Volume 26 of 'Progress in Drug Research' contains 10 articles, a subject index for this volume, an alphabetic subject index for volumes 1-26, and an author and subject index for all the volumes which have so far been published. The contributions of volume 26 cover a wide field of drug research and therapy, and some are directed towards tropical deseases. As in previous volumes, the authors have also tried not only to summa rise the current status of particular fields of drug research, but also to provide leads for future research activity. The articles in this volume will be of special value not only to those actively engaged in resolving the diverse problems in drug research, but also to those who wish to keep abrest of the latest developments influencing modern therapy. In addition, it is believed that the 26 volumes of "Progress in Drug Research" now available represent a useful reference work of an encyclo paedic character.