Although Christianity did not come officially from Rome to England until Augustine landed in A.D. 597, it had already found its way here indirectly during the Roman occupation. Obliterated by the pagan Anglo-Saxons, it had continued to flourish in Ireland, and the actual conversion of most of the English is believed to have been the work of Celtic Christians, who returned from Ireland and established missionary bases in Scotland and Northumbria. Their influence was so extensive that ‘Scotia’, the old name for Ireland, came to be applied to the country which we still know as _Scotland_. _Pat_ and _Taffy_, the popular nicknames for an Irishman and a Welshman, are descended from the Celtic saints, Patrick and David, and it is interesting to reflect that the Celtic missionaries were starting their work in Northumbria at almost exactly the same moment as St. Augustine landed in Kent. Thus Christianity enfiladed England, as it were, from both ends; and while the southern Anglo-Saxons were learning the Greek and Latin words to which we have referred, the Irish Christians in the north had been making the language a present of a few Celtic words, two of which—_druid_ and _lough_—have survived. Again, although the name for the instrument of the Passion comes to us ultimately from the Latin ‘crux’, yet the actual form which the word _cross_ has taken in our language is very largely due to these Irish Christians. But for them it would probably have been something like _cruke_, or _cruce_, or _crose_. This word has an interesting history. It was adopted from the old Irish ‘cros’ by the Northmen, and it is due to them that the final “s” took on that hissing sound which is represented in modern spelling by “ss”. We may suppose, therefore, that but for the Irish Christians the word would have been something like _cruce_, and but for the Northmen it might have been _croz_ or _croy_.