14 



Elementary Plant Physiology. 



Fig-. 5. — Structure of a monocotyledonous stem. -4, a grass with sheathing- leaf- 

 bases z/, w, z/, z/ ; B^ portion of a stem including a node cut longitudinally and 

 enlarged ; d^ point of union of two internodes above place of insertion of the 

 leaf sheath j, s; k^ A, enlarg-ed portion of leaf base, sheathing the growing region 

 of the internode designated by v. After Frank. 



the woody and firm cells. Secondary bundles may be found 

 between the primary ones seen myounger material. Note the 

 thin layer of cambium outside the wood (Fig. 3, C). 



