Conard: Structure of Simblum Sphaerocephalum 271 
nearly globular (fig. 4), with a short constricted base, and two 
short sterigmata at the apex. The basidium is about 2.5 in 
diameter and 4.5 tall, with sterigmata about 0.5 tall. The 
spores are ellipsoidal, with a single large nucleus, and measure 
3/x, by 1.5 /X. These dimensions, so characteristic of Phalloids, 
are of the same order of magnitude as those of bacteria — a fact 
which coincides with the idea that both of these groups of plants 
are distributed by flies. 
Summary 
1. Simblum sphaerocephalum Schlecht., a common fungus in 
parts of South America, is now known from New York, Mary- 
land, District of Columbia, Iowa, Nebraska, Kansas, and Texas. 
It shows every essential character of the Clathraceae. 
2. The stalk elongates by enlargement of the cells of the pseudo- 
parenchyma. 
3. The bars of the fertile receptaculum are superficial on the 
gleba. 
4. The plates which divide the volva- jelly are vertical in the 
region of the stalk, enclosing a mass of jelly for every mesh of 
the receptaculum. Their position is believed to be due to the late 
development of the stalk in a rudiment which would be identical 
in early structure with that of a Clathrus. The stalk of Simblum 
is therefore a highly developed basal ring of a clathrate receptac- 
ulum, *and not a fusion of vertical columns. 
5. Pseudoparenchyma of the receptaculum may be regarded 
as sterile hymenium. 
6. In the superficial portions of the gleba, at least, the cham- 
bers originate by growth of trama-plates from the branches of 
the central strand toward the receptaculum-arms. 
For use of the literature which has made this paper possible, 
I am indebted to the generous loan-system of the Missouri 
Botanical Garden. To the officers of the Garden I wish to extend 
hearty thanks. The photomicrographs are by Mr. Paul M. Smith. 
