10 IP Q 



83 NO. OF 

 LAKES 

 8.0 



14- 100 60 40 100 

 I I I II I • I 



ho 



7. 



GREEN ALGAE 



BLUE- GREEN 

 ALGAE 



Figure 4. Diagram showing the number of Wisconsin lakes (in a random 

 sample of 100) which lie within difiPerent pH readings; their bound carbon 

 dioxide content (expressed in parts per million); and the percentages of green 

 and blue-green algal species in their total algal flora. ( See discussion in text. ) 



[29] 



