26 Disease caused bij Bulgaria Polyinorpha 



pycnidial fructifications were abundant. Their regular occurrence and 

 relative importance appear to have been generally overlooked by later 

 writers although Tulasne refers to them as occurring not infrequently. 

 Fuckel(3) described them and identified them erroneously with Tre- 

 ?nella foliacea, Ters. {UlocoUa, Brefeld), with which they have no con- 

 nection. Fuckel had apparently never found thorn in conjunction with 

 the apothecia and says "Die Combination beider mag immerhin als 

 gewagt erscheinen ; die entfernte Aehnlichkeit aber der Conidien mit 

 den Schlauchsporen und die Analogie mit C'on/ne-Arten, verliehen 

 derselben doch grosse Wahrscheinlichkeit." 



The pycnoconidia are produced during the summer months, the 

 apothecia in the early autumn and they can frequently be found together 

 on the same stroma (Fig. 5). Biffen(O) observed the formation of the 

 pycnidia in his cultures of Bulgaria on oak wood and they have appeared 

 in all our cultures both on the bark and on plum agar. 



Other Records of Parasitism of Bulgaria. 



The suggestion that Bulgaria sliould be classed as a facultative 

 parasite was first put forward by Ludwig(4) who described in 1887 a 

 fatal attack on a fine specimen of Quercus rubra. A similar instance 

 is recorded by Hennings(5) on the same species of Quercus, and this 

 author is inclined to regard the fungus as a dangerous parasite. 



Bifien(6), who studied the effect of the hyphae on oak wood, found 

 that the action was too slight to warrant the supposition that the 

 fungus is capable of causing a really serious tree-disease such as Ludwig(4) 

 assumed. A reference to the latter's account however, shows that he 

 attributes the death of the oak to the destruction of the bark by 

 Bulgaria, and not to its effect on the wood. The results of the present 

 investigation clearly indicate that in the beech also, the fungus is 

 primarily a bark-parasite. 



So far as the authors are aware, no account has hitherto been published 

 of an attack on the beech, apart from a statement by Massee(7) that 

 he has seen it on living beech, and no infection experiments have been 

 recorded. It is noteworthy that at Burnham Beeches the pollard oaks 

 have so far been quite free from attack. 



The investigation has been confined to the pollard trees at Burnham 

 Beeches, but the Ranger, who has examined beech plantations in various 

 parts of the country, has found the disease on mature maiden trees in 

 several areas in l^uckinghamshire, at Tring in Hertfordshire, Walton- 

 on-Hill in Surrey, and in the Goring district of Oxfordshire. It is 



