Much attention has recently been given to the rôle and function of the spleen. Its relation to the destruction of red cells and to the catabolism of hemoglobin has been particularly emphasized, whereas much less has been noted concerning the function which it may play in controlling or affecting the histogenesis of these cells. The view that the histogenesis of red corpuscles is in some way dependent on splenic function is based primarily on the observation that following splenectomy the red blood cells show nuclear particles (so-called Howell-Jolly bodies), which were not present before the operation.
Howell1 in 1890 noted that following hemorrhage the erythrocytes of cats often showed small bodies, in many respects resembling nuclear material. These were described as "single, good-sized pieces of nuclear material, too large to be called granules, but having the shape and appearance of large nucleoli, which always lay imbedded in the periphery