PERIODIC * breathing, as it occurs classically in Cheyne-Stokes respiration or in such variants as Biot's breathing, came to be recognized clinically almost at the same time that the early experimental studies on the course and regulation of breathing began to emerge from the physiological laboratories of the 19th century. Then, as now, this dramatic alteration in the usual pattern of breathing demanded explanation in terms of the fundamental physiology of the genesis and control of respiration and has reflected since then the succession of hypotheses and the swings of emphasis and of interest in this sphere.
The experimental basis for a revised concept of the neurophysiology of breathing has recently been established through the analysis of breathing patterns in a total of more than 350 dogs and 50 cats, studied in the normal unanesthetized state, after a series of transections of the brain stem ranging from hypothalamus to medulla, and