Having shown that at the time when Christianity was introduced into Britain the native population, totally unacquainted with practical masonry, were yet expert and experienced manufacturers of highly ornamental baskets; and suggested the reasonable probability that they would employ their best talents in the service of their new religion, as they had previously devoted them to their earlier Pagan or Druidical superstitions, I proceed to offer some reasons for believing that the first crosses erected by Christian missionaries in Britain, Ireland, and the Isle of Man, were constructed of plaited osiers. Many of the Mediæval biographers narrate with much minuteness the particulars of stone crosses set up by Christian bishops; but no such notices occur before the sixth century, and from the great importance attached to them by the monastic historians, it is evident that they were objects of extraordinary interest, and moreover, of _exceptional material_. Such crosses were erected by St. Columba, St. Oswald, St. Cuthbert, Bishop Ethelwold, and other holy men. Of St. Kentigern—better known in Scotland as St. Mungo—it is said that, among many crosses which he put up, one in the city of Glasgow was taken from the quarry by his orders, and, by the united efforts of many men, erected in the cemetery of the Church of the Holy Trinity, in which his episcopal throne was set up. That this particular cross was of more than usual importance may be inferred from the statement of his biographer, that it was the custom of St. Kentigern to erect a cross in any place where he had converted the people, or had for a time resided. Such crosses, therefore, must have been executed by some less laborious process than was used for the one which he erected near his cathedral about the end of the sixth century, and which is said to have still marked the spot where the original edifice stood, when the Cathedral of the West was reconstructed five hundred years afterwards. But St. Kentigern erected one other cross, which demands the attention and consideration of archæologists. We are informed that at Locherward, a parish in Mid-Lothian now called Borthwick, he set up a cross constructed of _sea sand_. There is no hint of any miraculous assistance in the erection of this cross, and therefore we are constrained to look for some mechanical appliance by which sea sand could be made to cohere in the form of a cross.[23] But first I may be permitted to suggest a possible motive for the adoption of a material so unstable, and apparently so little fitted for the purpose.