HI surveys of the Magellanic system.

Observational data on the distribution of H I in the LMC, the SMC, the intercloud region, and the Magellanic Stream (MS) are summarized and illustrated with maps of the radial-velocity structure and histograms. Features noted include plane warping, complex z structure, and noncircular motions in the LMC due to LMC/SMC tidal interactions; evidence of tearing in the SMC during a near collision with the LMC about 200 MYr ago; interaction between halo gas and the 5 x 10 to the 8th solar mass of loosely bound intercloud gas; and disintegration of the MS as it nears the Galaxy. The arguments and evidence favoring a hyperbolic orbit which has brought the LMC/SMC system near the Galaxy only once in its 10-Gyr lifetime (assuming a Galactic halo of 10 to the 12th solar mass as proposed by Murai and Fujimoto, 1980) are reviewed.