Relations of Higher Plants to the Formation of Nitrates 109 



not due to any increased supply of nitrates, since the apparent stimulation 

 of growth occurred with nutrient solution in which all the nitrogen was 

 in the form of nitrates, as well as with the soil. 



ACKNOWLEDGMENT 

 The writers wish to express their obligation to E. W. Leland, who has 

 had charge of the field plats during nearly the entire time that these 

 experiments have been in progress and whose careful execution of that 

 part of the work has contributed much toward the accuracy of the 

 investigation. 



