1 88 FIELD OATS. 



8. The epidermal cells. 



a. The shape of those lying above a vein, together 

 with the short strong trichomes, each bearing a 

 very sharp point, directed forward. 



b. The shape of those lying among the stomata. 



c. The stomata. Note 



i. The regular arrangement in double or triple 



rows, 

 ii. The pair of narrow epidermal cells, which 



stand one on each side of the guard cells, 

 iii. The shape of the guard cells ; the thick walls 



of the body and thin walls of the ends, 

 iv. Draw, showing the several sorts of epidermal 



cells. 



9. The shape and contents of the mesophyll cells, some of 

 which will almost invariably adhere to the epidermis 

 when stripped off. Draw. 



10. Make a transverse section of the leaf sheath, and note 

 its intermediate character between that of the stem and 

 of the leaf blade already studied. Draw sufficient to 

 show the various tissues, and their arrangement. 



D. THE FLOWER. 



i. The glumes and palets. Make a transverse section 

 through the upper part of a spikelet and transfer it to 

 the slide without disarranging the parts. Note 



a. The thin-walled cells forming the inner portion, 

 and the thick-walled cells forming the outer por- 

 tion of each part. Draw from two or more 

 regions. 



b. The angles of the palets, bearing stiff trichomes. 

 Draw. 



