Leaf Curi. and Plum Pockets. 327 



the twigs are not deformed, but instead of forming spurs, or 

 flower buds, as in ordinary branches, twigs are produced and this 

 gives the broomy appearance. The presence of the mycelium 

 thus stimulates an early and profuse development of twigs so close 

 together that it roughly stimulates a broom. The asci in the 

 specimens which I have seen occur on the under side of the leaf, 

 though Robinson* says they occur on both surfaces. The leaf is 

 deformed, presenting a series of folds and wrinkles, and the fruc- 

 tification shows as a dense whitish laj^er on the surface. The 

 fungus was first described by Fuckelf as Exoascus deformans b, 

 cerasi. Rathayt made a critical study of the perennial mycelium 

 and the peculiarities of the infected branches, and named the 

 fungus Exoascus wiesncri. It has been considered by many as 

 only a form of Exoascus deformayis (Berk.) Fuckel, and Robin- 

 son|| refers it to that species though he notes that the asci are 

 much more slender than those of the typical form on the peach, 

 the stalk cells proportionately much longer and they do not taper 

 below as in that species. Sadebeckg regards it as a distinct 

 species but accepts the varietal name given it by Fuckel and 

 writes it Exoasais cerasi (Fuckel) Sadeb. It appears to me that 

 it is well distinct from the species on the peach. 



The asci are cylindrical and rounded or truncate at the free 

 ends. According to Sadebeck'^ in the European specimens they 

 measure 35-50 long by 7-10 in diameter. He remarks that there 

 is great variability in the size of the asci. In the specimens from 

 Germantown, Pa., which I have seen the asci measure 25-33, 

 long by 6-9 in diameter. The stalk cells 10-17 high by 5-7 in 

 diameter. The more common length for the asci is about 30. 

 The spores are approximately eight in an ascus, and are round or 

 oval. The details of the asci and spores are shown in fig. 25. 



*Noteson the genus Taphrina. Ann Bot. I, p. 169, 1887-8. 



tSymb. Mycol. p. 252, 1869. 



X Ueber die Hexenbesen der Kirschbaume und iiber Exoascus wiesneri, n. 

 sp. Sitzungsb. d. Math. Natunv. Classe d. k. Akad. d. Wiss. Bd LXXXIII, 

 Abth. I, p. 267, Wien, 1881. 



II Notes on the genus Taphrina. Ann. Bot. I, p. 168-169, 1887-S. 



J. Kritische Unters iiber die durch Taphrina-Arten hervorgebrachten Bauiu- 

 krankheiten. Abgedruck. a. d. Jahrb. Hamb. Wiss Anst. VIII, p. 26, 1891. 

 Die parasitischen Exoasceen. Ibid, x, 2, p. 49, 1893. 



«i 



