COMPARATIVE STUDIES ON RESPIRATION. 

 IV. The Effect of Ether on the Respiration of Wheat. 



By HELEN STILLWELL THOMAS. 



{From the Laboratory of Plant Physiology, Harvard University, Cambridge.) 

 (Received for publication, September 6, 1918.) 



Investigations on the effect of anesthetics on the production of CO2 

 in higher plants have yielded somewhat contradictory results. Apple- 

 man^ found that the respiration of potatoes exposed to ethyl bromide 

 vapor for half an hour was approximately doubled. Irving^ noted 

 that the respiration of barley shoots was first increased and then de- 

 creased by chloroform vapor. Lauren^ stated that some seedlings 

 showed an increase in respiration when exposed to ether or chloro- 

 form, provided the treatment was not carried far enough to injure the 

 plant permanently; other seedlings showed a decrease in respiration. 

 Elfving^ also observed an increase in respiration with ether and chlo- 

 roform. Ewart^ found that chloroform increased the respiratory 

 activity in Elodea. 



On the other hand, no increase in respiration was observed by 

 Detmer,^ nor by Bonnier and Mangin.'' Tashiro^ states that the 

 respiration of dry seeds under the influence of anesthetics was de- 

 creased. 



In no case where only a decrease was found was the time curve 

 determined, and it is therefore impossible to say whether there was a 

 preliminary increase. In Irving's experiments, where time curves 



^ Appleman, C. O., Am. J. Bot., 1916, iii, 223. 

 2 Irving, A. A., Ann. Bot., 1911, xxv, 1077. 



^ Lauren, W., tjber den Einfluss von Atherdampfen auf die Atmung von Keim- 

 lingen, Dissertation, Helsingfors, 1891 (Bot. Jahresher., 1892, xx, 92). 

 ^ Elfving, Ocfversigt Finska Vetensk. Soc. Fork., 1886, xxviii. 

 ^Ewart, A. J., Ann. Bot., 1898, xii, 415. 

 ^Detmer, W., Landw. Jakrh., 1882, xi, 227. 



' Bonnier, G., and Mangin, L., Ann. sc. nat., 1886, cxi, series 7, 16. 

 ^ Tashiro, S., Am. J. Physiol., 1913-14, xxxii, 107. 



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