262 MR. C. DARWIN ON THE ACTION OF 
The Action of Carbonate of Ammonia on Chlorophyll-bodies. 
By ÜHARLES Darw, LL.D., F.R.S. 
[Read March 6, 1882.]; 
Ix my 'Insectivorous Plants’ I have described, under the term 
of aggregation, a phenomenon which has excited the surprise 
of all who have beheld it *. It is best exhibited in the tentacles 
or so-called glandular hairs of Drosera, when a minute par- 
ticle of any solid substance, or a drop of almost any nitro- 
genous fluid, is placed on a gland: Under favourable circum- 
stances the transparent purple fluid in the cells nearest to the 
gland becomes in a few seconds or minutes slightly turbid. Soon 
minute granules can be distinguished under a high power, which 
quickly coalesce or grow larger; and for many hours afterwards 
oval or globular, or curiously-shaped masses of a purple colour 
and of considerable size may be observed sending out processes or 
filaments, dividing, coalescing, and redividing in the most singu- 
lar manner, until finally one or two solid spheres are formed which 
remain motionless. The moving masses include vacuoles which 
change their appearance. (I append here three figures of aggre- 
gated masses copied from my son Francis’s paper t, showing the 
forms assumed.) After aggregation has been partially effected, 
the layer of protoplasm lining the walls of the cells may be seen 
with singular clearness flowing in great waves; and my son 
observed similarly flowing threads of protoplasm which connected 
together the grains of chlorophyll. After a time the minute 
colourless particles which are imbedded in the flowing proto- 
plasm are drawn towards and unite with the aggregated masses ; 
so that the protoplasm on the walls being now rendered quite 
transparent is no longer visible, though some is still present, and 
still flows, as may be inferred from the occasional transport of 
particles in the cell-sap. The granules withdrawn from the 
walls, together probably with some matter derived from the flow- 
ing protoplasm and from the cell-sap, often form a colourless, 
or very pale purple, well-defined layer of considerable thickness, 
which surrounds the previously aggregated and now generally 
* Pfeffer, in his recent admirable work * Pflanzenphysiologie’ (B. ii. 1881, 
p. 248), speaks of the phenomenon as being in many respects interesting ; and 
Cohn writes (“ Die Pflanze,” Vortrâge aus dem Gebiete der Botanik, 1882, p. 361) 
in still stronger terms. 
T Quart. Journ. Mier. Sci. vol. xvi. 1876, p. 309. 
