  We review some properties of the Einstein-"Gauss-Bonnet" equations for
gravity--also called the Einstein-Lanczos equations in five and six dimensions,
and the Lovelock equations in higher dimensions. We illustrate, by means of
simple Kaluza-Klein and brane cosmological models, some consequences of the
quasi-linearity of these equations on the Cauchy problem (a point first studied
by Yvonne Choquet-Bruhat), as well as on "junction conditions".
