Fink: Nature and Classification of Lichens 241 



have surely arisen from lichens and have thereby separated them- 

 selves widely from the fungi. Lichenist, I,* 



Quotation 6 



Lichens are unquestionably cryptogams. They cannot be 

 classed as algae because they are not algae. They cannot be 

 classed as fungi, because they are not fungi. A lichen is the 

 mutualistic association of an alga and a fungus. This mutualism 

 has evolved to such a degree that a distinct autonomy is estab- 

 lished. Any attempt to separate the two mutualistically asso- 

 ciated components destroys the autonomy. It is true that lichens 

 on the one hand merge into the algae and on the other hand 

 into the fungi. Nevertheless there is no such thing as a lichen 

 unless we have an association of an alga and a fungus, an associa- 

 tion which is to be compared to the association of living plastids 

 in the cell. The relationship of fungus and alga in the lichen 

 is not parasitic for both symbionts are benefited. The biological 

 relationship has progressed so far that neither symbiont can 

 exist alone, excepting perhaps in the very lowest types. Such 

 a relationship of two or more originally wholly distinct organisms 

 is designated as individualism and constitutes a distinct autonomy. 

 There is no more excuse for classing lichens as fungi than there 

 is for classing fungi as algae. Fungi are supposed to be a degen- 

 erate off-shoot from the class algae, are therefore nothing but 

 modified algae and should, to follow the lead of the fungus-lichen- 

 ologists, be classed as algae. Mosses are evolved from liverworts, 

 and yet we do not class them as liverworts. Lichens are evolved 

 from fungi and algae and have acquired such distinctive charac- 

 ters that we cannot class them with either fungi or algae. 

 Lichenist, I, 3. 



Quotation 7 



I think that the lichens cannot constitute a distinct class of 

 cryptogams, but that in consideration of the character of the 



* Die Flechten miissen als eine besondere Klasse behandelt werden, da die 

 Anknupfungspunkte zu den Pilzen verschwindend wenige sind und fast alle 

 jetzt lebenden Arten sicherlich aus Flechten entstanden sind und sich dabei weit 

 von den Pilzen entfernt haben. 



