CRYPTOGAM1A. FERNS. 27 



make their appearance. Now of all trace of cotyledons, the 

 embryo of the Flowerless-plant is entirely destitute ; and the 

 whole group is hence spoken of as Acotyledonous. On the other 

 hand, of the Flowering-plants, some possess one, and others two 

 cotyledons ; and this difference in the structure of the seed is 

 accompanied by so many other differences in the structure of the 

 stems, the leaves, flowers, &c., that it serves to mark the two 

 principal subdivisions of this portion of the Vegetable Kingdom. 



ACOTYLKDONE.E. MONOCOTYLEDON KJE. DICOTYLKDONK.*:. 



CONFERVA. Cocos. tiiNApis. 



FIG. ]. 



That in which one cotyledon exists is termed Monocotyledonous ; 

 and that in which there are two, Dicotyledonous. The common 

 Bean or Pea will serve as a characteristic illustration of the 

 latter ; and the Wheat and other Grass-seeds, of the former. 



22. The general aspect of the Flowering-plants is sufficiently 

 well known, to render a more minute account of them here 

 unnecessary ; since the object of this preliminary view of the 

 Vegetable Kingdom, is to render the student, who may have 

 been previously entirely ignorant of the subject, prepared to 

 enter with advantage on that detailed description of the mode, in 

 which the several tribes grow and reproduce themselves, which 

 it is the object of the Physiological portion of this Volume to 

 communicate. A fuller sketch of the principal divisions of the 

 Cryptogamia will, however, now be given, as few ordinary 

 observers bestow much attention on them. 



23. Of all the CRYPTOGAMIA, the Ferns approach most nearly 

 to Flowering Plants. The general aspect of those inhabiting this 



