Dendrographs attached to the lower boles of large trees of several species indicated little change in diametral fluctuation patterns following decapitation or severe mechanical interruption of conducting tissues. Treated and undisturbed stems of a particular species, investigated concurrently, manifested striking similarities in the amount, trend, and duration of diameter shrinkage. The results of these experiments, in company with others dealing with continued moisture movement in experimentally treated trees, jointly suggest that the water-conducting system of large wood stems is one of great coherency and stability.