SUMMARY
The fungus Tolyposporium ehrenbergii infects its host by means of a dormant mycelium in the grain, spores lying in the soil, or air-borne sporidia. This study refutes the long-accepted belief that long smut infection of sorghum in nature results only from air-borne sporidia. This is probably the first report of a dormant mycelium in T. ehrenbergii.