S.S. Chern raised the problem
to find necessary and sufficient conditions for a given Riemannian manifold to be
realizable on a minimal submanifold of a Euclidean space. The aim of this paper is to
provide new necessary conditions. For minimal submanifolds in a Euclidean space we
consider the negative of the Ricci tensor as defining a new metric, which is
nothing but the third fundamental form, and seek curvature properties of this
metric.