  A majority of a complete sample of 3CR FR I radio galaxies show unresolved
optical nuclear sources on the scales of 0.1 arcsec. About half of the 3CR FR
II radio galaxies observed with the HST also show Compact Central Cores (CCC).
These CCCs have been interpreted as the optical counterparts of the non-thermal
radio cores in these radio galaxies (Chiaberge, Capetti, & Celotti 1999). We
show that the optical flux density of the CCCs in FR Is is correlated with the
radio core prominence. This correlation supports the argument of Chiaberge et
al. that the CCC radiation is of a non-thermal synchrotron origin, which is
relativistically beamed along with the radio emission.
