260 EXPERIMENTS. [CH. X 



tion has shewn these to be present) and amides in 

 extracts (made as for qualitative testing) of 



(1) seeds of Onobrychis sativa, 



(2) young shoots of Onobrychis sativa grown under 

 ordinary conditions, 



(3) young shoots of Onobrychis sativa which have 

 been grown in the dark or kept in the dark for several 

 days before extracting. 



Compare the amounts of ammonia, nitrates and 

 nitrites in 



(1) normal young shoots of Onobrychis sativa 

 which have grown in sand, 



(2) in normal young shoots of Onobrychis sativa 

 which have been kept for several days soon after germina- 

 tion in the dark in absence of free oxygen, 



(3) in normal young shoots of Onobrychis sativa 

 which have been grown in sand watered with a solution 

 containing ammonium nitrate ('5 p.c.). 



