Originally published in 1959, this book contains the noted discussions of the second conference on the co-ordination of galactic research, held at Saltsjoebaden, near Stockholm, in June 1957, by the International Astronomical Union. 'The editorial work in preparing the present report has been shared by six of the participants of the conference' and 'in accordance with a decision taken at the Stockholm conference, an attempt has been made to present the material in the same way as the report of the Groningen conference of 1953'. Notably, the differences in how the editors have presented the material 'add a certain variety in the way of presentation of the subjects'. Topics are detailed and varied; topic titles include, 'Clusters and associations', 'Spiral structure' and 'The magellanic clouds'. This book, containing symposium number seven, will be of significant value to anyone with an interest in astronomy, cosmology and the history of physics.