The development and present status of arachnology at the Senckenberg-Museum (Frankfurt) are critically reviewed. Extended periods of care and maintenance were followed, from 1955 onwards, by flourishing decades, including considerable enlargement of the collections. One of the most complete libraries in the field originated from this time. Progress culminated in the arrangement of meetings and finally of international congresses, including the foundation of what is now the International Society of Arachnology (formerly C.I.D.A.). Data on some relevant authors such as Roewer and Wiehle are included
