Space Sciences Center, University of Southern California, Los Angeles, CA 90089-1341; USA

The nature of the circumstellar material in interacting binaries of the Algol-type, including the accretion disk, gas stream, high temperature plasma, and domains of outflow is reviewed. Mass transfer is compared in six similar systems with early B primaries and short-moderate periods that approximately represent a series of snapshots of such binaries during their slow evolutionary phase. Evidence for moderate systemic mass loss during the current and earlier stages is presented.

To appear in "The Influence of Binaries on Stellar Population Studies", ed. D. Vanbeveren (Dordrecht: Kluwer)
Preprints from gjpeters@mucen.usc.edu