  We compare three 3CR samples of 11 FR1 galaxies, 17 FR2 galaxies and 18
lobe-dominated quasars contained in the ISO Data Archive. In contrast to the
powerful FR2 galaxies with edge-brightened lobes, the low radio power FR1
galaxies in our sample do not exhibit any high MIR or FIR dust luminosity,
which is typical for a buried, intrinsically more luminous AGN. This
consolidates the fact already inferred from optical studies that their AGNs
have only a relatively low luminosity. Also the FR1 galaxies show a high
FIR/MIR luminosity ratio, compared to quasars, suggesting that their FIR
luminosity is substantially powered by the interstellar radiation field (ISRF)
of the giant elliptical hosts. Finally, we discuss the FR1-FR2 morphological
dichotomy. FR1 galaxies do not have more interstellar matter (ISM) than FR2s as
traced -- on the large scale -- by the cool FIR emitting dust and -- in the
nuclear region -- by the warm MIR emitting dust. Due to the lack of central gas
we suggest that the black holes of our FR1 galaxies are fed at a lower
accretion rate than those of the FR2 galaxies.
