GROWTH OF MOXOCOTYLEDONES. 57 



rishment, and the means of increase, from 

 the leaf above it. 



Bv the above view of the vejretable cecono- 

 my, it appears that the vascular sj'stem of 

 plants is strictly annual. This, of course, is 

 admitted in herbaceous plants, the existence 

 of whose stems, and often of the whole in- 

 dividual, is limited to one season; but it is 

 no less true with regard to trees. The layer 

 of alburnum on the one hand is added to the 

 wood, and the I'lb^r, or inner layer of the 

 bark, is on the other annexed to the layers 

 formed in preceding seasons, and neither have 

 any share in the process of vegetation for the 

 year ensuing. Still, as they continue for a 

 long time to be living bodies, and help to 

 perfect, if not to form, secretions, they must 

 receive some portion of nourishment fro.m 

 those more active parts which have taken up 

 their late functions. 



There is a tribe of plants called monocoty-' 

 ledones^ having only one lobe to the seed*, 

 whose growth rec^uires particular mention. 

 To these belongs the natural order of 

 Palms, which being the most lofty, and, 



* Or rather no true cotvlcdon at all. 



