54 BULLETIN 380, U. S. DEPARTMENT OF AGRICULTURE. 
limits in Pennsylvania include the northern localities known for 
E. fluens, while the southern limits of this zone coincide closely with 
the southern limit of £. fluens. 
The Livingstons (47) have published maps based on temperature 
summations and temperature efficiencies, as well as maps in which 
isoclimatic lines of temperature are combined with precipitation 
indices and evaporation indices for the mean frostless season. 
While no very definite relations between these maps and the ranges 
of Endothia can be traced it is noteworthy that the localities where 
Endothia gyrosa is known to be abundant are all south of or near 
the 600 line of temperature efficiency, and only one collection of 
E. gyrosa has been made north of the 400 line. £. singularis, on the 
other hand, has thus far been found only north of the 400 line. 
Zon’s map (86) of vegetal regions of the United States is based on 
periods of growth and rest. The regions where E'ndothia gyrosa 
and Z’. fluens are abundant are all south of the line which marks the 
northern limit of seven months’ vegetation. In fact this coincides 
very closely with the northern limit of 2’. fuens, and no specimen of 
E. gyrosa showing ascospores has been found farther north. 
“The relations pointed out above strongly suggest the possibility of 
some causal connection between climatic conditions and the present 
ranges of Endothia species, but just what factors may limit the 
spread. of the species is not yet determined. The temperature tests 
recorded on pages 45 to 48 throw little light on this problem, for the 
maximum and minimum temperatures are about the same in the vari- 
ous species. L'ndothia fluens seems to be less resistant to the effects of 
high temperature (40° C.), but it is difficult to see that this fact alone 
has any direct bearing on the question of distribution. 
DISCOVERY OF ENDOTHIA PARASITICA IN CHINA. 
For eight years after its discovery in the New York Zoological 
Park in the summer of 1904, Endothia parasitica was known only 
from eastern North America. During this time two quite different 
opinions as to the origin of the fungus were advanced. Some in- 
vestigators maintained that Z. parasitica was an indigenous fungus 
(15); others that it had been imported from some foreign coun- 
try, probably oriental (51, 52.) In the fall of 1912, however, pyc- 
nospore material was sent from Agassiz, B. C., by H. F. Giissow, 
Dominion Botanist of Canada. Cultures made from this material 
were identical with /. parasitica, and a series of inoculations on 
Castanea dentata produced typical cankers. Later, a large quantity 
of material collected at Agassiz by Dr. James R. Weir was received, 
which included a few ascospores. These proved to be typical 
EL’. parasitica. 
