Abstract
The net loss of plasma from blood into tissues within the ventilated reptile lung is 10 to 20 times greater than that in mammalian lungs. When blood flow is reduced during breathholding by reptiles, the plasma loss stops, and a net reabsorption of fluid from the tissues occurs. Fluid movement dynamics and the relative "dryness" of the lung of reptiles and mammals thus differ in several important respects and reflect the more variable cardiovascular performance of reptiles.