48 PLANT LIFE. 



which are thus imprisoned.* The fungus hyphae usually pre- 

 dominate and in great measure determine the form of the 

 body and its texture. Sometimes the algae are present in 

 such numbers that the hyphae seem merely distributed among 

 them. In form the body may be broad and thin (fig. 225), 

 or slender and shrub-like. In texture it may be tough and 

 leathery, with the hyphae near the surface fused into a false 

 tissue (a, b, fig. 55). When gelatinous algae, such as Nostoc 

 (see 1" 13) are imprisoned, the body may be gelatinous. 

 In all cases the algae supply the fungus with food, and are in 

 turn supplied with water absorbed by the spongy mycelium. 

 (See further f f 195, 223, 462.) 



* Rarely about other small green plants. 



