﻿JULY 
  19, 
  1922 
  PROCEEDINGS 
  : 
  BIOLOGICAL 
  SOCIETY 
  317 
  

  

  Reverting 
  to 
  the 
  order 
  of 
  Short 
  notes, 
  Dr. 
  Shufeldt 
  said 
  he 
  had 
  found 
  a 
  

   method 
  of 
  blocking 
  out 
  undesirable 
  backgrounds 
  by 
  the 
  use 
  of 
  small 
  wedges 
  

   of 
  rubber, 
  illustrating 
  by 
  lantern 
  slides 
  taken 
  in 
  the 
  National 
  Museum, 
  but 
  

   provided 
  with 
  new 
  backgrounds 
  of 
  outdoor 
  scenes. 
  He 
  also 
  devised 
  the 
  use 
  

   of 
  an 
  umbrella 
  in 
  taking 
  pictures 
  of 
  wild 
  flowers 
  in 
  the 
  sun, 
  to 
  get 
  better 
  de- 
  

   tail 
  by 
  shading 
  the 
  object 
  during 
  exposure. 
  He 
  showed 
  a 
  copy 
  of 
  a 
  new 
  nature 
  

   magazine, 
  just 
  started 
  in 
  England, 
  called 
  Nature 
  Land, 
  edited 
  by 
  Graham 
  

   Renshaw, 
  and 
  published 
  in 
  Manchester. 
  

  

  Mr. 
  Hitchcock 
  asked 
  information 
  on 
  some 
  points 
  in 
  photographing 
  

   flowers 
  in 
  nature, 
  which 
  was 
  supplied 
  by 
  Mr. 
  Shoemaker. 
  The 
  main 
  diffi- 
  

   culty, 
  he 
  said, 
  is 
  wind. 
  A 
  lens 
  of 
  rather 
  long 
  focus 
  is 
  best. 
  

  

  The 
  president 
  called 
  upon 
  Dr. 
  W. 
  J. 
  Holland, 
  director 
  of 
  the 
  Carnegie 
  

   Museum 
  in 
  Pittsburgh, 
  for 
  remarks. 
  Dr. 
  Holland 
  responded 
  with 
  a 
  very 
  

   entertaining 
  account 
  of 
  the 
  circumstances 
  leading 
  up 
  to 
  the 
  discovery 
  of 
  

   Diplodociis 
  carnegiei, 
  an 
  immense 
  fossil 
  reptile, 
  and 
  how 
  he 
  came, 
  with 
  the 
  

   financial 
  support 
  of 
  Mr. 
  Carnegie, 
  to 
  present 
  plaster 
  casts 
  of 
  the 
  famous 
  skele- 
  

   ton 
  now 
  in 
  Carnegie 
  Museum 
  to 
  several 
  of 
  the 
  largest 
  museums 
  in 
  foreign 
  

   countries. 
  He 
  also 
  told 
  of 
  the 
  Dinosaur 
  quarry 
  opened 
  on 
  Green 
  River 
  in 
  

   Utah 
  by 
  his 
  Museum, 
  and 
  how 
  on 
  the 
  opening 
  of 
  the 
  region 
  to 
  settlement 
  it 
  

   was 
  found 
  necessary 
  to 
  designate 
  as 
  "Dinosaur 
  Monument," 
  and 
  to 
  withhold 
  

   from 
  entry, 
  eighty 
  acres 
  of 
  land 
  including 
  the 
  quarry. 
  

  

  639th 
  meeting 
  

  

  The 
  639th 
  meeting 
  was 
  held 
  at 
  the 
  Cosmos 
  Club 
  on 
  April 
  15, 
  1922, 
  with 
  

   President 
  Bailey 
  in 
  the 
  chair. 
  Roberto 
  Dabbene, 
  Wm. 
  A. 
  Dayton, 
  Geo. 
  

