"Siphonaptera" is a name used to refer to the following rhyme by Augustus De Morgan (Siphonaptera being the biological order to which fleas belong):
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.
The rhyme appears in De Morgan's A Budget of Paradoxes (1872) along with a discussion of the ...
