Quotation from: The Gods of Mars

Written by: Edgar Rice Burroughs

Presently we approached a great chamber more brightly lighted than
the corridors. Thuvia halted us. Quietly she stole toward the
entrance and glanced within. Then she motioned us to follow her.

The room was filled with specimens of the strange beings that
inhabit this underworld; a heterogeneous collection of hybrids--the
offspring of the prisoners from the outside world; red and green
Martians and the white race of therns.