  M. Daher [9] showed that if $(X_0, X_1)$ is a regular couple of uniformly
convex spaces then the unit spheres of the complex interpolation spaces
$X_{\theta}$ and $X_{\eta}$ are uniformly homeomorphic for every $0 < \theta,
\eta < 1$. We show that this is a rather general phenomenon of interpolation
methods described by the discrete framework of interpolation of [15].
