gS Minnesota Plant Life. 



cle of diet. Reindeer moss if cooked is edible, calling to mind 

 the blanc-mange made from the red seaweed, known by the 

 name of Irish moss or carragene, and previously alluded to. 

 Some also of the gelatinous lichens are edible, but none of them 

 is of any particular importance as an article of diet in Minnesota. 



Black-fungi-lichens. A very few lichens, in which the fungus 

 partner is a black fungus, are known to exist, in Minnesota. 

 They could not be recognized by their outward appearance from 

 certain forms of the disc-lichens, but their fruit-bodies are little 

 black bottle-shaped objects in which the spore-sacs are pro- 

 duced, and are quite different from the open plates and saucers 

 of the more common varieties. 



Lichen parasites. The study of lichens has been confused 

 by the presence upon their bodies of numerous kinds of parasitic 

 black fungi which really have no connection with the lichen 

 whatever, but merely come to attack it just as their relatives at- 

 tack the leaves and twigs of the forest. Yet when one remem- 

 bers that a portion of the lichen itself may be a black fungus, it 

 will be seen how puzzling might be the presence of a closely 

 related black fungus parasite, and it is not remarkable that some 

 of these parasites have been described as true fruit-bodies of the 

 lichen. 



Lichen partnerships. Although there are a great many part- 

 nerships in the plant kingdom there is no group of organisms 

 where the principle of partnership has been carried so far as in 

 the lichens, for the combination-structures have taken forms 

 under the stress of their struggle for existence that neither of 

 the two component elements would have been at all likely to 

 assume if living independently. The reindeer moss, for exam- 

 ple, has become a little shrub, while the "old man's beard" 

 dangles its cylindrical stems and branches from tamarack bark 

 much as if it were a plant of higher degree, and the flat leaf-like 

 lichens which live among mosses spread themselves out to the 

 sun quite like some of the flat liverworts. Indeed there arises in 

 lichens a physiological division of labor in view of which areas 

 similar to those in higher plants must appear. The outer layer 

 of the plant-body is made up of fungus elements and serves as 

 an epidermis, resisting the evaporation of moisture. The next 

 layers underneath are crowded with algal cells and do the work 



