“…36 P SOCIETY, 14 JANUARY 1956 of the centres upon which these impulses impinge. Certainly, evidence does exist that pulsatile pressures are more effective in eliciting barosensory reflexes than non-pulsatile pressures of the same mean value (McCrea & Wiggers, 1933;Strauss, 1940). Recently Ead, Green & Neil (1952) found that on conversion of a steady flow through the sinus region to a pulsatile flow, blood pressure fell and the previous continuous discharge in monitored sinus nerve fibres changed into bursts of impulses at a higher frequency: the total number of impulses occurring in a given time sometimes remained unchanged.…”