﻿Report 
  of 
  the 
  State 
  Geologisi. 
  869 
  

  

  might 
  be 
  in 
  some 
  way 
  connected 
  with 
  habits 
  of 
  foot 
  prehension 
  

   or 
  the 
  free 
  movement 
  of 
  the 
  foot 
  found 
  in 
  savage 
  man. 
  A 
  

   more 
  recent 
  French 
  writer 
  upon 
  the 
  subject, 
  Manouvrier,* 
  con- 
  

   siders 
  the 
  flattening 
  due 
  to 
  the 
  lengthening 
  and 
  straightening 
  of 
  

   the 
  posterior, 
  external 
  surface 
  of 
  the 
  bone, 
  that 
  portion 
  to 
  which 
  

   is 
  attached 
  the 
  tibialis 
  posticus 
  muscle. 
  This 
  change 
  he 
  

   regards 
  as 
  brought 
  about 
  by 
  a 
  so-called 
  inverse 
  action 
  of 
  this 
  

   muscle, 
  as 
  when 
  the 
  knee 
  is 
  raised 
  from 
  the 
  foot 
  firmly 
  planted 
  

   upon 
  the 
  ground. 
  In 
  his 
  recent 
  monograph 
  upon 
  the 
  u 
  Human 
  

   bones 
  of 
  the 
  Hemenway 
  collection 
  in 
  the 
  United 
  States 
  Army 
  

   Medical 
  Museum 
  "f 
  Dr. 
  "Washington 
  Mathews 
  accepts 
  this 
  expla- 
  

   nation 
  bv 
  Manouvrier 
  and 
  adds 
  that 
  the 
  strengthening 
  of 
  this 
  

   posterior 
  tibial 
  muscle 
  and 
  consequent 
  modification 
  of 
  the 
  bone 
  

   may 
  arise 
  in 
  three 
  ways 
  : 
  First, 
  by 
  increasing 
  the 
  distance 
  

   through 
  which 
  the 
  knee 
  is 
  moved, 
  as 
  would 
  be 
  required 
  in 
  

   traversing 
  a 
  mountainous 
  country 
  ; 
  second, 
  by 
  diminishing 
  the 
  

   time 
  in 
  which 
  the 
  muscle 
  can 
  act, 
  as 
  in 
  running 
  and 
  leaping; 
  

   third, 
  by 
  increasing 
  the 
  weight 
  to 
  be 
  lifted, 
  as 
  in 
  the 
  carrying 
  of 
  

   heavy 
  burdens. 
  To 
  this 
  latter 
  he 
  ascribes 
  the 
  probable 
  cause 
  

   of 
  the 
  flattening 
  in 
  the 
  case 
  of 
  the 
  Salado 
  Indians. 
  

  

  If 
  these 
  factors, 
  climbing, 
  running, 
  leaping 
  and 
  burden-carry- 
  

   ing, 
  could 
  really 
  bring 
  about 
  this 
  platycnemism 
  we 
  should 
  expect 
  

   to 
  find 
  it 
  much 
  more 
  commonly 
  present 
  in 
  our 
  modern 
  Indians, 
  

   but 
  so 
  far 
  as 
  known 
  it 
  is 
  as 
  rare 
  with 
  them 
  as 
  with 
  civilized 
  man. 
  

   In 
  the 
  case 
  of 
  the 
  kangaroo 
  we 
  find 
  these 
  same 
  factors, 
  distance, 
  

   time 
  and 
  weight 
  almost 
  ideally 
  represented, 
  and 
  yet, 
  instead 
  of 
  a 
  

   fore-and-aft 
  flattening, 
  the 
  two 
  tibial 
  diameters 
  are 
  nearly 
  equal, 
  

   thus 
  giving 
  a 
  relative 
  flattening 
  in 
  the 
  other 
  direction. 
  Another 
  

   objection 
  to 
  the 
  theory 
  of 
  Manouvrier 
  is 
  that 
  it 
  does 
  not 
  explain 
  

   the 
  anterior 
  variety 
  of 
  flattening, 
  this 
  being 
  the 
  most 
  common 
  in 
  

   this 
  country 
  and 
  Wales, 
  although 
  not 
  recognized 
  as 
  such 
  by 
  him. 
  

  

  According 
  to 
  this 
  author, 
  " 
  This 
  modification 
  is 
  not 
  only 
  for 
  

   the 
  purpose 
  of 
  furnishing 
  to 
  the 
  posterior 
  tibial 
  muscle 
  a 
  surface 
  

   of 
  insertion 
  larger 
  and 
  more 
  favorably 
  arranged. 
  It 
  renders 
  the 
  

   bone 
  more 
  resistant 
  in 
  the 
  anterior 
  and 
  posterior 
  direction, 
  that 
  

   is 
  to 
  say, 
  in 
  the 
  direction 
  in 
  which 
  it 
  is 
  not 
  sustained 
  by 
  its 
  

  

  *Buil. 
  de 
  la 
  Soc. 
  d" 
  Anthropologic. 
  Paris, 
  1887. 
  3d 
  ser., 
  vol. 
  X, 
  p. 
  138. 
  Also 
  Revue 
  

   d' 
  Anthropologic. 
  Paris, 
  1859. 
  3d 
  ser., 
  vol. 
  IV. 
  See 
  also 
  Kuhff 
  in 
  2d 
  ser., 
  vol. 
  IV, 
  p. 
  225. 
  

   t 
  Memoirs 
  of 
  the 
  National 
  Academy 
  of 
  Sciences. 
  Seventh 
  Memoir, 
  Washington, 
  1893, 
  p. 
  222. 
  

  

  