Abstract
Splenectomized sham-operated, and unoperated mice were exposed to 550r of X-rays, 1 group on the day of operation and 1 group 7 days after operation. Infant and pubertal mice were used. In all groups, the splenectomized mice had the highest 30-day mortalities. It is concluded that the unshielded mouse spleen plays a definite, but small, role in recovery after mid-lethal whole body irradiation.