[Reprint of Bureau of Plant Industry Bulletin No. 141, Pt. V, issued Aug. 30, 1909.] 
THE PRESENT STATUS OF THE CHESTNUT BARK DISEASE. 
By Haven Mercatr, Pathologist in Charge, and J. FRanKLIN Cotiins, Special Agent, 
Investigations in Forest Pathology. 
History oF THE CuEestNuT Bark DIsEAsE. 
In 1904 Mr. H. W. Merkel, of the New York Zoological Park, 
observed a disease which was destroying large numbers of chestnut 
trees in the city of New York. This disease is what is now known 
as the chestnut bark disease. Even at that time it is certain that it 
had spread over Nassau County and Greater New York, and had 
found lodgment in the adjacent counties of Connecticut and New 
Jersey. No earlier observation than this is recorded, but it is evident 
‘that the disease, which would of necessity have made slow advance 
at first, must have been in this general locality for a number of years 
in order to have gained such a foothold by 1904. Conspicuous as it 
is, it is strange that the fungus causing this disease was not observed 
or collected by any mycologist until May, 1905, when specimens were 
received from New Jersey by Mrs. F. W. Patterson, the Mycologist 
of the Bureau of Plant Industry. In the same year Dr. W. A. 
Murrill began his studies of the disease, publishing the results in the 
summer of 1906. By August, 1907, apeaniene received by this 
bureau showed that the disease had reached at least as far south as 
Trenton, N. J., and as far north as Poughkeepsie, N. Y., and was 
spread generally over Westchester and Nassau Counties, N. Y., Bergen 
ounty, N. J., and Fairfield County, Conn. 
PRESENT DISTRIBUTION. 
The present distribution of the chestnut bark disease is shown on 
the accompanying map (fig. 1). By this it will be seen that infec- 
tion is now complete in the general vicinity of the city of New York. 
Outside of this area the disease already occurs at scattering points 
in a number of States. In every case its occurrence has been defi- 
nitely authenticated by specimens which have been examined micro- 
scopically. Reports have been received indicating that the disease 
is found at many other places, but not being substantiated by 
specimens these localities have not been shown on the accompanying 
map. It is only fair to state, however, that such reports have been 
received from points as remote as Cape Cod, Wellesley, and Pitts- 
field, Mass.; Rochester and Shelter Island, N. Y., and Akron, Ohio. 
The bark disease is entirely different from a disease which during 
the past 20 years has caused the death of many chestnut trees on 
the Atlantic slope, periculat south of the Potomac River. The 
latter disease, which is now hang studied by the Department of 
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