One subject examined at Tuxtla Gutierrez was a woman some sixty years of age.

At birth she showed no symptom of the trouble, but spots began to appear when she was seven or eight years old.

She was naturally dark, and the white spots were in notable contrast to her normal color; the spots increased in number and in size until her face and arms looked as if they had been white and become brown-spotted, instead of _vice versa_.

After she was forty years of age her spots varied but little.

The cause of this disease is still obscure, although several treatises have been written upon it.