CURIOUS ANOMALY IN LICHENS 



therefore can live only on organic matter ready pre- 

 pared, and are either sacrophytes consumers of dead 

 organisms or parasites, living upon the tissues or 

 juices of living creatures, from which they derive 

 the juices for their own support. In almost every 

 instance this parasitic life is injurious to its host. 

 The latter suffers by the appropriation by another of 

 that which had been prepared for itself, and its death 

 often inevitably follows. The term parasite has 

 now the meaning of non-reciprocity, the advantages 

 being one-sided only, the one giving all and receiving 

 nothing. The Lichen presents, however, a curious 

 condition different therefrom, to which the term Sym- 

 biosis is applied, in which two separate and distinct 

 organisms inseparably live together to their mutual 

 advantage. Either, without the other would soon 

 perish. Every Lichen is now known to be the com- 

 bination of a Fungus and of an Alga, living individual 

 lives, but permanently associated. The fungoid por- 

 tion of the lichen seems to be the original plant 

 that seized upon the alga in accordance with the para- 

 sitic nature of the fungoid family. The association 

 thus formed, proving mutually advantageous, has been 

 perpetuated, and has become universal throughout 

 the numerous and various families of lichens. The 

 fungus is found in several varieties, each of which is 

 peculiar to the lichens, and is only found in connec- 



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