CHAPTER III. 



THE MICEOSCOPE AND CELL-STEUCTTJEE. 



93. Microscope Work, if not allowed to occupy time 

 which would (in the case of a beginner) be better spent in 

 making physiological experiments and in studying flowers, 

 fruits, plant-associations, etc., is valuable in helping one 

 to understand more fully the life-processes and adaptations 

 of plants, especially if minute structure is studied in close 

 connection with physiology. 



Fig. 29. Folding Pocket Lenses (Double and Triple). 



Lenses. The use of the simple lens has already been men- 

 tioned (Art. 4). A double or triple folding lens (Fig. 29) 

 is a great improvement on the simple lens, giving greater 

 magnifying power when the lenses are used together. A lens 

 of this kind is absolutely indispensable. 



58 



