Currently, the importance of the accessory olfactory system to the mating behavior of male hamsters is being tested. Following lesions of the vomeronasal nerves, 2 of 11 males at first failed to mate but recovered after 3 to 6 weeks. The other 9 males displayed subtle, but statistically significant, changes in mating behavior. BIBLIOGRAPHIC REFERENCES: Murphy, M. R.: Olfactory impairment, olfactory bulb removal and mammalian reproduction. In "Mammalian Olfaction, Reproductive Processes, and Behavior". Ed. R. L. Doty, Academic Press, N. Y. 1976.