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 usually 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 other plants, the 

 more it tends still further to lose its 

 ,„„ . .^. „ independence. 



122. A parasitic fungus, 



magnifled. The my- ^gG. EPIPHYTES. — To be distiu - 



celium, or vegetative 



dotted^- shaded ^parts g^^ishcd from the dependent plants are 

 ramifying in the leaf thosc which grow ou othcr plants with- 



tissue. The rounded = ^ 



haustoria projecting q^^ taking food from them. These are 



into the cells, are also " 



fi^ti^"' arts*'of^'thf green -leaved plants whose roots burrow 



MdCT%^ffel^*o? the ^^ *^® hdiV^ of the host plant and per- 



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. & ^^ 



13). The Spanish moss or tillandsia of the ^ ^©o<i 

 South is another. Mosses and lichens &^^ oT 

 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 magnified. 

 to these special places in which to find opportunity to 

 grow. Plants grow where they must, not where they 

 will. 



'^^ 



