Parasitic Fungi of Illinois. 1 47 



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. 

 Tn 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- 



