ADI A A r T UM PEDA TUM. 1 1 3 



with a thickening deposit, similar to that of the 



inner layers of the wall. 

 e. The abundance of starch in this tissue. 

 /. Draw several sclerenchyma cells showing these 



points. 



8. The cortical parenchyma^ lying just outside the bundle- 

 sheath in some places. Observe 



a. That the walls are thin and colorless, with trian- 

 gular intercellular spaces ; contents of the cells, 

 granular protoplasm and starch. 



b. Compare carefully the middle lamella of the 

 sclerenchyma with the walls of the parenchyma 

 where the two tissues merge. 



c. Draw several parenchyma cells. 



9. The bundle-sheath. Notice the emptiness 8 of the cells, 

 their shape, and the position of their longer axes. 



10. The fibro-vascular bundle; easily distinguishable into 

 two regions : first, a central one, the xylem, char- 

 acterized by the numerous large openings of the 

 scalariibrm vessels, with small cells, the xylem paren- 

 chyma, packed between them ; secondly, a peripheral 

 one, the phloem, showing cells of much more uniform 

 diameter, and lying between the xylem and the bundle- 

 sheath. This region contains phloem parenchyma and 

 sieve cells, Study carefully each of the above 

 named tissues. Commencing at the bundle-sheath, 

 examine 



a. The phloem parenchyma ; composed of two or three 

 (occasionally but one) irregular rows of small thin- 

 walled cells next the bundle-sheath and a few cells 



6 Sometimes a few starch grains appear to lie in them ; they have been 

 pulled over by the razor in cutting. 



