.114 THE NATURAL SYSTEM. 



345. The first and highest division of the vegetable kingdom, 

 namely, into the Phcenogamia or Flowering Plants, and the 

 Cnjptogamia or Flowerless Plants, has akeady been noticed, 

 and its distinctions explained, in Chapter III., and elsewhere. 

 These grand divisions He at the foundation of both the System 

 of Linnaeus and of Jussieu, and are truly founded in nature ; 

 for 



The Ph^xogamia 



1. Consist of a regular axis of growth with leafy appendages. 



2. They possess a woody and vascular structure. 



3. They develope flowers, and 



4. They produce seeds. On the other hand 



The CRYPTOGA3IIA 



1. Are destitute of a regular axis and of true leaves. 



2. They possess a cellular structure only. 



3. They do not develope flowers, and 



4. They produce spores (129) instead of seeds. 



346. These distinctive characters must not, however, be regarded as decisive in 

 all cases ; for the higher Cryptogamia, as the ferns, give indications both of a regu- 

 lar woody axis and of a vascular stinicture, while some of the lower Phgenogamia 

 can scarcely be said to produce flowers. And, universally, so gradual are the 

 transitions from family to family and tribe to tribe, that it is impossible to fix 

 upon characters so definite as to completely circumscribe any one group, while at 

 the same time, they exclude every member of surrounding and approximatmg 

 groups. 



347. There is a small and curious order of plants of comparatively recent dis- 

 covery, native chiefly of the East Indies, which appear, from the most authentic 

 accounts of them, to fonn the connecting link betAveen the Flowering and Flow- 

 erless plants, combining a part of the characters of each, so that botanists are at 

 a loss to which it belongs. They possess a cellular structure, develope flowers 

 immediately from the root, whence they are called Ehizanths (o(C»;, a root, avfloc, 

 a flower) ; but their ovaries are said to be filled vAih spores instead of seeds, and 

 hence they are also called Sporogens. Ex. Rafilesia. 



348. Again, the Phssnogamia are veiy naturally resolved into 

 two subdivisions, depending upon their manner of gi'owth, caUed 

 ExoGENS and Endogens, whose distinctions are briefly as fol- 

 lows : — 



ExOGENS, 



1. Growing by extemal accretions (196). 



2. Bearing leaves which have reticulated veins (229) and which fall off by 

 an articulation. 



3. Seeds with two or more cotyledons (127) or dicotyledonous. 



