APPENDIX 



187 



Table 6. The maximum^ the minimum, and the mean amounts of 

 organic matter in the net plankton of Lake Mendota for the different 

 years are shown in this table. The results for 1914 and 1917 do not 

 cover full years; in the former instance the observations extended only 

 to the first of July and in the latter to the first of June. The resxdts 

 are stated in milligrams of organic matter per cubic meter of water. 



Table 7. The variations in the percentage of nitrogen in the net 

 plankton and the mean percentage for the different years are indicated 

 in this table. Nitrogen determinations were not made on all of the sam- 

 ples collected in 1916 and 1917. The mean annual percentages are 

 based on the mean quantity of nitrogen and the mean quantity of or- 

 ganic matter in the samples on which nitrogen determmations tvere 

 made. In the first part of the table the percentages of total nitrogen 

 are indicated, but in the second part the percentages do not include 

 the nitrogen of the chitinous shells of the Crustacea. 



