Dr. BRUNO BLOCH, professor of the Dermatological clinic of Zurich, began a new era of eczema research by attempting to sensitize guinea pigs to primula. It was during this period that I had the pleasure of being Dr. BLOCH's chief resident, and could observe these experiments. It was only in 1955 that Dr. E. BUJARD, professor of Histology of the University of Geneva, Dr. R. BRUN, chief of laboratories of my Dermatology Department and I began to work in the field of experimental eczema on the nipples and flanks of guinea pigs. Besides these collaborators, to whom I am very grateful, a few others have participated in our experiments. Among these new co-workers the most im- portant was Mrs. NICOLE HUNZIKER, chief resident of my clinic. From 1960 on, she worked on the eczema experiments with guinea pigs. Our research has been conside- rably advanced by Dr. HUNZIKER. Untill now we have published 30 communica- tions on this subject, but the publications about our results have been very short. It now seemed appropriate to publish a monograph and Dr. HUNZIKER undertook this very toilsome task. I would like to take this occasion to thank her for her many years of collaboration both in the clinic and in the laboratory. I am also very grateful to Professor BUJARD who, in spite of the fact that he is retired, continues to work with us. We continually profit from his great experience. Dr.