ARTHUR: IMPORTANCE OF THE SPERMOGONIUM 117 
species is due to conditions of growth, to adaptations extending 
over a long period, to reduction as the result of parasitism, or to 
specific variation. All that can be said is that it seems probable 
that in some species the spermogonium is wholly wanting, but that 
in the great majority of species it is present. 
The general conception of the spermogonium is, I venture to 
say, that of a minute structure necessarily accompanying the 
aecidium, although in some exceptional cases it may occur in 
connection with the other spores. This view is the outgrowth of 
‘TTELEUTOSPORE 
a Sporipium eS TELEUTOSPORE 
SPORLDIUM 
of f 
Le 
ow 
SPERMOGONIUM 
<— ‘ Meg 
AECIDIUM 
A B 
TELEUTOSPORE TELEUTOSPORE 
DIUM 
g SPORIDIU SPoRIpium 
S, 
59° Peay, 
=, Jar, 
SPERMOGONIUM 
D 
Fic. 1. Diagrams to illustrate the succession of spore-forms in a cycle of develop- 
ment'; A, all spore-forms present; B, uredo-stage suppressed ; C, edeitnmmn-sings sup- 
Pressed ; D, both uredo and aecidium suppressed. The suppression of spore-forms 
Sometimes extends also to the spermogonium. 
the teaching of DeBary. The spermogonium was first described 
by Tulasne in 1851, and believed to be the male organ of repro- 
duction. In 1866 DeBary published his epoch-making work on 
the morphology and physiology of the fungi, and in this he says 
