  New information has recently become available on the fundamental plane for
various samples of early-type galaxies with redshift up to 1.3, both in
clusters and in the field. This information is reviewed and clues are derived
on the evolution of spheroids over the last two thirds of the Universe lifetime
as a function of galaxy mass and environment, in comparison with the
predictions of the hierarchical models of galaxy formation. Using the Universe
as a time-machine and interpreting changes in M/L ratio as age differences, we
see that the age increases with galaxy mass in all environments, cluster
galaxies with any mass are older than field galaxies with the same mass, and
the age difference between cluster and field galaxies increases with mass. The
first two results confirm those obtained with other methods, and are reproduced
by the most recent incarnation of the hierarchical models, while the third
result is new and appears in contrast with the predictions of these models.
