One of the many pleasures connected with the preparation of this monograph is that of expressing my gratitude to those instructors at Radcliffe College who have guided me. To Professor Sheldon and Professor Kittredge my indebtedness is very great for the advice that they have allowed me to feel might in times of perplexity invariably be had for the asking, and for the Share that they have assumed in the drudgery of proof-reading. Thanks are also due to Professor Robinson for occasional criticisms and sundry references to Celtic sources.