Subcellular Fractions Involved in Allograft SensitivityRecent years have seen extensive investigation in which it has been found that subcellular fractions may be involved in the transfer of allograft sensitivity. Attention has been paid to the possibility that viable sensitized cells capable of transferring allograft sensitivity may do so by passing on material, thought by some to be a special type of antibody100,104 to the reticuloendothelial cells of the host, enabling them to act as if they themselves had been directly sensitized.Lawrence and his co-workers have studied the problem extensively in man, in whom the situation has appeared to . . .