III. THE MANNER IN WHICH DIFFERENT 

 KINDS OF WORK ARE DIVIDED AMONG 

 THE MEMBERS OF THE BODY 



19. Kinds of work, or functions of the plant. 

 In accomplishing the purpose of its existence a plant 

 is compelled to do a large number of different things, 

 or carry on a variety of processes. Chief among 

 these are the absorption of material from which food 

 is to be formed from the soil and air ; the conversion 

 of these substances into compounds suitable for stor- 

 age, transportation, or use by the protoplasm; the 

 assimilation of the food into the living substance, 

 building up and enlarging its body, storing up surplus 

 food for future use, conducting water and other mate- 

 rial from one part of its body to another, digesting 

 the reserve material, such as starch, when needed for 

 food, breathing, throwing away the worn-out and 

 useless material, holding the body in the proper posi- 

 tion, and finally, and most important of all, taking 

 care that the species is preserved by giving rise to 

 new individuals by means of spores, seeds, runners, 



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