Abstract
An outline is given of the nature of the metal-insulator transition when the antiferromagnetic non-metals LaVO3 or La2CuO4 are doped with strontium or barium. It is suggested, following other authors, that a degenerate gas of spin polarons is formed, which particularly in two-dimensional structures, can form bipolarons, and that these could be the boson pairs which in the latter and similar oxides give rise to high temperature superconductivity