596 
Journal of Agricultural Research 
Vol. XI, No. ir 
ible, although it might be said that there was an intermediate condition, 
owing to the fact that there was considerable difference in the time 
of wilting of the first-generation plants as compared with plants grown 
from selfed seed from the susceptible parent. The second generation 
was almost entirely susceptible. These plants, however, were grown 
under more severe conditions than were the plants of the first genera¬ 
tion. The severeness of these conditions can be seen from results of 
the resistant control given in Table IV. 
In this case, as is shown by the table, the second-generation plants 
were grown under fairly severe conditions. Thirty of the eighty-four 
plants of the resistant control were infected. The second generation 
was grown on artificially infected soil. Considering the behavior of the 
first generation and the severe conditions under which the second gen¬ 
eration was grown, together with the results obtained, it seems impos¬ 
sible at present to give any direct explanation on a Mendelian basis. 
In order to see what the result would be if the seed from the crosses 
on a number of plants were mixed, seed from five different plants were 
thrown together and planted. In this case sight was lost of the indi¬ 
viduality of parent plants, due to the mixing; consequently, no definite 
ratios could be expected as individuals behave very differently. Table 
V gives the results obtained from mixed progeny. 
Table V.— Resistance to flaxwilt of the mixed progeny of crosses between resistant flax 
No. 4<$ and susceptible No. j 9 
Parent strain. 
Date of 
planting. 
Num¬ 
ber of 
plants 
grown. 
Ratio at end of 
three weeks. 
Ratio at end of 
experiment. 
Num¬ 
ber of 
plants 
killed 
X. 
Wilted. 
Not 
wilted. 
Wilted. 
Resist¬ 
ant. 
3 E-Mix. (EO. 
~ I ^ I 5 * 
Oct. 2 
r 53 
53 
100 
106 
47 
76 
Resistant No. 4. 
... do.... 
20 
0 
20 
O 
20 
0 
Susceptible No. 3. 
46 
43 
3 
46 
0 
46 
F 2 generation: 
1916. 
3E-Mix-i. 
Apr. 22 
89 
41 
48 
49 
40 
46 
3 E-Mix-2. 
8 l 
63 
18 
78 
3 
72 
3 E-Mix-3. 
88 
55 
33 
84 
4 
67 
Total. 
258 
159 
99 
211 
47 
18s 
Resistant No. 4. 
Apr. 22 
45 
1 
44 
a 3 
42 
O 
Susceptible No. 3. 
43 
33 
10 
43 
0 
43 
o Slight. 
As is shown by the controls in Table V, these plants were grown under 
very good conditions for the best test. The resistant parent strains 
stood up almost perfectly, while every plant of the susceptible parent 
strain died out completely. Since there are all gradations between an 
entirely resistant and an entirely susceptible first generation from indi¬ 
vidual crosses, we would expect the intermediate condition when seed 
