At first, I have to thank Dr. STROHMEIER sincerely for his invitation to the fifth colloquium on variable stars.

After SHAPLEY recognized the variable stars as a very useful tool in obtaining the distribution of stars in the galactic system, Dr. HOFFMEISTER was one of the first to investigate the distribution of variable stars by the aid of series of photographic plates of selected regions in the Galaxy. At his observatory at Sonneberg he and his collaborators took many plates which were searched for variables and on which the brightness of these stars was estimated and their distribution studied. The results of these studies are published in a long series of papers in the Sonneberg publications.