tor, bringing into effectiveness the hereditary weakness
of the nervous system. The influence of heredity in producing insanity
is variously estimated at from twenty-six per cent to sixty per cent
of all cases. This great difference in the estimation of the
hereditary influence is due to the personal equation of the
statistician, and the care with which other factors are eliminated. In
the more severe form of the hereditary degeneration the same
pathological conditions are repeated in the descendants. In certain
cases the severity of the condition increases from generation to
generation. According to Morel there may be merely what is recognized
as a nervous temperament often associated with moral depravity and
various excesses in the first generation; in the second, severe
neuroses, a tendency to apoplexy and alcoholism; in the third, psychic
disturbances, suicidal tendencies and intellectual incapacity; and in
the fourth, congenital idiocy, malformations and arrests of
development. There are some very definite data with regard to
inheritance in the nervous disease known as epilepsy. The essential
condition in this consists in attacks of unconsciousness, usually
accompanied by a discharge of nerve force shown in convulsions, the
attack being often preceded by peculiar sensations of some sort known
as the aura. In the most marked forms of the affection heredity plays
but little part, owing to the early supervention of imbecility and
helplessness, and it is a greater factor in the better classes of
society than in the proletariat. In the better classes, owing to the
greater care of the cases and the avoidance of exciting causes of the
attacks, the disease is better controlled and rarely advances to the
extent that it does among the poor. The association of epilepsy and
alcoholism is especially dangerous, for a slight amount of alcohol may
greatly accentuate the disease. In five hundred and thirty-five
children in whose parentage there were sixty-two male and seventy-four
female epileptics, twenty-two were born dead, one hundred and
ninety-five died from convulsions in infancy, twenty-seven died in
infancy from other causes, seventy-eight were epileptics, eleven were
insane, thirty-nine were paralyzed, forty-five were hysterical, six
had St. Vitus's dance, one hundred and five were ordinarily healthy.
That variations in the nervous system which produce more or less
unusual mental peculiarities and which do not take the form