after Robert Hooke, Micrographia (1665)

Their world is a glass of rainwater.
They move up and down through the clearness,
   swallowing their way,
or hang by their tails from the surface:

tiny transparent caterpillars
with their bristled segments of body,
   horned trophies of head.
The glass holds nothing that I can see,

but they find matter to eat in it,
which pulses through a black thread of gut.
   They graze what they breathe,
the blank element they dangle in.

After some days, I observed their heads
to fatten and grow monstrous, the tails
   to curl and dwindle.
They floated head-up now, like commas,

not feeding, yet they were still alive –
poked, they tumbled beneath the surface.
   I studied their eyes,
now stippled with lenses, for flying.

One head cracked. A leg feelered the air,
and it hauled itself, wisp by wisp, out
   of its case, and perched,
staring, on the skin of the water.

A gust of wing and it blew away
into the spaciousness of my room,
   leaving its old self
afloat in the glass, a raft of husk.