Xll INTRODUCTION 



the pupils for study, and then substitute the object. If 

 composition is to be taught let the pupils write upon 

 what they have seen. After a time, give ten min- 

 utes now and then to asking the children what they 

 saw on their way to school." 



It is often said that a person may learn a good 

 deal about plants with only a very ordinary hand lens. 

 This is true ; but he can also learn a good deal with- 

 out any lens. It is not impossible that in the haste 

 to give the pupil a microscope, we have forgotten 

 the training of the natural eye ; and it is upon this 

 natural eye that the great mass of people must de- 

 pend. These remarks are made simply to emphasize 

 the fact again that much more depends upon the 

 teaching power of the teacher than upon the mere 

 equipment of the school-room. It will not be neces- 

 sary for the pupil to have a lens in order to take up 

 the kind of work suggested in this book, but he 

 ought to have one. There are two essentials in a 

 pupil's microscope : a large field (not less than three- 

 fourths inch across), and a size which will allow of 

 its being carried in the pocket. Pupils generally think 

 of a lens as a piece of school -room apparatus, as 

 slates and pens are, but it should be a constant com- 

 panion in the field. If it can be used in only one 

 place, let that place be out of doors. These instru- 

 ments magnify three diameters or less, and the number 

 of lenses is two or three. For the use of advanced 



