The first volume in this series appeared in 1977, the second in 1980. From these volumes and the present one, some research trends in chemical communication can be perceived. In the 1977 volume, studies on 13 animal taxa were reported. In the present volume, the number is 25. This taxonomie diversi- fication of research since the first volume of this series demon- strates the wide variety of ecological adaptions, although no new general principles...