CLASSIFICATION. 



297 



Asexual, or Flowerless Plants^ 



rAIgales 

 Dteirj! and leaves imdistinguisliable I. Thaxlogens < Fuugales 



iLichenalea 



Stems and leaves distinguishable n. Aceogens < Lycopodales 



Sexual, or Flowering Plants. 



Wood of stem youngest in centre ; 

 cotyledon single. 



Leaves parallel-veined, permanent ; 

 wood confused 



III. Endogens 



Leaves net-veined, deciduous • 

 wood, when perennial, arranged 

 in a circle with a central pith 



Wood of stem youngest at circum- 

 ference, always concentric ; coty- 

 ledons two or more. 



Seeds quite naked 



IV, DiCTTOGENB. 



'Glumaltiu 



Arales 



Palm ales 



Hydrales 



Narclssalea 



Amomales 



Orchidalea 



Xyridales 



Juncales 



Liliales 



.Alismales 



V. Gymnogbns. 



Kee<ts enclosed in seed-v 



VI. ESOGENS 



Diclinous 



Hypogj'Tious 



Perigynous 



-EpigjTious 



/-Am en tales 

 J Urticales 

 ] Euphorbialos 

 *- &c. Ac. 



{Viol ales 

 Cistalea 

 Malvaifs 

 &c. &c. 

 rPicoidales 

 J Daphnales 

 ] Resales 

 ^ &c. &c. 

 rCampanales 

 J Myrtales 

 1 Caotales 

 ^ &c. &c. 



Here, linear arrangement has disappeared : there is a 

 breaking up into groups and sub-groups and sub-sub-groups, 

 which do not admit of being placed in serial order, but only 

 in divergent and re-divergent order. Were there space to 

 exhibit the way in which the Alliances are subdivided into 

 Orders, and these into Genera, and these into Species ; the 



the parts no longer needed, abort, and those parts develop which favour the 

 preservation of the race. Similarly in the ^hizoffens, the abortive development 

 of the leaves, the absence of chloropnyll, and the imperfect supply of spinil 

 vessels, are changes towards a structure fit for a plant which lives on the juices 

 absorbed from another plant; while the rapid and great development of the 

 fructifying organs, are correlative changes advantageous to a plant, the seeds of 

 which have but small chances of rooting themselves. And just the same reason 

 that exists for the production of immensely numerous but extremely small eggs 

 by Entozoay exists for the production by Rhizogens^ of seedh that ai"e great in 

 uumber and almost spore-like in size. 

 20 



