a sample of early-type galaxies, log S$_{CO}$=log S$_{100}$ - 1.76, is also plotted as comparison, as a dotted line.

The relations are evident, with this wider sample of galaxies. In these diagrams, active and non-active galaxies appear mixed together without clear differences and have been plotted together. The same behaviour appears for interacting and non interacting galaxies, that are not distinguished in our plots.

For all the galaxy types, we find: $$Log S_{CO}= 1.06\ Log S_{100} + 2.02
\label{eqCO_100}$$ with a correlation coefficient of 0.74 and a r.m.s. of 0.37. In the above formula, S$_{100}$ is in mJy and S$_{CO}$ is in Jy km/s.

Similar relations exist between the CO fluxes and the FIR magnitudes, defined as: $$m_{FIR} = -2.5\ Log(2.58\ S_{60}+S_{100})+ 22.25
\label{def_mfir}$$ where S$_{60}$ and S$_{100}$, the fluxes at 60 and 100 $\mu$m respectively, are in mJy. We find for all the galaxy types: $$Log S_{CO} = 0.41\ m_{FIR}+ 6.86
\label{CO_mfir}$$ with a correlation coefficient of 0.69 and a r.m.s of 0.40. The results are based on 179 early types and 170 late-type galaxies. For their similarity with Figures \[CO\_100\] these relations are not plotted in this paper.

We note that irregular galaxies are not fitted by these 