the middle ages, when the conversion of nations was effected or introduced by a few individuals as St. Patrick in Ireland, St. Columba in Scotland, St. Augustine in England, St. Boniface in Germany, St. Ansgar in Scandinavia, St. Cyril and Methodius among the Slavonic races. There were no missionary societies, no missionary institutions, no organized efforts in the ante-Nicene age; and yet in less than 300 years from the death of St. John the whole population of the Roman empire which then represented