“…The methods used have inc1udedobstruction boxes (Moss, 1924;Warner, 1927;Jenkins, 1928;Stone, Barker, & Tomlin, 1935), mazes (Kagan, 1955;Whalen, 1961), straight alleys (Beach & Jordan, 1956a;Ware, 1968;Sheffield, Wulff, & Backer, 1951), wheel-turning (Denniston, 1954), and leverpressing (Schwartz, 1956). All of these studies had a common feature: the paradigm either ignored or prec1uded the temporal pattern of male rat copulatory behavior normally' observed when a receptive female is freely available.…”