Do bipolar magnetic regions exist on the surfaces of early-type stars

The observations of relatively narrow absorption components of the UV resonance lines in the spectra of early-type stars are reviewed, and some new observational data are presented for rho Leo (B1 Ib). A geometrical theory is outline which will provide ionized gas in the appropriate place for the appropriate length of time to account for the observations. This theory is applied to rho Leo, and it is deduced that the source material for the discrete absorption components seen in the spectrum of rho Leo may be released at a height above the photosphere which is of the order of 2 R/sub asterisk/