430 CONNECTICUT EXPERIMENT STATION REPORT, I9Q12. 
aurantiacus-miniatus on the edges where it is in contact with 
glass or medium. 
On oat-juice agar the variety parasitica forms a somewhat 
more evident aerial mycelium, but has fewer pustules and less 
evident spore drops even than on the Lima bean-juice agar. It 
usually has a deeper color, which varies from albus to luteus. 
The species on oat-juice agar forms a very luxuriant growth, 
even more so than on Lima bean-juice agar, and though its 
fruiting bodies are not so numerous, they are often evident 
exposed pustules, only partially hidden by the spores mass, which 
exudes with difficulty. The color assumes its maximum develop- 
ment and is in strong contrast to that of the variety on the 
same medium. It is usually more uniform and intense in color 
than on the bean-juice agar, finally varying from luteus through 
aurantiacus to miniatus and even badius when in contact with 
the glass or medium. Part of the growth, especially on the 
upper edge, however, often remains albus. 
The color of the spore masses of both forms varies in dif- 
ferent cultures from sulphureus to nearly purpureus, depending 
apparently on age, variation of the medium, bacterial contamina~- 
tion, or other unknown factors. Likewise, a culture when 
renewed on the same medium sometimes acts somewhat differ- 
ently for some unknown reason, as to luxuriance in mycelial 
growth or spore development, or color characters. 
Tannic Acid in Cultures. Since tannin is found in such large 
quantities in the wood of chestnut, and since this varies accord- 
ing to the age of the tree, etc., it has been suggested previously 
in this paper that this variation may have some bearing upon 
the development of the chestnut blight. It was thought desir- 
able, therefore, to study both the saprophytic Endothia gyrosa 
and the variety parasitica in artificial cultures containing dif- 
ferent percentages of tannic acid (M. C. W. brand, U. S. P.) 
to determine how this affected their vigor, growth and spore 
production. These cultures have all been made by Mr. Stoddard 
under the writer’s direction, and the data here given should be 
credited to both investigators. We have used mainly for this 
work two rather recent cultures of E. gyrosa on two species 
of oak from Washington, D. C., and four cultures of E. gyrosa 
var. parasitica on chestnut, two from Washington and two from 
