TEACHERS DEPARTMENT. 
2 9 
ized plants with pathological conditions is probably known only 
to a few specialists. Such fungi have, however, been identified 
with certain diseases in man and other animals and form an inter¬ 
esting chapter in the economic importance of fungi. 
There are relatively few such pathogenic fungi and most of 
them are species of the mould Aspergillus, though species of 
Mucor and other Phycomycetes have also been identified. The 
parts of the animal body most frequently affected are the mouth 
and respiratory apparatus, the eye, ear, skin and some of the inter¬ 
nal organs. The most common disease is probably what is known 
as pulmonary mycosis, or a disease of the air passages and 
pulmonary tissues resembling tuberculosis. When this is caused 
by an Aspergillus the disease is termed aspergillosis. The first 
case of aspergillosis was observed as early as 1815 in the lungs 
of a jay, and in 1847 was reported an instance of its occurrence 
in man. Cattle, sheep, horses and dogs have also been the victims 
of mycotic troubles but the animals which seem to be peculiarly 
subject to them are birds, especially those living in a state of cap¬ 
tivity in zoological parks. 
Aspergillosis in man was observed at first in connection with 
tuberculosis and was regarded as a secondary occurrence and not 
of particular importance. It was later studied, however, very 
thoroughly as it occurs in a certain class of men in Paris. These 
men are engaged in feeding thousands of young pigeons daily by 
taking into their own mouths a mixture of grain and water which 
they force down the throats of the young birds, much in the way 
it is done by the old birds. It was discovered that these men suf¬ 
fered frequently from a pulmonary disease which was supposed to 
be tuberculosis until an examination was made and the spores 
and mycelia of Aspergillus fumigatus were found to be present 
in the lungs. Infection, it was decided, took place through 
inhaling spores present in the grain. There was apparently no 
trace of the tubercle bacillus. 
Inhalation of the spores seems, in fact, to be the usual way of 
acquiring the disease. The spores planted thus on the bronchial 
mucosa germinate, mature and produce fruit. These spores are 
then distributed through the bronchioles and even into the air 
