Date of this Version
The spore of Myxosoma cerebralis is redescribed and compared with that of a close relative, M. cartilaginis. M. cerebralis is smaller, with greater variability in size and shape. It possesses a mucous envelope whereas M. cartilaginis does not. The surface architecture of M. cerebralis, as seen with the scanning electron microscope, differs in possessing a conspicuous circumsutural groove, prominent polar filament pores, and a mucous envelope.