The survival and development of cow eggs in the rabbit oviduct after storage at room temperature and after cooling and storage at 0-7·5°C was examined. In PBS medium at room temperature 88% of Day-5 and 85% of Day-3 eggs showed normal development, but in TCM 199, 71% of Day-5 and only 49% of Day-3 eggs showed normal development. Duration of storage (1½-2 hr or 6½-7½ hr) and cleavage stage before storage had no appreciable effect on development. Some retardation of development occurred in Day-3 eggs after 96 hr in the rabbit oviduct when compared to Day-5 eggs after 48 hr. Cooling of Day-5 and Day-6 eggs to 0-7·5°C resulted in degeneration of a large proportion of eggs. Of the factors examined, storage medium (PBS or PBS+20% FCS), storage time (2 min, 30 min, 24 hr) and storage temperature (0, 2, 5 or 7·5°C) had little effect, but slower cooling rates tended to improve survival of eggs although the differences were not significant. More morulae (>32 cells) than 8- to 24-celled eggs developed normally.