During the last two decades many investigators-Kussmaul, Stumpf, Preyer, Oppenheim, Knoblouch, Charcot, etc.—have conclusively demonstrated that the musical faculty is older than that of speech; that music is a primary and simple phenomenon, while speech is secondary and complex. It is a well-known fact that many birds possess the faculty of producing and reproducing themes, whereas there are but very few that can reproduce the human voice, even after a long tutelage. According to Darwin, wild dogs and jackals howl and learn to bark only after they have been domesticated. Their howl corresponds to song, and their barking to articulated speech. Owen has heard a gibbon sing an octave up and then down the scale. Stumpf relates that his child, 9 months old, could sing two tones, and when 14 months old a full octave. Preyer testifies that children between 8 and 9 months old could correctly sing a tune