Ch. Ill, 10] PLANTS WITHOUT CHLOROPHYLL 83 



matter is simple; they take it from green plants, or from 

 animals which obtain it from green plants. When they take 

 it from living plants or animals, they are called parasites, 

 the one from which it is taken being known as the host; 

 and when they take it from dead plants or animals or decay- 

 ing remains thereof, they are called saprophytes. The 

 difference between 

 parasites and sapro- 

 phytes has no par- 

 ticular physiological 

 significance, but is 

 rather a convenience 

 in our description of 

 those plants. The 

 absorbing organs of 

 such plants are called 



HAUSTORIA. 



Among the Flower- 

 ing Plants, the most 



familiar parasite is Fig. 58. — The Telegraph Plant, Desmodium 

 doubtless the Dodder Qy rans ; X i • It is native to tropical Asia, but 

 _« x . is grown in greenhouses. (From Figurier.) 



(Fig. 59), a relative 



of the Morning Glory. Its slender, orange-colored, smooth 

 stem twines around and among various green herbs in the 

 fields ; and wherever it touches their stems it sends forth 

 aerial rootlets which penetrate the tissues until they reach 

 the veins (Fig. 59). Here a connection is established with 

 both ducts and sieve tubes, from which the parasite can now 

 draw both water and food. The most familiar flowering 

 saprophyte is doubtless the Indian Pipe or Ghost Plant 

 (Fig. 60), the roots of which are believed to absorb the 

 decaying material of green plants, not, however, directly, 

 but by aid of a Fungus (Mycorhiza, page 244). Such para- 

 sites and saprophytes, having no chlorophyll, need no leaves, 

 which accordingly are reduced to mere scales ; and these 

 persist only as relics of an evolution from chlorophyll- 



