"It is becoming increasingly evident that the group termed 'the hemorrhagic diseases' includes a large number of abnormal conditions, and that, at the present time, it is a fruitless task to attempt to unravel the various entities embraced by the clinical conditions which are assembled under this general head." This statement, made thirteen years ago in an oft quoted address by Alfred Hess,1is unfortunately still applicable today. Nevertheless, as time goes on, the accumulation of a sufficient number of atypical cases with similar manifestations permits the formation of new groups, and subsequently necessitates a partial reclassification. Such a group of cases has been reported by Glanzmann.2He has described in detail eight families with an unusual form of purpura and has proposed the name hereditary hemorrhagic thrombasthenia. The disease affects both sexes and is usually transmitted by the females. Briefly, the symptomatology consists of attacks of severe