DISTINCTION OF CLASSES. 



215 



As much of the facility of distinouishino^ Mono- 

 cotyledonous from Dicotyledonous plants depends 

 upon a familiarity with the appearance of their 

 leaves, let me recommend you, before we proceed 

 any further to procure those of Corn or Grass, of the 

 Pine Apple, the Hyacinth, the Tulip, or the Daffodil, 

 and compare them with any of the Dicotyledonous 

 plants, you are now familiar with. In the mean- 

 while I will sketch a comparative view of JNIonocoty- 

 ledonous and Dicotyledonous plants, which you can 

 afterwards study at your leisure. 



DICOTYLEDONOUS PLANTS. 



Stems generally branched, &wlien 

 old covered with cracked bark. ! 



MONOCOTYLEDONOUS PLANTS. 



Stems generally quite simple ; and 



when old covered with smooth 



I bark. 



Wood, consisting of concentric] TFbo^, not consisting of concentric 



circles; the central part the j circles; the central part the 



oldest and hardest; the bark 

 connected with a central pith, 

 by means of thin plates called 

 medullarv rays. 



youngest and softest; the bark 

 not connected with a central 

 pith by means of medullary 

 rays. 



Leaves, with veins arranged in a I Leaves, with simple parallel veins, 

 netted manner; usually jointed which are not netted; usually 



with the stem. 



Flowers, usually vrith the paits ar- 

 ranged in fours or fives. 



Embryo, with two or more seed- 

 lobes, or cotyledons. 



Found wild as trees all over the 

 world, except in thevery highest 

 latitudes. 



not jointed with the stem. 

 Flowers, usually with the parts ar. 



ranged in threes. 

 Embryo, with only one seed-lobe, 



or cotyledon. 

 Found wild as trees only in hot 



climates, and chiefly within the 



tropics. 



These preliminary observations will, I trust, have 

 conveyed to you some general notions of the nature 



