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

Abstract

15 strains of H. 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 temp, than southern strains, their spores are slightly larger, and they form chlamydospores at a lower temp. Unlike most southern strains they form nodules when injected subcut. 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 2 or more spp. 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.