An analysis is made of the distribution of the integrated radio emission, and it is shown that most of the emission is galactic in origin and arises from a spherical distribution having a radius greater than 10 kps; the emission per unit volume throughout this spherical region is remarkably constant. A further distribution which accounts for the greater part of the radiation at galactic latitudes less than 30° is found to be consistent with the radio model of the Galaxy proposed by Westerhout and Oort. A comparison of the Galaxy with M31 shows that, whilst the extents of the spherical components in the two galaxies are very similar, the emission per unit volume is about six times greater in the Galaxy than in M31.