D. Firth gives a comparison of the efficiencies of the gamma model when the errors are in fact log-Normal with the log-Normal model when the errors have a gamma distribution. With the exception of the intercept or constant term in the linear model, consistent estimates of the parameters and of their precision may be obtained by transforming to the log scale and applying ordinary least squares. By including a sufficient number of harmonic terms in the model, the mean deviance is reduced to a value close to unity, indicating a satisfactory fit. Consequently the simple Arrhenius model is unsatisfactory, even over small temperature ranges, as a description of the rate of development of Drosophila melanogaster. Since the reaction rate is inversely proportional to its duration, the Arrhenius model predicts a linear relationship in the graph of log(duration) against the reciprocal of absolute temperature.