80 Rhodora [APRIL 
unless examining the heads with a magnifier. The flowers of this 
plant are androgynous and it is apparently only in the pistillate ones 
that the smut is found. The removal of the calyx and corolla of 
such discloses a greyish oval body one to two millimeters in length. 
This is the infected ovary and it generally shows distinctly the two 
lobes. It is completely. filled with the spore-balls which are apt to 
give it a faintly nodulose appearance. The ovary-wall is easily rup- 
tured, the spore-balls falling out and resembling very minute seeds. 
They are black, perfectly opaque under the microscope, and vary from 
imperfectly oblong to sub-spherical, generally with sides somewhat 
angled through pressure. They range from 65-275 » in diameter. 
The spore-balls are made up of a large number of light-colored 
spores. These have a slight violet tint and are enveloped by a 
very thin outer coat provided with 
evident dark winged reticulations or 
wrinkles which firmly glue the spores 
together into the balls and give these 
their dark color. Upon the rupture 
of the spore-balls through pressure, 
these coverings are more or less 
broken showing on the spores as 
reticulations or spine-like processes 
or even becoming entirely detached. 
The spores (fig. 1) are subspherical, 
8—11 p in diameter (exclusive of 
the processes) and resemble closely 
those of ZoZyposporium bullatum on Panicum Crus-galli but are not 
angular. The character of the infected ovaries of the latter species 
is also quite distinct, though this is a character that is perhaps 
more dependent on the host than on the fungus. 
Attempts to germinate this smut were successful only in the cul- 
tures kept in the incubator, this being about 36° C. Germination, 
when successful, generally began by end of second day. In water a 
septate pro-mycelium several times the length of the spore and about 
2.5 p. wide was developed which generally became empty of proto- 
plasm at the apex or at the base and frequently developed a promi- 
nent lateral branch. Very often the germ-threads broke up into joints 
or became separated from the spore by the gelatinization of the empty 
base. The threads were finally emptied of protoplasmic contents by 
