1. Pure lines of Spirochœta eurygyrata were isolated and cultured.
2. They lived longest in a medium which was made up of sodium chloride and pig serum water.
3. They stained readily with iron-hematoxylin, Giemsa's stain, Cross' stain, and carbolfuchsin.
4. They did not stain with the vital dyes used.
5. They divide by transverse division.
6. Transverse bars, which are seen in stained spirochetes and in dead ones with dark-field illumination, are considered coagulated protoplasm, due to death.
7. Coccoid bodies were not seen in living individuals nor were they seen free in the culture medium.
8. Cats were fed cultures of Spirochœta eurygyrata but did not become infected with them.
9. Spirochœta eurygyrata is not of frequent occurrence in this part of the United States.