271 



From the preceding follows: 



For various Papilionaceae, excelling by their abundance of nitrogen compounds, 

 even when cultivated in media without such compounds, the number and volume of 

 the tubercles is so small, that if only within them the fixation of free nitrogen should 

 take place, the intensity of the process in these tubercles must necessarily be very 

 great. We have not, however, succeeded gazometrically in observing the process in 

 the tubercles at all. 



Neither do the tubercle bacteria fix the atmospheric nitrogen when cultivated 

 out the plant in nutrient liquids or in plate cultures, nor enclosed in solid media. 



The contradictory statements in the hand books of Plantphysiology are erroneous. 



