The .38 Colt was "stretched" when it transitioned from heeled bullets to inside lubricated bullets, and was called the .38 Long Colt (the original round, of course, was then called the .38 Short Colt.) Around 1898, Smith and Wesson stretched the .38 Long Colt to create the .38 Special. Around 1935, Smith and Wesson stretched the .38 Special to create the .357 Magnum.
Any cartridge in this series (and the .38 Special +P) can be fired in a .357 Magnum.
In a completely parallel scenario, the .44 Smith and Wesson was stretched when it transitioned to inside lubricated bullets -- and was called the .44 Russian, because it was done under contract to Imperial Russia. The .44 Russian was stretched in the 1890s to become the .44 Special, which was stretched again in the 1950s to become the .44 Magnum. Any cartridge in this series can be shot in a .44 Magnum revolver.