PROTOPLASM. 3 



parasrrapli 37, and Starch, paragraph 69), The thicker the layers of 

 water are, the more watery is the protoplasm, and nee versa. 



(c) Testa. 1. If a protoplasmic mass is moistened with a solution of 

 iodine, it at once assumes a deep yellow or brown color. 



2. If treated with a solution of copper sulphate aud afterward" with 

 potash, it assumes a dark violet color. 



Hg. 3.— Parenchyma cells from the central cortical layer of the root of Ft-MUm in 

 imperialUf longitudinal sections. A, very young cells lying closo above the apex of 

 the root, still without cell sap or vacuoles. £, cells of the same description ahout 

 two millimetres above the apex of the root ; by the entrance of cell sap the vacuoles 

 s, if, s have been formed. C, cells of the same description about seven to eight mil- 

 limetres above the apex of the root. In all the figures, h, cell-wall ; ;?, protopLasm ; 

 A, nucleus ; &&, nucleoli ; 5, vacuoles ; xy. swelling of the nucleus uuder the inila- 

 ence of the water in preparing the specimen. X 500. — After Sachs. 



3. Treated with a solution of sugar, and afterwards with sulphuric 

 acid, it becomes rose-red. 



4. The presence of protoplasm may he demonstrated in a tissue by 

 the application of various staiuing fluids, as magenta, carmine, etc. 



