THE LIVING PLANT 



17 



millions. They are of various sizes and shapes (Fig. 2), and are 

 modified to perform definite functions. 



28. Structure of 

 plant-cells. A section 

 of a living cell is shown 

 in Fig. 3. The cell- 

 wall surrounds a mass 

 within, largely made 

 up of a living sub- 

 stance called proto- 

 plasm. Protoplasm 

 enters into the com- 

 position of a body 

 within the cell known FlG " 2 -~ Plant - celIs of various sha P es - 



as the nucleus. The part of the protoplasm between the 

 nucleus and the cell-wall is known as cytoplasm. In the 



Cell Wall- 



-Cell Wai' 



-Ectoplasm 

 -Nuc/eus 



FIG. 3. A, Diagram of a cell. B, A plasmolyzed cell. The protoplasm has shrunk to 

 an irregular mass. 



cytoplasm may be found vacuoles, granules, plastids, and 

 crystals. 



