54 
— 
susceptble. In the corresponding series with the covered smut 
there were 42 I, progenies, and 15 were classified as resistant, 21 
segregating, and 6 susceptible. 
There were 71 I’, progenies of Hybrids 34, 35, and 36 inoculated 
with the loose smut, 17 being resistant, 31 segregating, and 23 sus- 
ceptible. In the corresponding series with the covered smut there 
were 72 progenies, of which 21 were resistant, 40 segregating, and 
— 
11 susceptible. 
In all of these hybrids there was a remarkable uniformity in the 
behavior of the different progenies to the two smuts. If a progeny 
was resistant to one, it was resistant to the other, or if it was sus- 
ceptible to one, it was susceptible to the other. There were a few 
departures from this general statement, but the correspondence in 
behavior is quite noteworthy. The results with the progenies of 
these different hybrids are in line with what have previously been 
obtained. Additional tests, however, will be made with the 
progenies which showed a different behavior toward loose and 
covered smut. 
A large number of fourth generation progenies of Hybrids 17, 
and 18, Silvermine X Black Mesdag, and Hybrids 33, 34, 35, and 
36, Early Champion >< Black Mesdag, were grown. All of these 
were chosen primarily on the basis of having proved to be resistant 
to both smuts im the third generation, and usually to one of the 
smuts in the second generation. All of the 286 fourth generation 
progenies grown were, with five exceptions, pure resistants, there 
being a total of 65 progenies of Hybrid 17, 64 of Hybrid 18, 58 of 
Hybrid 33, 59 of Hybrid 34, 30 of Hybrid 35, and 10 of Hybrid 
36. The five exceptions were grown from different I’, plants 
descended from the same second generation plant of Hybrid 306. 
our of these progenies gave less than 50 per cent. infection and 
one more than 50 per cent., there being a close correspondence in 
their reaction to the two smuts. A possible explanation of the 
behavior of this one group of fourth generation progenies is that 
the I, and EF, generations were not pure resistants, but chance 
escapes. [It is noteworthy, however, that only one such case of this 
sort appeared. 
Hybrids 29, 30, 31, and 32, Fulghum * Black Mesdag, involve 
a different combination of smut resistance. There were O98 third 
