17 



the two groups are not so disproportionate as the figures might 

 seem to indicate. For each one of the Cladocera there are 95 roti- 

 fers and almost 18,000 Protozoa. The latter are distributed as fol- 

 lows: There are 9 rhizopods, almost 2,400 ciliates, and over 

 15,000 flagellates for each one of the Cladocera. There are also 

 about 86,000 plants for each of these Cladocera. Of these plants, 

 64,000 are diatoms, 14,000 are Schizophycecz, 9,000 Chlorophycece, 

 while but 8 are desmids. The great abundance of diatoms, of 

 green and blue-green algae, and of chloryphyll-bearing flagellates 

 affords, it would seem, an abundant food supply for the zooplankton. 

 If of the Mastigophora the colorless flagellates only be retained in 

 the zooplankton, and the remainder which are predominantly 

 synthetic forms be included with the phytoplankton, we find the 

 latter outnumbering the analytic organisms (zooplankton) 18 to 1. 

 Quantitative values in the matter of food relationships are not 

 readily determined except by a combination of the chemical and 

 experimental method. These results by the statistical method 

 express, with more or less error, the equilibrium of the biological 

 components in terms of the individual organisms. 



