1917] 



GROVES— DURATION OF SEEDS 



179 



Table IV shows a limited number of data for wheat with 17. 5 

 per cent moisture. As would be expected, the time required to 



TABLE III 



Germination record of Turkey-red wheat 9 per cent moisture; theoretical tempera- 

 ture calculated by formula T=a — blogZ; T is temperature (Centigrade); Z is time 

 in minutes; a and b are constants; = 100.8; 2> = io.4; value of Q ro as calculated 

 by method of least squares = 9 . 23. 





Time in minutes 



8 



27 



45 



I40 



435 

 810 



2340(1.6 days). 



7200(5.0 days). 



19440(13.5 days) 



Calculated 

 temperature 



91 4° C. 



859 

 83.6 



82.1 

 78.5 



73-4 

 70.5 



65 7 

 60.6 



56.2 



Experimental 

 temperature 



90. 8° C. 



85-7 

 84.2 



835 

 79.8 



74-4 

 70.8 



66.0 



60.6 



56.3 







10 



13-49 

 (". o) 



7 03 

 (90) 



8.51 

 (10.2) 



Predicted life duration: 50" C, about 53.4 days; 25° C, about 37.3 years; 20° C, about in. 2 

 years; o° C, about 938 . 5 years. 



kill such seeds at the temperatures used in the former experiments 

 is exceedingly short. The error due to the time required for the 



TABLE IV 



Germination record of Turkey-red wheat 17.5 per cent moisture; theoretical 

 temperature calculated by formula T=a— b log Z; T is temperature (Centigrade); 

 Z is time in minutes; a and b are constants; = 81.73; £ = 8.04; value of Q m as 

 calculated by method of least squares for last 4 temperatures = 1 6 . 45 . 



Time in minutes 



3°- 



3-75 

 40. 



5-5- 

 8.0. 



230. 



140.0. 



440.0. 



Calculated 

 temperature 



77 



77 

 76 



75 

 74 

 70 

 64 

 60 



9 

 1 



9 



8 



5 



8 



5 

 5 



C 





87 

 83 

 83 



79 



74 

 70 



64 

 60 



1 



6 

 1 



5 

 7 

 5 



4 



6 



C. 



Experimental 

 temperature 



Q 



10 



2.22 



(7-6) 



4.90 

 (90) 



19.71 



(9 9) 



o Predicted life duration: 50° C, about 6. 1 days; 25 C, about 21.6 years; 20 C, about 64.4 years; 

 o C, about 2800 years. 



seeds to attain the temperature of the bath is therefore very appar- 

 ent here. The data of this table are expressed also as a time- 







