56 
This peculiar type of infection also appeared in all the hybrids in- 
volving Feterita and susceptible varieties. 
A series of 606 second generation plants of the same twenty 
hybrids was inoculated with the loose smut. The inoculated plants 
of the hybrid between the resistant leterita and Dwarf Yellow 
Milo were all normal. “Two hybrids between susceptible varieties 
gave 55.3 and 61.5 per cent. infection. When Milos were used 
as resistant parents in crosses with most susceptible varieties, the 
percentage of infection ranged from 20.5 to 66.6 per cent., and 
when Ieterita was used as the resistant parent the range of infec- 
tion was 0 to 10.7 per cent. These results agree with those ob- 
tained over a period of years, and suggest that in the Milo hy- 
brids susceptibility to the loose smut is probably due to a dominant 
factor, while in the Feterita hybrids it is due to a recessive one. 
The reaction of the different hybrids to the two smuts is exactly 
opposite. 
The results with a hybrid between Feterita and Dawn Kafir are 
especially interesting, since 53.7 to 66.6 per cent. of the inoculated 
plants were infected. The strain of Ieterita used as the parent 
in this cross was different from the one used in all the other 
crosses. Whether the difference in behavior of the hybrids is due 
to the difference in the Feterita strain or to the susceptible variety, 
Dawn Kafir, remains to be determined. The hybrid between Milo 
and Dawn Kafr is also interesting, since only 4.5 to 9.0 per cent. 
of the second generation plants were infected. 
The susceptible parental varieties gave from 5.8 to 81.3 per cent. 
infection with the loose smut. One strain of leterita was en- 
tirely free, while the other gave as high as 17.1 per cent. infection. 
None of the blasting characteristic of Feterita when inoculated 
with the covered smut appeared in any variety or hybrids inocu- 
lated with the loose smut. 
Third Generation Plants —Plants belonging to 98 third genera- 
tion progenies of different hybrids were grown in order to throw 
further light on the problem of inheritance of resistance to both 
the loose and covered smuts. 
In 1934, 64 second generation plants of a hybrid between 
Dakota Amber Sorgo and Feterita gave 44 typically smutted 
plants, 19 blasted, and 1 normal. Third generation progenies 
