sporophores of Polyporus pilotae were formed on living white oaks, on 
the ends of white-oak logs cut only one month, on old logs which evidently 
had been cut for several years, on a standing fire-killed yellow oak 
(Quercus velutina ), on a fallen and very rotten log of Texan oak (Q. 
texana) f on the trunk of a wind-thrown scarlet oak (Q. coccinea ), on old 
dead logs of chinquapin ( Castanea pumila) , on the inside of a hollow in a 
living chinquapin tree, and on chestnut trees (C. dentata). In the last 
instance the sporophores were resupinate and growing in the hollow 
butts of the living trees. Of the 302 chestnut trees studied in New York 
119 had this rot. The average diameter of the rot per tree was 6.5 inches, 
the average diameter of the stump 16.6 inches, and the average height of 
the rot per tree was 5.4 feet. The maximum diameter and height of the 
rot in any one tree was found in a tree 27 inches in diameter. The diam¬ 
eter of the rot in this tree was 20 inches and the height of the rot was 20 
feet. 
1 Schrenk, Hermann von, and Spaulding, Perley. Diseases of Deciduous Forest Trees. Bur. Plant In¬ 
dus., U. S. Dept. Agr., Bui. 149, p. 39,1909. 
2 Hedgcock, George G. Notes on some diseases of trees in our national forests. Phytopathology, v. a, 
no. 2, p. 73, 74, Apr., 1912. 
