unity. We prove a new restriction on the group-theoretic structure of the absolute Galois
group $ G_F $ of $ F $. Namely, the third subgroup $ G_F^{(3)} $ in the descending $ p $-
central sequence of $ G_F $ is the intersection of all open normal subgroups $ N $ such that
$ G_F/N $ is $1 $, ${\Bbb Z}/p^ 2$, or the extra-special group $ M_ {p^ 3} $ of order $ p^ 3$
and exponent $ p^ 2$.