My principal source of information concerning Weier-strass's theory has been the course of lectures on the Calculus of Variations of the Summer Semester, 1879, which I had the good fortune to attend as a student in the University of Berlin. Besides, I have had at my disposal sets of notes of the courses of 1877 (by Mr. Gr. Schulz) and of 1882 (a copy of the set of notes in the ''Lesezimmer'' at Gottingen for which I am indebted to Professor Tanner), a copy of a few pages of the course of 1872 (from notes taken by Mr. Ott), and finally a set of notes (for which I am indebted to Dr. J. C. Fields) of a course of lectures on the Calculus of Variations by Professor H. A. Schwarz (1898-99). - Oskar Bolza