280 ASPERGILLOSIS 
entrance of the latter‘into the air passages is favored by dryness of the 
grain. Neumann states that aspergillosis is common in Italian 
pigeons sold in Paris. Many of them show large mycotic swellings. 
Its localization in the beak of the pigeon gives it special prominence. 
It is thought by many authors that horses become infected when 
they are obliged to live on mouldy oats or forage. The extent to 
which the so-called “forage poisoning’’ is due to this fungus is not 
known. 
Description and method of cultivation. A. fumigatus grows on 
most of the ordinary culture media used in bacteriology if the reaction 
is acid; it develops poorly in alkaline media. The well-known 
Raulin’s fluid is reported to be the best medium for its cultivation, 
especially where the aspergillus must be isolated from mixed growths, 
as in the examination of sputum. Sabourand’s* solution of maltose 
also gives good results. 
For ordinary use potato, with or without glycerin, gives excellent 
results. A paste made by rubbing up crumbs of stale bread in water 
is also a good medium. Growth is said to be more rapid, however, in 
Raulin’s fluid than in any other medium, the mycelium appearing in 
from five to twelve hours and spores forming in from twelve to fifteen 
hours. The growth is first a velvety white, soon becoming a delicate 
bluish-green, which grows darker. On Raulin’s fluid it changes after 
some days to a dark brown. Cultures on potato retain the green 
color for a long time, while those on bread paste become brown. 
The fungus retains its vitality in cultures for many months unim- 
paired. Its development has been reported when inoculated from 
cultures three or four years old. Spores do not form in a temperature 
below 20° C. and like the mycelium they require fresh access to oxygen 
for their best development. They measure 2.5 to 34 in diameter. 
In nature the spores are widely distributed but seem to be especially 
abundant in grain and vegetable matter. They have considerable 
power of resistance to heat and to chemical agents. They are killed 
by a temperature of 60° C. in five and one-half hours. In moist heat 
*The formula recommended by Ravenel is as follows: 
Maltose, 3.70 grams. 
Peptone, 0.75 grams. 
Distilled water, 100.00 c. ¢. 
To this may be added gelatin or agar to solidify it, the latter being preferable, as the 
aspergillus grows best and forms fruit best at 37° to 39° C, 
