  We present preliminary results regarding the Fundamental Plane (FP) for
galaxies in the two rich clusters Abell 665 and Abell 2218. Both clusters have
a redshift of 0.18. We have compared the FP for A665 and A2218, and for the
cluster CL0024+16 at z=0.39, with the FP for the Coma cluster. The scatter
around the FP is similar for all four clusters. There may be indications that
the slope of the FP is more shallow for the intermediate redshift clusters than
for the Coma cluster. More complete samples of galaxies in intermediate
redshift clusters are needed to map in detail the possible change of the slope
as function of redshift. The mass-to-light (M/L) ratio as measured by the FP
changes with redshift. At z=0.18 the M/L ratio (in Gunn r) is 16+-9% smaller
than for the Coma cluster. Together with earlier results reported for CL0024+16
this implies that the M/L ratio changes with redshift as Delta log M/L_r ~ -0.4
Delta z. The results presented here are in agreement with passive evolution of
a stellar population, which formed at a redshift larger than one. However, the
possible presence of more recent bursts of star formation complicates the
interpretation of the data.
