A TEN A SATIVA. 181 



1. The cortical, thin-walled cells. 



2. The fibro-vascular, thick-walled cells. 

 Examine with a high power, and note 



3. The thin-walled epidermis. Observe its irregularity, 

 and the mode of attachment of the root-hairs. Draw. 



4. The cortical parenchyma, with sclerenchyma either 

 intermixed, or in older roots forming an outside layer. 

 Draw. 



5. The bundle sheath ; the relative thickness of outer and 

 inner walls ; the pits. Draw. 



6. The fibro-rasciilar bundle. Study 



a. The smaller thick-walled cells constituting most 

 of the bundle. 



b. The vascular tissue ; four to six (sometimes more) 

 \ax%t pitted vessels symmetrically disposed. Between 

 each of these and the bundle sheath (also some- 

 times near the center) a dozen (more or less) of 

 smaller pitted vessels. 



c. Numerous channel-pits in all the thick-walled 

 cells. 



d. Draw a portion of the bundle. 



Cut a longitudinal section of the same root. Examine 

 with a high power, and note 



7. The epidermal cells. Observe the bases of root-hairs, 

 and their relations to the epidermal cells. Draw. 



8. Elongated cortical parenchyma and occasionally 

 sclerenchyma. Notice the pits. Draw. 



9. The bundle, sheath ; cells elongated, rather difficult to 

 distinguish. Draw. 



10. The fibro-vascular bundle. Study 



