66 Proceedings of the Ohio State Academy of Science. 



Many of the smaller pools show the characteristic manner of 

 invasion by the meadow. The depression may have b'ut a plant or 

 two of Peltandra or Nymphaea advena. (Fig. 25). The margin 

 is banked up by the Sphagnum which grows over the edge and 



Fig. 24. — Typha lati folia in the bog-meadow. A lag- 

 gard from the marsh. 



into the pool, often under the water, thus filling the depression 

 from the margin to the water, raising the surface level so that 

 the marsh plant can no longer survive. 



In the northwestern part of the meadow the Sphagnum is 



