We have heretofore applied the term Spirillum obermeieri tothe organism isolated by Dr. Charles Norris, from a case of relapsing fever which occurred in New York, in the belief that it was identical with that described by Obermeier in 1873. We will continue to use this term for the present, although, as will be shown, there is reason to believe that the eastern relapsing fever is not identical with the American disease. When further evidence is obtained regarding the non-identity of the organisms found in these regions it may be necessary to restrict the use of the term Spirillum obermeieri to the organism found in the eastern disease.
On the other hand, the African relapsing fever, known also as tick fever, has been shown conclusively to be due to a different organism, the Spirillum duttoni. As far as we know, the first observation on this organism was made by Dr.