Abstract
1. The changes in lymphatic pressure in a limb whose circulation was temporarily arrested with a pneumatic cuff have been studied.2. Stimulation of the lumbar sympathetic chain caused an increase in lymphatic pressure. It has been shown that this is a primary not a secondary phenomenon, due to an active lymphomotor mechanism.3. The increase of lymphatic tone is proportional to the rate of stimulation; peak values are reached between 5 and 9 impulses/sec.