   C. 
  Hedgcock, 
  Ernest 
  Knaebel, 
  J. 
  Parker 
  Norris, 
  Jr., 
  Wilson 
  Popenoe, 
  

   Paul 
  G. 
  Russell, 
  Alden 
  Sampson, 
  and 
  Joseph 
  H. 
  Walton, 
  were 
  elected 
  

   to 
  membership 
  

  

  R. 
  P. 
  CowLES: 
  A 
  hydrographic 
  and 
  biological 
  survey 
  of 
  Chesapeake 
  Bay. 
  

  

  The 
  bay 
  is 
  comparatively 
  shallow, 
  with 
  some 
  deep 
  holes 
  along 
  the 
  east 
  

   shore. 
  The 
  bottom 
  is 
  composed 
  of 
  various 
  materials, 
  — 
  mud, 
  gravel, 
  sand, 
  

   peat, 
  fuller's 
  earth, 
  clay, 
  and 
  oyster 
  shells. 
  The 
  temperature 
  is 
  warmest 
  at 
  

   the 
  surface 
  and 
  decreases 
  downward 
  during 
  the 
  warm 
  part 
  of 
  the 
  year, 
  April, 
  

   June 
  and 
  July 
  and 
  August 
  ; 
  in 
  March 
  and 
  September 
  it 
  is 
  about 
  the 
  same 
  at 
  

   all 
  depths 
  ; 
  while 
  in 
  the 
  colder 
  months 
  it 
  is 
  colder 
  at 
  the 
  surface 
  and 
  becomes 
  

   warmer 
  at 
  greater 
  depths. 
  

  

  The 
  large 
  amount 
  of 
  fresh 
  water 
  meets 
  the 
  salt 
  water 
  of 
  the 
  ocean 
  and 
  mixes 
  

   only 
  imperfectly, 
  the 
  more 
  saline 
  water 
  being 
  heavier 
  and 
  lying 
  somewhat 
  un- 
  

   derneath 
  the 
  fresh 
  water. 
  By 
  means 
  of 
  the 
  current 
  meter 
  it 
  has 
  been 
  found 
  

   that 
  the 
  surface 
  water 
  may 
  be 
  moving 
  down 
  the 
  Bay 
  while 
  the 
  deeper 
  is 
  moving 
  

   up 
  in 
  the 
  opposite 
  direction; 
  at 
  other 
  times 
  the 
  surface 
  may 
  be 
  almost 
  stag- 
  

   nant 
  while 
  the 
  deeper 
  portion 
  may 
  be 
  in 
  motion 
  either 
  up 
  or 
  down 
  the 
  Bay. 
  

   The 
  water 
  has 
  usually 
  a 
  slightly 
  alkaline 
  reaction, 
  but 
  in 
  a 
  few 
  regions 
  it 
  is 
  

   slightly 
  acid, 
  indicating 
  pollution. 
  

  

  An}' 
  or 
  all 
  these 
  physical 
  data 
  may 
  have 
  an 
  important 
  bearing 
  on 
  the 
  dis- 
  

   tribution 
  and 
  activities 
  of 
  the 
  animals 
  and 
  plants 
  in 
  the 
  Bay. 
  

  

  After 
  describing 
  the 
  various 
  instruments 
  used 
  in 
  making 
  observations, 
  and 
  

   the 
  man}^ 
  cruises 
  taken 
  by 
  the 
  small 
  government 
  vessel 
  used 
  for 
  several 
  years 
  

   past, 
  Professor 
  Cowles 
  summarized 
  the 
  practical 
  bearing 
  of 
  the 
  work 
  as 
  follows 
  : 
  

  

  First, 
  an 
  effort 
  has 
  been 
  made 
  to 
  determine 
  the 
  normal 
  biological 
  and 
  phys- 
  

   ical 
  conditions 
  throughout 
  the 
  year, 
  so 
  that 
  when 
  great 
  mortality 
  of 
  fishes, 
  

  

  