  We analyze some of the kinematical and dynamical properties of flat infinite
membrane solutions in the conjectured M theory proposed by Banks, Fischler,
Shenker and Susskind. In particular, we compute the long range potential
between membranes and anti-membranes, and between membranes and gravitons, and
compare it with the supergravity results. We also discuss membranes with finite
relative longitudinal velocities, providing some evidence for the eleven
dimensional Lorentz invariance of the theory.
