Functional Components of Systems Controlling Behavior in Some Primitive Animals

The ultimate goal of a behavorial physiologist is to erect a complete, causal explanation for the total behavior of the organism which he is studying. The nature of the explanation which would be considered adequate depends to a large extent on the interests of the investigator and the level at which he works. For a behaviorist an acceptable explanation might be composed of concepts such as drives, consummatory acts and innate releasing mechanisms, while an electrophysiologist might want an explanation in terms like spike initiating loci, accommodation, and excitatory post-synaptic potentials. But at any level the goal of completely explaining the behavior of an animal is in most cases rather unrealistic. The complexity of the behavior of most animals precludes the possibility of complete analysis, at least in the near future, and investigators generally must content themselves with analyzing portions of the total behavioral repertoire; treating subsystems which ideally are complex enough to be interesting yet simple enough to be analyzable. The results considered in this paper come from work with coelenterates, animals which I feel are exceptional in that a complete analysis of their behavior is perhaps not an unrealistic goal.