No. 9.— NORTH AMERICAN USTILAGINEAE. 1 
BY G. P. CLINTON. 
Introduction. 
The present monograph is largely the result of studies made 
during the two years 1900-1902 in the Cryptogamic laboratory of 
Harvard university. The writer has, however, been greatly 
interested in the Ustilagineae during the past ten years. In the 
study of these fungi there has been kept in mind a fourfold treat¬ 
ment. (1) The earlier studies were confined to the species found 
in Illinois, especially to those of economic importance. As a partial 
result of these investigations, Bulletins 47 and 57 of the Illinois 
agricultural experiment station were issued. (2) A systematic 
treatment of the North American species was planned. The pre¬ 
liminary paper giving species, hosts, distribution, with some notes 
on excluded forms and synonymy, was issued in October, 1902, in 
the Journal of mycology. The present paper is the ultimate out¬ 
come of the work. (3) Distribution, in exsiccati form, was under¬ 
taken of available North American species on their various hosts. 
The first century was issued in January, 1903, as Supplement C of 
Seymour and Earle’s Economic fungi. Specimens for the second 
century are largely in hand. It is hoped, with the aid of those 
interested in the group, to extend this work until it includes all of 
the species and many of the hosts reported from this continent. (4) 
Studies of spore germination, growth of artificial cultures, sectioning 
of preserved material, and infection experiments, are subjects under 
investigation or contemplated. Illustration of all North American 
species by spore drawings is under consideration. 
Considerable labor has been required for the preparation of the 
present paper, especially in the examination of specimens and 
literature. For aid in these particulars the writer is indebted to a 
large number of botanists for specimens and is under especial obli¬ 
gations to a few for greater favors. Thanks are due to the 
following for specimens: Europe , J. Bresadola, P. Hennings, 
iContributions from the Cryptogamic laboratory of Harvard university, no. 57. 
