Volume 24 includes six contributions, the author and paper index of volumes 1-24 and the key-word index. Since volume 23 included an index for volumes 16-23 the reader has the possibility to use these monographs as an encyclopedia and is in the position to find references to almost all fields of drug research. The editor hopes that the articles of the present volume will prove interesting and useful to many scientists and would be grateful to receive suggestions and opinions from readers, as in the past case over the 20 years in which this series of monographs has existed. In this respect, thanks are due to all colleagues who have provided helpful criticism of past volumes, thereby helping the editor in his work. Dr. A. Naf again has assisted the editor and has carefully reviewed all manuscripts, formulae and references, and has corrected the proofs. Thanks are due to him for this immense work. At the same time, the editor would like to thank the publishers and printers, Verlag Birkhliu­ ser, in particular Messrs. Th. Birkhliuser and C. Einsele, for the excellent cooperation and the work they have accomplished.