The Relation of Animal Size to Oxygen Consumption in Some Fresh-Water Turbellarian Worms

Abstract

1. A size factor is demonstrated for the oxygen consumption at 14.5° C. of four species of fresh-water Turbellaria obtained from different habitats. 2. For three of the species studied (Polycelis cornuta, Crenobia alpina and Planaria polychroa) small animals were found to have a higher oxygen consumption per unit weight than large ones. In the case of Polycelis nigra small animals were shown to have a lower oxygen consumption per unit weight than large ones. 3. The adherence of the size factor to the surface law of Rubner is discussed. Only Crenobia alpina satisfies the theoretical requirements of the law, and in this species it is shown that the size factor is practically unchanged when the oxygen consumptions are determined at 7.0° C. instead of 14.5° C.