mentary sensations, of vague emotions, and of blind appetitions. In the myriapod it is the head or terminal segment that directs, sees, and smells, but all the other segments also fulfill their appropriate functions, and have their peculiar life in the midst of the collective life. If we cut the animal into several parts, the different parts will continue to move and react under external excitations; it is, therefore, improbable that the head should be the only part to possess sensibility and appetite. When a wound is inflicted upon the animal, it is felt in different degrees by all the segments, and the reaction is propagated from segment to segment. With the superior animals, which are a sort of very centralized states, the concentration of consciousness into the head only obscures the rudiment of sensibility which is still subsisting between the other parts.
For these reasons, we suppose a solidarity of the parts in the living body which, mechanical without, is mental and social within. Hence there can be no irritation of a part without its propagating itself by contagion to all the other parts; this is the germ of the diffused sensation which is felt in the whole body. Furthermore, this irritation being always either favorable or unfavorable to the life of the whole and of the parts, would be felt as rudimentary pain or pleasure—that is, as the germ of the diffused emotion. Finally, all the parts having power to react and a tendency to their own conservation, the irritation brings on a motive reaction of the whole body; this is the germ of the diffuse appetite, of the zest of life inherent in the whole. The solidarity, in the association of living cells, then takes the triple form of a solidarity of extension, of emotion, and of reaction. We could summarize this mutual communication of the organs with the words sympathy and synergy. We think we make a metaphor when we say, "I am suffering all over my body"; but we are only expressing the exact truth: when a part of the organism is suffering, all the other parts feel it by rebound, each according to its importance and its degree of organization. The cry of alarm that issues from the mouth is the translation to the ear of the alarm which is produced not in the brain only, but out to the smallest parts of the organism; it is the cry of an entire people which finds its life threatened. Expression is then a social phenomenon of sympathy and synergy, which is interior to the organism before extending to neighboring organisms.
Thus, we think, is explained the association of similar sensations with one another, and of sensations with emotions. Wundt has insisted upon these two psychological laws, while he has perhaps limited himself too much in establishing them. By virtue of the first law, analogous sensations are associated together; grave sounds have a relationship with somber colors; high tones with bright colors and with white. The sharp sound of the trumpet, and bright yellow and red, correspond. We say, with reason, that there are shrill colors, also that there are cold colors and warm. The reason of these existing
