We analyze some of the kinematical and dynamical properties of Bat inf
inite membrane solutions in the conjectured M theory proposed by Banks
, Fischler, Shenker and Susskind. In particular, we compute the long r
ange potential between membranes and anti-membranes, and between membr
anes and gravitons, and compare it with the supergravity results. We a
lso discuss membranes with finite relative longitudinal velocities, pr
oviding some evidence for the 11-dimensional Lorentz invariance of the
theory. (C) 1997 Elsevier Science B.V.