From the Greek settlement at Massilia (Marseille) two arts especially appear to have spread among the Celts of Transalpine Gaul: sculpture and the use of letters. The remains of Celtic sculpture in Gaul show evident signs of Greek origin. Cæsar makes the remarkable statement that the Gauls in his time use Greek writing in almost all their business, both public and private. The Romans of Cæsar's time had not long emerged, under Greek influence, from a state of comparative illiteracy, as every student of Latin literature must recognise. Among the spoils of the Helvetii captured by Cæsar, he found a complete census of the people written in Greek characters. Inscriptions in the Celtic language before the Roman conquest are in Greek characters, except in Cisalpine Gaul, where the characters are Etruscan. On the subject of ancient Celtic art on the continent, reference may be made to the book by Romilly Allen, from which also a good idea of the skill and taste of the Celts in metal work may be obtained. In general, it is clear that the Celts were a highly progressive people with a strong civilising tendency. Under the Druids, the western Celts developed a system of education and some kind of philosophy. With regard to their religion and to the part played by the Druids in Celtic life, I have summarised my own studies in a brochure entitled "Celtic Religion," which is published by the Catholic Truth Society of England. II. THE CELTIC COLONISATION OF IRELAND AND BRITAIN In the preceding lecture, I have claimed to show that, so far as positive knowledge goes, the period of Celtic expansion from Mid-Europe lies between the years 600 B.C. and 250 B.C. The spread of the Celtic peoples and of their power was arrested by a movement of German expansion on the north, beginning perhaps about 200 B.C., and by the growth of the Roman Empire, for which a starting point may be found in the final subjugation of Etruria, 265 B.C. I have also claimed to show that there was a large northward expansion of the Celts, resulting in a partial fusion of Celts and Germans, and that this Celto-Germanic population was afterwards for the most part, but not all, forced westward across the Rhine by the more purely German population, and was represented by the Belgae of Cæsar's time.