PLATE 4 



Sclerotium rolfsii: 



A. — Cabbage artificially inoculated. The rot is confined to the outer layers of the 

 head. 



B. — Cultures on artificial media. 



C. — Mustard-seed-like sclerotia on cantaloupe. 



D. — Formation of sclerotia at point of union of apparently plus and minus strains. 



