Abstract
Injn. into rabbits of splenic extracts from a patient with this condition depressed the leukocyte, erythrocyte and platelet count of the rabbits. Their hyperplastic marrow showed evidence of disturbed maturation. A similar extract from a patient with congenital acholuric jaundice did not produce similar changes. The humoral transmissibility of hypersplenic panhemocytopenia is thus believed to be proven. The significance of the hematological and histological changes and the question of the nature of the effective substances are discussed.