부산대학교 도서관

Department of Physiology, University Medical School, Teviot Place, Edinburgh EH8 9AG(Received 14th March 1975)The oestrous cycle of the mouse is influenced by environmental conditions (Merton, 1937; Van der Lee & Boot, 1955, 1956; Dewar, 1959). Contact with intact, but not castrated, male mice shortens the oestrous cycle (Whitten, 1958; Bruce, 1965). This effect is due to an olfactory pheromone in the urine of male mice (Parkes & Bruce, 1962; Marsden & Bronson, 1964; Bronson & Whitten, 1968). Isolated females usually have cycles 4 to 6 days long, but, if the females are caged in groups, the cycles become more irregular (Andervont, 1944; Whitten, 1957, 1959). Whitten (1966) suggested that this effect might be due to a female pheromone. Champlin (1971) has shown that oestrus is less frequent in a single female placed in a cage previously soiled by a group of females.In view of the finding of