ABSTRACTA marked strain variation in eosinophilia following oral infection withToxocara caniseggs was observed in mice. Mutual radiation chimeras between high and low responder mice in terms of eosinophilia were made and compared with the respective donor and recipient for eosinophilia after the infection. As a result, the degree and time course of eosinophilia in chimeric mice were similar to those in donors. The result suggested that genes which regulate inheritance of the trait, marked eosinophilia inT. canis-infected mice, might be expressed in bone marrow derived cells.
