Quotation from: The Gods of Mars

Written by: Edgar Rice Burroughs

"And should a plant man die?" I asked.

"Should he die before the expiration of the thousand years from
the birth of the thern whose immortality abides within him then the
soul passes into a great white ape, but should the ape die short
of the exact hour that terminates the thousand years the soul is
for ever lost and passes for all eternity into the carcass of the
slimy and fearsome silian whose wriggling thousands seethe the
silent sea beneath the hurtling moons when the sun has gone and
strange shapes walk through the Valley Dor."