12 PRACTICAL BOTANY. 



Bryophytes, Pteridophytes, and Spermaphytes, there is 

 less agreement among the authorities. Different princi- 

 ples have governed the separation into subdivisions. The 

 terms group, branch, class, order, and family are variously 

 and arbitrarily used by writers, and a comparison of the 

 schemes of classification of different authorities usually 

 leads to confusion of ideas. In the writer's judgment 

 too much stress should not be laid on classification in the 

 case of the beginner, and the minutiae of classification 

 should be wholly omitted. At the same time some out- 

 line of classification seems an absolute necessity to aid the 

 student in arranging the facts he acquires. 



The scheme of classification which forms the framework 

 for the following pages is, with some slight modifications, 

 that given by Goebel in his " Outlines of Classification 

 and Special Morphology of Plants." Its main features 

 are presented in the tabular view. 



