Hematopoiesis in the bone marrow, 14 days after transplantation.

(A) Appearance of bones following transplantation of Rho^lowcells (original magnification, × 20). (B) Dense megakaryocyte cluster, following transplantation of Rho^low cells (original magnification, × 200). (C) Empty marrow, 14 days after transplantation of Rho^high progenitors (original magnification, × 100). (D) Small erythroblastic colony in the marrow of animal 14 days following transplantation of Rho^highprogenitors (original magnification, × 200). Controls consisted of healthy animals and irradiated animals that did not receive a transplant.