Ten years after Kaznelson's1announcement of the dramatic results following splenectomy in a case of "essential thrombopenia," Whipple2was able to collect data concerning the effects of splenectomy in eighty-one cases. Spence3collected twenty-three additional records, and in 1932 Eliason and Ferguson4summarized a total of 213 cases. This number, however, did not represent the experience of any individual or group but was a compilation of reports by many writers, most of whom described only one or two cases, published within a year after splenectomy. The course of purpura haemorrhagica is so varied, and spontaneous remissions, relapses and recurrence many years after the initial episodes of bleeding are so common, that it must be evident to those familiar with this disorder that adequate appraisal of the effects of operation makes necessary the study of patients many years after splenectomy. Furthermore, the value of splenectomy can be