1917] GROVES— DURATION OF SEEDS 171 



long dead and in seeds killed by anesthetics. Miss White (33) 

 found no increase in the germination of seeds soaked in enzyme 

 solutions, but rather a decrease due to an increased fungal action. 

 She found the life duration of Triticum to be 17 years, with no loss 

 of enzyme activity. According to her work the enzyme theory of 

 the loss of viability is not tenable. 



Some very significant work has been done on the time- 

 temperature relation of coagulation of protein both in vitro and 

 in the living cell. Buglia (7) found that the time required for the 

 coagulation of blood serum varies with the temperature used. 

 The time of coagulation was found to be a logarithmic function of 

 the temperature. Chick and Martin (12) found that the time 

 required to precipitate egg albumen and haemoglobin from solu- 

 tion varies with the temperature and with the concentration of 

 the solution. Lepeschkin (22) showed that the death of active 

 plant cells by supramaximal temperatures is due to the coagulation 

 of the cell protoplasm. He applied a logarithmic formula to express 

 the relation of temperature to the time of coagulation of proteins 

 in vitro as well as in the living cell. By the application of this 

 formula to the determined time for coagulation at any two tempera- 

 tures, one can calculate the time necessary for coagulation at any 

 other temperature. On this basis Lepeschkin calculated the life 

 duration of active Tradescantia cells at 20 C. to be $$ days, and 

 at zero to be 3 years. He believes that the life duration of plant 

 cells is very much longer than indicated because of a redispersal 

 process, carried on by the active living cells, which counteracts 

 the coagulation process. 



The results of many workers in this field have been well sum- 

 marized in a recent monograph by Kanitz (20), who has brought 

 together the literature from several related subjects. He shows 

 that in general the effect of temperature upon the rate of chemical 

 processes is governed by the Van't Hoff law, that is, the coefficient 

 for a rise in temperature of io° C. (Q I0 ) is 2 to 3. From the experi- 

 mental results at any two temperatures the value of Q I0 may be 

 calculated from the following equation (referred to as formula 1 

 and formula 2) : 



IO IP (log * a -lpft k t ) 



Qio=[ k ) or (?i~=io 



