ATENA SATITA. 175 



6. The remainder of the section made up of large rounded 

 cells, parenchyma, scattered through which are 



7. Masses of firmer tissue, the fibro-vascular bundles, each 

 having three or four openings, the vessels. 



8. Draw the section. 



Cut a number of longitudinal sections ; in them make 

 out 



9. The denser cortical portion. 



10. The more transparent parenchyma. 



11. The fibro-vascular bundles. 



12. In a section not passing through a fibro-vascular bun- 

 dle, the strip of darker chlorophyll-bearing tissue 

 under a very narrow cortical layer. 



13. Draw a section, showing as much as possible of the 

 structure. 



D. THE LEAF. Note 



1. Its sheathing base. Observe the extent of stem cov- 

 ered by each sheath. 



2. The split in the sheath ; its position and extent. 



3. On the upper surface at the point where the sheath 

 ceases, a thin membranous outgrowth, the ligule. 

 Notice its shape and apex. Draw. 



4. The place of attachment of the leaves. 



5. The remainder of the leaf, the blade. Note 



a. Its shape. 



b. The numerous veins ; their direction and relation 

 to the ridges. 



c. The green tissue (bleached by alcohol) between 

 the veins, the mesophyll. 



