46 
Mycologia 
Mr. F. J. Veihmeyer, in Bulletin 127 of the U. S. Department 
of Agriculture, discusses the Mycogone disease of mushrooms 
and its control. This disease has been known in Europe for at 
least three generations and has been very destructive to mush- 
room beds. It was reported in America only a few years ago 
and now threatens the mushroom industry in certain localities. 
Methods of prevention and control are discussed at length in this 
bulletin. 
Plants of Oenothera Tracyi grown at the New York Botanical 
Garden during the past two years have had their leaves almost 
completely covered with mildew (Erysiphe) , which gives them a 
decided grayish-white color. Plants of O. grandiflora, however, 
growing by the side of O. Tracyi seem to be completely immune 
from the attacks of this fungus and their foliage has remained 
bright-green throughout. 
The Strumella disease of oak and chestnut trees is described 
and fully illustrated by F. D. Heald and R. A. Studhalter in Bul- 
letin 10 of the Pennsylvania Department of Forestry. This dis- 
ease very much resembles the chestnut canker and attacks not 
only chestnut but also various species of oak in the northeastern 
United States. The fungus, Strumella coryneoidea Sacc. & 
Wint., is an old species, but has not previously been considered 
parasitic in habit. The investigations in this bulletin have been 
confined to the state of Pennsylvania. 
A very interesting list of wood-destroying fungi which grow 
on both deciduous and coniferous trees, by James R. Weir, ap- 
pears in the August number of Phytopathology. These obser- 
vations show that too much dependence must not be placed on 
the host as an aid in determining certain wood-loving species. 
One of the most striking instances recorded by the author is that 
of Grifola Berkeleyi attacking the roots of the larch in the Kan- 
iksu National Forest of Idaho. This handsome species is 
known in the East only on oak. 
