272 MR. C. DARWIN ON THE ACTION OF 
bright light. In some of these leaves the basal cells of the 
longer exterior tentacles had become beautifully transparent 
from the ageregation of their contents into green or greenish- 
purple masses ; and here no chlorophyll-grains could be seen; 
but in other parts of the same tentacles, where the aggregated 
masses were of a purple tint, the chlorophyll-grains were still 
plainly visible. 
Finally, it appears certain that in the leaves of Drosera the 
grains of chlorophyll, if left long enough in a weak solution of 
the carbonate, sometimes break up and form translucent greenish 
globules, which are much smaller than the original chlorophyll- 
grains ; and that these, by coalescing, form larger masses, which 
again coalesce into a few spheres or into a single one. In other 
cases the chlorophyll-grains swell and coalesce without having 
previously broken up into globules. During these various 
changes the aggregated masses often become coloured by the 
modified cell-sap, more especially in the case of the epidermal 
cells; or they may form a zone round the already aggregated 
cell-sap, in which case a dark central sphere is surrounded by a 
less dark or by a light-green transparent zone of matter. 
It remains to be considered whether the grains of chlorophyll, 
. after complete fusion or aggregation, are ever reformed and re- 
assume their normal positions on the walls ofthe cells. Although 
the purple aggregated masses within the tentacles are soon 
redissolved, the cells becoming refilled with transparent purple 
fluid, it by no means follows that the chlorophyll-grains should 
be reformed ; and such a capacity would be an interesting point. 
To ascertain whether this occurred, drops of a weak solution of 
carbonate of ammonia (2 to 1000) were daily placed during 5 
days on several leaves on a growing plant; but, to my surprise, 
the tentacles remained after the first day expanded, with their 
glands bright red and copiously secreting, and they exhibited 
little aggregation. Large drops of a solution of 4 to 1000 were 
next placed on three reddish leaves, fresh drops being added in 
about 18 honrs. After an interval of 412 hours from the time 
when the drops were first placed on the leaves, three short cen- 
tral tentacles on one leaf were examined, and the cells were seen 
to be filled with quickly moving aggregated masses, and not one 
grain of ehlorophyll could be distinguished. In 66 hours after 
the drops had been given the leaves were well syringed with water ; 
and now the central tentacles of a second leaf were examined, in 
