Since the interesting discovery of the L. E. phenomenon by Hargraves and his co-workers,1 the diagnosis of systemic lupus erythematosus has been vastly facilitated and has been made in a number of hitherto obscure conditions. Moreover, certain cases of rheumatic and allied diseases have presented this blood picture, raising the question of whether or not this group of diseases is another manifestation of the etiologic agent which causes lupus erythematosus. Furthermore, the phenomenon has been reported in patients with drug allergies, and it has been suggested that the increase in the number of patients with lupus erythematous is due not only to more acute diagnosis and the rising interest in the disease, but also to the indiscriminate use of the sulfonamides and the antibiotics, especially penicillin. During the past year, we have examined a fairly large series of bloods from patients whose diseases