54 DROSERA ROTUNDIFOLIA. [Caar. II, 
Euphorbia peplus, being careful not to injure the roots; these were 
washed and placed in a little solution of one part of carbonate of 
ammonia to 146 of water. In less than one minute I saw a cloud 
travelling from cell to cell up the roots, with wonderful rapidity. 
After from 8 m. to 9 m. the fine granules, which caused this cloudy 
appearance, became aggregated towards the extremities of the roots 
into quadrangular masses of brown matter; and some of these soon 
changed their forms and became spherical. Some of the cells, how~ 
ever, remained unaffected. I repeated the experiment with another 
plant of the same species, but before I could get the specimen into 
focus under the microscope, clouds of granules and quadrangular 
masses of reddish and brown matter were formed, and had run far up 
all the roots. A fresh root was now left for 18 hrs.in a drachm of a 
solution of one part of the carbonate to 487 of water, so that it re~ 
ceived § of a grain, or 2°024 mg. When examincd, the cells of all 
the roots throughout their whole length contained aggregated masses 
of reddish and brown matter. Before making these experiments, 
several roots were closely examined, and not a trace of the cloudy 
appearance or of the granular masses could be seen in any of them. 
Roots were also immersed for 35 m. in a solution of one part of car- 
bonate of potash to 218 of water; but this salt produced no effect. 
I may here add that thin slices of the stem of the Euphorbia were 
placed in the same solution, and the cells which were green instantly 
became cloudy, whilst others which were before colourless were clouded 
with brown, owing to the formation of numerous granules of this tint. 
I have also seen with various kinds of leaves, left for some time in a 
solution of carbonate of ammonia, that the grains of chlorophyll ran 
together and partially coalesced; and this seems to be a form of 
aggregation. 
Plants of duck-weed (Lemna) were left for between 30 m. and 45 m. 
in a solution of one part of this same salt to 146 of water, and three of 
their roots were then examined. In two of them, all the cells which 
had previously contained only limpid fluid now included little green 
spheres. After from 14 hr. to 2 hrs. similar spheres appeared in the 
cells on the borders of the leaves; but whether the ammonia had 
travelled up the roots or had been directly absorbed by the leaves, I 
cannot say. As one species, Lemna arrhiza, produces no roots, the 
latter alternative is perhaps the most probable. After about 24 hrs. 
some of the little green spheres in the roots were broken up into small 
granules which exhibited Brownian movements. Some duck-weed 
was also left for 1 hr. 30 m. in a solution of one part of carbonate of 
potash to 218 of water, and no decided change could be perceived in 
the cells of the roots: but when these same roots were placed for 25 m. 
in a solution of carbonate of ammonia of the same strength, little green 
spheres were formed. 
A green marine alga was left for some time in this same solution, 
but was very doubtfully affected. On the other hand, a red marine 
alga, with finely pinnated fronds, was strongly affected. The contents 
