PHYTOLOGT. 291 



fuel in dry situations. They correspond to the Pyreno- 

 mycetes or Sphaeriaceae. 



1555. As the variegated colours appear in the blossom, 

 so do they also in the lichens ; but here they are for the 

 first time chemically developed, distributed throughout 

 the whole substance, and concealed. Most lichens yield 

 colouring matters. 



1556. As the stem is, in accordance with their signi- 

 fication, wanting to the lichens, they thus require a 

 foreign trunk for their nutrition. They are therefore 

 developed for the most part upon other plants, and prin- 

 cipally upon the bark. 



1557. Lastly, the fifth order, Fruit-mosses, originates 

 through the development of a self-substantial/raY upon 

 a cauliform stem the Mosses proper. 



1558. As these are the highest plants of this class, 

 and those that directly precede the tracheal formation, 

 so the bark already resolves itself into individual leaves, 

 which are, however, still destitute of spiral vessels. 



1559. What have been called the seeds or sporules 

 are accumulated in a capsule-like fruit upon the summit 

 of the stalk. This fruit corresponds to the pileated 

 fungus, and therefore springs up in an opercular manner 

 like the latter. 



1560. But this capsule is only a spermoderm, which 

 incloses albuminous granules that have no proper 

 germ or seed-lobes ; they are plants with seed-vessels or 

 pyxidia, upon an open-leaved stalk. 



1561. They divide likewise in to sixteen families. (Vid. 

 Tab. B.) 



CLASS III. 



Trachea-plants Ferns. 



1562. At first a fascicle only of spiral vessels can ori- 

 ginate, which is necessarily surrounded by cellular tissue, 

 and therefore lies in the middle of the plant. Such plants 

 are the Filices or ferns. 



1563. As the spiral vessels are the antetype of the 



