157 



For the first phase 



For the second phase 



Cal. 



0.0015 

 0.0117 

 0.0323 

 0.0598 

 0,0899 



%Diff. 



+31.8 

 -24.4 

 -13.7 

 + 0.2 

 + 6.9 



Probable % Diff. ±16.5?^. 



Probable % Diff. ±1.4?^. 



From these results,, it is evident that the agreement between calculated 

 and observed results is excellent. (Plate XVI.) 



SUMMARY. 



Thus, in the case of the growth of tree, it may be said that we 

 cannot consider the growth as illustrated by the autcatalytic reaction 

 only. In 1908, Robertson^ published in his work " On the normal rate of 

 growth of an individual and its biochemical significance " the proposition 

 that through any particular cycle the rate of growth is correlated in ac- 

 cordance with the formula: 



dy ^ 

 dt 



^y(A-y). 



I cannot, however, su"pport this proposition. In 1909, Enriques' proposed 

 in his work "Wachstum und seine analytische Darstellung" from the 

 biological point of view that the rate of growth is correlated in ac- 

 cordance with the formula: 



dy 

 dt 



=a+by+cy^ 



From my investigations, however, I arrived at the conclusion that through 

 any particular cycle the rate of growth accords with the formula: 



dy ^Q 1 

 dt f ' 



