Leningrad, January 5-9, 1949 S. I. Vavilov opens the session. Speakers: L. S. Berg, V. V. Danilevsky. At the podium: A. E. Arbuzov, A. F. Ioffe, V. P. Nikitin, M. A. Shatelen and others. Meeting dedicated to the opening of memorial plaques to 10 great Russian scientists: I. A. Petrov, B. S. Jacobi, Chebyshev, I. P. Pavlov, V. I. Vernadsky, V. Karpinsky and others.