The Effect of the Pulse upon the Formation

I t is well known that massage and muscular movement increase the formation and flow of lymph (1-4). Undoubtedly pressure changes in the tissue are largely responsible. Nevertheless, the mechanism of lymph formation under such circumstances is not understood. Clearly the solution of the problem waits upon a better understanding of the factors influencing the extravascular transport of fluids through the tissues. I t has seemed wise in view of these findings to investigate the influence of the most natural of mechanical effects, that of the pulse wave, upon the formation and flow of lymph and the spread of substances through the tissues. The thought has suggested itself that the pulsations of vessels must serve, not only to facilitate the escape of substances from the blood, but to increase their spread through the tissues following their escape and, by an internal massage, as it were, to promote lymph formation and flow.