378 



oxygen is always reduced in the hypolimnion. The. following lakes have n<j 

 free oxygen in their lower levels: Hammon, Lingle, Little Eagle, Pike, ( enter 

 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 cc. per liter to 60 ee. 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. 



