FIG. 158. A natural, but nearly overgrown lily pond. The lily pads may be seen 

 rising more or less above the water where they are thickest. The forest growth in 

 the background is probably a tamarack (larch) swamp. It is to be noticed that as 

 the lily pond loses its water it is being invaded by the coarse sedge and grass 

 growth of a swamp-moor. Between the lily pond and the forest is a swamp- 

 thicket. At least four distinct societies are represented in this view. A fifth is 

 probably represented in the form of plants of the reed-swamp type, which form a 

 transition between the lily pond and the swamp-thicket. 



