The name "roseola infantilis" had an important place in the medical terminology of writers on skin diseases fifty years ago. Willan distinguished several varieties, and subsequent writers followed his classification with some variations. The older works on pediatrics had descriptions of the disease, but it is obvious from these descriptions that many different eruptions were confused under this heading as Hardaway1pointed out. On the advice of the dermatologists the name was dropped and recent text-books on pediatrics do not mention this affection. For many years I have been interested in a symptom-complex, a febrile erythema, which occurs almost exclusively in infants and which deserves a place outside of the erythema group of skin diseases. To this the older writers gave the name "roseola infantilis," but did not differentiate this disease from rubella and toxic erythemata. In 1909 I discussed this subject before the St. Louis Pediatric society and