ABSTRACT
Coccidioides immitis is a pathogenic saprophyte with a dimorphic mode of growth in man and in the soil. In exudative lesions of man, it exists as a spherical thick-walled endospore filled with an organism called a spherule. The spherule measures 40-70 µm in diameter. When it ruptures, the spores are released, and each in turn repeats the replicative cycle. In culture the fungus develops a mole-like configuration identical to its growth in soil. The pathogenic form is non-contagious for humans. Infection is contingent on the development of arthrospores by the hyphae and their subsequent inhalation or inoculation.
