Abstract
1. Some strains of Trypanosoma lewisi may, at times, produce rapidly fatal infections in a large percentage of the rats infected. 2. In such strains of Trypanosoma lewisi, a sufficient degree of pathogenicity may persist to warrant the designation of these strains as pathogenic. 3. The pathogenicity of a given strain of Trypanosoma lewisi is not constant, but is subject to marked and even sudden variations.

This publication has 0 references indexed in Scilit: