R. J. Tabor and Kate Barratt 27 



obvious therefore, that the pecuhar circumstance of the pollard trees 

 is not alone responsible for their susceptibility, and it must be con- 

 cluded that Bulgaria may prove a dangerous parasite to old beeches, 

 more especially when from various causes their vitality may become 

 impaired. 



U]) to the present the actual source and nature of the " gum" has 

 not been determined. Preventive and remedial measures are under 

 consideration. 



Summary. 



A gumming disease of pollard beeches is described which is associated 

 with the presence of Bulgaria polymorpha, Wett. on the trees. 



A mycelium isolated from the diseased bark has been cultivated 

 and has produced the fructifications of Bulgaria. 



A pollard has been infected with the disease by grafting in a piece 

 of diseased bark, and also by introducing the mycelium of Bulgaria. 



Repeated infections of young, vigorous trees with the mycelium 

 failed to produce the disease. 



It is concluded that Bulgaria is a dangerous facultative parasite on 

 old beeches, but that young healthy trees are able to resist infection. 



We take this opportunity to record our thanks to M. C. Duchesne, 

 Esq., the Ranger of Burnham Beeches, for the facilities he has readily 

 ali'orded us and for the information he has placed at our disposal. 



BIBLIOGRAPHY. 



1. TuLASNE, L. R. Nouvelles Recherches sur rAppareil Reproducteur des Cham- 



pignons. Annales des Sciences Naturelles, in. Ser. t. 20, ]>. IHO, 1853. 



2. Brefeld, O. U liters uchungen aus dem Gesanimtgebiete der Mykologie, x, p. 



301, 1891. 



3. FucKEL, L. Symbolae mycologicae. Beitrage zur Kenntniss der rheinischeii 



Pilze. Jahrbilcher des Nassauischen Vereins ficr Naturkunde, xxni-xxiv, 

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4. LuDWiG, F. 1st Bulgaria inquinans ein Wund Parasit ? Centralblatt fur Bak- 



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lebenden Eichen. Zeitschriff fiir Pflanzenkrankheiten, iv, 266, 1894. 



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Botany, xv, p. 119, 1901. 



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