i So Schunck arid Brebner . — On the Action of Aniline 
coloration indicates the formation of a crystallisable body of 
well defined properties called anilophyll. 
(2) The same body is formed outside the plant by the action 
of hydrogen peroxide or ozone on aniline in the presence of 
a weak acid, but not at all, or at least very slowly, by the 
action of ordinary oxygen. There can be no doubt, there- 
fore, that the formation of this body in the cell is due to the 
presence there of some form of active oxygen. 
The question that remains to be considered is whether the 
active oxygen is present in the cell as such, or whether it is 
formed from passive oxygen by some process of activation. 
In Schoenbein’s experiments, as he himself allowed, the ex- 
pressed juices of plants did not in the first instance give the 
reaction of hydrogen peroxide, but only after a time, in con- 
sequence of the activation of atmospheric oxygen to which 
they were exposed. In our experiments, however, which were 
conducted with mechanically uninjured cells, there could be no 
question of expressed juices, the reaction with aniline taking 
place while the sap, etc. was still contained within the cells. 
Moreover these expressed juices do not react with aniline, so 
far as our experience goes, although with very few exceptions, 
plants, the expressed juices of which affect Wursters tetra- 
paper, also show a reaction when painted with aniline. It 
seems probable, indeed, that the reaction taking place within 
the cell and that shown by expressed juices are distinct. It 
is still possible, however, that the effect observed within the 
cell may be due to a rapid activation of the passive oxygen, 
which, according to Pfeffer, is diffused throughout the cell 
and pervades its contents. In support of this view it may be 
urged that the death of the cell is undoubtedly brought about 
by the action of the aniline and that the coloration of the 
corpuscles may therefore be a post-mortem phenomenon. On 
the other hand, the action of the aniline does not lead, as 
might have been expected, to very much disturbance in the 
cell-contents, only a slight amount of plasmolysis taking 
place, and the chlorophyll-corpuscles retaining much their 
original position at the periphery of the contents (see Fig. 4). 
