THE FLOWEEIlfG PLANT — STEMS 349 



ment and shape of the branches on the plant. Eemove 

 some to the laboratory, and study their structure as de- 

 tailed below. "When not in use keep the material, if 

 fresh, under large bell -jars or in closed boxes, with 

 plenty of moisture and protected from evaporation. 

 Examine alcohohc material in a mixture of equal parts 

 of glycerine and fifty per cent, alcohol. 



MOEPHOLOGT 



Naked-eye Characters. 



Examine the stem of the horse-chestnut, and 

 note the following characters : 



a. Shape. — "What is it ? "What variations do you find 

 in different specimens ? Is there a general shape 

 for all of the branches on the tree ? How does 

 the shape of the branch compare with that of the 

 main stem or trunk of the tree ? How do you 

 account for the bends in the stem ? Draw. 



h. Size. — "What is the diameter of the specimen under 

 examination? Is it the same throughout its 

 whole length? How do you account for the 

 facts observed ? 



c. Color. — "What is the general color of the branch ? 



To what is it due ? Do you find any variations in 

 color in different parts of the stem ? How do you, 

 account for such ? 



d. Structure. — ISTotice that the stem consists of a se- 



ries of sections or internodes connecting at 



joints or nodes. 

 1. The internode. — "What is the shape of an mter 

 node ? The average length ? Does the length 

 vary in different parts of the stem ? How do 



