1900 ] 
BRIEFER ARTICLES 
401 
the diseased leaves showed the presence of a much branched mycelium 
made up of hyphz which were both intercellular and intracellular. 
Owing to an interruption of several months, caused by the pressure of, 
classroom work and laboratory duties, no further observations were 
made until the following summer (1899). The progress of destruction 
during this interval was far beyond expecta- 
tion. Trees which but 
nine months before 
showed only a dead branch or two had now 
entirely succumbed, 
and 
spreading rapidly, many 
the disease was 
new points of infec- 
tion being noticed. Any doubts as to the full 
malignancy of the disease which may have 
existed when it first made its appearance were 
how dispelled, and it was but too evident that 
the injury to the balsam forests would be great. 
The diseased leaves at this time showed the 
presence of numerous black warty tubercles 
which proved to be the fruiting masses (sporo- 
dochia). 
A quantity of material was collected 
and brought to the laboratory for further exami- 
nation and study. Pure cultures were made on 
Many different media in 
tubes and plates, and 
steat difficulty was experienced in obtaining 
‘normal development and in many cases any 
Stowth at all. Blood serum (Loeffler’s mixture 
for diphtheria cultures, 
no. 8), potato agar, 
potato, beef agar (acid, neutral, and alkaline), 
and nutrient gelatin, were all tried and found 
“erviceable as indicated 
tioned. Hanging drop 
from the plate cultures 
In many cases the spores 
in the order men- 
cultures were made 
which proved pure. 
refused to germinate 
ee ee eee 
. Acculture tube 
showing the growth of 
Trimmatostroma abietina 
upon blood serum. 
Mwater. Those which germinated at all did so within thirty-six hours 
and the Majority within twenty-four, 
from each spore, or in some of the multicellular forms one fro 
Sal (fig. 2, d ). From observations which I have made upon cultures and 
“ctions of imbedded material, I would characterize the form as 
ae immatostroma abietina, n. sp.— Mycelium perennial, inter 
~ tracellular, hibernating during the first winter in the tls 
a single germ tube being put out 
m each 
follows : 
cellular 
sues of 
