“…First, removing the sources of rhythmic NAT activity in birds-the eyes, the pineal gland, or bothabolishes rhythms in locomotor activity (Gaston and Menaker, 1968;Nyce and Binkley, 1977;Ebihara et al, 1984;Underwood and Siopes, 1984). Second, continuous melatonin administration abolishes rhythmicity (Turek et al, 1976;Binkley and Mosher, 1985). Third, chick pineal glands are capable of rhythmic NAT activity, light responses, and rhythmic mel-atonin secretion when the pineal glands are isolated in organ cultures (Binkley et al, 1978;Deguchi, 19796;Kasal et al, 1979;Wainwright and Wainwright, 1979;Takahashi et al, 1980).…”