In the domain of Spanish letters, where the earnest student of literary history still finds himself lacking many necessary tools, there is a crying need of a new and critical edition of the works, and particularly the poetical works, of the monk Luis de León. One of the greatest of the Castilian lyric poets,—and, as such, a fellow to Garcilaso de la Vega and Herrera,—one of the most eminent among the masters of flexible and harmonious Spanish prose, which flows from his pen with none of the customary turgidness, he is best represented to-day only by the meritorious but rare edition of his works published by Merino in the early years of this century, and by the unsatisfactory edition of the Biblioteca de autores españoles, Tome XXXVII, which has not made the proper use of Merino's collection.