The Moon Pool by Abraham Merritt

She paused, running her long fingers through her own bronze-flecked ringlets. Selective breeding this, with a vengeance, I thought; an ancient experiment in heredity which of course would in time result in the stamping out of the tendency to depart from type that lies in all organisms; resulting, obviously, at last, in three fixed forms of black-haired, ruddy-haired, and silver-haired -- but this, with a shock of realization it came to me, was also an accurate description of the dark-polled _ladala_, their fair-haired rulers and of the golden-brown tressed Lakla!

How -- questions began to stream through my mind; silenced by the handmaiden's voice.