Polycythemia rubra vera is a distinct disease entity of chronic, slowly progressive type, characterized by a marked increase in the number of red blood cells and hemoglobin, cyanosis and splenic enlargement. To Vaquez belongs credit for the discovery of this entity. In this country credit is given to Sir William Osler for calling attention to the disease. Cabot had previously reported two cases, and Saundby and Russell one. The latter stated that the case of Purves Stewart's patient at Westminster Hospital was the first recognized in London.
ETIOLOGY
The fundamental etiologic factor seems to be stimulation of the hematopoietic system, without a corresponding stimulation of the organs that provide a balance by destruction of red blood cells. Therapy directed to the spleen alone causes no amelioration of symptoms or change in findings, while therapy directed to the bone marrow effects a prompt remission of variable duration. There is an overproduction