2 io RivelL — The Cytoplasm in the Cells of A licularia seal arts. 
fresh oil-bodies, it would seem probable that these substances form a solution 
with the ethereal oil. 
The behaviour of the oil-bodies on treatment with alcohol is interesting 
and peculiar; if a living leaf is mounted in water, the behaviour can be 
observed by irrigating with 70 per cent, alcohol under the cover-slip. It has 
already been described by Garjeanne, Pfeffer, and von Krister. Pfeffer con¬ 
sidered that the obvious membrane which is formed around the limits of 
the oil-body as the oil disappears is a wall or skin different from the 
surrounding cytoplasm. The wall can be stained with methylene blue and 
with iodine and looks a very distinct 
and conspicuous structure (see Text- 
fig. 2). If leaves are mounted in 30 
per cent, alcohol, the process of solution 
of the oil can be observed, as in this 
strength it takes place slowly. The 
oil-drop may divide into two, three, or 
numerous drops, and each of these 
becomes smaller; or the whole oil- 
drop may rapidly become spherical and 
gradually contract. The ‘ membrane ’ 
appears around the original limits of 
the oil-body. If, after the process of 
solution has gone on for a few moments, 
the slide is flooded with water, the 
membrane still appears conspicuous, 
and the partially dissolved oil-drops 
remain without further change. The 
process of solution is never complete in 
30 per cent, alcohol. 
Von Kiister ( 5 ), by plasmolysis 
bodies In surface view.^' B* The*same Irrigated experiments, satisfied himself that the 
with alcohol, s = < sac ’ of oil-drop. membrane was an artifact, and by dis¬ 
solving out the oil in two successive 
stages, first with weak alcohol and then with strong, showed that two 
membranes could be formed, one inside the other. Garjeanne (6) showed 
that the membrane can also be made visible by pressure on the cover-slip, 
and as a deduction from this in conjunction with von Krister’s experiments 
maintained that the so-called ‘ wall ’ (of Pfeffer) is a precipitation membrane 
formed by the action of the oil on the cell-sap ; thus the ‘ wall * is discovered 
whenever the protoplasm separating the oil and the cell-sap is destroyed. 
It seems to me that unnecessary stress is laid on the point whether the 
membrane is a differentiated wall or merely a protoplasmic binding. All are 
agreed that there is a protoplasmic covering round the oil; it is invisible 
Twvnn A *1 nr a wtiVi aiI 
