PART n.] INTRODUCTION. 237 



toofarase, which signifies that their flowers are 

 hidden. The most remarkable of the Crypto- 

 gamous plants are the ferns, some of which 

 become lofty trees ; the wood of which is in 

 curious wavy lines, as it appears to be formed 

 by the footstalks of the decayed leaves growing 

 together and becoming woody. The veins in the 

 leaves or fronds of the ferns are forked. 



Besides the great divisions already mentioned, 

 the Dicotyledonous plants have been divided 

 into the Dichlamydese, or those having both 

 calyx and a corolla ; and the Monochlamydese, 

 or those having only a calyx ; but there are so 

 many exceptions, as to render this division of 

 little value. The Monochlamydese are not sub- 

 divided, but the Dichlamydese are again divided 

 into the Thalamiflorse, in which the petals and 

 the stamens grow separately out of the thalamus 

 or flat part of the receptacle, and generally from 

 below the pistil ; the Calyciflorse, in which the 

 stamens and petals are either attached to the 

 calyx, or to a lining of it formed by the dilated 

 receptacle ; and the Corolliflorse, in which the 

 petals grow together, so as to form a cup for the 

 pistil, and which have the stamens attached to 

 the corolla, but quite distinct from the calyx. 

 The Monocotyledones have also been redivided 

 into the Petaloid, or those with regular flowers, 



