"He's fallen in da water ..."

Many years ago on the radio the Goon Show had a catch phrase or running joke, I suppose you might call it, where someone (little Jim?) would say (in a strange voice) "he's fallen in da water". This would for some reason have the audience in paroxysms of laughter. Ah those were the days, long ago, when there was probably some water to fall into at this point on the river, nowadays you'll most likely get a concussion from the mud and that's no joke.