The Jekyll-Hydes of Mycology

Abstract

Sectorial mutation, loss of ability to produce spores and the multiplicity of species, attest to the lability of the fungi. The size and morphological complexity of fungi reveal at once to the observer many overt aspects of variability and the physiologist easily detects other mutants which are masked by a common phenotype. The consequences and potentialities of the lability of fungi in didactic mycology, in use of fungi as research tools, in plant pathology, and in industrial mycology, are too many and varied to enumerate before an audience already familiar with them. I shall discuss those aspects of the adaptability of fungi which enable them, under appropriate conditions, to turn immediately from a saprophytic existence to parasitism of animal tissues. I submit that this aspect of the adaptability of the fungi places upon mycologists a responsibility which has been only partially acknowledged. Medical mycology should be the concern of mycologists generally and not a subspecialty of medical bacteriology or medicine. Specialization and complexity among the fungi are spectacularly mnanifested by those molds and yeasts which flourish under generally inhospitable environmental conditions, grow on substrates unavailable to most microorganisms or play sometimes beneficial, sometimes lethal roles in the economy of nature. Many of the fungi which are found in unusual habitats are now fixed in their present relationships. Some require special substrates, some are obligate parasites which require for survival