Ill] THE TEMPERATURE COEFFICIENT 223 



Then choosing two values out of the above experimental series 

 (say the second and the second-last), we have t = 23-5, n = 10, 

 and F, V = 10-8 and 69-5 respectively. 



. ,. - log 69-5 - log 10-8 , 

 Accordmgly, — ^ — — = log x, 



0-8414 - 0-034 

 or ^^ = 0-0808, 



and therefore the temperature-coefficient 



= antilog 0-0808 = 1-204 (for an interval of 1° C). 



This first approximation might be much improved by taking account 

 of all the experimental values, two only of which we have yet made 

 use of; but even as it is, we see by Fig. 63 that it is in very fair 

 accordance with the actual results of observation, within those 

 particular limits of temperature to which the experiment is confined. 

 For an experiment on Lupinus albus, quoted by Asa Gray* 

 I have worked out the corresponding coefficient, but a httle more 

 carefully. Its value I find to be 1-16, or very nearly identical with 

 that we have just found for the maize; and the correspondence 

 between the calculated curve and the actual observations is now 

 a close one. 



Miss I. Leitch has made careful observations of the rate of growth of rootlets 

 of the Pea; and I have attempted a further analysis of her principal resultsf . 



* Asa Gray, Botany, p. 387. 



t I. Leitch, Some experiments on the influence of temperature on the rate 

 of growth in Pisum sativum, Ann. Bot. xxx, pp. 25-46, 1916, especially Table III, 

 p. 45. Cf. Priestley and Pearsall, Growth studies, Ann. Bot. xxxvi, pp. 224-249, 

 1922. 



