  We compare the amplitudes for the long-distance scattering of three gravitons
in eleven dimensional supergravity and matrix theory at finite N. We show that
the leading supergravity term arises from loop contributions to the matrix
theory effective action that are not required to vanish by supersymmetry. We
evaluate in detail one type of diagram---the setting sun with only massive
propagators---reproducing the supergravity behavior.
