would probably remain for thousands of years, vegetation pre- 

 serving it from any tendency toward destruction by drainage 

 and until the ascending line from the Tippecanoe would reach 

 the lake's margin. This point is now located between A and 

 and B on map I. At this point! erosion is active. 



The lake itself presents a rare place for the aquatic plants 

 to perfect their types. The perfection of types, however, and 

 the enormous multiplicity of numbers means, sooner or later, 

 death to the lake itself. The shores low and marshy, also pre- 

 sent the most favorable surroundings for the furtherence of 

 vegetative growth. Great beds of Scirpus skirt .these shores 

 and extend far into the lake. Thick beds of Chara and pond weed 

 ^ Potamogeton) are closer in shore. In intervening places on the 

 marshy shores extensive beds of the pond-lilly (Nuphar) with 

 their heavy, soggy stalks and enormous spread of leaves are aid- 

 ing the other types in raising the lake's bottom with the de- 

 bris of the dead and dying plants. Back ot the immediate 

 margin of the lake but still in very wet soil, are beds of cat- 

 tail growing luxuriantly and beyond these the heavy swamp 

 grasses are established. Then the vegetation increases in 

 height and size and thick zones of brush intervene between 

 the lake and the first line of trees. Among the more plenti- 

 ful varieties of the trees associated with the lake and its life 

 history, is the willow and particularly, the Salix nigra. Wher- 

 ever one may go about the lake's vicinity, these black willows 

 are always in evidence. From the fact that most of them are 

 now in full maturity, their existence there seems to point to a 

 time when conditions differed essentially from the present. 

 Many of them are dying which also points to a changing en- 

 vironment. They stand for the most part in continuous 

 lines or zones and suggest the pre-existence of water lines. 

 They are in their youth, associated with running or quiet 

 water so that now one can say, since they are in full maturity 

 and far from any water, .that they once marked the edge of 

 the lake. This inference comes from observation of the 

 the habit of the tree and its love for water, for when 

 the spring comes and the young shoots appear, along the 

 water's edge a long line of willow shoots are seen bevond 

 where any other plant has ventured. The seeds ot other 

 plants have gone as far perhaps, but could not endure the 



