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oxygen is always reduced in the hypolimnion. The following lakes have no 
free oxygen in their lower levels: Hammon, Lingle, Little Eagle, Pike, Center 
and Webster. : 
All lakes that have been examined are hard water lakes. The maximum 
amount of carbondioxide as carbonates varies in the different lakes from 
27 ce. per liter to 60 ce. per liter. They are all increasingly acid in their lower 
levels, but in the epilimnion they are sometimes alkaline. This is due to 
photosynthesis. 
The above statements in this discussion apply only to summer con- 
ditions. 
No very general correlation has been found between the plankton and 
the dissolved gases. Some of the lakes are much richer in plankton than 
others. It seems probable at the present stage of the investigation that this 
is related to, and possibly caused by the varying amount of phanerogams 
that are produced in their littoral region. 
