200 



PLANKTON OF WISCONSIN LAKES 



Table 36. The range of the variations in the percentage and in the 

 amount of ether extract in the nannoplankton of Lake Monona. Com- 

 pare with the net plankton, table 32, and with the nannoplankton of 

 Lake Mendota, table 20. 



Year 



Number 



of 

 Analyses 



Per Cent, Ash Free 



Milligrams per Cubic Meter 

 of Water 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1915 

 1916 



7 

 9 



6.27 

 9.50 



3.34 

 2.00 



4.90 

 4.75 



201.5 

 154.2 



47.9 

 51.8 



125.9 

 95.5 



Table 37. The quantity of dry organic matter in the total plank- 

 ton of Lake Monona covering the period from May to November in 1915 

 and 1916. The averages for the different months are shown as well as 

 the mean for the entire series of 16 catches. The first part of the table 

 gives the results for the deep water, that is, the area within the 20 meter 

 contour line, and the second part shows the amount per unit of surface 

 when the entire lake is considered. Compare with Lake Mendota, 

 table 26. 





Deep Water 



Entire Lake 



Month 



Kilograms 

 per Hectare 



Pounds 

 per Acre 



Kilograms 

 per Hectare 



Pounds 

 per Acre 



May 



398 

 483 

 310 

 563 

 798 

 1,192 

 678 

 666 



355 

 431 

 276 

 502 

 712 

 1,063 

 605 

 594 



160 

 194 

 124 

 226 

 320 

 478 

 272 

 267 



143 



June 



173 



July 



111 



August 



September. . . . 



October 



November. . . . 

 Mean 



202 



285 

 426 

 243 

 238 



Table 38. The range of variation in the percentage and in the 

 quantity of nitrogen in the net plankton of Lake Waubesa. Compare 

 with Lake Mendota, table 7, and with Lake Monona, table 30. 



Year 



Number 



of 

 Analyses 



PerC 



3ent in Organic 

 Matter 



Milligrams per Cubic 

 of Water 



Meter 



Maximum 



Minimum 



Mean 



Maximum 



Minimum 



Mean 



1913 

 1915 

 1916 



2 



4 



12 



8.57 

 8.12 

 8.20 



7.44 

 5.14 



5.82 



8.00 

 7.45 

 7.50 



162.0 

 343.7 

 217.6 



139.0 

 81.2 

 36.1 



150.5 



239.6 



83.6 



