1916] AYRES—TEMPERATURE COEFFICIENT 69 
for barley grains, but is less than that found by Logs for sea urchin 
eggs and by Moore for hydroid stems. This result is of far too 
great a magnitude for any of the well known physical processes, 
whose temperature coefficients seldom reach a magnitude as great 
as 2 for a 10° C. interval (cf. SNYDER 8). 
Although there is some question as to the value of temperature 
coefficients as indicating the exact nature of physiological processes, 
it seems fitting to make this contribution to our knowledge of a 
subject which may sometime give us a better scant of 
fundamental biological phenomena. 
I wish to thank Professor SETCHELL and Dr. GoopsPEED of 
the botany department of the University of California for their 
continued interest and helpful criticism as this work has progressed. 
UNIVERSITY OF CALIFORNIA 
LITERATURE CITED 
1. Barry, F., The influence of temperature on chemical reaction in general. 
Amer. Jour. Bot. 1: 203-225. 1914 
- CLauseN, H., Beitriige zur Kenntnis der Athmung der Gewiéichse und 
des pflanzlichen Stoffwechsels. Landw. Jahrb. 19:893-930. 1890 
- GoopsPEED, T. Harper, The ier waning of the duration of 
life of barley grains. Bor. . 51:220-224. 
- Lorez, Jacques, Uber den Pecieeaeusknettatenten fiir die Lebensdauer 
kaltbliitiger Thiere und iiber die Ursache des natiirlichen Todes. Archiv. 
Ges. Physiol. 124:411-426. 1908. 
- MaAtruarl, GABRIELLE L. C., Experimental researches on vegetable 
assimilation and respiration. IIL. On the effect of temperature on car- 
bon dioxide assimilation. Phil. Trans. Roy. Soc. London B. 197:47-105. 
1904. 
- Moore, A. R., The temperature coefficient of the duration of life in 
rT: abelari crocea. Archiv. Entw.-Mech. 29:287-289. 1910 
- Price, H. L., The application of meteorological data in "the study of 
physiblogical ioneite Ann. Rep. Va. Agric. Exp. Sta. 1909-1910. 
8. Snyper, C. D., A comparative study of the temperature coefficients of the 
velocities of various physiological actions. Amer. Jour. Physiol. 22:309- 
334. 1908. 
vAN’T Horr, J. > P eoroeor iiber theoretische und physikalische 
Chemie 1:224. 18 
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