326 PROCEEDINGS OP THE ACADEMY OP [1886. 



Citations enough have doubtless been given, although several 

 pages of equally strong ones might be added, to show that fruit- 

 growers, who have the best opportunities for observation, con- 

 sider it a disease greatly to be dreaded and one of special economic 

 importance. Other sections of the country, notably those of 

 Ohio, western New York and Georgia, could furnish equally im- 

 portant proof of these propositions. All that is desired in this 

 connection, however, is to give those not familiar with the subject 

 some idea of the disease and its effects as ordinarily observed 



Early Records. The oldest mention of the disease, that gives 

 a good and reasonably full description of it, is in Coxe's work on 

 fruit-trees, bearing the date of 1817. The manner of the author 

 leaves no doubt that it was well known at that time, and the 

 reference to his losses during twenty years makes it reasonably 

 certain that he had observed the disease as early as the opening 

 of the century. The earliest notice, however, which has yet come 

 to hand, is in a letter written by Wm. Denning,^ describing the 

 disease in apples, pears, and quinces. He speaks of first observ- 

 ing it on the Highlands of the Hudson in 1780. 



There is no interest, however, in tracing chronologically the 

 various notices found in different publications, for without excep- 

 tion they have the tone of treating a familiar theme, and show no 

 evidence that the disease in the first part of the century was in 

 any respect different from to-day. 



Conjectures Regarding its Cause. A brief treatment of this 

 topic will be all that is required for the purposes of this paper ; 

 and only those hypotheses will be touched upon which received 

 such careful presentation as to attract the favorable attention of 

 the public. 



Few writers appear to ascribe the disease to a single agency, 

 but regard it as resulting from several causes, either acting to- 

 gether or brought about by dissimilar circumstances. Little dis- 

 crimination is made between predisi)Osing conditions and active 

 aoents. In fact sharply defined treatment could not be expected 

 when all was conjecture, and when the shrewdest observers did 

 not hesitate to avow that after years of loss under all kinds of 

 experimentation, and after interminable discussions, the cause 

 still lay shrouded in impenetrable obscurit3^ 



1 Trans. Soc. for Prom, of Agric, vol. 15, 1794, p. 219. 



