The requirement of an SL(2) duality symmetry, mixing the worldvolume field
equations with Bianchi identities, leads to a highly nonlinear equation
involving the transformation parameters and certain worldvolume currents. In
general, this equation seems to admit a solution only for a two parameter
subgroup of the seeked SL(2). These transformations also leave invariant the
first class constraints generating the worldvolume reparametrizations. In the
special case of p--branes in p+1 dimensions, the full SL(2) is realized.Comment: 7 pages, plain tex, contribution to the Proc. of the Gursey Memorial
Conf. I on Strings and Symmetries, Istanbul, Turkey, June 6-10, 199