The factors in rhythmic activity of the nervous system

In a communication upon the intrinsic factors in progression presented to the Society in July of last year the author drew the conclusion that the rhythm of progression is of central origin. In then enquiring into the nature of that central origin Re suggested that the movements are determined by a balance between equal and opposite states of excitation—flexion producing and extension producing. An obvious line of research is thus presented by the possibility that reflex stimuli which normally evoke opposite reactions (flexion and extension), that is, opposite states (of excitation and inhibition) in one and the same centre, when applied at the same time and with appropriate strengths of stimulus may give a rhythmic response.