Electron microscope and electron diffraction studies on the surfaces of CP‐4 etched germanium specimens have shown that the changes in etching behavior induced by fast neutron irradiation occur as a result of a gross change in chemical behavior and cannot be due to local variations in the etching rate in the vicinity of the structural defects introduced by the irradiation. Observations on network structures which are produced under certain conditions of etching indicate that these arise as a result of mechanical preparation of the surfaces or from changes in the etching process and are apparently unrelated to any prior substructure in the material.