

45° 



BOTANICAL GAZETTE 



[tone 



portion do not follow the contours but in some places cross them at 

 right angles. Their existence finds its explanation in part in the 

 fact that they are kept open by fishermen who approach the lake 

 chiefly from this side. It is doubtful, however, if this is the entire 

 explanation (4,5). The break in the tamarack zone on the south side 

 is due to two factors. At this point the water was rather shallow and 

 this hindered occupation by bog plants for a long period of years, 

 as has been pointed out; during late years the tamaracks have been 

 cleared away and the place kept open as a watering place for stock. 

 The large open area south of the tamaracks is an area suited for tama- 





1 

 i 



Fig. 4.— Profiles through Dead Lake. A through the eastern half; the small 

 body of "open water" is filled with lilies and submerged water plants. B conditions 

 in the western part of the lake. Scale: vertical, 1:600; horizontal, 1 : 4 8oo. 



rack growth. The tamaracks formerly growing there were removed 

 for wood and poles before the surface had been raised enough to make 

 it suitable for either the maple-poplar or the clearing society. It is 

 occupied chiefly by marsh ferns and sedges, with a few Rhus venenata- 

 A narrow border of Ulmus americana is found along the southeastern 



(fig 



Mu 



(6) 



It was a very large post-glacial lake but has been almost entirely filled 

 with marl and peat. The greatest deposit of peat is on the northern 

 side, and the open water is very close to the southern shore. In 



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