ECOLOGY 



91 



connection with the soil and obtain their necessary supply of 

 moisture from the humid atmosphere, from the moist bark of 

 the host, or from the sponge of vegetable detritus which accu- 

 mulates about the base of the plant. The epiphyte by its habit 

 merely obtains advantageous exposure to light. 



Fig. 45. — An epiphyte, Tillandsia, hanging from the branches of trees. Til- 

 landsia is a flowering plant but is erroneously called "gray moss." 



214. Saprophytes are plants found growing only on humus 

 or other decaying organic matter. They are of great impor- 

 tance in the economy of nature because of their share in the 

 process of decomposition and decay. They contain no chloro- 



