Nin's Limericks

There is something fitting about linking the Savoy operas with limericks. Both are likely to appeal to people with a certain type of sense of humour.
Why are the Savoy operas funny? Because they were written by a couple of geniuses who knew how to be funny ... never fall into the trap of assuming that Gilbert was the funny one. Gilbert himself discovered that his words didn't work half so well when set by other composers.
Why are limericks funny? That's a much more difficult question. Suffice it to say that, if The Lady of Shalot or the Mort d' Arthur were written to a metre of 8,8,5,5,8,
people would have roared their ribs out.
The really surprising thing, given that Gilbert used every trick in the book to make his verses funny, is that in the whole canon I can only find one example of a limerick written by Gilbert (double limerick, shameless man)