Algae, Fungi, and Lichens. 285 



Fungus and the Algae, the Fungus extracting water and 

 salts from the substratum and sharing it with the Algae ; but 

 it must be remembered that the Algae are able to flourish, 

 perfectly well without the intervention of the Fungi, while 

 those Fungi which form Lichens are, with few exceptions, 



FIG. 149. 



Section through the fruiting part of a Lichen. The stratum of dark rounded bodies 

 (h) represents the algal part of the Lichen; m t the thread-like hyphae of the 

 Fungus constituting the bulk of the body of the Lichen ; s (at the top in one of 

 the sacs), sacs or asci in which the spores of the Fungus are borne. After 

 SACHS. 



not known to exist without the assistance of the Algae, with 

 which they associate themselves. Figure 148 shows dif- 

 ferent forms of Lichens, and Figure 149 represents a cross 

 section through the body of a Lichen, revealing the tissue 

 formed by the filaments of the Fungus and the embedded 

 Algae. 



