THE STEM AND BOOT. 



175 



Are they regular or irregular I 



Where do the root-branches start from ? 



Pull up another plant and examine the root and 

 stem in the same way. Do you find the same differ- 

 ences as before? 



Examine as many plants as you can, by thus com- 

 paring the root and stem, so as to find out for your- 

 self the differences between them. 



Get a potato that has begun to sprout, and observe 

 its surface ? 



Have you seen any thing like this upon roots ? 



Did the potato grow under or above the ground ? 



Have you ever found buds upon roots ? 



EXERCISE LXVI. 

 Tubers, Hulks, Corms, Rhizoma, 



FIG. 286. 



TU'BERS, thickened portions of underground stems. 



