THE ETIOLOGY of the diseases or syndromes of the pemphigus group is a challenging subject which remains undisclosed despite the large volume of research done upon it. The number of theories on the cause of pemphigus is a good index of the tremendous confusion prevalent not only in the etiology, but in the pathogenesis, epidemiology, and other domains of the knowledge on pemphigus as well. The existence in the literature of rather numerous reports of isolation of a virus from pemphigus vulgaris cases* as well as several suggestive observations on pemphigus foliaceus4 motivated the work reported here.
Attempts to isolate a virus from pemphigus foliaceus material are apparently found only in the Brazilian literature which is explainable by the relative abundance of cases in Brazil. Lindenberg5 was the only worker who reported success, but his work is open to criticism due to poor technique and small number of