  Let X be a variety over an algebraically closed field, \eta:\Omega^1_X\to L a
one-dimensional singular foliation, and C\subseteq X a projective leaf of \eta.
We prove that 2p_a(C)-2=\deg(L|C)+\lambda(C)-\deg(C\cap S) where p_a(C) is the
arithmetic genus, where \lambda(C) is the colength in the dualizing sheaf of
the subsheaf generated by the K\"ahler differentials, and where S is the
singular locus of \eta. We bound \lambda(C) and \deg(C\cap S), and then improve
and extend some recent results of Campillo, Carnicer, and de la Fuente, and of
du Plessis and Wall.
