After studying botany at Penn College and the host-parasite relationship of Ampelomyces quisqualis at Columbia University, he transferred to the School of Tropical Medicine in Puerto Rico, where he confirmed that Actinomyces bovis is present in the mouths of healthy people.

Shortly before his death, he had disclosed that he felt his biggest contribution was demonstrating that fungal infections were common and widespread, and that their causal organisms were everywhere.

[2] After completing his Ph.D. he took up a post at the School of Tropical Medicine in Puerto Rico, where he would continue research on fungi that cause disease in humans.

[2] In Puerto Rico, he confirmed Frederick T. Lord's conclusions of 1910, that Actinomyces bovis is present in the mouths of healthy people.

[1] In 1934, back at Columbia,[1] he published his first medical papers in which he proposed that the genera of common fungal causes of infections of the skin; Microsporum, Trichophyton and Epidermophyton should be redefined according to the structure of the fungi, not the varying clinical features of the disease.

[3] In 1936, Emmons became the first medical mycologist appointed by the US government, after the National Institutes of Health (NIH), then in Washington DC, was given permission to finance the post.

[4] They initially felt them to belong to the genera Coccidioides, but following culture they defined it as a new species Haplosporangium parvum,[4] a fungus that caused adiaspiromycosis, a lung disease in wild animals, but rare in people.

[1] In 1977, he modified Raymond Sabouraud’s agar to produce a more pH neutral substance with a lower glucose concentration, to allow a better culture medium for fungi that cause disease in humans.

[1] The Association Mexicana Microbiologia made him an honorary member and the World Health Organization Expert Advisory Panel on Parasitic Diseases enrolled his expertise from 1960 to 1975.

[1] He also held posts at the College of Physicians and Surgeons, the Vanderbilt Clinic in New York, and the Georgetown University School of Medicine.

[1] Two years earlier he had disclosed to mycologist Michael W. McGinnis, that he felt his biggest contribution was demonstrating that fungal infections were common and widespread, and that their causal organisms were everywhere.