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  shown 
  on 
  the 
  same 
  sheet 
  with 
  the 
  curves 
  of 
  surface 
  tempera- 
  

   ture. 
  

  

  The 
  thermometers 
  were 
  in 
  phxce 
  too 
  late, 
  and 
  for 
  too 
  short 
  

   a 
  period, 
  to 
  allow 
  any 
  safe 
  conclusions 
  to 
  be 
  based 
  upon 
  the 
  

   information 
  given 
  by 
  them, 
  but 
  it 
  is 
  noticeable, 
  as 
  an 
  inter- 
  

   esting 
  coincidence, 
  that 
  the 
  curves 
  of 
  both 
  surface 
  and 
  bottom 
  

   temperatures 
  show 
  the 
  greatest 
  variations 
  about 
  the 
  time 
  

   when 
  the 
  young 
  were 
  what 
  is 
  known 
  as 
  " 
  spat," 
  or 
  during 
  

   the 
  period 
  of, 
  and 
  just 
  before, 
  attachment, 
  the 
  young 
  on 
  the 
  

   shoal 
  beds 
  presumably 
  attaching 
  by 
  early 
  August, 
  and 
  those 
  

   on 
  the 
  deep 
  water 
  or 
  southern 
  beds 
  somewhat 
  later. 
  

  

  I 
  regret 
  that 
  it 
  was 
  impossible 
  for 
  me 
  to 
  more 
  thoroughly 
  

   study 
  the 
  effects 
  of 
  the 
  change 
  of 
  temperature, 
  as 
  I 
  think 
  the 
  

   failure 
  or 
  success 
  of 
  the 
  spatting, 
  other 
  things 
  being 
  equalj 
  

   w^ill 
  be 
  found 
  to 
  depend 
  mainly 
  upon 
  the 
  temperature 
  to 
  which 
  

   the 
  mature 
  oyster 
  and 
  embryos 
  are 
  exposed 
  during 
  the 
  spawn- 
  

   ing 
  seasons. 
  

  

  INVESTIGATIOX 
  OF 
  THE 
  CHANC4ES 
  IN 
  DENSITY 
  OF 
  THE 
  WATER. 
  

  

  In 
  order 
  to 
  have 
  definite 
  information 
  as 
  to 
  the 
  change 
  of 
  

   density 
  of 
  the 
  water 
  surrounding 
  the 
  oysters, 
  and 
  regarding 
  

   such 
  changes 
  during 
  the 
  spatting 
  season 
  as 
  of 
  most 
  import- 
  

   ance, 
  and 
  as 
  the 
  maximum 
  change 
  would 
  be 
  most 
  likely 
  to 
  

   occur 
  about 
  the 
  time 
  of 
  the 
  spring 
  tides, 
  I 
  determined 
  to 
  ob- 
  

   tain 
  several 
  specimens 
  of 
  water 
  on 
  a 
  certain 
  number 
  of 
  sec- 
  

   tions 
  across 
  each 
  Sound 
  at 
  high 
  and 
  low 
  water 
  of 
  the 
  spring 
  

   tides. 
  

  

  The 
  sections 
  were 
  located 
  as 
  follows, 
  and 
  are 
  shown 
  on 
  the 
  

   sketches 
  accompanying 
  this 
  report 
  : 
  

  

  Section 
  No. 
  1 
  was 
  just 
  above 
  Hooper's 
  Straits 
  and 
  at 
  the 
  

   mouths 
  of 
  the 
  Nanticoke 
  and 
  Wicomico 
  Rivers, 
  in 
  order 
  that 
  

   the 
  influence 
  of 
  both 
  the 
  straits 
  and 
  rivers 
  might 
  be 
  shown. 
  

  

  Section 
  No. 
  2, 
  for 
  the 
  same 
  reason, 
  w^as 
  north 
  of 
  Kedge's 
  

   Straits 
  and 
  across 
  the 
  mouths 
  of 
  the 
  Manokin 
  and 
  Big 
  Anne- 
  

   messex 
  Rivers. 
  

  

  Section 
  No. 
  3 
  was 
  across 
  the 
  entrance 
  of 
  both 
  Sounds, 
  south 
  

   of 
  Watts' 
  Island. 
  

   13 
  

  

  