IV PREFACE. 



the study of material easily collected. This emphasizes the de- 

 sirability of supplementing the regular laboratory course with 

 the out-door work, or with observations on material suitable to be 

 employed in out-door work when conditions permit. The third 

 chapter then treats of protoplasm (the living substance) in the 

 root hairs of seedlings, followed by a similar study in spirogyra. 

 In the following chapters much the same order is used as in the 

 larger book, but there has been an attempt to simplify the 

 treatment. Very much of the technical matter in the larger 

 book has been omitted here, and in consequence much of the 

 matter which is useful for reference to those who desire supple- 

 mentary reading and explanations. For this matter the larger 

 Elementary Botany should be consulted. 



The studies indicated in the part on ecology are not intended 

 to be pursued as a distinct and separate piece of work, but they 

 may be made the basis of excursions during the progress of the 

 work on physiology and morphology. It is possible to indicate 

 definitely where some of these out-door studies are applicable. 

 At the same time the retention of the third part as a distinct 

 subdivision of the book serves to emphasize the importance of 

 ecological study, or perhaps rather of the study of plant life on 

 a larger scale, and some of the interesting problems connected 

 with the environmental influences on plant life and plant com- 

 munities. It should be recognized that plant distribution, as 

 well as many of the other important problems connected with 

 ecological study, cannot be carried on in the secondary schools 

 with the rigid system applicable in the college or university, or 

 even with the precision which the student of ecology would 

 desire, since a considerable previous technical knowledge of 

 plants would be necessary. The chief importance of the study 

 in the secondary schools is, I believe, to get the pupil interested 

 in observing living plants, and in gaining a general impression 

 of the fundamental laws, and in leading the pupil to realize, in a 

 measure, the great influence which environment has on living 

 beings. 



