1. The literature concerning inhalation infection with Coccidioides immitis is briefly reviewed.
2. A laboratory technique for exposing animals to inhalation of the spores of Coccidioides immitis is described.
3. Primary pulmonary infection was produced in 42 per cent of 72 animals exposed by this method.
4. No marked weight loss was apparent in the animals infected.
5. Skin tests with coccidioidin were not entirely satisfactory in diagnosis. Positive skin tests with coccidioidin were obtained in many of the infected animals, but inconsistencies occurred.
6. The gross and microscopic lesions are briefly described and illustrated.