Table 3. The total nitrogen content of various segments of 

 Elodea occidentalis harvested when nitrogen 

 deficiency had reduced the rate of growth as 

 indicated by length increase. 



Plants harvested 



-42.0mg N/L 



Plants harvested 

 4.2 mg N/L 



Days of growth 



Figure 3. Daily increase in total length of stems and 

 lateral branches of Elodea occidentalis grown in tray 

 cultures under high and low levels of N03-N. 



17 



