STATE POMOLOGICAL SOCIETY. 73 



dip it in spirits of tui'pentine and thoroughly saturate the knot, 

 being careful not to touch the tree except' in the diseased part. It 

 stops the knot, and the tree puts out healthy branches below it. 

 I am careful to burn all branches removed in pruning*. As the 

 summer is the time the mischief is done, every fresh excrescence 

 should be pared off, the turpentine applied, and it will harden in a 

 week." I will add the testimony of my own experience as to the 

 eflScacy of the pruning off of all appearances of black knot ; and in 

 practising this from year to year, I have preserved several of the 

 Late Kentish trees from destruction, and they have, nearly every 

 year during the last fifteen, borne fair crops of fruit. 



While engaged in the preparation of this paper and seeking for 

 information respecting the cause of black knot, I became incident- 

 ally much interested in the perusal of a series of articles published 

 in the Boston CuUivalor, over the signature of Lyman Reed, on the 

 subject of the potato rot, in which the writer with much energy, 

 and as I think, successfully, refutes the old and apparently well 

 settled theory that fungus is the cause of that disease. In his 

 summing up of the case he states several facts and reasons for be- 

 lieving the old theory to be wrong, two of which are as follows : 

 "That larvas of insects are the original cause of the potato x'ot." 

 "That the potato fungus is a sequence, and not a cause." 

 The suggestion at once flashed to my mind whether this dis- 

 covery, made and completed through many years of patient inves- 

 tigation under varying circumstances, with the best aids which 

 science has provided, might not afford a clue to the cause of the 

 cherry tree disease; for, as I reasoned, "if tlie potato fungus is a 

 sequence rather than a cause, why not the fungi upon our cherry 

 trees?" Acting upon this suggestion, in pursuance of my in- 

 quiries, I addressed a letter to Mr. Reed at Boston, asking him if 

 he had ever given any attention to microscopic or other investiga- 

 tions of the cause of the black knot in cherry trees, and if so to 

 describe the result of such methods of investigation. I have much 

 pleasure in submitting herewith his reply ; and I will say, although 

 I have in previous pages stated the opinion that " no true diagno- 

 sis of this disease has ever been obtained," I am since constrained 

 to admit the conviction that Mr. Reed's discoveries in this direc- 

 tion point to the real cause of the decline and failure of cherry 

 culture in many parts of our country. 



