THE ANGIOSPERMAE : LEAVES 1013 



often an increase of frequency from the base to the tip of the lamina and 

 from the midrib towards the margins in the individual leaf. 



Stomata in Dicotyledons are characteristically orientated at random (Fig. 

 1000), that is to say, their long axes do not lie in any particular direction. 



f 



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r 









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Fig. 1 000. — Forsythia siispensa. Epidermis from the lower 

 surface of leaf showing random orientation of stomata. 



Careful analysis has shown, however, that this irregularity is only apparent 

 and is not related to the irregularity of the epidermal cells (Fig. looi), but 



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^ 





H-^..; ■-■V- 





Fig. iooi. — Paeonia corallimi. Lower epidermis of leaf 

 showing random distribution of stomata and the 

 irregularity of the cell walls. 



