xl DIVISIONS -OF THE NATURAL SYSTEM. 



SUB-CLASS A.^EI^LOIPE^,'. . t . . . . Page 155. 

 Floral envelopes verticillate, mostly petaloid. Perianth 

 single, or sometimes none. 



SUB-CLASS 2. GLUMACE^E, . . . Page 174. 



Perianth none. Floral envelopes imbricated, consisting of 

 chaffy scales or glumes. 



Division B. CRYPTOGAMOUS or flowerless plants. 



CLASS III. 



ACOTYLEDONS OB ACROGENS, . . . Page 202. 



Plants bearing no true flowers ; the organs of reproduction are 

 bodies resembling seeds called spores, having no embryo, conse- 

 quently without any cotyledons. Increase of growth takes place 

 at the apex of the stem when present, and the woody bundles are 

 arranged in a zigzag manner. The venation of the leaf or frond 



by repeated forkings, often rather complicated. 



