DEPENDENCE UPON LEAVES AND CHLOROPHYL 77 



throwing off waste oxygen from photosynthesis or waste carbon 

 dioxid from oxidation, without regard to what its neighbor is 

 doing. And each cell may also divide itself into two new cells 

 independently of what its neighbor is doing. It thus comes 

 about that we often find groups of cells in which some are 

 seen to have grown faster than others, or to have divided more 

 quickly, as is shown in the illustration. 



In plants like this each cell carries on all the activities that 

 together make up being alive all the activities that in larger 

 and more complex plants are carried on by different special 

 parts or organs. But even in the most complex plants there 

 are some activities that are carried on by every cell. Only 

 certain processes are specialized. 



