The initiative in the organization of the conference was taken by the President of Commission 33 of the International Astronomical Union and financial aid was received from U.N.E.S.C.O. At the invitation of Dr P. J. van Rhijn, Director of the Kapteyn Astronomical Laboratory, Groningen, the meeting was held in the estate ‘Vosbergen’ near the city of Groningen and owned by the University of Groningen. The organizing committee consisted of J. H. Oort (Chairman), W. Baade, B. J. Bok, Ch. Fehrenbach, B. Lindblad, W. W. Morgan, P. P. Parenago, and A. Blaauw (Secretary), all of whom attended the conference. The other participants, who were invited either because they represented institutions which might take part in future galactic research, or because of the character of their research, were V. A. Ambartsumian, W. Becker, P. Couderc (representing the Commission for the Carte du Ciel), G. Haro, O. Heckmann, H. Spencer Jones, B. V. Kukarkin, J. J. Nassau, P. Th. Oosterhoff, L. Plaut (local Secretary), J. M. Ramberg, C. Schalen, J. Schilt, R. H. Stoy, B. Strömgren, P. J. van Rhijn. V. Kourganoff, P. G. Kulikovsky and O. A. Melnikov were present as interpreters.