PREFACE. V 



credited, were drawn from nature by the author, and nearly 

 all expressly for this work. 



A list of the most useful books of reference is appended, all 

 of which have been more or less consulted in the preparation 

 of the following pages. 



The classification adopted is, with slight changes, that given 

 in GoebePs " Outlines of Morphology and Classification " ; while, 

 perhaps, not in all respects entirely satisfactory, it seems to 

 represent more nearly than any other our present knowledge 

 of the subject. Certain groups, like the Diatoms and Chara- 

 cece, are puzzles to the botanist, and at present it is impossible 

 to give them more than a provisional place in the system. 



If this volume serves to give the student some comprehen- 

 sion of the real aims of botanical science, and its claims to be 

 something more than the " Analysis " of flowers, it will have 

 fulfilled its mission. 



DOUGLAS H. CAMPBELL. 



BLOOMINGTON, INDIANA, 

 October, 1889. 



