﻿CAMOUFLAGE 
  — 
  FRIEDMAN 
  N 
  265 
  

  

  not, 
  although 
  to 
  our 
  eyes 
  both 
  would 
  seem 
  equally 
  well 
  con- 
  

   cealed 
  by 
  their 
  color. 
  This 
  problem 
  is 
  well 
  known 
  to 
  the 
  military 
  

   camouflage 
  experts 
  in 
  their 
  experiments 
  in 
  concealing 
  buildings, 
  etc., 
  

   with 
  green 
  paint 
  or 
  with 
  leafy 
  branches, 
  the 
  paint 
  absorbing 
  the 
  

   infrared 
  light 
  and 
  the 
  chlorophyll 
  in 
  the 
  leaves 
  reflecting 
  it. 
  

  

  Just 
  as 
  we 
  may 
  consider 
  the 
  general 
  applicability 
  of 
  color 
  resem- 
  

   blance 
  in 
  animals 
  by 
  virtue 
  of 
  the 
  impressively 
  large 
  numbers 
  of 
  

   species 
  that 
  show 
  some 
  general 
  color 
  similarity 
  to 
  their 
  surround- 
  

   ings, 
  we 
  may 
  also 
  sense 
  its 
  importance 
  by 
  considering 
  the 
  diversity 
  

   of 
  coloration 
  in 
  related 
  species 
  with 
  diverse 
  habits 
  and 
  habitats. 
  Not 
  

   only 
  may 
  we 
  say 
  that 
  many 
  forest 
  denizens 
  are 
  greenish, 
  many 
  ter- 
  

   restrial 
  dwellers 
  brownish, 
  many 
  beach 
  forms 
  sandy 
  in 
  color, 
  but 
  also 
  

   that 
  within 
  single 
  groups 
  of 
  animals 
  with 
  diverse 
  habitats 
  we 
  find 
  all 
  

   types 
  of 
  coloration 
  in 
  greater 
  or 
  lesser 
  harmony 
  with 
  their 
  back- 
  

   grounds. 
  In 
  spiders, 
  for 
  example, 
  the 
  bark-dwelling 
  species 
  are 
  

   usually 
  brownish, 
  those 
  that 
  live 
  on 
  stones 
  are 
  frequently 
  grayish 
  or 
  

   with 
  a 
  broken 
  pattern 
  of 
  dark 
  and 
  light; 
  grass 
  spiders 
  are 
  often 
  

   green, 
  while 
  flower-inhabiting 
  forms 
  are 
  whitish, 
  yellow, 
  pink, 
  etc., 
  

   in 
  keeping 
  with 
  the 
  flowers 
  in 
  each 
  case. 
  

  

  Going 
  still 
  further, 
  we 
  find 
  that 
  color 
  resemblance 
  to 
  particular 
  

   local 
  backgrounds 
  varies 
  geographically 
  within 
  single 
  species. 
  For 
  

   example, 
  in 
  northern 
  Africa 
  crested 
  larks 
  of 
  the 
  genus 
  Ammomcmes, 
  

   birds 
  that 
  dwell 
  on 
  the 
  ground 
  in 
  open 
  arid 
  places, 
  match 
  surpris- 
  

   ingly 
  the 
  color 
  of 
  the 
  earth 
  and 
  sand. 
  In 
  one 
  spot 
  the 
  ground 
  color 
  

   may 
  be 
  pale 
  and 
  tawny, 
  so 
  are 
  the 
  larks 
  in 
  that 
  place. 
  In 
  another 
  

   area, 
  the 
  terrain 
  may 
  be 
  dark 
  brown 
  — 
  so 
  are 
  the 
  larks 
  ; 
  in 
  still 
  another 
  

   where 
  blackish 
  lava 
  is 
  a 
  prominent 
  feature 
  of 
  the 
  substrate, 
  the 
  larks 
  

   are 
  similarly 
  blackish. 
  Yet 
  all 
  are 
  one 
  species, 
  and 
  intergrading 
  

   specimens 
  may 
  be 
  obtained 
  between 
  all 
  their 
  various 
  extremes 
  of 
  

   color. 
  A 
  similar 
  condition 
  has 
  been 
  demonstrated 
  in 
  numbers 
  of 
  

   small 
  mammals, 
  such 
  as 
  deer 
  mice, 
  pocket 
  mice, 
  etc., 
  by 
  Benson 
  (Con- 
  

   cealing 
  Coloration 
  among 
  Some 
  Desert 
  Rodents 
  of 
  the 
  Southwestern 
  

   United 
  States, 
  Univ. 
  California 
  Publ. 
  Zool., 
  vol. 
  40, 
  p. 
  1-70, 
  1933) 
  . 
  

   The 
  cases 
  of 
  this 
  kind 
  could 
  be 
  greatly 
  multiplied, 
  and 
  practically 
  

   every 
  group 
  of 
  animals 
  would 
  be 
  found 
  to 
  contain 
  instances 
  of 
  the 
  

   sort. 
  

  

  In 
  some 
  animals 
  we 
  find 
  a 
  seasonal 
  change 
  in 
  coloration 
  which 
  ap- 
  

   pears 
  to 
  be 
  directly 
  correlated 
  with 
  seasonal 
  changes 
  in 
  the 
  back- 
  

   ground. 
  Well-known 
  examples 
  of 
  this 
  type 
  are 
  many 
  of 
  the 
  ptarmi- 
  

   gan, 
  a 
  group 
  of 
  northern 
  grouse 
  which 
  are 
  mottled 
  gray, 
  brown, 
  and 
  

   black 
  in 
  the 
  summer, 
  blending 
  remarkably 
  well 
  with 
  the 
  pebbly 
  and 
  

   grassy 
  habitat, 
  and 
  pure 
  white 
  in 
  winter 
  when 
  their 
  environment 
  is 
  

   covered 
  with 
  snow. 
  The 
  arctic 
  fox 
  shows 
  a 
  similar 
  seasonal 
  change 
  

   in 
  color. 
  This 
  type 
  of 
  color 
  resemblance 
  is, 
  however, 
  not 
  very 
  fre- 
  

  

  