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. Between the lily pond and the forest is a swamp-thicket. 

 At least four distinct associations are represented in this view. A fifth is prob- 

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

 transition between the lily pond and the swamp-thicket. 



