COMPARATIVE STUDIES ON RESPIRATION. 



XVI. Effects of Hypotonic and Hypertonic Solutions upon 



Respiration. 



By O. L. INMAN. 

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



(Received for publication, January 15, 1921.) 



Studies showing the effects of the osmotic pressure of the medium 

 upon the organism have been numerous and various. Little work, 

 however, has been done upon the relation of the production of carbon 

 dioxide as affected by varying the osmotic pressure of the medium 

 in which the organism lives. 



Smith^ reports that stems of Tropceolum, stems and roots of bean 

 seedlings, and leaves of snowdrops, after deprivation of one-third to 

 one-half of their total water by drying, respired more than normal 

 plants. No increase in the respiration was observed on partly drying 

 young stems of peony and asparagus. 



Palladin and Sheloumova^ observed that potato tubers, when al- 

 lowed to lose water by drying in the air or by immersion in a 10 per 

 cent solution of sodium chloride, in general showed a decrease in the 

 amount of carbon dioxide produced. 



Bailey and Gurjar^ have investigated the respiration of seeds as 

 related to the amount of water present. In general it is shown the 

 respiration falls o£f as the moisture diminishes. 



Warburg* stated that hypertonic solutions may increase the con- 

 sumption of oxygen by fertilized eggs of the sea urchin as much as 

 three or four times. Loeb and Wasteneys^ repeated these experi- 



' Smith, A. M., Rep. Brit. Assn. Advancement Sc, 1915-16, Ixxxv, 725. 

 2 Palladin, V. I., and Sheloumova, A. M., Bull. Acad. Sc. Petrograd, 1918, 

 801, abstracted in Chem. Abstr., 1918, xii, 1889. 



^ BaUey, C. H., and Gurjar, A. M., J. Agric. Research, 1918, xii, 685. 

 * Warburg, 0., Z. physiol. Chem., 1909, Ix, 443. 

 ^ Loeb, J., and Wasteneys, H., /. Biol. Chem., 1913, xiv, 469. 



533 



