CLASSIFICATION. 



297 



rAlgales 

 I. THALLOGENS < Fuugalee 



Asexual, or Floioerless Plants* 

 Btemfl and leaves undistinguishable 

 Stems and leaves distinguishable 



Sexual, or Flowering Plants. 



II. ACBOGENS 



v.Licheuales 

 rMuscales 

 < Lycopodales 

 iFilicalea 



Wood of stem youngest in centre ; 

 cotyledon single. 



Leaves parallel-veined, permanent j 



wood confused III. ENDOGENS 



Leaves net-veined, deciduous ; 



wood, when perennial 

 in a circle with a cent 



th a central pith IV. DICTYOGENS. 

 Wood of stem youngest at circum- 

 ference, always concentric ; coty- 

 ledons two or more. 



Seeds quite naked V. GYMNOGENS. 



Glumales 

 Arales 

 Palmales 

 Hydrales 

 Narcissalea 

 Amomales 

 Orchidales 

 Xyridales 

 Juncales 

 Liliales 

 ^Alismales 



beeds enclosed in seed-vessels VI. EKOGENS 



/Amen tales 

 I Urticales 

 | Euphorbialcs 



Hypogynous 



Perigynous 



Epigynous 



o. &c. 

 rFicoidalcs 

 J Daphnales 

 I Resales 

 &c. Ac. 

 Campanales 

 Mvrtales 

 Cactales 

 &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 Ehizogens, the abortive development 

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

 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 Entozoa, exists for the production by Rhizogens^ of seeds that ure great HI 

 flumber and almost spore-like in size. 

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