188 



PLANKTON OF WISCONSIN LAKES 



Table 8. The maximum, minimum, and mean percentages and 

 amounts of crude protein in the organic matter of the net plankton 

 of Lake Mendota. This table is based on the second part of table 7. 

 Crude protein equals N X 6.25. 





Number 



Per Cent of Crude Protein 



Crude Protein, Milligrams per 



Year 



of 

 Analy- 



in the Organic Matter 



f| Cubic Meter of Water 





















ses 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



Maximum 

 Minimum 



1911 



22 



59.0 



37.1 



49.6 



255.0 



21.2 



87.0 



12.0 



1912 



29 



59.4 



35.0 



50.7 



531.2 



48.1 



199.1 



11.1 



1913 



35 



70.0 



39.1 



50.9 



374.4 



49.4 



189.8 



7.6 



1914 



1'- 



69.3 



43.4 



54.1 



244.3 



43.7 



156.2 



5.6 



1915 



34 



67.0 



45.1 



55.4 



449.4 



58.7 



203.7 



7.6 



1916 



26 



56.2 



34.5 



51.0 



581.3 



32.5 



2 0.0 



17.8 



1917 



6 



69.4 



52.6 



63.8 



232.5 



109.3 



159.9 



2.1 



Table 9. The percentages of four forms of nitrogen found by Schu- 

 ette in some net plankton from Lake Mendota. (Trans. Wis. Acad. Sci., 

 Arts, and Let., Vol. XIX, 1918, p. 604.) 



Sample 



Total 



Nitrogen 



Di-amino 



Mono-amino 



"Humic" 





Nitrogen 



asNH 3 



Nitrogen 



Nitrogen 



Nitrogen 



A 



6.15 



0.70 



1.22 



3.69 



0.39 



B 



5.58 



0.70 



0.96 



3.35 



0.38 



C 



8.25 



0.97 



1.90 



4.77 



0.30 



D 



8.55 



0.76 



2.14 



5.16 



0.32 



E 



9.94 



1.09 



2.79 



5.39 



0.67 



Table 10. The variations in the percentage and in the quantity of 

 ether extract in the net plankton of Lake Mendota are shown in this 

 table. 





Number 



Per Cent, Ash Free 



Milligrams ner Cub] 



c Meter 



Year 



of 

 Analyses 











of Water 







Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1911 



22 



26.58 



7.37 



13.57 



52.4 



6.6 



21.9 



1912 



28 



24.3 



5.93 



11.70 



135.8 



11.1 



43.5 



1913 



35 



20.16 



3.12 



10.03 



102.7 



4.0 



42.7 



1914 



13 



18.06 



6.23 



13.00 



70.7 



6.4 



37.9 



1915 



33 



21.28 



6.07 



12.42 



113.1 



12.9 



46.6 



1916 



7 



14.48 



7.55 



11.17 



60.5 



16.9 



38.1 



