CHESTNUT BARK DISEASE. 373 



the other hand, the writer holds the view, at least tentatively, 

 that the chestnut blight has not spread from a single central 

 locality in New York City, but that at the time of its discovery 

 there in 1904 it occurred in an inconspicuous way in widely 

 scattered spots in several states, and that it has been in these 

 localities for years. 



The reasons for this belief are as follows: (i) While origi- 

 nally reported from the New York Zoological Park in 1904, sub- 

 sequent information has shown that at about that time, or even 

 earlier, in several cases already cited, the disease was present 

 in such widely separated places as Woodbridge, Stamford and 

 Greenwich, Conn. ; Huntington, L. I. ; Bronx Park, N. Y. ; 

 Bergen County, N. J. ; Lancaster County, Pa., and Bedford 

 County, Va. (2) Its sudden appearance and quick destruc- 

 tion of the trees where first found (98 per cent, infected by 

 end of 1905, as reported by Merkel) indicate that there was 

 some other factor involved than the spread of a virulent para- 

 sitic fungus, since such quick work is without parallel in the 

 history of other fungous diseases of trees, or even with this 

 one in its later history. (3) Recent investigations have shown 

 that the fungus is more likely native than imported, and if 

 native, there is no good reason why it should have been limited 

 to the immediate vicinity of New York City. (4) Our investi- 

 gations in Connecticut have shown it present in some localities 

 in an inconspicuous way at the base of the trees, as if it were 

 a native instead of an introduced fungus, just as its nearest 

 relative is found to-day in the South. This latter fungus, 

 Endothia gyrosa, is so generally distributed in the South that 

 there is no doubt that it has occurred there since Schweinitz's 

 time, and yet no one had, previous to our investigations, 

 reported it on chestnut in that region. 



We believe that the chestnut blight fungus existed in the 

 North previous to its outbreak in 1904 as a weak parasite in a 

 number of scattered localities. From these centers it spread 

 with greater or less rapidity according to local conditions. 

 This belief does not in any way contradict the possibility of 

 the disease being carried longer or shorter distances by such 

 agencies as infected nursery stock, birds, etc. Perhaps the 

 strongest evidence against this belief is the fact that the greatest 

 damage has occurred in the vicinity of New York City, and 



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