37* ELEMENTARY ORGANS. CHAP. III. 



pearance is again exhibited, and so on in suc- 

 cession throughout the whole of the leaf-stalk, 

 which shows that they must be pretty closely in- 

 serted on the internal surface of the tubes or 

 apertures, on a thin and longitudinal slice of which 

 they may also be seen even in their consecutive 

 order. 



