i86 



BOTANICAL GAZETTE 



[march 



marked longevity which they show. Wheat seeds stored in absence 

 of oxygen might give longevities more comparable with calculated 



values. 



Summary 



i. The life durations of wheat with 9 per cent moisture at the 



various temperatures are: 



















Life durations in 

 minutes 



8 



27 45 



\ 



A1Z 



810 



2340 



7200 



19440 





[ 



~-r— -TkJU 



Temperatures in de- 

 grees Centigrade . . . 



90.8 



85.7 



84.2 



835 



79.8 



74-4 



7 o.8 



66.O 



6O.6 



S6.3 



2. The life durations for 12 per cent moisture are: 



Life durations in minutes . . . 

 Temperatures in degrees 



7 



8 



Centigrade 



92 



9 



10 



.287. 



7 



87. 5 



87-5 



J 5 



84.4 



18 45 



84.4 



78.9 



5° 



50 



120 XI 



315 



79-i 78.5 75-8 



7i -3 



3. The life durations for 17.5 per cent moisture are: 



Life durations in minutes 



Temperatures in degrees Centigrade 



30 



3-75 



4.0 



5-5 



8.0 



23.0 



140.0 



87.1 



83.6 



83,1 



79-5 



74-7 



70S 



64.4 



440.0 



60.6 





4. The application of the Lepeschkin formula at high tempera- 

 tures as checked by actual measurements gives an average error of 

 0.6 per cent for 9 per cent of moisture; 0.8 per cent for 12 per 

 cent of moisture; and 8. 25 per cent for 17.5 per cent of moisture. 



5. The data available for testing the application of the formula 

 at storage temperatures are exceedingly limited. White found 

 that 25 per cent of wheat would grow after being stored for 8.5 

 years. Assuming that they w T ere exposed to an average tempera- 

 ture of 20 C. and had an average moisture content of 12 per cent 

 according to formula 3, applied to the experimental data of this 

 paper, they should have a life duration of 15.5 years. However, 

 since the variations and averages of temperature and moisture, 

 together with other conditions, are not known, we are not justified 

 in pushing comparisons too far. 













