Why trepan weasels (at their slumber)?

In the G&S operetta, Princess Ida, the protagonists sing of the accomplishments possible for the women of the college at Castle Adamant. These include squaring the circle, sending a wire to the moon, getting sunbeams from cucumbers, and making silk purses from Circe’s pigs. Whether these are desirable goals or not, they are understandable.

But why the heck do they include “And weasels at their slumbers they trepan….”? (Trepan=trephinate=perforating the skull) Am I missing a cultural reference here? I fail to see the purpose, nonsensical or not, of putting holes in weasels’ heads, slumbering or not.

See “English > etymology 2” here.

The line basically means “catch the weasels napping.”

I’ll accept that. But I think one has to admit that the idea of trepanning them while they’re napping is a bit odd.

It also feels like a lot of unnecessary & cruel work!

If I had the skill and learning to sneak up on sleeping weasels, I’d be much more likely to draw dicks on their foreheads with permanent marker. Or fill their little paws with shaving cream and tickle their noses with a feather.

It is a variation of “salting a bird’s tail to immobilize them”.

I also object!

The “sunbeams from cucumbers” bit is a riff on the same experiment at the Academy of Lagado in Jonathan Swift’s Gulliver’s Travels.

Yes, the use of “trepan” here is doubtless just meant to imply the secondary etymology of “trepan” (or “trapan”) as a synonym for “to trap, ensnare, trick”. No skull-boring involved.

Very interesting! I had not realized the alternate meaning. I’m now an enlightened person.

That link spells the “tricks” meaning as trepen instead of trepan. I wonder if original transcripts of the song used the alternate spelling which became forgotten over time.

Maybe that double meaning is part of the joke?

I saw a trepanned weasel swim the Tappan Zee-sul.

(Don’t believe me? Just ask Cecil)

I don’t have an original libretto, but the ones I have seen on-line spell it “trepan” very consistently. And many of these include annotations that indicate other changes in spellings or lyrics that were made later.

Might the suggestion be that these ladies are practicing at brain surgery?

Ah, well, it was an idea.

And having looked at the whole lyrics of that song, I can see why changes need to be made. A modern eye goes along in delight at the words and then gets suddenly and unpleasantly derailed.

I doubt it. I don’t think there’s anything more obscure here than a comically pretentious rephrasing of the well-known idiom “to catch a weasel asleep”, as Cervaise noted.

If you trepan a weasel, do they go pop?

Especially since, in performance, you can’t tell which spelling Gilbert was using for the last word of the line “each newly joined aspirant to the clan.”

That was a clever catch!

Rocket science wasn’t available as a course of study back then.