LABORATORY PRACTICE 



4. The very outermost skin-like layer, the epidermis. 



(This, in the Sunflower, is rough, with hair-like 

 outgrowths. 



5. Make a sketch or diagram to show the arrangement of 



these parts. 



III. Examine one vascular bundle carefully and notice : 



1. The inner porous portion, the woody portion or xylem. 



2. The outer denser portion, the hard bast. 



3. The central portion, a band-like layer, which under the 



higher powers of the compound microscope may be 



seen to consist of two parts. 



(a) the cambium or actively growing portion, a nar- 

 row layer next the xylem, and 



(h) The soft bast or phloem, occupying the greater 

 part of this region and lying toward the hard 

 bast. (The hard bast makes up that part of 

 the stem known as the inner bark.) 



IV. The parts of the Sunflower stem are : 



V. Take from half to three-quarters of an inch of an 

 internode of Sunflower stem, and with a sharp scalpel or 

 penknife blade, scrape away carefully the epidermis and 

 cortex, exposing : 



i. The vascular bundles. Notice their longitudinal course 

 and the fact that they run parallel to one another. 



