Cagney in “Hard to Handle” playing innocent.

“I use the words ‘Cagney’ and ‘Jim’ somewhat interchangeably, but usually the former refers to the performer in action and the latter to the man. ‘Jim’ was the name he always used in personal reference. He did not care for ‘Jimmy,’ a Warner Brothers locution.”

— John McCabe, in his biography “Cagney.” McCabe was also ghost writer on Cagney's autobiography, “Cagney on Cagney.”