Fig. 5. Flexible response of the liver to feeding measured from ultrasonographs. Multiple measurements of each individual were averaged by individual and day; to account for size differences among individuals, measurements are expressed relative to the size (cross-sectional diameter) of the liver of each individual on the day before the experiment started. Values are means ± S.D. from the four snakes in each group. Dotted lines indicate feeding events. (A) Fasting snakes, open symbols; (B) snakes fed every other day, black symbols; grey symbols are for snakes that did not feed; (C) snakes fed once a week, grey symbols.