The first person to get the joke/pun/quotation and post it in the comments may have the original drawing of this illustration in return for evidence of a donation to a recognised fund for Australian flood, fire or cyclone relief. Congratulations to my mother, who worked it out. Next time, no family. Our brains are too alike. The answer is:
Why is a banana like the laws of the Medes and the Persians? Because neither can be repealed.
Pen and ink, with thanks & apologies to Albert Racinet’s costume encyclopaedia.