Fig. 3. (A) A straight line was fitted by ordinary least squares to log-transformed data for mammals weighing less than 260 g. (B) A straight line was fitted by ordinary least squares to log-transformed data for mammals weighing more than 260 g. (C) A two-parameter power function was fitted by non-linear regression to values for metabolic rate and body mass for mammals weighing less than 260 g. (D) A two-parameter power function was fitted by non-linear regression to values for metabolic rate and body mass for mammals weighing more than 260 g. (E) Equations fitted to data for small mammals by non-linear regression (solid black line) and back-transformation (dashed red line) are displayed against the backdrop of values in the original scale. (F) Equations fitted to data for large mammals by non-linear regression (solid black line) and back-transformation (dashed red line) are displayed against the backdrop of values in the original scale.