CONTENTS pAGE 



Introduction 



Acknowledgments 5 



General features of San Joaquin River basin 6 



General characteristics 6 



Location ' 



Similar geographic localities • 7 



Geographic areas of middle California 7 



Size and form of San Joaquin drainage area 7 



Forest areas 8 



Rainfall 8 



Important tributaries of San Joaquin River 8 



The Kings River 8 



The Merced River 9 



The Tuolumne River 9 



The Stanislaus River 10 



The Calaveras River 10 



Turbidity 1° 



River conditions near Stockton H 



Relation of Stockton to tide-water 11 



River gradients above Stockton 11 



Opportunities for plankton development 11 



Effect of the mountains 12 



Temperature 12 



Light I 3 



Air currents 13 



Chemical conditions not studied 14 



Tide 14 



Aquatic and marginal vegetation 14 



The Collecting stations 15 



Station 1 16 



Station II 16 



Station III 16 



River currents and depths 10 



Comparison of stations 10 



Methods of securing data 18 



Time of collecting 18 



The form of net 19 



The amount of haul 20 



Depth and rate of haul 20 



Records 20 



Preservation of material 21 



Tests of salinity 21 



Measurement of volume 22 



The enumeration 22 



Apparatus 22 



Procedure 23 



Standard concentration 23 



Method of filling Sedgwick-Rafter cell 23 



