LESSON 5.J MORPHOLOGY OF ROOTS. 85 



aspect. For these are not merely fixed upon other plants, as air- 

 plants are, but strike their roots, or what answer to roots, into them, 

 and feed on their juices. Not only Moulds and Blights (which are 

 plants of very low organization) live in this predacious way, but 

 many flowering herbs, and even shrubs. One of the latter is the 

 Mistletoe, the seed of which germinates on the bough of the tree 

 where it falls or is left by birds ; and the forming root penetrates the 

 bark and engrafts itself into the wood, to which it becomes united as 

 firmly as a natural branch to its parent stem ; and indeed the parasite 

 lives just as if it were a branch of the tree it grows and feeds on. 

 A most common parasitic herb is the Dodder; which abounds in 

 low grounds everywhere in summer, and coils its long and slender 

 leafless, yellowish stems resembling tangled threads of yarn 

 round and round the stalks of other plants ; wherever they touch 

 piercing the bark with minute and very short rootlets in the form of 

 suckers, which draw out the nourishing juices of the plants laid hold 

 of. Other parasitic plants, like the Beech-drops and Pine-sap, fasten 

 their roots under ground upon the roots of neighboring plants, and 

 rob them of their rich juices. 



