vi Preface 



the relative interest they have manifested in different kinds of 

 subject matter, and their responses to various methods of pres- 

 entation have furnished a valuable basis for evaluating ideas and 

 suggestions from the first two sources. 



A fourth set of suggestions has come from the questions asked 

 by the public. These inquiries are usually very practical. Often 

 they are unanswerable, but an introductory course should en- 

 able a student either to answer many of them or to find the 

 information that is called for. 



Suggestions from the above four sources have been consciously 

 sought during the working out of the course. We have at- 

 tempted to avoid trespassing on allied fields, but we have not 

 hesitated to point out many important uses and applications of 

 botanical principles. 



The selection of subject matter, however, is only one of two 

 important elements in presenting any science course. Equally 

 important is the efficient use of the time given to field and lab- 

 oratory exercises, which after all are the heart of the course. 

 Textbooks may furnish a fund of information that will conserve 

 time in the classroom, but it is the work in the field and the lab- 

 oratory that tests the ability and insight of the student, and 

 makes real (or sometimes unreal) classroom and textbook state- 

 ments. 



The use of the field and laboratory time for the answering of 

 questions and the solving of problems, rather than for the making 

 of detailed drawings, has changed the attitude of our students 

 toward laboratory work. It has also made it possible to cover a 

 far greater range of materials and principles than formerly, and 

 to give the student with a scientific mind as good a chance as the 

 student with an artistic hand. We prefer to use the laboratory 

 and field periods not for drawing exercises but for study and 

 recitation in the presence of the materials. 



Although the laboratory and field work were developed first, 

 the textbook is being published in advance of the laboratory out- 



