Dear Sir,—I think that perhaps before this reaches you, you will have heard from the Rev. E. N. Blomfield that these curiously formed damsons, of which you have forwarded me such excellent specimens, owe the galled growth to the attack of a parasite fungus. They are what you called popularly Bladder plums, or Pocket plums (fig. [39]), and the cause of this extraordinary growth is the presence of the fungus Exoascus pruni. I do not myself work on Fungi, so I should not have considered myself qualified to give you trustworthy information, but I see in Professor Marshall Ward’s good account of this attack, that, besides reproduction taking place by means of the spores carrying the disease from tree to tree, he mentions that the fungus can carry on its existence from year to year by means of its mycelium in the branches. Consequently much pruning back, as well as collecting and burning the “pockets,” is needed to combat the attack to any serviceable extent. I am not troubling you with details, for you would find them so well entered on in Ward’s useful little book, of which I gave the name yesterday to Mr. Blomfield, that I think you would prefer them in his wording. Hoping I may have assisted you a little in the matter.
FIG. 39.—POCKET OR BLADDER PLUM INFLATED AND DISTORTED BY THE FUNGOID ATTACK OF EXOASCUS PRUNI (After Sorauer).
December 19, 1900.
I am greatly obliged to you for the kind thought of sending me the photo of the Bladder plums. This shows the difference between the healthy and the diseased fruit so well that if I had not secured a figure of the diseased growth I think I should have asked your permission to copy part for my next Annual Report. This assuredly is not an insect attack. Still, as it may very often give rise to much perplexity, I thought that (with due explanation) there could be no objection to including your good contribution, and I hope that when in due time you receive your “contributor’s copy” you will not disapprove.
About Dr. Nalepa’s publications; I dare not offer to lend them, for all I have are copies presented successively during a long course of years, and if any mishap occurred, I should be in a difficult position. But if you have not yet applied to them, Messrs. W. Wesley & Son would be more likely to help you than anybody I am acquainted with. They would almost certainly be able to give you the titles of the successive publications and prices, and also procure for you such as are published. At one time I worked a great deal on vegetable galls, Cynips galls chiefly, but Phytoptus galls I have always found so very troublesome in several points of view that I have never worked on them more than I can help. Very truly yours,
Eleanor A. Ormerod.
To Messrs. W. J. Coleman & Sons, Fruit, Pea, and Potato Salesmen, Covent Garden Market.
Torrington House, St. Albans,
August 1, 1900.