  To a family of smooth projective cubic surfaces one can canonically associate
a family of abelian fivefolds. In characteristic zero, we calculate the Hodge
groups of the abelian varieties which arise in this way. In arbitrary
characteristic we calculate the monodromy group of the universal family of
abelian varieties, and thus show that the Galois group of the 27 lines on a
suitably general cubic surface in positive characteristic is as large as
possible.
