Chap. m. THE PROCESS OF AGGREGATION. 65 



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 solu- 

 tion, but was very doubtfully affected. On the other hand, a 

 red marine alga, with finely pinnated fronds, was strongly 

 affected. The contents of the cells aggregated themselves into 

 broken rings, still of a red colour, which very slowly and 

 slightly changed their shapes, and the central spaces within 

 these rings became cloudy with red granular matter. The 

 facts here given (whether they are new, I know not) indicate 

 that interesting results would perhaps be gained by observing 

 the action of various saline solutions and other fluids on the 

 roots of plants. 



