Enpotuia CANKER OF CHESTNUT 539 
“There is reliable evidence, however, that it was present on Long Island 
at least as early as 1893.” This statement was based entirely on the 
recollections of certain observant nurserymen. 
ORIGIN OF THE EPIPHYTOTIC, 
In his first publication Murrill (1906 a:153) advances the theory that 
“it is possible that the conspicuous ravages of the disease about New York 
City are largely due to the severe and prolonged winter of 1903-04, during 
which many trees of various kinds were killed or injured.” Metcalf 
(1908 a:56) believed it possible that the Japanese chestnut had been 
the means of introducing a new fungous disease to this country. Clinton 
(1909: 887), after discussing observations that he had made, states: 
“From the preceding account one can readily see that the writer believes 
that the fungus alone is not entirely responsible for the havoc. . . . . 
Winter injury in 1903-04, aggravated by the droughts, especially that of 
1907, we believe to have been important factors in handicapping the trees 
so that the way was opened for further serious injury by the fungus.” 
From these statements and the evidence cited for upholding this view, 
it is seen that Clinton did not believe a new and dangerous pathogen 
was being dealt with; but, as he states later, he believed that a native 
obscure fungous disease had suddenly sprung into prominence, due more 
to the condition of the host than to the potentialities of the organism. 
These two quite divergent opinions were each based on circumstantial 
evidence which will be more fully treated under etiology and ecologic 
relations. As a solution of the problem pathologists welcomed the 
finding of the disease in China in 1913, for this furnished a satisfactory 
basis for explaining many factors concerning the epiphytotic. 
It therefore seems certain that Metcalf’s assumption as to the origin 
of the outbreak has been proved correct. The opposing views of others, 
which no longer have any significance in accounting for the origin of the 
disease, are névertheless important points to be considered under the influ- 
ence of ecologic factors on the fungus, the susceptibility of the host, and 
the possible augmentation of the epiphytotic. 
SPREAD IN THE UNITED STATES 
The rapidity of spread has been phenomenal, and the completeness 
of destruction is without parallel in the annals of plant pathology. Merkel 
(1906) wrote in November, 1905: “Since that time [1904], however, 
it has spread to such an extent that to-day it is no exaggeration to say 
that ninety-eight per cent of all the chestnut trees in the parks of this 
borough [Bronx] are infected.” Metcalf and Collins (1909: 45) state that 
specimens were received from New Jersey in May, 1905. Murrill (1906 a: 
