mental images may be mistaken for objective reality, as in the case of the hallucinations that are frequent in these phenomena.
The moral peculiarities of an epidemic are of a similar kind. Under the influence of a craze, the moral character of a people suffers a reversion to a primitive type. In times of epidemic waves the moral standards of the crowd approach those of the savage. We observe the exhibition of primitive instincts, such as cruelty, revenge and bloodthirstiness, together with changeableness, fanaticism, self-sacrifice and enthusiastic devotion to a leader. All these moral traits were well illustrated in the Revolution crazes in France and in the persecution of witches in the sixteenth and seventeenth centuries. Even in our own times a striking example of the primitive character of the morality of a people under the influence of social excitement was seen in the battle-cry of our American sailors in the recent Spanish war, 'Remember the Maine/ the ethical motive being a precipitate impulse to seek revenge. An instance like this can not be explained upon the theory that it represented the actual individual morality of the sailors participating in the battles, for it was echoed and apparently endorsed by the press throughout the country and upon the platform and even in the pulpit. It is hardly conceivable that an Englishman of noble birth should openly boast of his joy in being revenged upon an enemy; yet collective England is wild with delight when 'Majuba Hill is avenged!'
We are thus led apparently to the theory that, for some reason not yet evident, under the influence of social excitement, something takes place in the brain of the individual not unlike the action of hypnotism, by which the higher centers representing the more recent moral and mental acquirements of the race are temporarily paralyzed, reducing the subject in a greater or less degree to the condition of the child and of the primitive man. The observation of certain physical phenomena which often accompany mental epidemics tends to confirm this theory and at the same time to suggest a possible explanation. Epidemics of the more extreme kind are apt to be accompanied by great muscular excitability, varying all the way from mere extreme mobility, such as shouting, jumping and throwing the arms, to convulsions like those of epilepsy. The dancing manias of the fourteenth and fifteenth centuries furnish the best illustrations of this, although these phenomena did not equal in intensity the frightful physical convulsions during the religious revivals in Kentucky at the beginning of this century. The particular character of these muscular movements is determined by imitation and suggestion. The movements themselves are no doubt due to congestion and irritation of the motor centers, or at least to a rapid overflow of nervous discharges at these centers, an accompaniment of the excessive emotion which attends all mental epidemics. In such a condition of the nervous system, thought, reasoning, memory and