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A QUANTITATIVE ANALYSIS OF PLANT GROWTH. 



PART I. 



By G. E. BRIGGS, M.A. (Cantab.), 

 FRANKLIN KIDD, M.A. (Cantab.), D.Sc. (Lond.), 



AND 



CYRIL WEST, A.R.C.Sc., D.Sc. (Lond.). 

 (With 9 text-figures.) 



PAGE 



Introduction ........ 103 



Chapter I. The Relative Growth-Rate Curve for Maize 106 

 Average Growth-Rate . . . .120 



Summary ...... 120 



Introduction. 



The quantitative analysis of plant growth is a branch of plant physiology 

 to which adequate attention has not as yet been paid, but which should 

 be able nevertheless to yield results of much theoretical interest and 

 economic importance. Methods for obtaining data for the analysis of 

 plant growth under ordinary cultural conditions are in genera] simple, 

 consisting principally of periodic dry- weight and leaf-area measurements, 

 and a quantity of excellent data of this nature has already been collected 

 and exists in the literature. As yet a thorough analysis of these results 

 has not been presented. Attempts have been made to fit in a few isolated 

 results with various empirical laws without wide examination of existing 

 data. 



For example it has been recently suggested by V. H. Blackman(i) 

 that the growth of an annual plant can be treated as a process following 

 the compound interest law expressed by the formula 



W = W e rt , 



where W = the dry- weight of the plant at time t, W = the initial dry 

 weight of the plant, r = the rate of interest or "efficiency index" of dry- 

 weight production, and e = the base of the natural logarithms. 



