Treatises de modis significandi are known to have been a favorite genre of scholastic literature. One of them, by Martinus de Dacia, has lately been made the subject of a thorough study by Father Heinrich Roos, S.J., and will be briefly discussed in these pages. The text of this treatise, and commentaries on it, are found in a fairly large number of manuscripts, of which Fr. Roos presents a list, and which he endeavors to determine in their mutual relation in order to lay the groundwork for a future edition, apparently — as much as any one not himself familiar with the manuscripts can judge — with thoroughness and reliablity (chs. I, II). In some of the manuscripts and in certain other sources the treatise is ascribed to one Martinus de Dacia (Denmark). Very convincingly Fr. Roos demonstrates (ch. III) that this bit of information is correct and that the author was identical with a high-ranking Danish cleric of that name, who at one time was the chancellor of King Eric VI Menved. It is likely that Martinus composed his treatise while he was a professor in the Liberal Arts Faculty of the University of Paris, probably around 1250. The treatise seems to have enjoyed a great reputation, which would be accounted for if Fr. Roos is right in assuming that Martinus set the model for the entire type. In the last two chapters (IV, V) Fr. Roos describes the character and basic ideas of the tractate against the background of the development of scholarship and higher education during the Middle Ages. This historical outline is very interesting and instructive indeed. Nevertheless it provokes criticism regarding two interrelated points, namely, the characterization of scholastic grammar and its position in the history of linguistic studies.