FEW SURVIVING INSTITUTIONS are born of artists self-organizing in times of extreme stress. On February 15, 1931, in the depths of Poland’s interwar depression and deeply uneven modernization, Katarzyna Kobro and her husband, Władysław Strzemiński, attended the opening of a room in the new municipal museum of Łodz, an industrial city two hours southwest of Warsaw. Though “room” might sound modest, this particular one became central to the story of European modern art: Here, Kobro and Strzemiński, together with friends and colleagues such as Henryk Stażewski, presented the International Collection