PLATE 46 
A. —Flax plants growing in soil inoculated artificially with Fusarium Uni . a, 
Resistant No. 4. b, Susceptible No. 3. c-h, First-generation plants from crosses 
between these two strains. Notice that some of the crosses were almost entirely 
resistant to the disease while others wilted almost as badly as plants of the susceptible 
strain. 
B. —Second-generation flax plants growing on artificially infected soil, a, Sus¬ 
ceptible No. 3. b t Resistant No. 4. c-h, Second-generation plants from crosses 
between these two strains. These plants show the difference in individual plants of 
the first generation, c and d, e and /, g and h, respectively, came from individual 
plants of the first generation. 
C. —Second-generation flax plants growing in North Dakota "flax-sick soil.” 6, 
Susceptible No. 3. c, Resistant No. 4. a, d-h, Second-generation plants from 
the cross 4D20 in which the first generation were all resistant. Of the 530 plants of 
this F 2 generation 162 were resistant and 368 susceptible. 
