BRIEFER ARTICLES 
NOTES ON EFFECT OF DYES ON ENDOTHIA PARASITICA 
Some experiments were made in growing the chestnut blight fungus, 
Endothia parasitica, in a liquid medium to which stains had been added. 
The dyes were congo red, trypan blue, methylene blue, and neutral red 
plus 7 per cent NaCl, all “vital stains.”” They were added to a nutrient 
medium, Pasteur’s solution. This solution was not a particularly good 
one for the cultivation of the fungus. Congo red, trypan blue, and 
methylene blue were used in 1/1000 of 1 per cent solutions. The dilu- 
tion of neutral red plus 7 per cent NaCl was not known. This solution 
had been successfully used in the vital staining of some animals of the 
lower orders, and it was tried on the fungus by diluting it 1 cc. to 500 cc. 
of Pasteur’s solution. The cultures were started from conidia mixed 
with a little mycelium taken from a test tube culture. 
Record of experiments 
Conco RED (1/1000 of 1 per cent congo red! in Pasteur’s solution).— 
Conidia germinated and produced normal mycelium. The hyphae 
became red colored. When the cultures were 5 days old, hyphae and 
—— had the same color. Reaction of moduay acid to litmus paper- 
on +o pale Laiebeon. : 
almost colorless, andclear. Th li s acid to lit 
red colored mycelium which had been spreading steadily over the mote 
of the medium showed in sharp contrast. Seven days later the fully and 
normally developed fungus had produced pycnidia and conidia. The 
1, and th ycnidia looked 
yellow. Under the ‘microscope, the color of the hyphae was red to a 
a opaque. The colored hyphae turned blue at once on being placed in oo 
oF per cent sulphuric acid and later lost their color. The pycnidiaon : 
being tested in sulphuric acid yerct reaction; some of — turned 
o : phe, eneaid aoe Ot 
. ‘Tryvan aioe (1/1000 of r per cent trypan? blue in n Pasteur’s ae 
ce tion).—All the conidia, stained a - = so that their — wes could 
