LABORATORY PRACTICE 



3. An outer dense layer, the rind. What is this rind for? 



4. Make a sketch of the section to show these points. 



IX. Take several inches of an internode of the stem of 

 Indian Corn, cut a thin slice lengthwise from the middle, 

 hold it up to the light, examine with the lens, and notice : 



1. The vascular bundles pursue direct longitudinal courses 



through the pithy portion and are approximately 

 parallel. 



2. Make a sketch or diagram to show this. 



X. The stem of Indian Corn is a good type of an endoge- 

 nous stem, or one which has the vascular bundles distributed 

 fairly uniformly through the pith and not forming a cylinder 

 outside it. Plants with endogenous stems, usually have 

 parallel-veined leaves, monocotyledonous embryos and the 

 parts of the flower arranged in threes. 



XI. Take a piece of a Walnut or Butternut about a foot 

 long and notice : 



1. The regular succession of nodes and internodes. 



2. The consistency of the stem (see I, 2, of this chapter). 



3. How long does the stem of the Walnut or Butternut live ? 



\ (see I, 4, of this chapter) . Plants with considera- 

 .v^ 1 ble wood and which remain from year to year without 

 > Y dying down to the ground (as the Sunflower and 



Indian Corn do) are either shrubs or trees. 

 A shrub is smaller than a tree and does n 

 vA? " possess a distinct trunk. Give some examples. 



The stem of a shrub is said to be fruticose, suf- 

 fruticose or suffrutescent. How do the stems to which V* 

 these terms are applied, differ from one another ? 





^ **" 



> 



: . 



