98 



The Ohio Journal of Science [Vol. XXI, No. 3, 



5. There is also a general correlation between the H ion 

 concentration and the relative activity of diastase and maltase 

 and the consequent concentration of glucose and maltose in the 

 tissues. The optimum H ion concentration for diastase is 

 somewhat more acid than for maltase. 



6. Maltose is most abundant and glucose is least abundant 

 in summer and autumn, when acidity is highest and nearer 

 the optimum for diastase than for maltase. On the other 





3.0 



til 

 hi 

 5.0 



<o 5.8 



fct 



7^ 



(y J /y 



f^a 



y Jum. July Wx.g 



Se/, Oct- fVo^^ Z>«.t- 



Tan Feb 



Nctr Af>r. 



Fig. 7. Curves showing the seasonal changes in Ph value of acidity in fruit 

 spurs and two-year-old seedlings of apple from November to June, 1919-1920. 

 The ordinates represent the acidity in Ph and the abscissae, the season of the 

 year. Unfortunately, no data were obtained from July to October. 



hand, maltose is lowest and glucose is highest during the dor- 

 mant period, when acidity is lowest and nearer the optimum for 

 maltase than for diastase. The maltose is thus hydrolyzed to 

 glucose at this time almost as rapidly as it is formed from starch. 

 These facts suggest an explanation of why maltose is the most 

 important sugar of translocation from leaves to stem in summer, 

 while glucose is the most important sugar of translocation from 

 root to stem at the close of the dormant period. 



7. The presence of invertase has been found by experiment 

 to be much more in abundance in the tissues of fruit spurs and 

 seedlings than either diastase or maltase. It is for this reason 

 that sucrose is rapidly hydrolysed in October and November, 



