RADIATION AND RESPIRATION 



1071 



stant temperature apparatus reduces the considerations to the single 

 point of deciding at what temperature the process should be kept. In 

 some cases it may be necessary to use more than one temperature in 

 order to cover all possible variations. 



The working range of temperature for yeast and alcoholic fermenta- 

 tion is 0° to 50°C. with the optimum at or near 30°. The temperature 

 coefficient (Qio) is thought to be about 2, as would be expected for a 

 process so clearly based on a series of chemical transformations. Of 

 course, in their relations to other forms of experimentation with fermenta- 

 tion, these data emphasize the need of careful control of temperature 

 during any series of measurements or growth tests. 



SUMMARY 



As an aid in picturing the direct effects of radiation upon plant 

 metabolism, the more or less well supported conclusions are stated by 

 short phra.ses in the following table: 



REFERENCES 



1. Bersa, E. Strahlenbiologische Untersuchungen III. tTber den Einfluss der 

 Rontgenstrahlen auf die Atmung der Wurzelspitzen von Vicia faba. Sitzungsber. 

 Akad. Wiss. Wien. Math-Naturwiss. Kl. Abt. 1, 136 : 403-419. 1927. (Extensive 

 bibliography of preceding work with X-rays.) 



2. DE Boer, S. R. The effect of ionized air on the rate of respiration of fungi. 

 Annals Bot. 44: 989-999. 1930. 



3. DE Boer, S. R. Respiration of Phycomyces. Rec. Trav. Bot. N6erland. 25: 

 117-239. 1928. (Full bibliography of influence of light on respiration.) 



4. Day, T. C. The influence of light on the respiration of germinating barley and 

 wheat. Trans, and Proc. Bot. Soc. Edinburgh 20: 185-213. 1894. 



5. Hubert, A., and A. Kling. De I'influence des radiations du radium sur les 

 fonctions chlorophyllienne et respiratoire chez les vegetaux. Compt. Rend. 

 Acad. Sci. [Paris] 149: 230-232. 1909. 



6. JoHxsoN, Edxa L. Effects of X-rays upon growth, development and oxidizing 

 enzymes of Helianthus annuus. Botan. Gaz. 82: 373-402. 1926. 



