154 
Journal of Mycology 
LVol. 12 
cause to account for the breaking up of a primitive species into 
two or more modern parallel species with different lengths of 
life-cycle, I think it may be found in the augmented influence of 
parasitism. In the primitive times the rusts were doubtless but 
weakly parasitic, but in their onward development parasitism 
with its restricting and reducing effects became constantly more 
pronounced. To develop the theory here would extend this 
article beyond reasonable limits, but it is believed to fully ac¬ 
count for the observed parallelism. It also accounts for the 
fact that essentially the same shortening of the life-cycle occurs 
or may be looked for in every group of the Uredimles, but is 
most extensive in the groups showing the greatest differentia¬ 
tion and highest development. And finally it does not militate 
in the opinion of the writer against the validity of genera whose 
ultimate distinction is that of the length of the life-cycle, but 
lends important aid in tracing their relationships. 
The arguments in this article have in the main been directed 
against or received their support from the old-time genus Puc- 
cinia and its consort Uromyces, believing that whatever would 
prove acceptable to systematists in this connection can readily 
be extended to the whole order of the Uredimles. I have thus 
presented some of the reasons which appeal to me for desiring 
a better classification of the Uredinales, believing that when 
obtained it will promote the study of the order and facilitate 
.an understanding of relationships. 
NORTH AMERICAN SPECIES OF LEPIOTA. 
A. P. MORGAN. 
The name Lepiota was given by Persoon to the first section 
of his genus Agaricus; it had a wider application in the “Syn¬ 
opsis” than is assigned to it in the genus of the same name at the 
present time. Fries in the “‘Systema” made of the term Lepiota 
a tribal designation, restricting it to the species of Agaricus about 
as understood at present. The species thus included are well 
worthy of generic distinction. 
Fries in the Hymenomycetes Europaei enumerates 45 species 
of Lepiota. Since the publication of this volume (1874) Euro¬ 
pean mycologists have increased the number to more than 100. 
'The region most prolific in species of this genus so far dis¬ 
covered is the island of Ceylon where upward of 70 species were 
enumerated and described by Berkeley and Broome. Sacardo in 
the different volumes of the Sylloge Fungorum enumerates more 
than 300 species. 
Schweinitz in the North American Fungi (1834) gives a list 
<of 5 species of Lepiota. In Lea’s Catalogue (1849) there is a 
