CONTENTS. 



I. THE MICROSCOPE 1 



II. THE MOUNTING OF OBJECTS . 10 



III. VEGETABLE ELEMENTS AND TISSUES 19 



IV. VEGETABLE OEGANS 31 



V. FERNS 49 



VI. MOSSES 54 



VII. ALG^E 64 



VIII. LICHENS 91 



IX. FUNGI 96 



X. ANIMAL ELEMENTS AND TISSUES 113 



XI. AKTICULATA 127 



XII. RADIATA 153 



XIII. PROTOZOA , 155 



XIV. OPTICAL PRINCIPLES . 167 



