of Guerrero and Chiapas, and we had heard that it was very common
in Chiapa. Perhaps twenty per cent of the population really has the
disease; at San Bartolome perhaps seventy-five per cent are affected; in
some towns an even larger proportion is reported. The white form appears
the commonest. 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. Authorities do not even
agree as to the sequence of the forms of the disease, if there be such
sequence. Some assert that the white form is the early stage and that
the disease may never progress beyond it; others assert that the white
spots are merely the permanent scars, left after the disappearance
of the disease itself. Maps of distribution seem to show a distinct
relation of the disease to altitude and character of water-supply. The
common herd attribute it to an insect sting, to drinking of certain
water, or to bathing in certain pools. Usually, there is no pain or
danger connected with the trouble, except in the red form, but if the
person affected changes residence, itching and some discomfort may
temporarily ensue. The _presidente_ at Chiapa took us to the jail, where
the prisoners were filed before us and made to hold out hands and feet
for our inspection. Such cases of _pinto_ as were found were somewhat
carefully examined. All we encountered there were of the white variety.
Later, at private houses, we saw some dreadful cases of the purple form.
Very often, those whose faces were purple-blotched had white-spotted
hands and feet.