Abstract
Extended series expansions for the mean size and the first and second moments of the pair connectedness for both bond and site percolation on the directed square and triangular lattices have been obtained. Analysis based on differential approximants allows the critical percolation probabilities and exponents to be estimated, and as a result the critical exponents are conjectured to be gamma =41/18, nu perpendicular to =79/72 and nu /sub ///=26/15. Scaling then gives beta =199/720, alpha -=-299/360 and delta =1839/199.