Etudes sur la pathologie des huîtres

French summary: In 1974, at the request of a group of oyster farmers in the Brittany region, the Pathology Laboratory of the U.E.R. Medicine of Brest undertook a series of theoretical and applied research projects concerning the problem of flat oyster digestive gland disease, due to Marteilia refringens, the primary economic problem of that time. In 1978, in the research report of Contract C.N.E.X.O. 77/1690, the main results obtained since the beginning of the study of the parasitosis were made public. The present report has as its objective to show: - The results obtained in 1978-1979 while monitoring the parasitosis, and most especially the epidemiological evolution of the disease; - Information concerning the presence of other infectious diseases detected in Ostrea edulis, but of currently limited pathological importance. - The research in progress on tumorous processes in the flat oyster.