branches of the trigeminus, especially of the supraorbital
nerve.

Temporary and Partial Canities.--Of special interest are those cases in
which whiteness of the hair is only temporary. Thus, Compagne mentions
a case in which the black hair of a woman of thirty-six began to fade
on the twenty-third day of a malignant fever, and on the sixth day
following was perfectly white, but on the seventh day the hairs became
darker again, and on the fourteenth day after the change they had
become as black as they were originally. Wilson records a case in which
the hair lost its color in winter and regained it in summer. Sir John
Forbes, according to Crocker, had gray hair for a long time, then
suddenly it all turned white, and after remaining so for a year it
returned to its original gray.

Grayness of the hair is sometimes only partial. According to Crocker an
adult whose hair was generally brown had a tuft of white hair over the
temple, and several like cases are on record. Lorry tells us that
grayness of one side only is sometimes occasioned by severe headache.
Hagedorn has known the beard to be black in one place and white in
another. Brandis mentions the hair becoming white on one side of the
face while it continued of its former color on the other. Rayer quotes
cases of canities of the whole of one side of the body.

Richelot observed white mottling of hair in a girl sick with chlorosis.
The whitening extended from the roots to a distance of two inches. The
probable cause was a temporary alteration of the pigment-forming
function. When the chlorosis was cured the natural color returned.
Paullini and Riedlin, as well as the Ephemerides, speak of different
colored hair in the same head, and it is not at all rare to see
individuals with an anomalously colored patch of hair on the head. The
members of the ancient house of Rohan were said to possess a tuft of
white hair on the front of their heads.

Michelson of Konigsberg describes a curious case in a barrister of
twenty-three affected with partial canities. In the family of both
parents there was stated to be congenital premature canities, and some
white hairs had been observed even in childhood. In the fifteenth year,
after a grave attack of scarlet fever, the hair to a great extent fell
out. The succeeding growth of hair was stated to have been throughout
lighter in tissue and color and fissured at the points. Soon after
bunches of white hair appeared on the occiput, and