88 



DEPENDENT PLANTS 



absorb its juices, but they also appropriate and use the 

 carbon dioxid of the air. In some groups of colored 



bacteria the process of photosynthesis. 

 or something equivalent to it, takes 

 place. 



185. Parasitism and saprophytism 

 are usuall}" regarded as degeneration, 

 that is, as a loss of independence. 

 The ancestors of these plants might 

 have been independent. Thus, the 

 whole class of fungi is looked upon as 

 a degenerate evolution. The more a 

 plant depends on oilier plants, the 

 more it tends still farther to lose its 

 independence. 



122. A parasitic fungus, 



magnified. The my- JgQ EPIPHYTES. To be distiu- 



celium, or vegetative 



dotted 8 shaded b parts guished from the dependent plants are 



tfsTue^The 1 rounded tll0Se wnicn g r0W 0U otner P^ntS witll- 



haustoria projecting out taking food from them. These are 



into ine ceils, jii*e jiiso 



fniithig' arts e f 1( thl green -leaved plants whose roots burrow 

 fungus hiiiiK from the - m t he \y ar ]^ f the host plant and per- 



under surface ot the if 



leaf - haps derive some food from it, but which 



subsist chiefly on materials which they secure from air- 

 dust, rain-water and the air. These plants are epiphytes 

 (meaning "upon plants") or air-plants. 



187. Epiphytes abound in the tropics. Orchids are 

 amongst the best known examples (Fig. g> ^^> 



13). The Spanish moss or tillandsia of the <S3 c <3i 

 South is another. Mosses and lichens e?^ esa? 

 which grow on trees and fences may also be ^ 



called epiphytes. In the struggle for exis- 123. Bacteria, much 

 tence, the plants probably have been driven m gmfied. 

 to these special places in which to find opportunity to 

 grow. Plants grow where they must, not where the}' 

 will. 



