Fink: Classification of Lichens 
103 
(49, 50), Treboux (122), Famintzin (52) and Danilov (46), 
with the recent enlargement of Reinke (105, 106) upon his 
original statement, place before us several interesting hypotheses 
regarding the relation of the lichen to the alga which lives with it. 
We shall revert to some of these researches toward the close of 
this paper. Suffice it to state here that Elenkin’s hypothesis of 
endosaprophytism and Danilov’s and Peirce’s views of parasitism 
of the lichen upon the alga are quite opposed to the hypotheses of 
Reinke and Schneider or the more extreme views of Famintzin. 
In short, the evidence furnished by recent investigation is, as a 
whole, against all hypotheses of individualism or mutualism. 
However, granting for the moment, that the relationship is 
thoroughly mutualistic; that the statement that neither symbiont 
can live alone, disproved as it is by the cultures of Bonnier (31), 
Bornet (32), Moller (87, 88) and others, is true; and that the 
hinted suggestion of Famintzin (52) that the chlorophyll gran- 
ules of higher plants resemble certain algae and may be such is 
also proved, some of us would not even then believe the indi- 
vidualism hypothesis to be tenable. 
Should such an improbable thing as proving the chlorophyll 
granules to be veritable algae which could not exist outside the 
tissue of higher plants come to pass, the writer at least would be 
disposed to regard these structures, which would not then be 
genetically related to the plants in which they occur, not parts of 
the plants, but foreign to them. In short, neither the present 
relation of the lichen to its symbiotic alga nor any mutualistic 
relation that may possibly come to pass in the future seems to 
constitute individualism in any true sense. 
It seems remarkable that Danilov (46), Elenkin (49, 50) and 
Peirce (98, 99, 100) could favor parasitism or saprophytism of 
lichens upon the algae, and still believe in the dual-nature hypoth- 
esis. It will be pointed out below that de Bary did the same in 
his text-book, and this unreasonable position can be due to noth- 
ing else than blindly adhering to the traditions regarding the 
nature of lichens. 
Those who believe that lichens are fungi have not made long 
arguments for their view. Their efforts have necessarily been 
