The concept of the epidemiology of Cryptococcus neoformans as the causative agent of cryptococcosis and as a basidiomycetous yeast is based on the fact that bird manure has been until now its only known habitat but not plant material which likewise harbours various nonpathogenic Cryptococcus species. It could be shown that the possible influence of nutritional factors on the morphology and morphogenesis earns attention not only in view of the epidemiology of C. neoformans but of its perfect states, too.