In order to explain the small scale-lengths detected in the recent deep field
observations performed from large ground-based telescopes and from the Hubble
Space Telescope, we investigate the predictions at high redshifts for disk
galaxies that formed by infall. Changes with redshift in the observed
properties of field galaxies are directly related to the evolution of the disks
and of the stellar populations. We see that changes in the rest frame
luminosity of a galaxy induce smaller values of half-light radii than are
predicted assuming no evolution. Comparisons are presented with two observed
samples from Mutz et al. (1994) and Smail et al. (1995).Comment: plain tex file + 3 postscript figures. To be published in ApJ