SttJDY OF PATHOLOGY. itf 



biological development of this fungus also points to such 

 a conclusion. The developed fungus is found on the bark 

 of the tree ; through the bark it sends only single threads 

 of mycelium, but these become developed into large 

 skinny paperlike patches, measuring many centimetres ; 

 and by means of this subcortical growth the connection 

 between the bark and the tree becomes extensively per- 

 forated with holes ; through these the moisture gains 

 access, and the bark soon crumbles off. Here the advice 

 may be given, keep a watchful eye open for the first 

 appearance of the postia in the forest, and remove as 

 speedily as possible any trunks seized upon by it, and get 

 these removed to a distance, and disposed of as firewood, 

 guarding strictly against their being used as timber or for 

 building purposes. 



'A very similar development in the wood is seen in the 

 Merulius seppens, Fr., Der Kreickende Holzschwxmm, the 

 nearest relation of the dreaded Haussch-chwamm. Thus far 

 positive observations are awanting, but in any circum- 

 stances it would be well that the practical forester 

 should keep a watchful eye upon this species. Analagous 

 are the relations between the Stereum pini, Fr., or Kiejern- 

 hartschiebe, and the Cenangium ferruginosum, Fr., or Rosl- 

 brauiien Leersckuessel that is to say, there is a possibility 

 that eventually, in one of its development forms, it does 

 damage to the plant on which it has found a lodgement. 

 The investigations and experiments on this point have not 

 yet been prosecuted so far as to warrant a decisive state- 

 ment on the subject being given. 



'By far the most destructive of the fungi infesting the 

 black pine is the Lophodermiam pinastri, Chev., the producer 

 of the tickuette. This species in its parasitic injurious 

 form, growing on the living leaves of the tree, has not as 

 yet been observed in the forests of black pine in Austria ; 

 but it has baen seen in Denmark, where, as has been 

 intimated, this tree has been largely cultivated. But oa 

 dead leaves there, as every where, the species is known and 

 is common on all species of Pinus and of Picea. But 



