The tracery which decorates the thrones of the chessmen is a small example of the elaborate interlaced scroll-work, which is a leading feature in Keltic and Anglo-Saxon work. In the manuscripts it is often reduced to a series of calligraphic flourishes, but it also develops into serpents and dragons inextricably woven together, and, later, more varied animal forms are introduced and even human figures are seen crushed in the serpentine rings. Forms from vegetation are rarely seen, and the introduction of the acanthus into these intricacies is due to the Carlovingian scribes of the ninth century and may be seen in the Bible written for Charles the Bald. Several objects decorated with the earlier forms of this wild tracery are found in the great abbeys of Germany and Eastern France, and are thought to have been made in Great Britain or Ireland and brought over by the throng of missionaries who flocked on to the continent to convert the wild tribes of Frisia, Germany and Switzerland, bearing with them culture and learning. Little Ireland in early days was a centre of artistic diffusion, almost more important for the Northern nations than that of Constantinople. Owing to freedom from invasion, Christianity and civilization had continued to flourish and the remnant of the old Latin literature was carefully preserved. Not long after the death of St. Patrick, the Irish Church, having increased in strength and learning, sent forth the famous St. Columba to minister to the hordes of barbarians who were over-running Britain. St. Columba met with great success and founded several large monasteries which became powerful centres of religion and learning in Scotland and England. For hundreds of years the schools of Ireland continued in great repute, numerous bands of missionaries were sent across the sea to convert the Germanic tribes on the continent. Most famous among these was St. Columbanus, who laboured in the East of France for many years, and afterwards in Switzerland and Italy, dying in 615 at the monastery he had founded at Bobbio. Everywhere these monks went they took with them the seeds of art and learning, beautiful illuminated manuscripts and other small works of art, which formed an inexhaustible store of _motifs_ for the sculptors and goldsmiths of the following centuries. One of the disciples of Columbanus, St. Gall, who was called the “Apostle of Switzerland,” founded there the great monastery named after him, which became a most flourishing art centre in later years. The Anglo-Saxons were not idle, and in the eighth century St. Boniface and many others pierced far into the wild forests of Germany, founding the great monastic establishments which exist to this day. This was not a fleeting movement, but a close relation was kept up between England and the continent till well into the eleventh century. III. THE CARLOVINGIAN RENAISSANCE.