THE causal organism of spirochaetosis,Borrelia anserina, was first reported from geese in the Caucasus, and has since been isolated from the blood of infected geese, turkeys, ducks, fowls, partridges, crows and sparrows from all parts of Africa, Australia, Austria, Bulgaria, Brazil, Egypt, East Indies, Germany, Greece, Hungary, India, the U.S.S.R., Rumania and Turkey.