Publisher The characteristics of the particular spinal circuitry of which the Mauthner neurons are a part might well define the limits of probable functions of Mauthner cells. The richness of the neural inputs to, and interconnections between, the two Mauthner neurons in the brain is remarkable and intriguing; it has, however, to be interpreted with close regard to the findings in the spinal cord. Only then can a satisfactory estimation of the total functions of what may be called the Mauthner cell system be made. This chapter is largely based on data from a small number of species of teleost fish. Of course, Mauthner cell functions might well have developed in a variety of ways to suit the special needs of particular animal types. Based on experimental observations, the chapter provides a model schema of Mauthner cell function, which can be used as a basis for comparison and help to explain any apparently disparate appearances or functions of Mauthner cells in other piscine or amphibian species. Because of its particular specialization, the Mauthner cell system presents some rather striking examples of neuronal morphology and function, which may throw light on the behavior of neurons in general. The possible wider implications of selected features that seem clear and comprehensible are also discussed.