Minnesota Plant Life. qg 



of starch-makino- for the partnership. The central layers in 

 cylindrical lichen-bodies are of a fnngus character and perform 

 the office of conducting moisture. The whole double organ- 

 ism, then, is built upon the same physiological plan as are the 

 higher plants and has work to do which neither an alga nor 

 a fungus living by itself could well do on land. It is true some 

 algae, like the gulf-weed, develop leaves and branching stems, 

 recalling in their appearance the higher plants, but on land it 

 would scarcely be possible for an alga to adopt such a form, 

 wdiile it w^ould be unnecessary for a fungus, having no leaf-green 

 to illuminate, to assume structures essential to the requirements 

 of leaf-green at work. But when the two organisms ha\'e been 

 brought together into a partnership it becomes possible for this 

 partnership to assume forms and structures favorable for the 

 illumination of leaf-green, for the proper protection of it while 

 at w^ork, and for the maintenance of a sufficient supply of water. 

 Beetle-fungi. The group of plants to wdiich I have given 

 here the common name of beetle-fungi is so remarkable as to 

 deserve separate treatment. In structure the plants are extra- 

 ordinarily unlike any other fungi. They are certainly not un- 

 common in Minnesota, although from the peculiar places in 

 which they live they have never been brought in by collectors, 

 and, indeed, I have seen but a single specimen collected within 

 the borders of the state. It is their habit to attach themselves 

 by a tiny disc to the bodies of water-beetles and other insects 

 living in damp places. Some varieties of them are occasionally 

 to be found attached to the wing-cases of the little scurrying 

 beetles that get together and whirl about upon the surface of 

 quiet water. The plants resemble tiny brushes of camel's hair, 

 a sixteenth of an inch in length or less, and when examined 

 closely they have been found to be, in their structure, very much 

 like the red algae. Indeed, they might almost be taken for 

 red algae, which at some remote time had contracted the habit 

 of obtaining food without the aid of leaf-green. Yet, in the 

 details of their structure, in some respects they widely differ 

 from the red algae. The character in which they most resemble 

 the red algae is their method of breeding. Just as in the algae 

 the egg-cells are here provided with slender cylindrical projec- 

 tions upon wdiich the sperm-cells fix themselves, thus fecundat- 



