The Host

Jonathan Swift, commenting wryly,

Just past the dawn of microscopy,

Had no idea how prescient was his

Flea / Hath smaller Fleas that on him prey,

And these have smaller yet to bite ‘em,

And so proceed ad Infinitum.

He was taking a shot at poets,

The smaller ones biting the greater,

That macaronic Infinitum

There just for rhyme and to drive the jibe

Into satiric absurdity,

But it’s the joke that proved prophetic.

The smallest bacteria contend

With hordes of bacteriophages,

Among Earth’s most ancient and febrile

Parasite-host elaborations,

Some billions of years in the making,

Far more important than mites on fleas

Or fleas on humans (to say nothing

Of lesser poets on greater ones).

Electron microscopes trained at dirt

From unpromising yards and bare lots

Can image phages at densities

Of millions per gram, and the latest

Contenders for final parasite

Are fragmentary vampire phages,

Too stripped to invade bacteria

Or hijack bacterial genomes

On their own, that wrap themselves around

Flagellar necks of larger phages

Then hitchhike into bacteria

To use the larger phage’s genome

To command bacterial genome

To make swarms of copies of themselves

To latch on to more larger phages,

And so repeat, ad Infinitum.

Life is parasites, all the way down,

To steal another infamous phrase,

But who knows how high up hosting goes?