"0 FLOWERLESS PLANTS 



by side with the fact that they form the really 

 essential element in the lichen alliance, it is 

 easy to understand how it is that these plants 

 can grow almost anywhere. 



We have seen that the algae which go to 

 form a part of the lichen can, and do at times, 

 support a separate existence, and it is not un- 

 natural to inquire whether the fungus is able 

 to do so. In the majority of cases the answer 

 to this question is No. In recent years certain 

 instances have come to light in which the 

 fungus element of a Uchen alliance has been 

 found living apart from its helpmates, relying 

 for its sustenance upon some organic material, 

 of course, after the manner of its kind. Gener- 

 ally speaking, however, if the fungus portion 

 of a lichen is separated from the algae it soon 

 languishes and dies, no matter how carefully 

 it may be tended. This experiment has been 

 actually carried out, and, more wonderful still, 

 the constituents of a lichen have been artifi- 

 cially blended. The spores produced by the 

 fungus element of a lichen have been scattered 

 on algae, and the result has been the develop- 

 ment of a well-known species of lichen. This 

 is an absolutely conclusive proof of the dual 



