Color is fairly uniform among spores in a given population.
Mostly globose, subglobose, occasionally irregular. It often is adherent to the spore wall in which case it cannot be detected. Folds produced by iw1 often can be deceiving and erroneously suggest additional flexible inner walls. This wall often does not separate readily from the spore wall or produce folds that make interpretation difficult. However, enough spores are found in all isolates which show two distinct thin layers with differential contrast optics.