The Plants and the Music. — The valuable contribute that the Biology may offer to the scientific study of the « essence » of the Music is pointed out. The plants as Animals and as remotest ancestors of the humanity, contribute to form what the A. calls the « Promusic », that is the natural and necessary starting-point of the evolution of the Music, which is exclusive work of the man. The Plants particularly, although indirectly, showing wonderful instances of transformations and associations of simple in complex forms, as well of colours and scents, have certainly inspired to the Man the Harmony, which is just in Music the Art, unknown to the Ancients, in associating aesthetically sounds and timbres.