PRESENT STATUS OF CHESTNUT BARK DISEASE. 47 
as 1903, and that in Lancaster County, Pa., it probably was present 
as early as 1905. All other points shown on the map outside of the 
area of general infection appear to have been infected only within 
one or two years. 
The bark disease appears practically to exterminate the trees in 
any locality which it infests. A survey of Forest Park, Brooklyn, 
showed “that 16,695 chestnut trees were killed in the 350 acres of 
woodland in this park alone. Of this number about 9,000 were 
between 8 and 12 inches in diameter, and the remaining 7,000 or more 
were of larger size.” 
In a recent publication Dr. W. A. Murrill estimates the financial 
loss from this disease “in and about New York City” at * between 
five and ten million dollars.” The aggregate loss throughout the 
whole area of country affected must be much greater. 
The bark ‘disease occurs on both chestnut and chinquapin, regard- 
less of age, origin, or condition. It does not occur on any other 
tree so far as known. All reports of its occurrence on the chestnut 
oak (Guercus prinus) have proved to be unfounded. It is not yet 
known whether the goldenleaf chinquapin of the Pacific coast (Cas- 
tanopsis chrysophylla) is subject to this disease. 
According to Sudworth, the range of the native chestnut is “ from 
southern Maine to northwestern Vermont (Winooski River), southern 
Ontario, and southern shores of Lake Ontario to southeastern Mich- 
igan; southward to Delaware and southeastern Indiana, and on the 
Allegheny Mountains to central Kentucky and Tennessee, central 
Alabama, and Mississippi.” The range of the chinquapin is * from 
southern Pennsylvania (Adams, York, Franklin, and Cumberland 
counties) to northern Florida and eastern Texas (Neches River).” 
The bark disease may, therefore, be expected to occur at any point 
within these limits, as well as in any other localities where the chest- 
nut is grown as an ornamental or orchard tree. 
CAUSE AND SYMPTOMS. 
The disease is caused by the fungus Yiaporthe parasitica Murrill 
(also known as Valsonectria parasitica (Murrill) Rehm). The 
spores of this fungus, brought by some means from a previously dis- 
eased tree, enter the bark through wounds; possibly also in other 
ways. The leaves and green twigs are not directly affected. From 
the point of infection the fungus grows in all directions through the 
inner bark until the growth meets on the opposite side of the trunk 
or limb, which in this way is girdled. The wood is but little affected. 
Limbs with smooth bark attacked by the fungus soon show dead, 
discolored, sunken patches of bark covered more or less thickly with 
the yellow, orange, or reddish-brown pustules of the fruiting fungus. 
141—y 
