28 



THE ROOT, OR DESCENDING AXIS. 



135. THE CIRRHOUS ROOTS 

 of certain climbing vines (Euro- 

 pean ivy, poison ivy, trumpet- 

 creeper) put forth in great 

 numbers from the stem, serv- 

 ing for its mechanical support 

 and no other known use. 

 Again, 



136. THE FULCRA of certain 

 endogenous plants originate 

 high up the stem, and descend- 

 ing obliquely, enter the soil. Of this kind 

 are the roots of the screw-pine (Panda- 

 nus) of the conservatories, which are often 

 several feet in length before reaching the 

 ground. The figure represents a screw- 

 pine which was wholly propped up by 

 roots of this kind as if on stilts. Sim- 

 ilar roots occur, in a smaller way, at the 

 lower joints of the Indian corn. 



137. THE BANYAN TREE (Ficus Indica) develops 

 adventitious roots on a grand scale. When the 



branches have stretched out so far as to need ad- 35. Screw-pine (Pnndanus). 

 ditional support, they send forth adventitious roots, descending to the earth. Hav- 

 ing penetrated the soil, these roots become supporting columns. The branches 



8G. Banyan (Ficus Indica). 



