Section Page 



16 Multiple concentration, flow-through diluter with con- 

 trolled light and temperature used to determine sublethal 

 effects of toxaphene on growth and reproduction of channel 

 catfish 173 



16 Effects of toxaphene on backbone structure of fathead 



minnows 175 



16 Effects of toxaphene on backbone structure of channel 



catfish 1/7 



16 Comparison of viability and hatch in eggs from brook 

 trout exposed continuously or by simulated usage pattern 



to TFM 178 



17 Sequence of changes in biological indices of Lebistes 

 reticula tus (P) in phenol concentrations 188 



17 Effect of phenol on bioelectrical activity of peripheri- 

 cal , central nerve system and neuromuscular conjunction 

 of fish 189 



17 Accumulation of phenol in model communities 191 



18 The St. Lawrence Great Lakes with interstate and inter- 

 national boundaries 195 



18 Average number of pounds and kilograms of fish produced 

 per acre and hectare by the commercial fishery of the 

 Great Lakes for 10-year intervals 2U0 



18 The St. Lawrence Great Lakes showing canals between 



central Atlantic Ocean and the lakes 202 



19 Range of the sea lamprey 219 



19 Life cycle of the sea lamprey 220 



19 The mouth of the sea lamprey 221 



19 Production of lake trout, 1930-66, and number of sea lamp- 

 reys caught in index streams in Lake Superior, 1953-69 . . 222 



19 The Great Lakes 223 



19 Sea lamprey catch from eight streams tributary to Lake 



Superior 225 



IX 



