116 



THE RATE OF GROWTH 



[CH. 



Or, 



Therefore 



and 



10 log X = log 3-33 - -52244. 

 log X - -05224, 

 x= 1-128. 



That is to say, between the intervals of 10° and 20° C, if it 

 take m days, at a certain given temperature, for a certain stage 

 of development to be attained, it will take m x 1-128" days, 

 when the temperature is n degrees less, for the same stage to 

 be arrived at. 



25'C. 



20 



0° 



15° 10° 



Temperature 



Fig. 29. Calculated values, corresponding to preceding figure. 



Fig. 29 is calculated throughout from this value; and it will 

 be seen that it is extremely concordant with the original diagram, 

 as regards all the stages of development and the whole range of 

 temperatures shewn : in spite of the fact that the coefficient on 

 which it is based was derived by an easy method from a very few 

 points in the original curves. 



