\ - If the protective raterial comes from another species of animal the protection is very short lived and not nearly as effective, In principal the transplantation of bone marrow would significantly increase the survival rate of exposed human beings in the group 2 (Survival possible) and possibly to a lesser extent in the group 1 (Survival improbable) casualties, The amounts of bone marrow needed are large and the mongrel nature of man takes it unlikely that very much could be expected in the way of long term protective effect. In my opinion it would be the worst type of wishful thinking to expect that one could !ave an effective bone marrow bank in the case of an atomic catastrophe, Mudiwork is yet to be done under carefully ecntrolled clinical conditions before one could be optimistic about the use of this procedure in man under highly controlled conditions, for an individual patient let alone under conditions of a nuclear catastrophe. However, the treatment of group2 casualties is not at all hopeless There is ample clinical experience in conditions where the bone marrow is severely depressed and in which there are inadequate numbers of circulating cells. In these relatively common clinical conditions produced by sensitivity to drugs, or occurring naturally as disease processes, the combined use of the wide spectrum antibiotics that are now available, and the judicious use of blood transfusions significantly increases the survival time of the individuals, thus giving nature a longer period of time to repair spontaneously the damages that has been suffered, Accordingly one could feel optimistic in respect to increasing significantly the survival rate of the group 2 (Survival possible) casualties by wide spread controlled use of antibiotics.* Preparation and stockpiling for such an emergency is obviously required. Group III Survival Probable This group consists of individuals who may or ray not have hed fleeting nausea * Blood transfusions would be helpful to a limited extent for anenia. of availability of enough blood for burns and other injuries is low, blood may be needed for radiation injury supply may be exhausted. The probability Fence when