Consider an initial value problem (1) \(u'\in F(t,u)\) a.e. on J, \(u(0)=x_ 0\) where \(J=[0,a]\subset R\), \(X=R\) n and F:J\(\times X\to 2\) \(X\setminus \phi\) is a multivalued map. Let \(K\subset R\) n be a cone and \(\leq\) the partial ordering defined by K, i.e. \(x\leq y\) iff y-x\(\in K\). The author considers the question of extending the solutions of (1) with respect to this partial ordering, emphasizing the existence of minimal and maximal solutions.