THE TEMPERATURE COEFFICIENT OF THE DURATION 
OF LIFE OF BARLEY GRAINS 
T. HARPER GOODSPEED 
Lor’ believes that the chemical reactions underlying the 
development of organisms differ widely from those that bring 
about natural death. This author has found, for sea urchin eggs, 
the temperature coefficient of duration of life to lie between 500 
and tooo for a rise of temperature of 10° C., while that of develop- 
ment was 2.86 for a similar temperature interval. This latter 
figure is identical with that previously calculated by PETER’ 
from the results obtained by Hertwic' in experiments upon the 
effect of temperature on the rate of development of frogs’ eggs. 
Moore,‘ using Tubularia crocea, states that the temperature 
coefficient of life duration in this hydroid was about 1000 for a rise 
of temperature of 10° C., and that the average temperature coeffi- 
cient for the process of regeneration was 3.4 for a 10° C. interval. 
The influence of temperature. upon the development of plants has 
been given some attention; but the results, as given in the litera- 
ture, with a few exceptions yield no accurate conclusions. The 
obvious effect upon reaction velocities of even slight variations 
in the temperature, when the whole temperature range employed 
lies well within that which is normal for the subjects investigated, 
is the cause assigned for the inaccuracy of the results obtained. 
However, the careful experiments of CLAUSEN® upon the influence 
of temperature on the excretion of carbon dioxide by bean germs, 
wheat germs, and syringa buds have been widely recognized, and 
set a criterion of accuracy and technic for the investigations of 
plant physiologists along these general lines. 
It was suggested to me that a temperature coefficient for the 
* Logs, Jacques, Archiv. Ges. Physiol. 124411. 
* Perer, Kart, Archiv. Entw.-Mech. 20: 130. 
3 Hertwic, O., Archiv. Mikr. Anat. u. Entw.-Gesch. 51:893- 
4 Moors, A. R., Archiv. Entw.-Mech. 29: 145, 287. 
5’ CLAUSEN, Landwirtschaftliche Jahrbiicher 19 : 893. 
Botanical Gazette, vol. 51] [ase 
