  This paper provides an estimate of the sum of a homogeneous polynomial $P$ of
degree $\nu$ and mean zero over the lattice points inside a sphere of radius
$R$. It is proved that $$ \sum_{\mathbf x \in \mathbb Z^3 \atop |\mathbf x| \le
R} P(\mathbf x) = O_{\epsilon,P}(R^{\nu + 83/64 + \epsilon}) $$
