Parasitic Fungi of Illinois. 147 
much attention has been given to contagious diseases of ani- 
mals. The importance of scientific investigations in this latter 
direction cannot be overestimated, yet it would not be difficult 
to show that every argument in: support of these is applicable 
also to encouragement upon the study of the diseases of plants. 
In fact, it has now come to be generally admitted that these 
very maladies of animals are directly due to various species of 
the same classes of low vegetable organisms which afflict, as 
parasites, the valuable plants and crops. In some instances the 
very same species of fungi prey upon plants or plant-products 
and living animals. The common moulds are fungous growths, 
and mouldy grains and other articles of vegetable foods are 
commonly believed to be injurious to man and animals. Some 
contagious diseases of man have been proved to be due to or- 
ganisms normally living on vegetable substances, and there is 
much reason to suppose that all the pathogenic bacteria, and 
their allies, are or were primarily simply decomposing agents of 
dead substances. Certainly the nature of the contagious dis- 
eases of animals cannot be fully known without the closest 
investigations of the life of the disease organisms outside of the 
animal body. The studies of fermentations and putrefactions 
have already lead to most important results in pathology, and 
it is confidently believed that there is much more to be gained 
in the same way for the advancement of knowledge in regard 
to disease and injury, not of animals only, but of plants as 
well; while a proper study of the diseases of plants must help 
to a better understanding of the serious maladies of man and 
the domestic animals. 
The nomenclature adopted in this paper has been the re- 
sult of considerable inquiry and an earnest endeavor to con- 
form to the latest opinions of the best authorities, as well as to 
most nearly fulfill the requisites of this branch of science. 
Unfortunately, in numerous cases there are many synonyms, 
and as names were given to species before any natural classifi- 
cation could possibly be made, and as the life history was in the 
earlier times usually unknown, different writers assigned the 
- same species to widely different positions in their systems of 
arrangement. The descriptions by the older authors are mostly 
meager, and entirely devoid of accurate microscopic character- 
