1. The organization of the receptive field of each command neuron differed from the structure of the receptive fields of other command neurons. 2. The receptive field of the command-neuron system underlying defensive behavior was nonuniform in its structure. Specific regions were distinguished in the field that corresponds to ecologically important regions of the animal body where the neuronal reponse to tactile stimulation achieved the greatest magnitude, while the rate of habituation was least.