i'age 



Chloride and nitrogen 80 



Conclusions regarding pollution 85 



Sewage dilution in the tributaries 86 



Portage River Section 88 



Oxygen, carbon dioxide, and hydrogen-ion concentration.... 88 



Chloride and ni trogen 90 



Conclusions regarding pollution 93 



Maumee Baj'- Section 93 



Oxygen, carbon dioxide, and hydrogen-ion concentration.... 93 



Season of 192B 93 



Season of 1929 9h 



Season of 1930 97 



Chloride and nitrogen 103 



Conclusions regarding pollution 110 



River Raisin Section Ill 



Oxygen, carbon dioxide, and hydrogen-ion concentration.... Ill 



Chloride and nitrogen 117 



Conclusions regarding polxution 122 



Detroit River Section 122 



Oxygen, carbon dioxide, and hydrogen-ion concentration.... 122 



Chloride and nitrogen 130 



Conclusions regarding pollution 13U 



Cheinical conditions near the west shore in winter 13U 



Evidence of poisons in the water 137 



Chloride content of Lake Erie 139 



The phytoplankoon of Western Lake Erie 139 



Introduction 139 



Previous investigations in the Great Lakes 139 



Materials and methods l[i2 



Acknowledgments 1U7 



Data and discussion l[i7 



Quali tati ve data lUl 



Quantitative data ll^J 



Island Section Ili7 



Horizontal distribution lli7 



Vertical distribution l[i8 



Seasonal distribution liiB 



Season of 1929 lU8 



Season of 1930 l55 



Comparison of the s easons of 1929 and 1930 l62 



Adequacy of the sampling program 171 



Abundance of phytonlankton compared with that of other 



lakes 173 



Portage River Secti on 179 



Maumee Bay Section l82 



River Raisin Section I89 



Detroi t River Section I92 



Comparison of abundance of phytoplankton in different 



sections of Western Lake Erie I97 



