1. The desire which prevailed in the early centuries of Christianity to imitate even the accidental features of the Apostolic system naturally suggested the adoption of the number _twelve_ in the adjustment of missionary societies. Thus we find it recorded that in Clonard the “Twelve Apostles of Erin” were educated. St. Columba set out about 562 A.D. with _twelve_ companions to convert the Picts. St. Columbanus with _twelve_ brethren left Ireland about 612 to undertake his great missionary work on the Continent. St. Killian was the chief of a company of _twelve_ who founded a monastic institution in Würzburg. St. Eloquius, disciple of St. Fursa, with _twelve_ companions whose names are preserved, propagated the Gospel in Belgium.[109] Thus except in the case of the founders of monasteries there is a very natural tendency to overlook the other workers, sometimes their names are not even recorded. 2. During the Danish incursions of the ninth and tenth centuries many of the Irish monasteries were destroyed and the monks went to Europe and set up monasteries wherever they settled. Sometimes they carried their books with them, but more frequently their libraries were burned or “drowned” by the pagan invaders who hated Christianity and learning, thus the Irish Annals and other documents are very defective as a means of supplying the necessary data for the compilation of a tolerably complete list.[110] 3. Even when the names of Irish missionaries are recorded in Continental MSS. there is often a difficulty in recognising an Irish name in its Continental dress. Many of the Irish monks who went abroad were “re-christened,” sometimes Biblical names like Joseph or Isaias were adopted, or the Irish name was latinized to make it more euphonious to Continental ears. Hence we find _Moengal_ figuring as Marcellus, just as _Maelmuire_ appears as Marianus and Mylerius, _Maelmeadhog_ as Malachy, _Giolla Iosa_ and even _Cellach_ become Gelasius, _Giolla an Coimded_ figures as Germanus, _Tuathal_ as Tutilo, _Domnall_ or _Donal_ as Donatus, _Aed_ as Aidan and Hugh, _Siadhal_ as Sedulius, _Cellach_ sometimes became Gall, while others chose to remain anonymous or describe themselves vaguely as _Exul_, or _Hibernicus_, or _Scottus_. In the Continental libraries there are many MSS. in Irish script and the scribes have concealed their identity in the vague manner just described.[111] 4. Naturally there were many others whose work was teaching rather than writing, consequently there is no record in such cases. Columba and Columbanus were lucky in having biographers but many others were less fortunate. GEOGRAPHICAL DISTRIBUTION OF IRISH MONASTIC SCHOOLS: We give a partial list of the better-known monastic institutions which were at one and the same time advance posts of civilization and centres of Christian learning. Many of these date from that great period of Irish missionary activity, the seventh century. SCOTLAND: