ENDOTHIA PARASITICA AND RELATED SPECIES. 59 
PRESENT DISTRIBUTION OF ENDOTHIA PARASITICA IN AMERICA. 
The present range of E'ndothia parasitica in America, as shown by 
the map (fig. 4), is probably merely the extent to which it has been 
able to spread in the time since it was first introduced. 
Whether Endothia parasitica was introduced inte one locality or 
several is uncertain, but the studies of Heald (40, 41) and others have 
shown clearly that the spores of £. parasitica are carried by the wind, 
by insects and birds, and on nursery stock, which would account 
for its wide distribution and for its occurrence in isolated localities, 
long distances away from the main body of the disease. It also makes 
it seem probable that the fungus will continue to spread with some 
rapidity. 
Certainly, there is no evidence that any factor, climatic or other- 
wise, is likely to prevent the spread of this fungus into the large area 
of chestnut south of its present range. On the contrary, the duplicate 
inoculations made by the writers show clearly that the fungus grows 
more rapidly at the southern limit of its present range than farther 
north, where it is much more common. The longer growing season 
in the South is also no doubt an important factor. 
In this connection, it may be noted that Képpen (46), in his map 
of the vegetation regions of the earth, places the portion of China 
where Endothéa parasitica has been found indigenous in the same 
climatic region as that portion of the United States where it is now 
doing such destructive work. He designates this region as the 
“ Hickory ” division of the mesotherms. 
HOST RELATIONS OF THE SPECIES OF ENDOTHIA. 
ENDOTHIA GYROSA. 
Endothia gyrosa occurs commonly on Liquidambar, Fagus, and 
Quercus, occasionally on Castanea, and has been found on Vitis in 
Alabama, but the writers were unable to obtain fresh material from 
this host. 
While Fagus and Quercus are, of course, closely related, it seems 
remarkable that a fungus should be abundant on hosts so different 
as Liquidambar and Quercus, yet so rare on any other host as to be 
only once reported. It seemed possible, indeed, that the fungus on 
Liquidambar, while morphologically and culturally identical with 
that on the various other hosts, might prove to be physiologically dif- 
ferent, In order to obtain more definite information on this point, 
several series of cross inoculations were made. 
It had been observed that Endothia gyrosa was found most fre- 
quently on the cut or broken ends of branches or on exposed, bruised, 
or broken roots. In making inoculations, therefore, a small branch, 
