STEVENS: PREVALENCE OF ENDOTHIA GYROSA 139 
a 
~ 
Quercus phelios 6 
Quercus prinus 
Quercus velutina 
er[. 
bra 
Quercus virginiana 
Quercus pumila 
Fic Ranges of several other species of Quercus in the United States. Map 
AEN i W. H. Lamb. 
red oak among the locally characteristic species. It is suggestive 
that in only one locality, Central Michigan, has E. gyrosa been 
found in the northern forest, especially as that region in New 
York, Pennsylvania, Maryland, and adjoining portions of West 
Virginia has been the scene of much recent collecting in connection 
with work on chestnut blight. There seems to be no climatic 
reason why E. gyrosa should not occur on beech in the northern 
states of New England, and the writer believes it may yet be 
found there. Host relations alone would, however, prevent its 
becoming prevalent. 
SOIL RELATIONS 
Within the Central and Southern Forest Regions where its 
hosts are abundant, the relative amount of opportunity for infec- 
tion is greatly influenced by soil and cultural conditions. As has 
already been mentioned, exposed and injured roots of Fagus and 
