40 
ferent strains of Red Rustproof, the percentage varying from 
25.9 per cent. to 70.8 per cent. ule an occasional plant of 
some other variety was infected, the evidence is that the Red 
Rustproof race is largely confined to strains of this variety. 
The extensive specialization of both loose and covered smut 
greatly complicates the studies on varietal resistance as well as 
rendering more complex the study of inheritance of smut resist- 
ance in hybrids. Certain varieties seem to be susceptible to a 
very large number of races, such as Canadian, Early Champion 
and Victor. The variety Monarch has proved quite resistant to 
the Missouri race of loose smut, but shows some susceptibility to 
the newly described Fulghum race. It is particularly interesting 
that so far Black Mesdag has proved entirely resistant to all the 
races studied, 
Inheritance of Smut Resistance in Oats 
Studies on the progeny of a cross between the very resistant 
Black Mesdag and the susceptible Hulless varieties have already 
been published. The second and later generations of this cross 
were studied with reference to their behavior towards the Mis- 
sourt race of loose smut. Additional crosses between these two 
varieties have been made, and during the past year the data on 
the second generation have been obtained, the results confirming 
those previously published. In the four families studied, the 
percentage of infection varied from 19.1 per cent. to 25.8 per 
cent., 107 plants out of a total of 465, or 23 per cent., being in- 
fected. Additional second generation plants of these same 
crosses were also tested with the covered smut, and the per- 
centage of infection varied from 12.2 per cent. to 26.5 per cent., 
40 plants out of a total of 196 inoculated in all the crosses, or, 
20.4 per cent., being infected. 
The second generation of crosses between varieties, both of 
which were susceptible to loose and covered smut, have also bee 
studied. One of these crosses was between Victor and Canadian, 
and the other between Hulless and Silvermine. All the plants 
inoculated in each experiment proved to be susceptible, 100 per 
cent. infection being obtained. A cross between Victor, which is 
susceptible to both smuts, and Early Gothland, which is sus- 
