Volume V JULY, 1918 No. 1 



PHYSIOLOGICAL PKE-DETERMINATIONi: THE IN- 

 FLUENCE OF THE PHYSIOLOGICAL CONDITION 

 OF THE SEED UPON THE COUPxSE OF SUBSE- 

 QUENT GPvOWTH AND UPON THE YIELD. 



I. THE EFFECTS OF SOAKING SEEDS IN WATER. 

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



AND 



CYRIL AVEST, D.Sc. (Lond.), F.L.S. 

 (With Plates I and II.) 



INTRODUCTION. 



In a survey of the literature of the last fifty years dealing with the Seed 

 it is interesting to note that attention has been almost entirely con- 

 centrated upon the question of germination. The effect upon germination 

 of every manner of treatment and of every sort of condition has been 

 investigated in the case of the seeds of a great range of cultivated and 

 wild plants. 



In only a very few cases has attention been directed upon the question 

 suggested by the title of this paper, namely, as to how far the physio- 

 logical condition of the plant in the seed-stage {i.e. in maturation, 

 dormancy and germination) may exert a pre-determining influence upon 

 the whole subsequent course of growth and development. It is obvious 

 from the point of view of crop production that this question as to the 

 quality and size of the plants produced from- any sample of seed may 

 be even more important than the question as to what percentage of the 

 sample is capable of germination. The degree of importance to be at- 

 tached to this question appears when it is said that the yield from an 

 equal number of plants of a pure line may vary to an extent of 50 per 



1 Balls, L. W. 'The Pre-Detcrmination of Fluctuating Characteristics," Proc. Cnmhrkhjp 

 Phil. Soc., 1914; also, 'Analyses of Agricultural Yield,' Part iii; 'The Influence of Natural 

 Environmental Factors upon the Yield of Egyptian Cotton,' Phil. Trans. lio;/. Soc. (Lond.), 

 B, 208, 1917. 



Ann. Biol. v. 1 



