another have removed so many difficulties from my path. To two scholars, however, my debt is too extensive and general to have received adequate recognition in the footnotes. Mommsen's article, 'Die Conscriptionsordnung der römischen Kaiserzeit,' was written thirty years ago; I have, I hope, been diligent in collecting the evidence which has since accumulated, but I have found little to induce me to leave the path indicated by the founder of the scientific study of the Roman Empire. I own much to Professor A. von Domaszewski's ingenious and comprehensive work, Die Rangordnung des römischen Heeres, and feel my obligation to its learning and suggestiveness none the less that I have sometimes been compelled to differ from the conclusions stated in it. I am also deeply indebted to Professor Haverfield for constant encouragement and much valuable criticism, and can only wish that this essay were a more adequate testimony to the value of his influence upon the study of Roman history at Oxford. I desire also to express my gratitude to my colleague, Mr. N. Whatley, of Hertford College, for reading this essay in manuscript, and making many valuable suggestions.
New College, Oxford.
