184 



PARASITIC PLANTS. 



develop new roots, which grow perpendicular to 

 the axis of the branch, and become gradually sur- 

 rounded with wood, exactly as happened to the 

 first root. As this is continued every year, the 



FIG. 46. 



I. Mistletoe (Viscum album), Parasitic on the Branch of a Tree. Cross-Section through 

 Branch and Parasite. 2. Piece of Fir Wood, pierced by the Root- Fibres of the Mistle- 

 toe. (" Pflanzenleben.") 



branch becomes pierced with many roots, sur- 

 rounded with yearly rings of wood, which decrease 

 in number in proportion as the distance from the 

 original root increases (Fig. 46, 1). 



As the Mistletoe has green leaves, it can digest 



