FORMATION OF PEAT IN DEAD LAKE. 



77 



other will soon be exterminated. It owes its longer existence entirely 

 to its great depth. Carex filiformis is unable to extend into the lake until 

 the lake has been filled within at least twenty-four inches of the surface 

 by the lilies and other water plants. 



The western half contains a large area of open water. Vegetation has 

 advanced on tlie south about one-half the way across the lake, the nortli 

 shore is destitute of water plants. This side of the lake is filling rapidly 

 on the south and west, but owing to its great depth it will be many years 

 before it will be entii-elv covered. 



EXPLANATION OF FIGURE. 



Profile through Dead Lake, running north and south, scale: Vertical, 

 61 cm. to mm.; horizontal 8 m. to mm. 



1. Quercus alba, L. 



2. Ulmus Americana, L. 



3. Larix Americana. 



4. Cai'ex filiformis, L. 



5. Channels through sedges, filled largely with Nuphar, Utricu- 



laria sp. 

 . 6. Salix sp. 



7. Remaining lake. 



Obokge p. Burns, Ph. D., 



Botanical Department, University of Michigan. Ann Arbor. 



