50 THE LIFE OF DEVILS LAKE 



not obvious. It would appear that the Crustacea and rotifer*?, 

 which constitute the great bulk of the zooplancton, finding in Mis- 

 sion Lake a favorable environment, had multiplied rapidly; and, 

 using the plants as food, had reduced the latter accordingly. At 

 present, (1924) the Crustacea (except Marshia) and the rotifers have 

 apparently disappeared. 



LAMOREAU LAKE (pl. 8). 



This was formerly the eastern end of Devils Lake, but about 

 1903 was separated from East Lake by the construction of a high- 

 way across the Odessa Narrows. Its size, depth, drainage area and 

 possibly some supply from springs have sufficed to keep it in about 

 the same condition as Main Lake, so that its life, in general, is 

 similar to that of the latter. It covers an area of about 15 km. and 

 in 1914 had a maximum depth of 7 m., slightly greater than Main 

 Lake at the same time. The chemical analysis together with osmotic 

 pressure is given in table 3, while Og, and temperature are shown 

 in figure 12. Quantitative plancton collections are too few to havs 

 much significance. They indicate a smaller number of plancton ani- 

 mals (especially rotifers) than were present about the same time 

 (8/6/14) in Main Lake, and a somewhat greater abundance of 

 Crustacea than were present in the adjoining East Lake. 



In the algae the most conspicuous differences between La- 

 moreau and Main Lakes at this time were the large numbers of 

 the diatom Cyclotella in the former and its comparative rarity in 

 the latter. 



Nodularia, which is so characteristic of these lakes, was also much 

 more abundant in Lamoreau than in Main Lake (Creel Bay) at this 

 time, but much less so than in East Lake. These differences, how- 

 ever, may have been due to some local conditions and of no import 

 in reference to the life of the lakes as a whole. 



STUMP LAKE (pl. 5) 



"With the possible exception of Main Lake this is the largest 

 body in the whole complex and its depth is greater than any. 



As with Devils Lake, the shores are in places rocky, in others 

 muddy and flat. On a flat at the southeastern end are the stumps, 

 from which the lake derives its name. In places the old shore Lines 

 can be traced, marking the levels of glacial lake Minnewaukan, 



The lake is mainly supplied by run-off, but in places, especially 

 at the southern end, are some considerable springs, while near the 

 northwestern end are a series of small ponds, seepage from which 

 may reach the lake underground. There are no records of the 

 levels of Stump Lake, but the old shore lines, and the character of 

 the water teU a story similar to that of Devils Lake. 



