﻿MUSSELS 
  OF 
  CENTRAL 
  AND 
  NORTHERN 
  MINNESOTA. 
  13 
  

  

  on 
  each 
  valve, 
  at 
  other 
  times 
  the 
  whole 
  mterior 
  of 
  the 
  shell 
  is 
  dis- 
  

   colored. 
  The 
  stain 
  usually 
  affects 
  only 
  the 
  interior 
  layer 
  or 
  coat 
  of 
  

   nacre 
  and 
  when 
  this 
  is 
  removed 
  the 
  rest 
  of 
  the 
  shell 
  is 
  perfectly 
  clean 
  

   and 
  uninjured. 
  Such 
  spotting 
  of 
  the 
  shell, 
  of 
  course, 
  injures 
  their 
  

   commercial 
  value 
  and 
  reduces 
  the 
  material 
  to 
  the 
  second 
  or 
  third 
  

   grade. 
  In 
  other 
  respects 
  the 
  shells 
  have 
  a 
  fine 
  luster 
  and 
  good 
  tex- 
  

   ture, 
  and 
  would 
  make 
  excellent 
  button 
  material. 
  

  

  PEARLS. 
  

  

  A 
  few 
  pearls 
  and 
  about 
  the 
  usual 
  number 
  of 
  slugs 
  were 
  obtained 
  

   from 
  the 
  carload 
  of 
  shells 
  sent 
  from 
  Fergus 
  Falls. 
  At 
  Little 
  Pine 
  

   Lake 
  we 
  also 
  received 
  reliable 
  information 
  that 
  pearlers 
  had 
  worked 
  

   the 
  Red 
  River 
  above 
  Mud 
  Lake 
  two 
  years 
  before, 
  and 
  that 
  they 
  

   obtained 
  an 
  abundance 
  of 
  mussels, 
  with 
  a 
  fair 
  amount 
  of 
  pearls. 
  

   Further 
  than 
  tliis 
  there 
  has 
  been 
  no 
  search 
  for 
  them 
  in 
  the 
  Red 
  River. 
  

   If 
  the 
  discoloration 
  noted 
  above 
  is 
  due 
  to 
  some 
  sort 
  of 
  parasite, 
  it 
  

   would 
  very 
  likely 
  affect 
  the 
  pearls 
  and 
  slugs 
  as 
  weU 
  as 
  the 
  shells, 
  

   but 
  no 
  data 
  could 
  be 
  obtained. 
  There 
  is 
  no 
  reason 
  other 
  than 
  this 
  

   why 
  the 
  Red 
  River 
  should 
  not 
  be 
  as 
  prolific 
  of 
  pearls 
  as 
  the 
  Mississippi, 
  

  

  PROPAGATION. 
  

  

  The 
  conditions 
  at 
  Ottertail 
  Lake 
  are 
  very 
  favorable 
  for 
  the 
  propa- 
  

   gation 
  of 
  certain 
  species 
  of 
  mussels. 
  The 
  lake 
  is 
  10 
  miles 
  long 
  by 
  4 
  

   miles 
  wide, 
  and 
  is 
  remarkably 
  clean 
  and 
  free 
  from 
  weeds. 
  It 
  is 
  sur- 
  

   rounded 
  also 
  with 
  fine 
  sand 
  and 
  gravel 
  beaches 
  and 
  contains 
  many 
  

   large 
  sand 
  bars. 
  The 
  Red 
  River 
  enters 
  at 
  the 
  northeastern 
  corner 
  

   and 
  flows 
  the 
  entire 
  length 
  of 
  the 
  lake. 
  Similar 
  conditions 
  exist 
  at 
  

   Lost, 
  West 
  Lost, 
  Pine, 
  and 
  Little 
  Pine 
  Lakes, 
  but 
  the 
  lakes 
  them- 
  

   selves 
  are 
  much 
  smaller. 
  At 
  little 
  Pine 
  Lake 
  the 
  bottom 
  was 
  nearly 
  

   covered 
  with 
  CTiara 
  and 
  algse, 
  but 
  wherever 
  there 
  was 
  a 
  bare 
  spot 
  

   the 
  mussels 
  were 
  present 
  in 
  large 
  numbers. 
  As 
  these 
  lakes 
  are 
  

   full 
  of 
  just 
  the 
  kind 
  of 
  fish 
  to 
  serve 
  as 
  hosts 
  the 
  conditions 
  are 
  ideal 
  

   for 
  mussel 
  propagation. 
  On 
  the 
  river 
  itself 
  the 
  conditions 
  are 
  less 
  

   favorable. 
  There 
  are 
  several 
  dams 
  in 
  Fergus 
  Falls, 
  and 
  a 
  large 
  

   powder 
  dam, 
  36 
  feet 
  in 
  height, 
  4 
  miles 
  below 
  the 
  city. 
  None 
  of 
  these 
  

   dams 
  are 
  provided 
  with 
  suitable 
  fishways, 
  so 
  that 
  they 
  form 
  an 
  

   effective 
  barrier 
  to 
  the 
  ascent 
  of 
  all 
  fish. 
  

  

  RECOMMENDATIONS. 
  

  

  \. 
  Evidently 
  the 
  first 
  thing 
  to 
  be 
  done 
  is 
  to 
  determine 
  the 
  cause 
  

   of 
  the 
  stains 
  which 
  are 
  so 
  abundant. 
  A 
  satisfactory 
  solution 
  of 
  tliis 
  

   question 
  would 
  be 
  of 
  immense 
  practical 
  value, 
  not 
  merely 
  here 
  in 
  the 
  

   Red 
  River 
  drainage 
  but 
  wherever 
  mussels 
  are 
  found. 
  Different 
  

  

  22889°— 
  14 
  30 
  

  

  