The Mechanism of Enzyme Actions.

The Mechanism of Enzyme Actions: DR. K. GEORGE FALK .................................. 471 Obituary: Michael Idvorsky Pupin: PROFESSOR A. P. WILLS 475 Scientific Events: Annual Meeting of the Trustees of Science Service; Annual Meeting of the American Academy of Arts and Sciences; Betirement of the Secretary of the Zoological Society of London; Award of the Daniel Guggenheim Medal for Aeronautic Achievement to William Frederick Durand; Recent Deaths ............ 479 Scientific Notes and News ............................................. 481 Discussion: Foreign Geographic Names: DR. EUGENE VAN CLEEF. Further Attempts to Grow -Chilomonas paramecium in Inorganic Media: J. B. LOEFER and PROFESSOR R. P. HALL. Shall Smoky Cities Go Treeless?: PROFESSOR H. B. MELLER and L. B. SIssoN. The William Herbert Centennial: DR. HAMILTON P. TRAUB. The Ganesh Prasad Prize: PROFESSOR DAVID EUGENE SMITH .......................................... 484 The American Association for the Advancement of Science: Minutes of the Executive Committee Meeting: DR. HENRY B. WARD .............................................. 487 State Academies: The Pennsylvania Academy of Science: DR. BRADFORD WILLARD. The Alabama Academy of Science: PROFESSOR P. H. YANCEY. The Tennessee Academy of Science: PROFESSOR J. T. MCGILL. The Minnesota Academy of Science: PROFESSOR H. K. WILSON ................. ............................ 489 Scientific Apparatus and Laboratory Methods: On an Arrangement for Studying the Conditions within Diffusion Layers: DR. TORSTEN TEORELL. A Simple Beliable Time Clock: DR. G. B. RAY and H. LEWINE ............................................ 491 Special Articles: Mutation Rate from Old Datura Seeds: DR. J. L. CARTLEDGE and DR. A. F. BLAKESLEE. The Relation of Water and Electrolytes to Metabolism: Da. HARRY A. DAVIS. Calcifying Factors in the Diet of Salamander Larvae: DR. ESTHER M. PATCH .......492 Science News ........................................... 6