The rhythm which stimulated primitive men to speak in song, also impelled them to accompany it with gestures and movements of the body, and this was the origin of the dance, which, when the body moved in correspondence with cadenced utterances, was at first merely the accompaniment of song. Tradition, modern ethnography, and the primitive habits of children bear witness to this fact. In addition to the rhythmic motion of all parts of the body, there is the practice of spontaneously beating time with the hands and feet, which were doubtless the first instruments used by man as a musical accompaniment. Hence, owing to the facility of, construction, there arose percussion instruments, which were at first made of stone or pieces of wood. So that singing, dancing, accompaniment with the limbs or with some rudely fashioned object arose almost simultaneously, as soon as the process of specification had established a distinction between song and ordinary speech. The first simple instruments which we have described only made the song, shout, war-dance, or religious ceremony more effective. When chanted speech was formulated in a fixed order by means of rhythm and the modulations of the voice, it became verse, and the melody itself, as the simple expression of the song which had been cast into verse, or even into an inarticulate chant, was naturally evolved from it. An artistic education is not needed in order to experience the pleasure of rhythmic order in the succession of sound, for a predisposition of the nervous system will suffice. Savages, children, and even animals are sensible of rhythm, which is the order and symmetry of sensations. The dance, as Beauquier justly observes, is the practical form of rhythmic motion and the gesture of music. The motion impressed by sound on the internal organism tends to manifest itself in external gesture, and in fact, the rhythm of the music is repeated in dancing in the limbs and in the whole body of the dancer. The rhythm, regarded in its material cause, need not be accompanied by any very musical sound. The percussion instruments were at first only used to mark and intensify the rhythm.