We propose to carry out far-infrared observations of a complete
 and homogeneous sample of 200 galaxies selected in radio
 (1.4 GHz) wavelengths to a flux limit of S(1.4) ~ 0.3 mJy,
 covering an area of 2 square degrees. To this limit,
 a significant number of ultra-luminous infrared galaxies and
 Seyferts are expected to be detected. We propose to investigate
 if the absence of high-redshift galaxies from deep optical
 surveys is due to dust extinction of starforming ellipticals.
 Also, Far-infrared observations will be used to estimate the
 space densities of different classes of objects in deep radio
 surveys and to investigate if the radio-60 micron relation,
 found for local galaxies, holds for the fainter, more distant
 sources as well. Nature of the excess population, detected in
 in optical and far-infrared surveys will also be studied.