SUMMARY 



41 



I give below a curve (fig. 17) constructed from the above 

 data, showing the relation between temperature and rate 

 of growth. 



The methods described possess important advantages. 

 In place of measuring the average change in the rate of 

 growth in a number of plants, the variation is recorded in 

 an identical specimen. The employment of magnification 

 reduces, moreover, the period of the whole experiment to 



ofe/rnfimxttUne, 



Fig. 17. 



Curve showing relation between temperature and 

 rate of growth. 



about 20 minutes, and thus eliminates the complication 

 arising from the diurnal variation in the rate of growth. 



Summary 



Methods of experimentation have been described for 

 rapid determination of the effect of variation of temperature 

 on the rate of growth. 



Radiant heat induces a retardation of growth which 

 antagonises the acceleration due to rise of temperature; 

 the gradual rise of temperature of the plant has therefore 



