45 
the susceptibility of Black Mesdag. In the greenhouse and in the 
field a total of 77 plants of this variety inoculated with one collec- 
tion were grown, and 44 (57.1 per cent.) were infected; 45 plants 
were inoculated with the other collection and of these 22 (48.8 per 
cent.) were infected. In both cases approximately 50 per cent. of 
the inoculated plants were smutted. 
Positive results were obtained with both collections on such 
varieties as Hull-less, Green Mountain, Canadian, Victor, Early 
Champion, Monarch, and Joanette, as well as Fulghum and 
Kanota. In most cases, 100 per cent. of the inoculated plants 
were smutted. One of the collections infected a few plants of 
Avena brevis and A. strigosa. Several other varieties, however, 
gave entirely negative results; these included Scottish Chief, 
Danish Island, Early Gothland, Monarch Selection, Orientalis, 
Danish, Rossman, and Markton. 
Cultural Characteristics of the Oat Smuts 
A detailed study of the characteristics of the various collections 
of races of both loose and covered smut in culture has been under- 
taken by Mr. L. Gordon Utter. Many of the races are sharply 
differentiated o their capacity for infecting certain varieties of 
oats. The problem, then, is to determine whether corresponding 
differences exist in the characteristics of these races as grown in 
artificial media in the laboratory. Further infection experiments 
are being carried out with pure line cultures thus obtained.  In- 
teresting progress has been made during the past year. 
Sorghum Smuts 
A series of second generation plants of a large number of 
sorghum hybrids was inoculated with both the loose and covered 
smut. It was possible to grow these through the courtesy of Dr. 
R. A. Harper, who provided land on his farm near Ridgewood, 
New Jersey. Valuable additional data on the inheritance of smut 
resistance in these sorghum crosses have been obtained. 
During the past few years a large amount of material of various 
sorghum hybrids has been collected in connection with the smut 
resistance studies. Miss Elizabeth Marcy has undertaken a study 
of the morphological characters of the hybrids with a view to 
