Von Jaksch1 in 1889 described a chlorotic type of anemia occurring in infancy and early childhood and accompanied by great enlargement of the spleen, hepatic swelling, leukocytosis and marked changes in the size and shape of the red blood cells. The syndrome he described became known as von Jaksch's anemia or pseudoleukemic anemia. Later a similar syndrome was described in cases of rickets, deficiency diseases, congenital syphilis, congenital hemolytic icterus and sickle cell anemia, thus discrediting von Jaksch's disease as an exact clinical entity. Many investigators felt the condition to be only a variety of secondary anemia, or, in the words of Naegeli,2 "not a special entity but an extreme reaction." In 1925 Thomas B. Cooley, of Detroit, published with Lee an article3 entitled: "A Series of Cases of Splenomegaly in Children, with Anemia and Peculiar Bone Changes," on a condition which occurred in patients with von