From the objects discovered at Hallstatt, the early period of Celtic art in the Iron Age is called by archæologists the Hallstatt period. It is succeeded by a later stage and higher development of ornamental art, exemplified in discoveries at La Tène in Switzerland. The period in which this higher development is found has been named the La Tène period; but the same stage of Celtic art is exemplified by objects discovered in the valley of the Marne in northern France, and the term "Marnian period" is used by French archæologists as an equivalent of "La Tène period." So far as I am aware these Marnian remains represent the earliest known substantial appearance of Celtic work, of Celtic activities of any kind, in the north-western parts of Europe. The La Tène or Marnian period is estimated to begin about 400 B.C., and not earlier than 500 B.C. This estimated date is an important part of the evidence that goes to establish the date of the Celtic migrations to Britain and Ireland. Before going more fully into the evidence, it is necessary to deal with the theory which at present holds the field in British archæology, and which is based principally on the authority of the late Sir John Rhys. So completely has his theory dominated, that we find it stated in summary in books for general instruction. I find a good exemplification in the volume on Lincolnshire of the Cambridge County Geographies, a series devised for school study and general information. The following paragraph purports to tell us how Britain was peopled before the Roman occupation: "We may now pause for a moment," says the writer, "to consider who these people were who inhabited our land in these far-off ages. Of Palæolithic man we can say nothing. His successors, the people of the Later Stone Age, are believed to have been largely of Iberian stock--people, that is, from south-western Europe--who brought with them their knowledge of such primitive arts and crafts as were then discovered. How long they remained in undisturbed possession of our land we do not know, but they were later conquered or driven westward by a very different race of Celtic origin--the Goidels or Gaels, a tall light-haired people, workers in bronze, whose descendants and language are to be found to-day in many parts of Scotland, Ireland, and the Isle of Man. Another Celtic people poured into the country about the fourth century b.c.--the Brythons or Britons, who in turn dispossessed the Gaels, at all events as far as England and Wales are concerned. The Brythons were the first users of iron in our country."