266 MR. C. DARWIN ON THE ACTION OF 
They are also capable of self-division *. Now, if it can be shown 
that a solution of carbonate of ammonia tends to cause the grains 
of living chlorophyll to become confluent one with another and 
with previously aggregated masses, this fact would support the 
conclusion that the aggregated masses consist, at least in part, 
of living protoplasm, to which their incessant movements may be 
attributed. And it is the object of the present paper to show 
that chlorophyll-bodies are thus acted on in certain cases by car- 
bonate of ammonia. The fact by itself possesses some little in- 
terest, independently of the light which it throws on the remark- 
able phenomenon of aggregation. 
Dionea muscipula.—The effects of carbonate of ammonia are 
best shown in the case of young, small, and thin leaves produced 
by starved plants, as these are quickly penetrated by the solu- 
tion. Transverse sections of such leaves and of others were made 
before they had been immersed +; and the cells, including those 
of the epidermis, could easily be seen to be packed with grains 
of chlorophyll. It is, however, necessary to avoid examining a 
leaf which has ever caught an insect; for in this case many of 
the cells will be found filled with yellowish matter instead of 
with chlorophyll-grains. Several leaves were left for different 
lengths of time in solutions of different strengths; but it will 
suffice to describe a few cases. A small thin leaf was immersed 
for 24 hours in a solution of 7 parts of the carbonate to 1000 of 
water, and transverse sections were then examined. The cells 
near the margin of the leaf, throughout its whole thickness, did 
not now exhibit a single chlorophyll-grain, but in their place 
masses of transparent yellowish-green matter of the most diver- 
sified shapes. They resembled those of Drosera shown at fig. 3, 
if we suppose several of them to be pressed lightly together. 
Some of the masses in the same cell were connected by ex- 
tremely fine threads. Spheres of more solid matter were some- 
times included within the oddly-shaped greenish masses. The 
contrast in appearance between these sections and those taken 
from one corner of the same leaf before it had been immersed 
was wonderfully great. The sections were then clarified by 
being left for some time in alcohol, but not a grain of chlorophyll 
could be seen; whereas the fresh slices similarly clarified exhi- 
* Van Tieghem, ‘Traité de Botanique; 1882, p. 493. 
T These sections and many others were made for me by my son Francis, to 
whom I owe much information and other assistance. 
