SummaryA pressure‐box was used to reduce mean perfusion pressure in the upper limb. Pressure‐flow curves for the skin of the hand and forcann were‐ constructed under a variety of conditions. The blood flow to the skin of the forearm was examined by plethysmosraphy before and after adrenaline ionto‐ phoresis, after alterations to the local thermal environment and after body‐ heating. The skin of the hand was examined by the latter two technique's and by heat‐flow discs. No evidence was fonnd for antorcgulation of blood flow in skill under any of these circumstances.