Leaf Curl and Plum Pockets. 335 



during three years, 1890-92, I observed it as very abundant at 

 Auburn, Ala., both on the wild P. angustifolia and its cultivated 

 varieties. It produces in the young leaf buds and the ends of 

 the young twigs an enlarged structure, the tissue of which is very 

 much like that of the plum "bladders." The swollen bud or 

 twig is usual I5' whitish or yellowish white in color, the tissue is 

 soft and spongy, and the structure is hollow at the center. They 

 vary greatly in form, being clavate, oval, lanceolate, or elliptical; 

 while the surface varies also to an equal extent, depending upon 

 the stage of development of the bud or twig at the time that the 

 growth is arrested. The bud may be brought well under contri- 

 bution before the leaves have begun to open, when the large mass 

 of tissue will present no appearance of even the leaf tips. Some- 

 times the leaves partly separate and then short or long points 

 which are of the same kind of tissue will project from the bulk of 

 the mass. Again, the leaves may be more or less expanded, so 

 that some of them present green normal tips projecting from the 

 swollen bud, and from this the green expanded portion varies 

 through different specimens so that in some there are normal 

 leaves standing out from it. Two of these conditions are repro- 

 duced from photographs of fresh specimens in figures 10 and 11, 

 Plate V. 



The asci are developed all over the surface of the spongy por- 

 tion of the structure, and give it a mealy appearance. The twig 

 is sometimes enlarged and deformed to some distance below the 

 enlarged spongy end, and it is not rare to find, especially at a 

 rather late period for the development of the asci, twigs slightly 

 enlarged for a considerable distance, but bearing no asci. The 

 fungus in structure is rather closely related to Exoascus pruni, 

 and at one time I considered it identical with that species. Spe- 

 cimens collected by myself in Alabama were distributed by Sey- 

 mour and Earle* as Taphrina deformans (Berk.) Tul. 



The asci are slightly clavate, rounded or truncate at the free 

 ends, and measure 25-45 long by 8-10 in diameter. The stalk 

 cells are 10-18 high by 5-8 in diameter, and are usually rounded 

 or truncate at the base. They do not intrude between the cells of 

 the epidermis. The spores are quite regularly elliptical, or rarely 



* Economic Fungi, No. 129. 



