Long-term Survival of Irradiated Mice treated with Homologous Tissue Suspensions

RECENTLY, Barnes et al. 1 reported the survival for 150 days of CBA mice subjected to a dose of 950 r. X-radiation and treated with spleen or liver suspensions from new-born or unborn C 57 BL mice. In an attempt to clarify the secondary phase of the irradiation death syndrome, Uphoff 2 observed the 90-day survival of ( C 57 BL × DBA /2) F 1 hybrids subjected to 800 r. X-radiation following injections of suspensions made from C 57 BL or DBA /2 tissues. She reported that the use of fœtal hæmatopoietic tissues precluded the secondary phase of the irradiation syndrome for 90 days after irradiation, whereas injection of bone marrow suspensions did not.