PREFACE vii 



courses dealing with plants are often in need of pruning in 

 the interest of the fruit desired. 



It is a pruned-back course which is presented herewith, 

 even though the informal style of presentation may lead 

 the reader sometimes to think it otherwise. Omissions 

 have been weighed equally with inclusions. In the inter- 

 est of a certain end in view, whatever seemed dispensable 

 has been dispensed with. That certain end in view is a 

 broad and a true conception of plants and of their princi- 

 pal relations to mankind. If our subject is to be a science, 

 and not a mere mass of information, then such a concep- 

 tion is the first claim upon plant knowledge which we are 

 called upon to satisfy, as well as the necessary foundation 

 for additions of special knowledge. All that is herein 

 included is meant to be contributory to that conception ; 

 bricks, as it were, in that foundation. 



Style. The manner of the book has been determined 

 by a desire to make what is important seem interesting to 

 young readers. If the author has been successful in what 

 he has attempted, the intellectual effort per page needed 

 to comprehend the text will be considerably less than if 

 the book had been written with the idea of a formal text- 

 book in mind. The teacher, in making assignments, should 

 take this matter into consideration. 



Introduction. The introduction aims at appreciation. 

 It rests on the principle of Herbart that "the pupil must 

 know from the beginning what is aimed at if he is to 

 employ his whole energy in the effort of learning." It is a 

 frank attempt at motivation. It may be included or it may 

 be omitted in the assignments. It falls into two parts. 

 The first is devoted to appreciation of the subject matter to 

 be studied ; the second, to appreciation of the method of 

 study to be used. The idea of this second part is to get 



