[en] The statistical model for fission is used to calculate the isotopic distribution of Rb and Cs in the fission of ²³⁸U induced by high-energy protons and reactor neutrons. The double-humped behaviour of the isotope yield curve as observed in high-energy proton-induced fission and the experimentally observed hump on the neutron-rich side in neutron-induced fission are semi-quantiatively reproduced. (orig.)