PLATE A 
Spongospora subterranea and Phoma tuberosa on Solatium tuberosum: 
Fig. 1-5.— Spongospora subterranea as found on different varietiesof the Irish potato. 
Figure 2 shows the sori on the Green Mountain variety. The sori shown in figures 1, 
3,4; and 5 are from seedling varieties not yet distributed. 
Fig. 6 , 7.—Stages in the development of dryrot caused by Phoma tuberosa. Figure 
6 shows a very early stage and figure 7 a stage commonly found in April in storage 
houses. 
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