PREFACE 



THIS book is written upon the same plan as the author's 

 Elements of Botany. A few chapters stand here but little 

 altered from the former work, but most of them have been 

 rewritten and considerably enlarged, and many new ones 

 have been added. The principal changes in the book as a 

 whole are these : 



1. Most of the discussion of ecological topics is put by 

 itself, in Part II. 



2. The amount of laboratory work on the anatomy and 

 physiology of seed-plants is considerably increased and addi- 

 tional experiments are introduced. 



3. The treatment of spore-plants is greatly extended, so as 

 to include laboratory work on the most important groups. 



4. The meagre Flora which accompanied the earlier book 

 has been replaced by one which contains fairly full descrip- 

 tions of nearly seven hundred species of plants. Most of 

 these are wild, but a considerable number of cultivated species 

 have been included, mainly for the convenience of schools in 

 large cities. 



Ample material is offered for a year's course, four or five 

 periods per week. The author is well aware that most schools 

 devote but half a year to botany, but the tendency sets strongly 

 toward allowing more time for this subject. Even in schools 

 where the minimum time allowance is devoted to botany, there 

 is a distinct advantage in being provided with a book which 

 allows the teacher considerable option as regards the kind 

 and amount of work which he shall offer to his classes. 



