30 
THE PLANT WORLD. 
sacs of birds. The food required for these processes is obtained 
from the tissues of the host. It has been claimed by some inves¬ 
tigators that a dangerous toxin is produced by the fungus during 
growth. Their work, however, has not been confirmed and it is 
generally believed that mechanical irritation alone serves to ac¬ 
count for the harm done by the fungus. The temperature of the 
human body and the still higher temperature of birds seem to be 
peculiarly adapted to the growth of Aspergillus fumigatus though 
most of the other fungi grow best at a lower temperature. The 
moisture and plentiful supply of oxygen present in the lungs and 
air passages furnish excellent conditions for luxuriant growth. 
In America very few cases of aspergillosis have been reported, 
only three or four in man and several in birds. One of the latter 
was investigated recently by Mohler and Buckley of the Govern¬ 
ment Bureau of Animal Industry.* Their subject was a flamingo 
which had been captured in Cuba, was brought to the National 
Zoological Park in Washington and died within three weeks. A 
post-mortem examination showed the lungs covered with grayish 
spots and the supra-sternal air-sacs were lined with a velvety 
green growth which proved to consist of masses of mycelia and 
fruiting heads of Aspergillus fumigatus. This fungus is a typical 
Aspergillus, having a branched septate mycelium, white at first, 
later green and gradually turning to brown. The spores are cut 
off in chains from the ends of short knobs which radiate from the 
surface of a globular head. The spores are spherical and color¬ 
less, and are capable in a dried condition of retaining their vitality 
for many months and even years. In order to determine the 
amount of harm which may be done by the fungus, the investi¬ 
gators experimented with a number of animals, chickens, pigeons, 
guinea-pigs and rabbits, inoculating them with spores of Asper¬ 
gillus. In the majority of cases death resulted although a few 
animals seemed able to resist the attacks of the fungus and 
survived. 
A short summary of various studies made of aspergillosis is 
given by the authors just mentioned: (i) Aspergillosis is a spon¬ 
taneous disease affecting the bronchi and lungs of birds and mam- 
* Mohler, J. R. and Buckley, J. S., Pulmonary mycosis of birds. U. S. 
Dept. Agric., Bureau of An. Ind., Annual Report, 20: 122-138. 1903. 
