66 



THE STORY OF THE LIVING MACHINE. 



At Fig. 10 will be seen the tip of a root, plainly 

 made of cells quite similar to the typical cell de- 

 scribed. At Fig. n will be seen a bit of a leaf 



FIG. 10. Cells at a root tip. 



showing the same general structure. At Fig. 12 is 

 a bit of plant tissue of which the cell walls 

 are very thick, so that a very dense structure is 



formed. At Fig. 13 

 is a bit of a potato 

 showing its cells 

 filled with small 

 granules of starch 

 which the cells 

 have produced by 

 their activities and 

 deposited within 

 their own bodies. 

 At Fig. 14 are sev- 

 eral wood cells 

 showing cell walls 

 of different shape 

 which, having be- 

 FIG. ii. Section of a leaf showing come dead, have 



cells of different shapes. lost their Contents 



and simply remain 



as dead cell walls. Each was in its earlier 

 history filled with cell substance and contained 

 a nucleus. In a similar way any bit of vegetable 



