1 6 EXAMINATION OF [CHAP. 



transpiration, assimilation, and respiration. The stem, 

 when green, assists the leaves in their work; but, speak- 

 ing generally, it may be regarded merely as the support 

 of the leaves, maintaining their connexion with the root. 



In our next chapter we shall inquire into the mutual 

 relations and functions of the leaves which compose the 

 flower, deferring further reference to the chemistry of the 

 organs until we speak of their minute structure. 



