12 



Elementary Botany 



Cell Sap. — In the young cell the whole of the wall, with the 

 protoplasm and other contents, is saturated with a watery fluid 

 containing various mineral and other substances in solution. 

 This constitutes the cell sap. As the cell increases in age this 

 sap collects in drops {vacuoli), which gradually run together 



Flc. II. — Cells from the root of Fritillaria 

 hnfierialis. A, very young cell from near 

 apex. £, from 2 mm. above the apex, C, 

 from about 8 mm, above the apex : /z, cell 

 wall : /, protoplasm ; /i, nucleus ; ^A, nu- 

 cleoli : s, vacuoles and cell-sap cavity. 

 (After Sachs.) 



Fig. 12.— Crystals of calcium oxa- 

 late in the cell wall. Wetivit- 

 schia mirahilis. (After Sachs.) 



until the whole of the interior of the cell is filled with sap, 

 presenting the appearance of being surrounded by two coats — 

 viz., within, the layer of protoplasm ; and without, the cell wall. 

 This sap is most important, as it contains much of the food 

 material of the plant. 



