Fig. 6. The relationship between phospholipids and cholesterol in pulmonary surfactant from the developing lung of the snapping turtle, demonstrating (A) disaturated phospholipids (DSP) expressed as a percentage of total phospholipids (PL), (B) the cholesterol (Chol)/PL ratio and (C) the Chol/DSP ratio. Values are means ± S.E.M. Paired symbols indicate a significant difference between adjacent groups. (A) *P=0.019, (B) *P=2.6x10^–4, (C) *P=3.2x10^–4.