Monday, March 13.

PRESIDENT AND FELLOWS OF HARVARD COLLEGE. Meeting at No. 50 State street, Boston, 10.30 A. M.

SEMINARY OF ECONOMICS. "Marx's Theory of Value," Mr. F. W. Johnston. University 23, 4.30 P. M.

*ZOOLOGICAL CLUB. "The Marine Biological Laboratory of the Carnegie Institution at Tortugas, Florida; its Aims and Problems," Dr. Alfred G. Mayer, Geological Lecture Room, 4.45 P. M.

**PHYSICAL COLLOQUIUM. "Radio-active Change," Mr. Hodge; "The Secondary Spectrum of Hydrogen," Dr. Lyman. Jefferson Physical Laboratory, Room 25, 5 P. M.