Observations on the Nature of the Erythropoietic Serum Factor

Serum and plasma from anemic rabbits were found to contain a factor capable of inducing a reticulocytosis when injected into normal animals. This erythropoietic factor seems to be attached to, or to behave like, a serum albumin, alpha globulin or beta globulin.

The production of the erythropoietic factor was found to be normal in rabbits in which the lymphatic and the hematopoietic tissues had been damaged through the administration of nitrogens mustard.