University Calendar.

Wednesday, April 6.

**ZOOLOGICAL CLUB: Inhibition and Reinforcement of Reaction in the Frog. Dr. R. M. Yerkes.--Short Papers. Room 1. fourth floor, Museum of Comparative Zoology, 4.45 P. M.

**TRAVELLERS CLUB. Practical Talk on Mountaineering. (Illustrated.) Professor Charles E. Fay, of Tufts College. Harvard 1, 8 P. M.

*DUDLEIAN LECTURE. The Roman Catholic Church and the Modern Sense of Nationality. Rev. Professor A. V. G. Allen. Lecture Room of the Fogg Museum, 8 P. M.

HAMLET ON AN ELIZABETHAN STAGE. Mr. J. Forbes-Robertson. Sanders Theatre, 8 P. M. Admission by ticket only. Tickets, at $2.00 and $1.50, for sale at Sever's Bookstore, Cambridge, and at Herrick's Copley square, Boston.