Page:Popular Science Monthly Volume 29.djvu/794

774 the whistling of the bullet has a significance to him. He knows, without having thought long about it, that it is death passing by him. And before he has performed any conscious reasoning concerning the effects of a whistling bullet, the association of ideas has worked in his mind and determined his sudden movement.

If, while an athlete was performing his exercises on the trapeze, one of the cords should break, the host of spectators would be overcome by great emotion. Some of the women would turn away sick, and others would scream; and the bravest would shiver and turn pale. These phenomena are certainly involuntary and reflexive; but they could not exist without some intelligent comprehension of what has taken place. The breaking of a cord is not an excitant of reflex actions, and, if there were no man's life in the case, the crowd would not feel them.

The lower animals are not susceptible of having psychical reflex emotions, only simple ones; for they have no knowledge, and no judgment respecting the nature of the. exciting cause. Many of man's reflex acts are of similar character, as the flow of tears, the reddening, and the vigorous winking when one gets a speck in his eye. Nearly all the psychical reflex acts have as their starting point an excitation of the senses. Such excitations can not of themselves be competent to provoke an organic reflex movement; but, if they are comprehended by an intelligence, and are accompanied by a notion of the exterior phenomenon, they can then determine a reflex act which is the consequence of that notion.

Thus, fear, as a psychical reflex emotion, results doubly: first, in a phenomenon of consciousness, or the fright felt by the me; and, second, in a series of characteristic reflex motive phenomena. The whole central nervous system is disturbed, and the disturbance is communicated to all the motive and glandular apparatus: to the heart, whose beatings are arrested or accelerated; to the muscles, which vibrate; to the salivary glands, which cease to produce saliva; to the intestines, which contract with force; to the vessels of the pallid face; to the sudoriferous glands; to the dilating pupil; and to the features, which reflect the distress of the consciousness.

M. Brown-Séquard has proved by numerous experiments that the nervous system, when it has been subjected to an exterior stimulation, may be excited or paralyzed. The emotions of fear are likewise either stimulating or paralyzing, or inhibitory. Examples of both kinds of effect are numerous. Thus, when a rabbit is overtaken by a dog, it runs away immediately, the faster the more it is frightened. It will leap over wide ditches, pass through almost impenetrable hedges, and strike against objects it would ordinarily avoid, so much is its course precipitated by fear. If the dog pursues it, it leaps and bounds here and there, frightened out of its wits, but more agile and fleet in consequence of its very terror. Another rabbit, under precisely similar