A book intended for psychologists and ethologists working on animal behaviour, psychopharmacologists and neurobiologists interested in the simple nervous system and advanced undergraduates in animal behaviour courses. This series aims to serve the increasing number of scientists who are engaged in the study of animal behaviour by presenting theoretical ideas and research to those in this as well as neighbouring fields. Traditional areas of animal behaviour research have achieved new vigour through the links they have formed with related fields and the closer relationship that now exists between those studying animal and human subjects. While the recent rise of behavioural ecology and sociobiology has tended to overshadow other areas, scientists studying behaviour today have a broader background, from ecologists and evolutionary biologists to geneticists, endocrinologists, pharmacologists, neurobiologists, and developmental psychobiologists, not to mention the ethologists and comparative psychologists for whom this subject is prime domain. The series does not focus narrowly on one or a few of these fields, but features articles covering the best behavioural work from a wide spectrum, as is well-illustrated by the range of articles in this volume. The skill and concepts of scientists in such diverse fields necessarily differ, making the task of developing co-operation, and communication among them a difficult one. But it is one that is of great importance, and one to which the editors and publisher of "Advances in the Study of Behaviour" are committed.