15. Cartoon for a St. Ann, lost but represented by sketches at Venice, 1503. 16. Madonna of the Distaff, represented by old copies. 17. Cartoon for Battle of Anghiari, only central group painted, partly represented by sketches and old copies, 1504. 18. Portrait of Mona Lisa, Paris. 19. Cartoon for a standing Leda, probably only the figure, since numerous old copies have widely varying accessories. 20. Madonna of the Rocks, 1507, London. 21. Cartoon for a Kneeling Leda, the figure only. Sketches and old copies. 22. Madonna and St. Ann, Paris. 23. St. John, half-length, Paris. All Leonardo’s main activity as a painter lies from 1470–1500. He painted a picture about every two years. Various sculptures have been ascribed to Leonardo. Of these only two, which will have been made in Verrocchio’s _bottega_ and under his direction, seem to me to deserve the distinction. A terra cotta Madonna and Child in the Metropolitan Museum, there ascribed to Verrocchio’s school, may represent Leonardo’s modelling about 1465. A stucco Madonna owned by Mr. George Diblee, at Oxford, is perhaps ten years later. The first is discussed by me in _Art and Archaeology_, Vol. IV, p. 122; the second is reproduced and accepted as a Leonardo by Prof. A. Venturi in _L’ Arte_, Vol. XXV, p. 131. Footnote 52: The best study of this picture and of its contemporary influence is that of George Gronau in _Zeitschrift für bildende Kunst_. N. F. Vol. XXIII, pp. 253–259. He fails to perceive that so primitive a picture as late as 1478 furnishes the best reason for accepting most of the rejected early Leonardos. Footnote 53: In all this matter Jens Thys’s admirable studies are indispensable. See note 5 above. Footnote 54: The Lady and the Ermine and the Belle Ferronnière are thoroughly discussed by H. Ochenkowski, _Burlington Magazine_, Vol. XXXIV, p. 186 _f._, where a full bibliography will be found. Footnote 55: This error which has persisted since Vasari was finally corrected by the great restorer Cavenaghi in his report of the last restoration. Malaguzzi Valeri in _Milano_, Bergamo, 1906, pt. 2, p. 14, first advanced the correct view that the painting was done in tempera. Footnote 56: Kenyon Cox, _Concerning Painting_, New York, 1917, p. 73. Footnote 57: _Fra Bartolommeo._ The standard work is Fritz Knapp’s _Fra Bartolommeo della Porta_, Halle, 1903. H. v. d. Gablentz, _Fra Bartolommeo_ in 2 vols., Leipzig, 1922. Footnote 58: _Andrea del Sarto._ H. Guinness, _Andrea del Sarto_, London and New York, 1901. Andrea’s drawings are finely analyzed by Bernard Berenson in _The Drawings of the Florentine Painters_. Footnote 59: _Bronzino._ Hans Schulze, _Die Werke Angelo Bronzino’s_, Strassburg, 1911. Footnote 60: