TI4 



ther out in the axis. This young blade possesses on the side marked T* 

 uniformly connected bark tissue; on the opposite side /i, however, the 

 first sheath-formed leaf (sch) which remains colorless, and the bud of the 

 next higher leaf, the first green one (bl), which is completely developed later, 

 have been difYerentiated from the bark tissue. In the axis of this first leaf may 

 be seen the meristematic position of the first lateral bud ^^nj which pushes 

 out the green leaf lying in front of it with its already clearly developed epi- 



Fig. 10. Cross-section through the lowest node of a young rye plant. 

 Explanation of lettering in text. (Orig.) 



dermis (e ) ; e is the epidermis of the sheath leaf which is already being 

 differentiated from the axis. If the (dotted) tissue of the bud of the first 

 green leaf (bl) be traced backward in this cross-section toward the side 

 marked V it is seen that this passes over into a colorless tissue ring char- 

 acterized, however, by its comparatively large intercellular spaces contain- 

 ing air (i) ; the bark tissue of the young blade. It is seen from this that each 

 grain leaf is a direct continuation of the bark of the blade. This bark ring 



