vi CONTENTS 



PAGE 



Principal Focus 26 



Fooal Distance 26 



Real Images 27 



Virtual Images 28 



Spherical and Chromatic Aberrations 29 



The Simple Microscope 31 



Construction and Uses 31 



The Compound Microscope 33 



Optical Parts 35 



Objectives 35 



Oculars 38 



Condensing Lenses and Mirror 39 



Mechanical Parts 41 



Use of the Compound Microscope 44 



Position of Microscope and Worker 45 



Lighting 45 



Focusing with Low Powers 46 



Focusing with High Powers 48 



Summary of Focusing Technic 49 



Use of the Eyes . 49 



Cleaning the Microscope 50 



Interpretation of Images 51 



Drawings 52 



CHAPTER IV 

 THE CHEMICAL REACTIONS OF PLANT TISSUES 



Chemical Properties of Cell Walls 57 



Cellulose Walls 58 



Lighified Walls 58 



Cutinized and Suberized Walls 59 



Gums and Pectinous Substances 59 



Chemical Properties of Cell Contents 60 



Starch 61 



Inulin 61 



Sugars 62 



Alkaloids 62 



Glucosides 63 



Calcium Oxalate 63 



Aleurone 64 



Tannins 64 



