292 



Mycologia 



Through the experiments of Bonnier, Matruchot, and Combes 

 (Compt. Rend. 152: 652-659. 191 1 ) , it has been demonstrated 

 that the air of forests contains nearly three hundred times as 

 many spores of fungi as of bacteria, and that at high altitudes 

 the number of spores of all kinds present in the air is much 

 reduced. 



A canker of the chestnut in southern Europe somewhat similar 

 to that caused by Diaporthe parasitica in America, is claimed by 

 Briosi and Farneti to be due to Melanconis perniciosa, which, 

 according to these authors, is distinct from Melanconis modonia 

 causing black canker of the chestnut in Brittany. 



P. Vuillemin has called attention to a minute fungus, Cicin- 

 nobolus Cesatii Euonymi, which is parasitic on the oak oidium 

 in the forests of France, and suggests that this prevalent disease 

 may be held in check elsewhere by the introduction of the para- 

 site. The oidium has been abundant in the eastern United States 

 in recent years. 



Dr. W. A. Murrill visited Stockbridge, Massachusetts, on Sep- 

 tember 4 and 5, and returned with a large number of fleshy fungi, 

 collected with the assistance of Dr. W. Gilman Thompson and 

 Mr. Hoffmann. The invasion of the chestnut canker at several 

 points in the vicinity of Stockbridge was also investigated and 

 specimens of infected branches secured. 



A disease of plum trees known as " silver-leaf," caused by 

 Stereum purpureum, has been investigated quite thoroughly in 

 England by the Duke of Bedford and S. U. Pickering, who claim 

 that the discoloration of the leaves is due to their cells becoming 

 partially disconnected, owing to disturbance in nutrition by 

 poisons formed by the growing fungus. No satisfactory treat- 

 ment has been discovered. 



Dr. H. D. House, of the Biltmore Forest School, has done con- 

 siderable collecting the past season in Michigan and Oregon. 



