A simple one - fleas

[Postdog]

How does that poem/ditty go about fleas - the big ones, and the little ones, ad infinitum, etc. I've been going mad trying to think of it.

[SaxyJag]

Great fleas have little fleas upon their backs to bite 'em,
And those fleas have smaller fleas,
And so ad infinitum.

[Postdog]

ta muchly

[SaxyJag]

That wasn't quite right. Just been browsing through a book looking for something else and found this, by A. de Morgan:

Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.