﻿28 
  WATER-POWER 
  DEVELOPMENT 
  IN 
  THE 
  MISSISSIPPI. 
  

  

  The 
  fact 
  that 
  the 
  herring 
  became 
  abundant 
  at 
  Lake 
  Pepin 
  shortly 
  

   after 
  they 
  ceased 
  to 
  be 
  observable 
  at 
  Keokuk 
  suggested 
  that 
  they 
  

   might 
  have 
  passed 
  through 
  the 
  lock. 
  However, 
  the 
  examples 
  

   received 
  from 
  Lake 
  Pepin 
  were 
  noticeably 
  smaller 
  than 
  the 
  examples 
  

   taken 
  at 
  Keokuk. 
  This 
  fact 
  suggested 
  the 
  inference 
  that 
  the 
  Lake 
  

   Pepin 
  herring 
  might 
  not 
  have 
  come 
  from 
  the 
  river 
  below 
  Keokuk, 
  

   but 
  might 
  represent 
  younger 
  fish 
  that 
  had 
  wintered 
  at 
  intermediate 
  

   points 
  or 
  possibly 
  in 
  Lake 
  Cooper. 
  Here 
  the 
  matter 
  must 
  rest 
  pend- 
  

   ing 
  further 
  and 
  more 
  adequate 
  studies. 
  It 
  is 
  noteworthy 
  that 
  the 
  

   herring 
  seem 
  to 
  have 
  appeared 
  in 
  Lake 
  Pepin 
  earlier 
  in 
  1914 
  than 
  in 
  

   1913, 
  and 
  that 
  they 
  appeared 
  to 
  be 
  more 
  numerous 
  in 
  the 
  later 
  year, 
  

   notwithstanding 
  that 
  the 
  river 
  was 
  obstructed 
  at 
  Keokuk 
  throughout 
  

   1914 
  but 
  not 
  in 
  the 
  earlier 
  part 
  of 
  1913. 
  

  

  In 
  August, 
  1914, 
  a 
  number 
  of 
  very 
  young 
  herring 
  were 
  collected 
  

   by 
  Mr. 
  Teachout. 
  In 
  one 
  shipment, 
  August 
  26, 
  1914, 
  21 
  specimens 
  

   were 
  received 
  of 
  fingerlings 
  or 
  yearling 
  herring, 
  the 
  lengths 
  ranging 
  

   from 
  122 
  to 
  165 
  millimeters 
  (5 
  to 
  6^ 
  inches). 
  On 
  September 
  5, 
  six 
  

   somewhat 
  smaller 
  specimens 
  were 
  sent 
  us, 
  having 
  lengths 
  of 
  107 
  to 
  

   128 
  millimeters, 
  the 
  smallest 
  bemg 
  scarcely 
  over 
  4 
  inches. 
  Such 
  

   specimens 
  are 
  of 
  particular 
  interest 
  as 
  the 
  first 
  young 
  herring 
  observed 
  

   at 
  our 
  laboratory 
  and 
  as 
  indicating 
  that 
  Lake 
  Pepin 
  is 
  a 
  place 
  where 
  

   the 
  herring 
  breed. 
  Mr. 
  H. 
  W. 
  Clark, 
  who 
  has 
  exammed 
  these 
  speci- 
  

   mens, 
  reports 
  that 
  even 
  many 
  of 
  these 
  small 
  herring 
  are 
  infected 
  

   with 
  glochidia 
  of 
  mussels. 
  

  

  o 
  

  

  