Dactyl

Quackily, swimmingly
Duck on the lake.
Syndactyl oddity,
Web feet did make.
_____________

Higgidy Piggidy,
Pig in a stye.
Double his dactyly,
Trotters to fry.
_____________

A cat with polydactyly
Had seven extra toes.
Her feet were big, but actually,
She 's very good on snow!

Does anyone know what I'm talking about? Kalleh mentioned dactyl in one chat and I asked her what it was. She said, a poem. I looked it up and it is a Greek name for a pattern of long - short -short sounds in poetry. Dactyl means finger. The mnemonic is to associate the pattern with the pattern of one long and two short bones in a finger.

To an old biologist like me, dactyly refers to the condition of having fingers. The normal hand or paw forms as a paddle shape which is then subdivided into fingers.
In web footed ducks, the fingers don't separate and that is syndactyly. Syn = together. It helps ducks swim.
Pigs feet separate into two, rather than five digits. I think pigs feet are eaten in England and called "trotters."

Polydactyly means having extra fingers or toes. It is relatively common in cats. The cats have wide feet. We have an expression in the US that if someone has big feet he is "good on snow."

I hadn't really caught that when I first glanced at your post. I'd made the (completely unfounded) assumption that you weren't up to speed on how double dactyls work.

Now that I realise what you were doing, well done. Very clever.