Many learned works on the subject of Greek Sculpture have been written in various languages. Three standard authorities are the English work by A. S. Murray, "History of Greek Sculpture," second edition, London, 1890; the French work by Collignon, "Histoire de la Sculpture Grecque," Paris, 1892; and the German work by Furtwängler, translated into English by E. Sellers, "The Masterpieces of Greek Sculpture," London, 1895. Naturally these three writers are not always of one opinion, and the student must turn from one to another to learn all the arguments concerning a disputed point. For the practical every-day use of the reader who has no time to sift the evidences on difficult questions of archæology, Gardner's "Handbook of Greek Sculpture" is an excellent outline summary of the history of the subject. Charles Waldstein's "Essays on the Art of Pheidias," New York, 1885, is an exceedingly valuable and suggestive volume. Two small books, written in a somewhat popular vein, make very pleasant reading for those pursuing these studies: "Studies in Greek Art," by J. E. Harrison, London, 1885, and "Greek Art on Greek Soil," by J. M. Hoppin, Boston, 1897. Besides the works devoted exclusively to the subject of Greek sculpture, the subject receives due attention in various general histories of art, of which may be mentioned, Lucy Mitchell's "History of Ancient Sculpture," Lübke's "History of Sculpture," and Von Reber's "History of Ancient Art." A valuable bibliography is given in Gardner's "Handbook." III. HISTORICAL DIRECTORY OF THE MARBLES REPRODUCED IN THIS COLLECTION. _Frontispiece._ Terminal bust of Pericles, after an original by Cresilas. Approximate date, 440-430 B. C. In the British Museum, London. 1. _Bust of Zeus Otricoli._ Considered by Brunn and others a copy from a head of the statue by Phidias. Later critics do not agree with this opinion, and Furtwängler calls the head a Praxitelean development of the type of Zeus created in the time of Myron. Now in the Vatican Gallery, Rome. 2. _Athena Giustiniana_ (_Minerva Medica_). Considered by Furtwängler a copy, after Euphranor, of a statue dedicated below the Capitol, called Minerva Catuliana, set up by A. Lutatius Catulus. The ægis and sphinx are copyist's additions. Found in the gardens of the convent of S. Maria sopra Minerva, Rome. Both arms are restored. Now in the Vatican Gallery, Rome.