PLANKTON OF LAKES WAUBESA AND KEGONSA 



133 



^^oo 



-4000 



3000 



s320O 



£600 



2400 



2000 



lOOO 



I200 



fiOO 



400 



Fig. 40. — The quantity of organic matter and of crude protein in the nanno- 

 plankton of Lake Waubesa in 1916. Curve A represents the dry organic 

 matter and curve B the crude protein. The amounts are indicated in milli- 

 grams per cubic meter of water. See table 48. 



1916 the extremes were 341.2 milligrams and 2,800.0 milligrams. In the 

 former year the mean quantity was 2,404.4 milligrams per cubic meter 

 of water and in the latter year 1,378.1 milligrams, so that the mean for 

 1916 was only a little more than half as large as that of 1915. 



Figure 40 shows graphically the relation of the crude protein to the 

 organic matter in the nannoplankton material collected from Lake 

 Waubesa in 1916. The curve marked A represents the quantity of 



