1917] GROVES— DURATION OF SEEDS 187 



No definite trend appears in the value of the coefficient Q 



10 



*-^ 



limits. For wheat wi 



from 



average of 9.23; for 12 per cent moisture the range varies from 

 4.8 to 12.6 with an average of 10. 14; while for 17.5 per cent the 

 range varies from 2 to 20 with an average of about 10 for the whole 

 scope of the experiment. 



7. Since the range of temperature used in these experiments 

 is comparatively short, we are not justified in placing too much 

 emphasis on predicted longevities at low temperatures. Such 

 longevities as have been calculated by formula 3 are large when 

 compared with observed longevities by White and others. 



8. This work shows possibilities of throwing some light on the 

 nature of the processes of the loss of viability in seeds in storage 

 conditions. It also makes possible a quantitative statement of the 

 significance of various storage conditions, especially moisture 

 content and temperature, upon the longevity of seeds. 



* 



I wish to acknowledge many helpful suggestions by Dr. William 

 Crocker and Dr. Sophia Eckerson, under whose direction this 

 work has been done. I am also indebted to Mr. L. L. Thurstone of 

 the Carnegie Institute of Technology for aid and advice in making 

 mathematical calculations. 



University of Wyoming 



Laramie, Wyo. 



LITERATURE CITED 



1. Acton, E. H., Changes in reserve material of wheat on keeping. Ann. 

 Botany 7:383-387. 1893. 



2. Askenasy, E., t)ber die Temperatur, welche Pflanzen im Sonnenlicht 



annehmen. Bot. Zeit. 33:442-455. 1875. 



J 

 propriete diastasique. 



8-60 



4- Ayres, A. H., The temperature coefficient of the duration of life of Cera- 

 fnium tenuis simum. Bot. Gaz. 52:65-69. 1916. 



5. Becquerel, P., Recherches sur la vie latente des graines. Ann. Sci. Nat. 

 Bot. 5:193-320. 1907. 



6. Blackman, F. F., and Matthaei, A., Quantitative study of CO* assim- 

 ilation and leaf temperature in natural illumination. Proc. Roy. Soc. 

 London B 76:402-460. 1905. 





