PAPERS ON BOTANY 



135 



duration of about 11, but since he did not control the water 

 content, we are not justified in making a comparison. Loeb° 

 working with sea urchin eggs found a coefficient of 500 to 

 1,000, while Moore" working with hydroids found a coeffi- 

 cient of about 1,000. The high water content in these cases 

 probably materially affects the value. It should be noted that 

 we are not dealing with a homogeneous system, but with a 

 colloidal system and that it is not remarkable that the Van't 

 Hoff temperature law for the rate of reaction does not apply. 



Since here is a close agreement between the calculated and 

 found values it seems probable that the time temperature form- 

 ula for protein coagulation can be applied as a formula for the 

 temperature-life duration for seeds. In order to establish the 

 general application of this principle much more work is needed 

 and several influencing factors are to be considered as here-to- 

 fore outlined by Crocker and Groves'. The work shows pos- 

 sibilities of throwing light on the nature of the process of loss 

 of vitality in seeds and of leading to a quantitative statement 

 of the significance of various storage conditions, especially 

 moisture content and temperature, upon the longevity of seeds. 



This work was done under the direction of William Crocker, 



University of Chicago. 



TABLE I 



RECORD SHEET NO. 21, TURKISH RED WHEAT 



Temp. 87.5. Moisture 12%, April 10, 1914. 



5. Archiv. Ges. Physiol. 124:411. 



6. Archiv. Entiv. Mech. 29:145-287. 



7. Proc. Ntl. Acad, of Sci., Vol. I, p. 152, 1915. 



