198 DROSERA ROTUNDIFOLIA. Cuar. VIIL 
dency ; in these two latter cases the surrounding fluid 
was not coloured pink, and the leaves were not 
poisoned. On the other hand, propionic acid, which 
is poisonous, does not cause much mucus to be 
secreted, yet the surrounding fluid became slightly 
pink. Lastly, as in the case of saline solutions, 
leaves, after being immersed in certain acids, were 
soon acted on by phosphate of ammonia; on the 
other hand, they were not thus affected after immer- 
sion in certain other acids. To this subject, how- 
aver, I shall have to recur. 
