The nuclei of the giant traps of a mutant of Monacrosporium bembicodes (Drechsler) Subram (Dactylella brochopaga Drechsler).

A mutant strain, MG-20, of the predacious hyphomycete Monacrosporium bembicodes(Drechsler) Subram (Dactylella brochopaga Drechsler) develops giant ring traps, as well as normal ones when supplied with prey. Both types are functional. Giant traps contain more nuclei per cell than normal ones, and as they age, all their nuclei break into fragments which persist in the cell. These findings are briefly discussed.