  The Shapley-Ames Catalog of 1276 galaxies with B < 12.5 is compared with the
Sanders et al. all sky sample of the 629 galaxies with 60 m flux density > 5.24
Jy. The fraction of Shapley-Ames galaxies that are visible in the IR is found
to increase from 0.006 for E or E/S0 galaxies to 0.384 for Sc galaxies. The
subset of Shapley-Ames galaxies that are detected in the IR has a median blue
luminosity that is ~0.8 mag fainter than that of all Shapley-Ames galaxies.
Most of this difference is due to the fact that late-type galaxies (which
contain dust and hot stars) are systematically less luminous in blue light than
are early-type galaxies. Within individual stages along the Hubble sequence no
significant differences are found between the luminosity distributions in blue
light of galaxies that were detected in the infrared and those that were not.
However, our data show a puzzling exception (significant at 99.9%) for SBc
galaxies. For reasons that are not understood Shapley-Ames SBc galaxies, that
are visible in the IR, are more luminous in blue light than those SBc galaxies
that are not detected in the infrared. An other peculiarity of the data is that
Shapley-Ames Sc galaxies galaxies are (at 99.6% confidence) more luminous than
objects of type SBc .
