192 



PLANKTON OF WISCONSIN LAKES 



Table 17. Maximum, minimum, and mean quantities of material 

 in the nannoplankton of Lake Mendota expressed in milligrams of dry 

 organic matter per cubic meter of water. Compare with the results 

 given for the net plankton in table 6. 



Year 



Number of 

 Samples 



Maximum 



Minimum 



Mean 



1915 

 1916 

 1917 



I 35 I, 



L 41 - f 

 F ii : 



i 2, 776. 2 \ 

 1 13,151.5 1 

 12,603.4 



944.2 

 v .3|ffc 962.3 



;? :' 795.2 



- • mum 



1,622.0 

 1,640.7 

 1,621.3 



Table 18. This table shows the maximum, minimum, and mean per- 

 centages of nitrogen on an ash free basis in the nannoplankton of Lake 

 Mendota and also the quantity per cubic meter of water. Compare 

 with the net plankton in table 7. 



Year 



Number' 



of 

 Analyses 



Per Cent, Ash Free 



Milligrams per Cubic Meter 

 of Water 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1915 

 1916 

 1917 



35 

 41 

 11 



10.44 



8.77 

 10.66 



5.32 

 4.24 

 5.91 



7.07 

 6.27 

 8.27 



174.2 



249.7 

 222.5 



63.2 

 49.8 

 47.8 



114.7 

 102.9 

 134.1 



Table 19. The annual range of variations in the percentages and 

 in the amounts of crude protein in the nannoplankton of Lake Mendota. 

 These results are based on those given in table 18. Compare with the 

 net plankton, table 8. 



Year 



Number 



of 

 Analyses 



Per 



Cent, Ash I 



'ree 



Milligran 



is per Cubic 

 of Water 



Meter 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1915 

 1916 

 1917 



35 

 41 

 11 



65.25 

 54.81 

 66.62 



33.25 

 26.50 

 36.93 



44.19 

 39.19 

 51.68 



1,088.7 

 1,560.6 

 1,390.6 



395.0 

 311.2 



298.8 



716.6 

 642.8 

 838.0 



Table 20. The range of variation in the percentage and in the quan- 

 tity of ether extract in the nannoplankton of Lake Mendota. Compare 

 with the net plankton in table 10. 



Year 



Number 



of 

 Analyses 



Ether I 



]xtract, Per 

 Ash Free 



Cent 



Ether Ext 

 Cubic 



ract, Milligrams per 

 Meter of Water 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1915 

 1916 

 1917 



35 

 41 

 11 



15.77 



12.50 



7.07 



3.02 

 2.56 

 2.21 



7.38 

 6.17 

 5.36 



355.6 

 287.7 

 184.0 



49.0 

 31.2 

 17.6 



119.7 



101.2 



87.0 



