But let’s slow down and take it one creature — and one poem — at a time. Consider the turtle, as captured by Kay Ryan.

Turtles may not have the charm or charisma of other beasts — they don’t dominate the human imagination like eagles or lions, or domesticate it like dogs or cats — but they have a notable presence in literature and myth. They are symbols of wisdom and longevity; their shells are sturdy enough to hold up the world. The cosmos, in one famous account, consists of “turtles all the way down.”

In Aesop’s fable, the turtle (traditionally called a tortoise, which is a type of turtle) is a winner, a perpetual underdog who defeats the arrogant hare. The tortoise’s slowness turns out to be a virtue.

In Ryan’s poem, the turtle’s physical attributes — her cumbersome shell and short legs, above all — seem only to be liabilities. That armor may have evolved as protection against predators, but it’s a lot of baggage for a poor, halting herbivore to lug around. Her patience isn’t going to win her any races: It’s her best response to a tough break; a way of making light of a heavy situation.

But at the same time, the poem’s mood and manner, its sense and sound, defy the constraints of turtleness. To read it a second time — or aloud — is to note how nimbly and swiftly it moves.