THE WORK OF STEMS 



225 



Fig. 131 in the essential points. In each of the angles 

 of the stem is a large, fibrous bundle or strand; alter- 

 nating with these are five bundles toward the center of 

 the stem. The central portion of each bundle (the 

 wood) is colored red by the fluid; on each side of the 

 wood is a mass of softer tissue somewhat translucent 

 (the soft bast), from the cut surfaces of which issue 

 mucilaginous drops. 



Allow the branch to stand in the solution until the 

 leaves become colored red, and then cut the stems 

 lengthwise and trace the course of the 

 bundles up through it and out into the 

 leaves. Hold the leaf up to the light 

 and notice the branching of the bun- 

 dles, or veins. Use a lens to follow the 

 finer branches. Place a very young 

 leaf, not over a quarter of an inch long, 

 on a glass slide in a drop of alcohol to 

 which lye has been added, and allow it to bleach; rinse 

 with water, mount on a slide in water, examine with 

 the microscope and try to find the ends of the veins. 

 Trace the bundles down into the root. Pull up some 

 vigorous plants by the roots, cut off the ends of the 

 roots, place the plants in eosin solution, and follow the 

 path of the solution into the root and up into the stem. 

 Make a diagram of the path of the solution in the root 

 (see Fig. 90). Examine the Corn (Fig. 132), tracing 

 the bundles up through the stem and out into the 



132. Corn stalk show- 

 ing arrangement of 

 fibrous bundles. 



