DIVISION II 



PHANEROGAMS ou 



SEED-PLANTS 



THE CLASSIFICATION OF PLANTS 233 



CLASS I 



GYMNOSPERMS or seed-plants with naked ova- 

 ries, such as pines, spruces, cedars, and many 

 other evergreen trees. 



f SUBCLASS I 



CLASS II 

 ANGIOSPERMS or 



seed-plants with 

 closed ovaries 



MONOCOTYLEDONQUS 



PLANTS 



SUBCLASS II 

 DICOTYLEDONOUS 



PLANTS 



256. The Groups of Cryptogams. The student is not 

 to suppose that the arrangement of cryptogams into the 

 four great groups given in the preceding table is the only 

 way in which they could be classed. It is simply one 

 way of dividing up the enormous number of spore-bearing 

 plants into sections, each designated by marked character- 

 istics of *its own. But the amount of difference between 

 one group and another is not always necessarily the same. 

 The pteridophytes and the bryophytes resemble each 

 other much more closely than the latter do the thallo- 

 phytes, while the myxothallophytes are but little like other 

 plants and it is extremely probable that they are really 

 animals. 



The classes given in the table do not embrace all known 

 cryptogams, but only those of which one or more repre- 

 sentatives are described or designated for study in this 

 book. Lichens in one sense hardly form a class, but it is 

 most convenient to assemble them under a head by them- 

 selves, on account of their extraordinary mode of life, a 

 partnership between algae and fungi. 



257. The Classes of Seed-Plants. The gymnosperms 

 are much less highly developed than other seed-plants. 



