The Pulmonary Fungus Haplosporangium Parvum. II. Strain and Generic Relationships

Abstract

SUMMARY Fifteen strains of Haplosporangium parvum derived from Arizona, Texas, Montana, Idaho and Alberta animals were studied comparatively. Their colonial morphology reflects to some extent their geographic origin. Northern strains are slower growing at room temperature than southern strains, their spores are slightly larger, they form chlamydospores at a lower temperature. Unlike most southern strains they form nodules when injected subcutaneously into guinea pigs and mice. One Montana strain was like northern strains in some particulars and like southern strains in others. All strains are similar in microscopic morphology. The differences among strains do not justify splitting H. parvum into two or more species. The possession of erect fertile hyphae and chains of conidia will necessitate the exclusion of H. parvum from the genus Haplosporangium Thaxter. H. parvum is probably not related to Coccidioides, or any other Phycomycete. Its closest affinity is with Blastomyces dermatitidis.