of harmonies as representing another key centre, and this made an orderly succession of key centres the new basis of organization. Then the human mind grew to be able to discern these principles of order when composers dispensed with the sounding of the concrete harmonies and only represented them by ornamental procedures; through which the trained mind can perceive and infer the groups of harmonic successions which are implied and recognize the respective keys to which they belong. Complication yet further expanded the basis of organization as composers approached what may be called the extreme of sophistication, which became attainable by a reversion to the linear system, in which harmony was again suffused by polyphonic methods, and the individual notes of the ornamental formulas themselves are made to represent centres of activity and have their own harmonization; which harmonization subsists in spite of its apparent clashing with the harmonization of other ornamental notes, which the mind is able to endure because it intellectually segregates the notes which represent different systems and allots them to their respective centres and so keeps them apart from one another. The superimposition of device upon device is like a perpetual budding from a germ cell, with the additional analogy to things physical, that each generation is always consistent in its characteristics and identifiable. The quickness of the human mind at grasping the especial type of organization which it has to accept, in order to follow the idea of the composer, is one of its most extraordinary capacities; as is the development of the art which enables the adequately equipped composer to be sure that his most subtle sophistications are sure to meet with understanding from the auditors who are equally well equipped. When an ignoramus looks at a full score of any big modern work and sees there the hundreds of notes that are to be sounded in a few seconds, and sounded also for the fraction of a second and no more, most of which are not harmony notes but only suggest them by the way they are grouped, and yet convey to the qualified auditor a perfect sense of orderliness and coherence, it will either give him the sense of the amazing development of art and of human capacity to follow what is offered to it as art, or incredulity, in accordance with his temperamental bias.