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, tahle 32, and with the nannoplankton of 

 Lake Mendota, taUe 20, 



Per Cent, Ash Free 



Maximum 



6.27 

 9.50 



Minimum 



Mean 



4.90 

 4.75 



Milligrams per Cubic Meter 

 of Water 



Maximum 



201.5 

 154.2 



Minimum 



47.9 

 51.8 



Mean 



125.9 

 95.5 



Table 37. The quantity of dry organic matter m 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 tahle 

 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, 

 tahle 26. 



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

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

 with Lake Mendota, tahle 7, and ivith Lake Monona, tahle 30. 



