118 



Vegetable Physiology. 



confused mass, with strings or fibres interspersed. A longit u . 

 dinal section of the same stem is represented in b, in which the 

 membranes between the cells are more distinctly shown. ^ 

 fig. 10, a, is represented the germination of a monocotyledonous 

 seed, and b shows the leaf of a plant of this class, with its 

 characteristic parallel veins. 



Fig. 11. 



a 



Figure 10. 



Figure 11, represents a transverse section 

 of the stem of an Exogen or Dicotyledonous 

 plant. In this, the distinctions of wood, pith 

 and bark, the concentric rings, and the me- 

 dullary rays are apparent. The seed of an 

 Exogen is represented in a state of germina- 

 tion, in fig. 12, «, and an exogenous leaf, with 

 its reticulated structure, in b. 



Figure 12. 



Such are the very plain distinctions between the two great 

 Masses of Flowering plants, and it will at once be evident that 



