PEDATUM. 109 



a. The shape as to outline and margin. 



b. Draw carefully an outline of the pinnule studied. 



c. Compare the shape of the terminal pinnule with 

 those near the middle of the rhachis. Note that 

 it is like two of the latter joined by their bases. 

 Compare also the basal pinnules with the middle 

 ones. Draw an outline of the terminal and basal 

 pinnules. 



d. The surface, texture, and color. 



e. The structure. Notice 



i. The slender stalk at the angle formed by 

 the lower and basal edges, attaching the pin- 

 nule to the rhachis. 



ii. The slender branching threads, veins, ex- 

 tending from the apex of this stalk and 

 supporting 



iii. The green substance of the pinnule, the mes- 

 ophyll, which fills all the space between the 

 veins. 

 /. The arrangement of the veins, venation. Notice 



i. One vein a little stronger than the rest, par- 

 allel with and close to the lower edge. 

 The mode of branching. 

 That the veinlets are not connected into a 

 network. 



iv. Compare with the venation of the basal and 

 terminal pinnules. 



v. In the outline drawings of the terminal, basal 

 and middle pinnules already made draw the 

 veins. 



4. The reproductive bodies. Observe 



a. On the upper edges of the under side of the pin- 

 nules a large number of crescent shaped spots, 



