8 STRUCTURAL BOTANY 



that is, it endeavours to construct a natural classifica- 

 tion of the vegetable kingdom. Classification is often 

 treated as a separate part of the science, called 

 Systematic Botany, and this is a convenient division, 

 but Systematic Botany can only be satisfactorily based 

 on the comparative study of plants that is, on 

 morphology. 



While it is easy to distinguish sharply between the 

 physiology and morphology of plants, it is more 

 important to remember that neither can be pursued 

 to any advantage without the other. Physiology 

 without morphology would teach us much about the 

 life of individual plants, but could give us no idea of 

 the vegetable kingdom as a whole, or of the relation- 

 ship between the innumerable species of which it is 

 composed. Morphology without physiology, on the 

 other hand, would be just as barren, for the complex 

 modifications of the organs -of plants would be wholly 

 unintelligible without reference to the functions to 

 which they are adapted. Only by examining plants 

 from both points of view can we attain to any 

 knowledge of them which deserves the name of 

 science. 



The method pursued in this book is to take in 

 succession a series of types representing important 

 groups of plants, to examine each of them as fully as 

 our space permits, with reference to both structure 

 and function, and to compare them together. It will 

 often be necessary to supplement the study of our 

 main types by that of other plants which resemble 

 them on the whole, but better illustrate some particular 



