8 INTRODUCTORY 



For convenience in study we will divide the subject into 

 three parts as follows : 



Plant structures, in Avhich we will study the structure of the 

 higher plant (see page 9) ; 



Plant activities, in which we will study the physiology of 

 the plant (see page 147) ; and 



Classification and economics, in which we will study the 

 classification and uses of plants (see page 255). 



