﻿352 
  BABCOCK: 
  NEW 
  ENGLAND 
  TIHTLES. 
  

  

  a 
  large 
  surface 
  of 
  light 
  of 
  low 
  intensity 
  rather 
  than 
  to 
  an 
  illuminated 
  point 
  of 
  high 
  intensity. 
  

  

  "(6) 
  The 
  reactions 
  of 
  the 
  young 
  turtle 
  are 
  not 
  modified 
  by 
  sound 
  or 
  odor 
  of 
  the 
  sea, 
  nor 
  

   by 
  a 
  tank 
  of 
  sea-water 
  in 
  which 
  there 
  is 
  not 
  sufficient 
  quantity 
  to 
  give 
  color. 
  

  

  " 
  It 
  might 
  be 
  well 
  to 
  state 
  here 
  that 
  the 
  colors 
  used, 
  both 
  glass 
  and 
  paints, 
  were 
  far 
  from 
  

   monochromatic, 
  so 
  that 
  their 
  exact 
  values 
  are 
  not 
  kno\TO, 
  but 
  at 
  the 
  same 
  time 
  it 
  should 
  be 
  

   remembered 
  that 
  most 
  or 
  all 
  of 
  the 
  colors 
  in 
  natm-e 
  are 
  polychromatic. 
  An 
  excess 
  of 
  any 
  

   particular 
  color 
  seems 
  to 
  give 
  the 
  effect. 
  That 
  we 
  are 
  deahng 
  here 
  with 
  a 
  case 
  of 
  true 
  chro- 
  

   motropism 
  is, 
  perhaps, 
  somewhat 
  doubtful. 
  Indeed, 
  true 
  chromotropism 
  is 
  so 
  rarely 
  met 
  v^ith 
  

   and 
  so 
  many 
  other 
  factors, 
  as 
  intensity, 
  the 
  " 
  color-bhndness 
  " 
  of 
  lower 
  eyes, 
  etc., 
  contribute 
  

   to 
  it 
  or 
  to 
  startlingly 
  similar 
  reactions, 
  that 
  I 
  have 
  studiously 
  avoided 
  the 
  term. 
  I 
  must 
  also 
  

   confess 
  myself 
  unable 
  to 
  satisfactorily 
  explain 
  the 
  cause 
  of 
  the 
  response 
  obtained 
  at 
  night 
  

   on 
  the 
  beach. 
  While 
  the 
  moon 
  shone 
  brightly 
  the 
  differences 
  in 
  colors 
  were 
  much 
  reduced 
  

   to 
  the 
  human 
  eye, 
  so 
  much 
  so 
  that, 
  as 
  far 
  as 
  color 
  was 
  concerned, 
  the 
  bushes 
  and 
  the 
  water 
  

   were 
  practically 
  the 
  same. 
  However, 
  the 
  sea 
  was 
  shiny 
  and 
  the 
  bushes 
  were 
  not. 
  This 
  

   reaction 
  seems 
  to 
  me 
  to 
  be, 
  as 
  I 
  have 
  before 
  stated, 
  a 
  transitional 
  stage 
  between 
  the 
  color 
  

   reaction 
  and 
  the 
  photophilous 
  response, 
  but 
  this 
  helps 
  us 
  Uttle 
  in 
  explanation 
  of 
  its 
  ultimate 
  

   factors. 
  

  

  "In 
  regard 
  to 
  the 
  responses 
  in 
  the 
  daytime, 
  we 
  may 
  speak 
  with 
  a 
  little 
  more 
  certainty, 
  

   although 
  here, 
  too, 
  the 
  intensity 
  of 
  the 
  colors 
  is 
  a 
  bothering 
  element. 
  Practically 
  all 
  the 
  inves- 
  

   tigators 
  who 
  have 
  worked 
  on 
  color 
  responses 
  have 
  found 
  that 
  blue 
  or 
  the 
  blue 
  end 
  of 
  the 
  spec- 
  

   trum 
  acts 
  as 
  white 
  fight 
  and 
  the 
  red 
  end 
  of 
  the 
  spectrum 
  as 
  shadows 
  would 
  in 
  phototropic 
  

   responses. 
  In 
  the 
  case 
  of 
  these 
  loggerhead 
  turtles 
  we 
  find 
  blue 
  chosen 
  in 
  preference 
  to 
  the 
  

   directive 
  rays 
  of 
  the 
  sun. 
  WTiether 
  this 
  indicates 
  a 
  true 
  chromotropism 
  or 
  not 
  we 
  can 
  not 
  be 
  

   entirely 
  sure. 
  

  

  "The 
  application 
  of 
  the 
  bare 
  facts 
  obtained 
  to 
  their 
  biological 
  significance 
  in 
  the 
  life 
  of 
  

   the 
  animal, 
  is, 
  I 
  think, 
  clear. 
  Bushes, 
  green 
  in 
  color, 
  grow 
  on 
  all 
  islands 
  of 
  any 
  size, 
  above 
  the 
  

   high-water 
  mark. 
  The 
  shores 
  of 
  all 
  islands 
  slope 
  down 
  to 
  the 
  water. 
  All 
  turtles' 
  nests 
  are 
  

   laid 
  just 
  above 
  the 
  high-tide 
  mark, 
  at 
  or 
  near 
  the 
  bush 
  fine. 
  The 
  young 
  turtle, 
  hatching 
  out 
  

   and 
  crawling 
  up 
  to 
  the 
  surface 
  of 
  the 
  sand, 
  avoids 
  the 
  bushes, 
  goes 
  down 
  the 
  shore, 
  and 
  easily 
  

   finds 
  the 
  water. 
  Once 
  in, 
  the 
  darker 
  blue 
  of 
  the 
  deeper 
  water 
  attracts 
  it 
  out 
  of 
  the 
  danger- 
  

   ous 
  fish-infested 
  shoals 
  of 
  the 
  reefs." 
  

  

  Habits. 
  — 
  The 
  Loggerhead 
  Turtle 
  is 
  a 
  strong 
  swimmer 
  and 
  has 
  been 
  taken 
  in 
  mid-ocean, 
  

   apparently 
  asleep 
  on 
  the 
  surface 
  of 
  the 
  water. 
  It 
  also 
  enters 
  the 
  mouths 
  of 
  rivers, 
  sometimes 
  

   travelling 
  several 
  miles 
  upstream. 
  Adult 
  specimens 
  are 
  often 
  caught 
  which 
  are 
  covered 
  -nlth 
  

   barnacles, 
  even 
  inside 
  the 
  mouth. 
  Ditmars 
  (1910, 
  p. 
  45) 
  thus 
  describes 
  its 
  actions 
  when 
  on 
  

   shore: 
  "To 
  discover 
  one 
  of 
  these 
  sea 
  monsters 
  on 
  the 
  beach 
  is 
  to 
  experience 
  a 
  certain 
  feeUng 
  

   of 
  awe. 
  The 
  great, 
  floundering 
  brute, 
  in 
  the 
  fulfillment 
  of 
  parental 
  duties, 
  is 
  practically 
  at 
  

  

  