World in a shell

For the dverse prosery prompt, to fit the line from Oliver Wendell Holmes: Through the deep caves of thought, I hear a voice that sings into a 144-word piece of prose.

World in a shell

I hold the shell to my ear and listen to the rise and fall of the ocean. Where are they born, these echoes that roll through the deep? Caves of thought? I hear a voice that sings with the voice of the whales, and the song is older than mankind, old as the ocean and those who first learned the currents and the tides.
The song tells of the making of the world from air and water and woven strands of kelp, the birth of mountains and rivers that run always back to their sea-home. Of trees that mimic coral forests where birds dart like feathered fish.
The shell spirals in and out, chambered like a heart, all the pearly hues of a dawn sky and it sings the ages of the earth until the silence after the final echo, the age of Man.