Some Remarks on the Methods Formulated in a Recent Article on “The Quantitative Analysis of Plant Growth.”

S ummary The methods of calculation formulated by Briggs, Kidd and West for the analysis of plant growth are inaccurate, (i) in introducing a large exaggeration when the plant is increasing in mass, (ii) in applying to periods of varying length a method of calculation which thereby becomes self‐inconsistent. The correct measure for the mean value of the relative growth rate over any period, long or short, is that advocated by Blackman under the name of the “efficiency index.”