PROTOPLASM. 



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

 water are, the more watery is tlie. protoplasm, and vice versa. 



(c) Tests. 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 and afterward* with 

 potash, it assumes a dark violet color. 



....^ir M^ S 



Fig. 2. — Parenchyma cells from the central cortical layer of the root of Fi'i(Ulari'7 

 imperialia, longitudinal sections. A, very young cells lying close above the apex of 

 the root, still without cell sap or vacuoles. B, cells ot the same description about - 

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

 5, *■, 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, A, cell-wall ; p, protoplasm ; 

 k, nucleus ; kk, nucleoli ; s, vacuoles ; xi/, swelling of the nucleus under the influ- 

 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 be demonstrated in a tissue by 

 the application of various staining fluids, as magenta, carmine, etc, 



