TABLE OF CONTENTS xv 



LESSON XIII. 



PAG F. 



SPECIES AND THEIR ORIGIN : THE PRINCIPLES OF CLASSIFICA- 



TION .................. 135 



LESSON XIV. 

 THE FORAMIN'IFERA ............... 146 



THE RADIOLARIA ........... ..... 



THE DIATOMACE/E ............... 153 



LESSON XV. 



MUCOR ....... ........... 156 



LESSON XVI. 



VAUCHERIA . . . ............... 167 



CAULERPA .......... ........ 173 



LESSON XVII. 



THE DISTINCTIVE CHARACTERS OF ANIMALS AND PLANTS . . 174 



LESSON XVIII. 



PENICILLIUM . . ............... 



AGARICUS . , , ............... 



LESSON XIX. 



SPIROGYRA . . .............. 1 9 2 



LESSON XX 



MONOSTROMA ...... ..... J 99 



ULVA. ... ..... ..... ... 201 



LAMINARIA, &C ....... ......... 2OI 



