Summary
With the use of a two‐label fluorescent antibody technique, it was demonstrated that the bone marrow of a patient suffering from myeloma contained two groups of cells, each possessing a different protein antigen in its cytoplasm. The antigen corresponded to an 18 S and a 7 S globulin occurring in the patient's serum. This finding is discussed in relation to the current hypotheses concerning the origin and identity of the abnormal globulins of myeloma.