In more than 300 sympathectomies or ramisections, at all levels, no matter how extensive, lasting vasomotor disturbance was not produced, restoration to pre-operative conditions being invariably the rule. Only 1 hypothesis seems possible; viz., that the regulation of local vasomotor activity is a peripheral manifestation, though the authors realize that a valid theory of vasomotricity can not be elaborated without the demonstration of degeneration after sympathetic neurotomy. Without proposing any general theory they believe that in view of these experiments the classical idea of a centrifugally directed vasomotor mechanism should be discarded.