LETTEK OF TRANSMITTAL. 



Hon. Eobert S. Conklin, 



Commissioner of Forestry: 



Sir: I Lave the honor to present my report on the deadly fungus, 

 DiapoiiJie puinsifica, that has caused the destruction of many chest- 

 nut trees within the borders of the State of Pennsylvania. The in- 

 vestigations have been carried on to ascertain the presence of this 

 disease in the valleys of the Delaware and Susquehanna rjvers. Ac- 

 companying the report of its geographical distribution is an account 

 of its life history, its prolific propagation, the damage already done, 

 and suggestions for remedial treatment. 



Thanking you aiid your associates for many courtesies, I have the 

 honor to be, 



Most respectfully yours, 



JOHN MICKLEBOEOUGH, Th. D. 



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