PLATE ii 
Dryrots associated with Spongospora subterranea: 
Fig. A.—A potato tuber showing natural infection with Phoma sp. The color of the 
spot is much darker than that of the healthy tissues. No pycnidia are present as yet. 
Fig. B, C.—Sections through tubers showing more advanced stages of a rot caused 
by a species of Phoma. A variety of other fungi have entered, causing further decay 
of the tuber. 
Fig. D.—A potato tuber showing injury immediately around the sori, due partially 
to the work of the plasmodium. The lower side of the tuber also shows the beginning 
of the rot caused by Phoma sp. 
Fig. E-—Infection due to Phoma sp. on a potato tuber infected with Spongospora 
subterranea , followed by another, due probably to Fusarium coeruleum. 
Fig. F, H.—Potato tubers infected with Spongospora subterranea about three weeks 
after harvesting, showing the effects of desiccation injury. 
Fig. G.^Section through a tuber, showing the depth to which rot caused by Phoma 
sp. extends. In this case no other fungi had entered. 
