SORGHUM SMUTS AND VARIETAL RESISTANCE 11 
reported as somewhat injurious to the sorghums in the station garden 
of Marangu. This smut occurs in the individual flowers of the head, 
but many flowers remain normal and produce seed. The infected 
ovaries are converted into a more or less spherical smut ball, 5 to 
8 millimeters in diameter. The spherical or ovoid spores are united 
into spore balls, consisting of 5 to 10 spores. This species differs 
from Tolyposporium ftliferum in the size and shape of the smut ball, 
the spore balls also being smaller and consisting of fewer spores. It 
has not been noted elsewhere so far as the writers are aware. 
Ustilago bulgarica Bubak. — Bubak (15) described this species from 
a single collection on sorghum grown in the experiment field at 
Sadovo, Bulgaria. It infects the ovaries of the flowers, forming smut 
balls which extend considerably beyond the glumes and are covered 
with a gray membrane which is furrowed and pitted. The general 
appearance of the head is unchanged. The spore mass is greenish 
brown. The spores are bright olive green, spherical or ovoid, 5.5 to 
9 m in diameter, with a thin, smooth wall. This species is closely 
related to Sphacelotheca cruenta (Kiihn) Potter. Infected panicles, 
however, remain normal in general appearance, the sori being confined 
to the ovaries. 
Ustilago sorghicola Spe'g. — Spegazzini (107) described this sorghum 
smut from specimens gathered near La Plata, Argentina. The ovaries 
are converted into sub cylindrical smut balls. The spores are smooth, 
7 to 8 fi in diameter. It is very similar to Sphacelotheca sorghi (Link) 
Clinton, if not identical with it. 
Sorosporium simii Evans. — Evans (37) has described this new spe- 
cies on Johnson grass (Holcus halepensis) from Natal, South Africa. 
The sori destroy the entire inflorescence while still inclosed in the 
sheathing blade; they are 5 to 7 centimeters long and 1 to 2 centi- 
meters broad, at first covered with a rather thick white membrane. 
The spore balls are subglobose or ellipsoid, black, 60 to 150 n in diam- 
eter. The spores are globose or subglobose, olivaceous or olivaceous 
brownish, very delicately echinulate, 12 to 13 /x in diameter. It is 
impossible from the description to distinguish this smut from Soro- 
sporium reilianum (Kiihn) McAlpine. The fact that S. reilianum has 
been reported frequently on Holcus halepensis by other workers lends 
further evidence as to the identity of S. simii with the head smut. 
Sorosporium ehrenbergii Kiihn. — Schweinfurth collected a smut on 
sorghum near Cairo, Egypt, which was distributed by De Thumen 
in Mycotheca universalis, No. 725, as Ustilago reiliana Kiihn f. sorghi- 
cernui. Kiihn (61, 62) studied the fungus and decided that it be- 
longed to the genus Sorosporium because the spores were united in 
spore balls. According to his description of the new species, the 
smut balls are 8 to 13 millimeters long and 3 to 5 millimeters wide. 
The spore balls are spherical to ovoid in shape and measure 36 to 
94 m by 43 to 131 //. The spores are spherical or irregular in shape, 
verrucose, and measure 12.4 to 17.2 /* in diameter. The specimen 
of De Thumen's Mycotheca universalis, No. 725, at the New York 
Botanical Garden was examined and in external appearance can not 
be distinguished from Sphacelotheca sorghi (Link) Clinton. The 
spores were found also to be indistinguishable. Kiihn's description, 
however, corresponds closely to that of Sorosporium reilianum. 
