a JeLLy-fiSH

Visible, invisible,
A fluctuating charm,
An amber-coloured amethyst
Inhabits it; your arm
Approches, and
It opens and
It closes;
You have meant
To catch it,
And it shrivels;
You abandon
Your intent -
It opens, and it
Closes and you
Reach for it -
The blue
Surrounding it
Grows cloudy, and
It floats away
From you.

(Marianne Moore)
.