The second to be called either “Mediæval,” or more properly “Christian Art.” This again subdivides itself into three easily-understood divisions. 1. The Byzantine or Eastern Christian style; 2. The Romanesque or transitional style which prevailed between the Roman and the Gothic styles; and 3. The Gothic or western Christian style. The Byzantine style comes first because its development was so rapid that already in the 6th century it had reached its culminating period, and throughout the Middle Ages it exercised considerable influence in various parts of Italy and France; an influence the extent of which it is only possible to follow after its study. It is difficult, for instance, to understand the churches in Ravenna or St. Mark’s in Venice, or the churches at Périgueux, and in the Charente, until the churches of Sta. Sophia and of St. Sergius, Constantinople, and of St. Demetrius, Thessalonica, have been studied; and although it is advisable when describing the style to carry it through its later developments in Greece, in Russia, and in the East, these variations and developments are not of a nature to distract the reader or cause him to lose sight of the leading characteristics of the style. There is some difficulty in knowing where to draw the line between the Romanesque and the Gothic style; as generally accepted now, the term Romanesque includes all the round-arched Gothic styles, and although many of the leading principles of Gothic work are to be found entering into buildings constructed prior to the introduction of the pointed arch into transverse and diagonal ribbed arch vaulting, it was this latter which led to the great development of the Gothic style in France, England, and elsewhere in the 12th and 13th centuries. The third great division of the subject I would suggest might conveniently be denominated “Pagan.”[21] It would comprise all those minor miscellaneous styles not included in the two previous divisions. Commencing with the Saracenic, it would include the Buddhist, Hindu, and Chinese styles, the Mexican and Peruvian, and lastly that mysterious group which for want of a better name I have elsewhere designated as “Rude Stone Monuments.”[22] No very consecutive arrangement can be formed for these styles. They generally have little connection with each other, and are so much less important than the others that their mode of treatment is of far less consequence. Nor is it necessary to attempt any exact classification of these at present, as, owing to the convenience of publication, it has been determined to form the Indian and allied Eastern styles into a separate volume, which will include not only the Buddhist and Hindu styles, but the Indian Saracenic, which, in a strictly logical arrangement, ought to be classified with the western style bearing the same name. The styles of the New world, having as yet no acknowledged connection with those of the Old, may be for the present treated of anywhere.