From 585 radial-velocity measures of the forty-seven brightest Pleiades stars and from measures published previously, orbital elements are derived for five newly discovered spectroscopic binaries. Among the thirteen stars no short-period (P < 100 days) binaries were found, and it is suggested that the unusually rapid rotational velocities in these stars are due to an absence of tidal interaction in close binaries. Among the twenty B9.S V-A3 V stars the frequency of short-period binaries seems normal and the rotational velocities are normal compared to similar field stars. Among the fourteen A4 V-A9 V stars no good examples of metallic4ine (Am) stars are known and no short-period binaries have been found. It is suggested that, since Am stars are generally members of close binary systems and the Pleiades has none in that spectral range, the cluster will never have Am stars.