Volume VI SEPTEMBER, 1919 No. 1 



PHYSIOLOGK^AJ. PRE-DETERMINATION: THE 

 INFLUENC^E OF THE PHYSIOLOGICAL CONDI- 

 TION OF THE SEED UPON THE COUPvSE OF 

 SUBSEQUENT GROWTH AND UPON THE YIELD. 



V. PvEVIEW OF LITEPvATURE. CHAPTER IV. 



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

 Fellow of St John^s College, (Ja)iibridge, 



AND 



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



{Ii)tperud College of Science and Teehnologi/). 



(With Plate I.) 



PAGE 



Cha2)ter IV. The Effect of Conditions During CJerniination and 

 in tiie Early Seedling Stage upon Subsequent 

 Growth and Final Yield .... 1 



Introduction ......... 1 



Physical Treatments of the Seed: 



(a) High Temperatures ...... 3 



(b) Low Temperatures ...... 6 



(c) Electrical Discharge ...... 



(d) X-Rays 12 



Chemical Treatments of the Seed which do not obviously 



affect its Nutrition: 



(a) Acids ......... 13 



(6) Chemical' Agents other than Acids 



i. CuSOi 17 



11. Other Salts I'd 



ui. H2O2 22 



Conclusions 22 



CHAPTER IV 



THE EFFECT OF CONDITIONS DURING GERMINATION AND IN 



THE EARLY SEEDLING STAGE UPON SUBSEQUENT GROWTH 



AND FINAL YIELD. 



Introduction. 

 In the previous chapter of this review we (18) dealt with seed-treatments 

 which could be classed as treatments affecting nutrition. The pre- 

 determininp; effect of increased or decreased nutritional supply operating 

 for a limited period during the critical stages of early development was 

 demonstrated. The proportionaHty established between seedling weights 

 due to differential nutrition is maintained when the nutritional supply 

 Arm. Biol, vi 1 



