PHYSICS OF STREAMING 



SECTION 14. The Influence of Free Oxygen upon Streaming. 



Corti 1 was the first to state that the presence of oxygen was an 

 essential condition for streaming, and Chara was expressly included in this 

 statement. I have already shown (I.e.) that streaming may continue in 

 cell-preparations of Chara and Nitella for days or even weeks, though 

 ringed with vaseline and kept in darkness. This was especially the case 

 when only a thin ringing was applied, but streaming often continued for 

 weeks in Nitella, even when the preparations were thickly ringed and 

 immersed in oxygenless water kept in sealed bottles in absolute darkness. 

 A few of the experiments upon which the above conclusions are based are 

 given in detail beneath. 



End-cells of Chara, axial cells of Nitella, leaves of Elodea in water, 

 were covered, thinly ringed with vaseline, and kept in darkness at 15-18 C. 



Under the conditions given, minute traces of oxygen were able to 

 diffuse in, although not in sufficient quantity to maintain the movement 

 of strongly aerobic bacteria or infusoria. Occasional cells of Chara and 

 Nitella cease to stream and die in from one to a few days under the above 

 conditions. This may be due to some individual peculiarity, or to the 

 metabolism of the cell being such as to temporarily demand relatively 

 large supplies of free oxygen. 



1 Quoted by Dutrochet and also by Meyen, Pflanzen-Physiologie, Bd. II, p. 224. 



