[The mechanism of pleural liquid transudation and absorption following a new hypothesis].

We have put forward a hypothesis that the pleural fluid is filtered at the arterial ends of the pleural blood capillaries and is absorbed mainly at the venous ends, partly at the lymphatic channels, as it is in the other tissues. Then we have calculated the pleural liquid pressure following the Starling equation applying the ordinary value of factors. The result is that the calculated pleural liquid pressure is low enough to expand the lung.