APPENDIX 



189 



Table 11. Some of the physical and chemical constants of the ether 

 extract of three samples of net plankton as determined by Schuette. 

 (Trans. Wis. Acad. Sci., Arts, and Let., Vol. XIX, 1918, p. 599.) 



Sample 



Percent of ether extract in dry sample 



Index of refraction at 25° C 



Iodine Number 



Saponification number 



Reichert-Meissl number 



Polenske number 



8.01 

 1.4777 

 102.08 



13.47 



1.4785 



87.58 



248.60 



1.16 



1.55 



No. 403 



21.25 



1.4810 

 172.88 

 208.56 



0.94 



1.22 



Table 12. The variations in the percentage and in the quantity of 

 the pentosans in the net plankton of Lake Mendota are indicated in 

 this table. 



Year 



Number 



of 

 Analyses 



Per Cent, Ash Free 



Milligrams per Cubic Meter 

 of Water 





Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1912 

 1913 

 1914 

 1915 



17 

 32 

 12 

 31 



4.08 

 3.90 

 3.65 

 5.16 



1.38 

 1.79 

 1.18 

 1.38 



3.06 

 2.86 

 1.71 

 3.41 



36.1 

 23.8 

 10.7 

 33.6 



5.0 

 1.8 

 3.6 

 3.0 



15.3 



10.9 



5.4 



12.9 



Table 13. The changes in the percentage of crude fiber in the or- 

 ganic matter of the net plankton are shown for the different years in 

 this table, as well as the variations in quantity per cubic meter of 

 water. The mean percentage is based on the mean quantity of crude 

 fiber and the mean quantity of organic matter in the samples on which 

 crude fiber determinations were made. 



Year 



Number 



of 

 Analyses 



Percent, Asfr Free 



Milligrams'per Cubic Meter 

 of Water 





Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1911 

 1912 

 1913 

 1914 

 1915 



17 

 21 

 35 

 13 

 33 



17.74 

 20.21 

 12.71 

 12.11 

 10.32 



6.80 

 3.54 

 2.67 

 3.68 

 4.15 



10.34 

 6.86 

 6.19 

 6.12 

 6.00 



52.2 

 67.0 

 55.3 

 28.3 

 37.9 



3.7 



10.8 

 5.8 

 6.4 

 5.9 



17.7 

 30.4 

 23.1 

 17.5 

 22.0 



