Introduction

Abstract

Textbooks of comparative physiology tend to begin with biochemistry and stop short of a discussion of animal behaviour. Their authors are obliged to handle things the way they do because they are hunting for statements that can be made about animals generally, and the further one proceeds towards the molecular basis of life, the easier it seems to be to do this. Their problem is how to hold things together after the first few chapters. Krebs cycle and the genetic code seem to apply to all of us, but the attempt to compile a universal story begins to go to pieces and the account becomes little more than a catalogue as soon as contact is made with the great range of solutions that have arisen at an organ rather than at a cellular level. The eyes, brains, guts and motor systems of animals always seem to include features unique to the creature in question which one could hardly expect to predict simply from a knowledge of its cell biology. Why was the basic molluscan design extended in the particular ways that we find in an octopus? Chemistry cannot tell us. But perhaps behaviour can. This is why this book, unfettered by the need to be comparative, includes much about behaviour, and rather little about biochemistry. If we examine the behaviour of cephalopods now, and the probable behaviour of cephalopods in the past, we can come a long way towards understanding their present structure and physiology.