278 



CORRESPONDENCE ON THE BLACK WARTS OF THE PLUM TREE. 



(unless very lately,) been determined to the 

 entire satisfaction of all. 



The tree, from which the enclosed piece 

 was taken, is young, and was brought last 

 spring from one of the nurseries at New- 

 burgh. The variety is " Smith's Orleans." 

 It may be not unimportant, in this connec- 

 tion, to state that " the warts," or " canker," 

 made its appearance in this garden some 

 few years since, attacking first one tree and 

 then another; no remedy having been ap- 

 plied, from the supposition that it was "a 

 disease," and not to be cured, until finally 

 every plum tree on the premises perished ; 

 since which time, no trees have been grow- 

 ing here or in the immediate neighborhood. 



I have just now commenced the cultiva- 

 tion anew, with the trees above spoken of, 

 and have paid pretty close attention to them 

 through the summer. A few days since, 

 I discovered upon a small branch of a tree, 

 of the " Bleecker's Gage," a small exuda- 

 tion of gum; and, upon examination, I 

 found it to be an embryo "wart." I cut it 

 off, at once, and burned it. Yesterday I 

 discovered the enclosed, — the deposit of 

 gum being as large as the half of a Mar- 

 rowfat Pea, perhaps. I determined to exa- 

 mine it for myself, without any very great 

 hopes, however, of being able to make a 

 discovery of that which had so long escaped 

 the observation of some, at least, of our 

 most scientific pomologists. 



Upon removing the gum, and opening 

 the branch cut off, I was astonished to see 

 clearly and distinctly the part affected, filled 

 with small white grubs, which you will be 

 able to see, unless they shall have perished 

 before this reaches you. It appears to me 

 highly probable, that they remain two years 

 in the tree before they undergo their final 

 transformation ; as it seems impossible that 

 they should be able, in the brief space of 

 mild weather of this season, and the spring 



months of the next, to produce tliose im- 

 mense excrescences which appear finally 

 upon the trees attacked. But of this fact,, 

 you are the best judge. 



I hope you will pardon me for troubling 

 you, if you shall have, before this, made 

 the discovery satisfactorily; and if not, the 

 importance of the subject will, I trust, be a 

 sufficient apology. I am, sir, with great 

 respect, your ob't serv't, 



Fbed'k Weston. 



Sandy Hill, N. Y., lith Oct., 1848. 



A. J. Downing, Esq. — Dear Sir: Agreea- 

 bly to your request, I have examined the 

 plum tree twig, enclosed in your letter of 

 the 20th instant. The piece is nearly one 

 quarter of an inch in diameter. There is 

 a wound on the surface, one inch long, in 

 a longitudinal direction, caused by a series 

 of punctures, passing obliquely downwards 

 and penetrating the pith. By splitting the 

 twig, I have ascertained that these punc- 

 tures or perforations w ere twenty-three in 

 number, arranged in two contiguous rows, 

 and alternating with each other; there be- 

 ing twelve perforations in the one, and 

 eleven in the other row. Each of these 

 perforations contained a cream-coloured 

 egg, of a cylindrical form, rounded at the 

 ends, and about one-tenth of an inch long. 

 Many of the eggs were destroyed in split- 

 ting open the twig; but several of them 

 still remain within the holes, drilled for 

 their reception. All of them appear to 

 have perished without hatching; perhaps 

 because the twig was too soon cut from the 

 tree. The whole surface of the twig, 

 around the wound, is covered with a 

 glazing, like the white of an egg. The 

 drilling of the holes has, in a singular 

 manner, loosened and furred up the fibres 

 of the wood, portions of which project 

 around the orifices, where, however, they 



