Ch. Ill, 101 PLANTS WITHOUT CHLOROPHYLL 



83 



matter i.s simple ; they take it from green plants, or from 

 animals whicli 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, thej' are called saprophytes. The 

 difference between 

 parasites and sapro- 

 ph^'tes 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 oyrans -. x }. it is native to tropical Asia, but 

 "is grown in greenhouses. {From Figurier.) 



(Fig. 59), a relative 



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

 stem twines around and among various green herbs in the 

 fields ; and whereA'er it touches their stems it sends forth 

 aerial rootlets which penetrate the tissues until they reach 

 the veins (Tig. 59). Here a connection is established -nith 

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

 draw both water and food. The most famihar flowering 

 saprophyte is doubtless the Indian Pipe or Ghost Plant 

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

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

 but by aid of a Fungus {Mycorkiza, page 244). Such para- 

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

 which accorcUngly are reduced to mere scales ; and these 

 persist only as reHcs of an evolution from chlorophyll- 



