44 ANATOMY AND PHYSIOLOGY 



Experiment 17. To demonstrate transverse tissue- 

 tension. 



1 6. Take short portions (about 15 or 20 mm. long) 

 of some woody stem 15 to 20 mm. in diameter, 

 and with the scalpel make a clean cut lengthwise 

 through the bark, and remove the bark, being 

 careful not to crack or break it. 



17. At once, or at the end of four or rive minutes, 

 try to replace the bark. Describe your success 

 in so doing. Draw, end view and side view. 



1 8. What must be done to the bark in order to restore 

 its original length? 



19. From this study what further do you know of the 

 condition of the -tissues in a plant stem? Explain. 



