xxiv DIRECTIONS FOR STUDY. 



species that do not occur in this country, and illustrations 

 of the classes of flowerless plants have been added for 

 which Prof. Henslow did not find room. 



In the plan of the charts, the plant is first represented 

 of its natural size and colors ; then a magnified section of 

 one of its flowers is given, showing the relations of the 

 parts to each other. Separate magnified views of the 

 different floral organs, exhibiting all the botanical charac- 

 ters that belong to the group of which it is a type, are also 

 represented. The charts contain nearly five hundred fig- 

 ures colored to the life, and which represent twenty-four 

 orders and more than forty species of plants, showing a 

 great variety of forms and structures of leaf, stem, root, 

 inflorescence, flower, fruit, and seed, with numerous in- 

 cidental characters peculiar to limited groups. All these 

 are so presented as to be readily compared and contrasted 

 with each other. 



The charts are not designed to supersede the study of 

 plants, but only to facilitate it. Their office is the same 

 as the illustrations of the book ; but they are more perfect, 

 and bring the pupil a step nearer to the objects themselves. 



Besides this special assistance in object-study, the 

 charts will be of great value in illustrating the Flora. In 

 fact, they are designed to present, fully and clearly, those 

 groupings of characters upon which orders depend in 

 classification ; while in several cases of large and diversi- 

 fied orders the characters of leading genera are also given 

 by typical specimens. The charts will thus be found 

 equally valuable to the beginner, the intermediate pupil, 

 and the advanced student. A Key accompanies the charts, 

 and they can be used with any botanical text-books, and 

 during the season of plants they should be upon the walls 

 of every school-room where botany is studied. 



