It was found that bone marrow obtained from the tibium or the femur (locally irradiated with 2000 R) and transplanted subcapsularly into the kidney of mice of the same strain 0-4 months after the irradiation was always resorpted. As to the bone marrow from the nonirradiated bones of the same donors--it always possessed osteogenic potencies. Stroma of the irradiated limb was defective ang failed to regenerate at the expense of repopulation of the stroma elements from the nonirradiated sections. Analogous conclusions were drawn on the basis of the experimental results with repeated irradiation of mice with the shielded extremity. In difference to the hemopoietic, stromal elements were incapable of repopulation (according to the data of heterotopic transplantation).