C 1 DIIOSEK A ROTUNDIFOLIA. CIIAV. Ill 



ful 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 appear- 

 ance, 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, however, remained unaffected. I repeated the experi- 

 ment 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 437 of water, so that it received J of 

 a grain, or 2'024 mg. When examined, 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. Boots were also immersed for 35 m. 

 in a solution of one part of carbonate 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 l 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 2 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 o> 



