200 TRILLIUM. 



Tease a bit of the stem in a drop of water on another 

 slide, treat with iodine, and note 



ii. The color imparted to the food material, indi- 

 cating its nature. 



c. Scattered irregularly through the section the 

 comparatively few small dark areas, the fibro- 

 vascular bundles. 

 Make a longitudinal section, and notice 



5. The three parts seen in the transverse section ; the 

 bundles branching irregularly and obscurely. 



6. The growing apex. Note 



a. The shape. 



b. The sheathing membranous scales. 



c. The position of the aerial branch. 

 Bisect the apex, and upon the cut surface notice 



d. The two or more rather thick projecting bracts. 



e. Beneath these a very small protuberance, the grow- 

 ing point of the stem, sometimes accompanied by 

 smaller lateral protuberances, the rudimentary 

 scales. 



/. Draw the bisected apex. 



D. THE BRANCH (Aerial Stem). Note 



1. The absence of nodes below the whorl of leaves. 



2. The smoothness of the surface. 

 Mount a transverse section. Notice 



3. Ite three parts : 



a. The very narrow cortical region. 



b. 'Yhe fundamental parenchyma, forming the ground 

 work of the section ; the cells appearing empty. 



c. The limited number of fibre-vascular bundles; note 



i. Their arrangement and relative size, 



