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  ANNUAL, 
  KEPORT 
  SMITHSONIAN" 
  INSTITUTION, 
  1927 
  

  

  These 
  views 
  fail, 
  however, 
  because 
  of 
  two 
  vital 
  conditions. 
  The 
  

   one 
  is 
  that 
  according 
  to 
  all 
  tests 
  man 
  is 
  still 
  as 
  plastic 
  — 
  that 
  is, 
  im- 
  

   pressionable 
  and 
  changeable 
  — 
  as 
  he 
  ever 
  was, 
  if 
  not 
  more 
  so; 
  while 
  

   the 
  second 
  is 
  that 
  man 
  is 
  developing 
  new 
  and 
  powerful 
  evolutionary 
  

   factors 
  of 
  his 
  own. 
  

  

  That 
  man 
  is 
  still 
  plastic 
  — 
  reactive 
  to 
  all 
  changed 
  or 
  new 
  influences 
  

   by 
  proper 
  accommodation 
  — 
  is 
  plain 
  enough, 
  especially 
  to 
  the 
  medical 
  

   observer 
  and 
  the 
  anthropologist. 
  In 
  pigmentation, 
  in 
  stature 
  or 
  

   strength, 
  in 
  form 
  and 
  size 
  of 
  the 
  teeth 
  and 
  jaws, 
  in 
  the 
  dimensions 
  of 
  

   all 
  other 
  organs, 
  including 
  the 
  brain, 
  and 
  in 
  his 
  functional 
  qualities 
  

   and 
  effectiveness, 
  including 
  those 
  of 
  the 
  mental 
  powers, 
  he 
  is 
  seen 
  to 
  

   respond 
  to 
  changing 
  conditions; 
  and 
  these 
  reactions 
  are 
  observed 
  to 
  

   be 
  the 
  more 
  prompt 
  and 
  effective 
  the 
  higher 
  in 
  civilization 
  and 
  re- 
  

   finement 
  is 
  the 
  individual. 
  It 
  may 
  be 
  stated, 
  and 
  that 
  as 
  an 
  organic 
  

   law, 
  that 
  every 
  reaction, 
  whether 
  in 
  the 
  direction 
  of 
  more 
  or 
  of 
  less, 
  

   unless 
  artificially 
  counteracted, 
  leads, 
  if 
  repeated 
  often 
  enough 
  and 
  

   within 
  the 
  healthy 
  limits, 
  to 
  an 
  organic 
  habit 
  and 
  organic 
  modifica- 
  

   tion. 
  And 
  such 
  habits 
  in 
  the 
  course 
  of 
  time 
  lead, 
  in 
  some 
  way 
  that 
  as 
  

   yet 
  is 
  not 
  fully 
  understood, 
  to 
  more 
  or 
  less 
  hereditary 
  traits 
  — 
  which 
  

   are 
  items 
  of 
  evolution 
  or 
  devolution. 
  

  

  Acquired 
  characteristics, 
  the 
  influence 
  of 
  which 
  does 
  not 
  reach 
  

   deep 
  enough 
  to 
  the 
  trophic 
  centers 
  of 
  the 
  brain 
  or 
  nervous 
  system 
  

   and 
  the 
  germ 
  cells, 
  are 
  as 
  a 
  rule 
  not 
  inherited. 
  But 
  there 
  are 
  many 
  

   functional 
  acquirements 
  that 
  evidently 
  in 
  time 
  do 
  reach 
  these 
  depths, 
  

   as 
  a 
  result 
  of 
  which 
  they 
  tend 
  to 
  become 
  fixed 
  and 
  hereditary 
  in 
  

   families 
  or 
  even 
  in 
  large 
  groups 
  of 
  men. 
  

  

  Studies 
  on 
  the 
  descendants 
  of 
  the 
  older 
  American 
  families 
  have 
  

   shown 
  conclusively 
  that 
  stature 
  in 
  these 
  families 
  has 
  materially 
  in- 
  

   creased 
  since 
  their 
  coming 
  to 
  this 
  country 
  (see 
  Old 
  Americans, 
  8", 
  

   Bait., 
  1925). 
  

  

  The 
  form 
  of 
  the 
  head 
  has 
  been 
  slowly 
  changing 
  within 
  the 
  last 
  

   thousand 
  years, 
  as 
  shown 
  by 
  the 
  works 
  of 
  Matiegka, 
  von 
  Luschan, 
  

   Fleure, 
  and 
  others, 
  in 
  Bohemia, 
  Austria, 
  England, 
  and 
  Germany. 
  

  

  Changes 
  in 
  pigmentation 
  have 
  greatly 
  affected, 
  and 
  have 
  become 
  

   more 
  or 
  less 
  fixed 
  in, 
  the 
  Aryan 
  population 
  of 
  India 
  since 
  their 
  com- 
  

   ing 
  to 
  that 
  country; 
  while 
  others 
  of 
  opposite 
  nature, 
  ^. 
  e., 
  in 
  the 
  

   direction 
  of 
  lightening, 
  may 
  now, 
  according 
  to 
  various 
  indications, 
  be 
  

   slowly 
  proceeding, 
  as 
  in 
  the 
  Eskimo, 
  the 
  civilized 
  American 
  Indian, 
  

   and 
  the 
  North 
  American 
  Negro. 
  

  

  The 
  civilized 
  white 
  male 
  shows 
  everywhere 
  an 
  increasing 
  weakness 
  

   of 
  the 
  hair, 
  and 
  early 
  baldness 
  is 
  already 
  a 
  hereditary 
  trait 
  in 
  the 
  

   males 
  of 
  many 
  otherwise 
  normal 
  families. 
  

  

  There 
  is 
  perceptible 
  in 
  the 
  civilized 
  man 
  of 
  all 
  races 
  a 
  progressive 
  

   refinement 
  of 
  the 
  physiognomy, 
  with 
  diminution 
  of 
  the 
  protrusion 
  

  

  