THE STORY OF THE LICHENS 113 



from the parent by the wind, and are in this 

 way carried to new situations where, given the 

 right conditions, they will develop on the lines 

 of the plant in which they originated. 



It has been said that the algse enclosed 

 within the embrace of the fungus, as evinced 

 in the lichen, do not suffer from their imprison- 

 ment at all, but even seem to benefit by their 

 captivity. We may push this point stiU fur- 

 ther, and say that in their new conditions 

 they are able to live in situations which would 

 otherwise be impossible for them. To come 

 back to our rock}^ islet, it is very doubtful 

 whether these algae would be able to settle and 

 grow for many years on a surface which is, first 

 of all, deluged with salt spray, then baked by 

 the summer sun ; under the protection of the 

 fungus this is rendered quite a simple matter. 

 Moreover, the part which the fungus element 

 plays in supplying the algae with water and 

 mineral matter already mentioned, is a real 

 service. We must always remember that the 

 inorganic material is probably of no direct use 

 to the fungus, and it is simply transmitted to 

 the algse for treatment. 



Certainly one of the most interesting fea- 



