In this case all three effects were valid when comparing homogeneity of variance using Cochran test. Therefore temperature, pH and the interaction between temperature and pH are confirmed by the analysis to have significant effects on oxygen consumption. Although oxygen consumption was not significantly different between pH 8 and 7.5 at any temperature tested, it was significantly elevated above these pHs at 7. [ Stat a few values – read these off from the figure]. Oxygen consumption increased with temperature at all pH between 24 and 40. The greatest oxygen consumption at 40C was 320 mg/h (per snail) (check).