﻿1875.] 
  

  

  'Anatomy 
  of 
  the 
  Umbilical 
  Cord. 
  

  

  499 
  

  

  "Well-marked 
  stomata, 
  both 
  spuria 
  and 
  vera, 
  are 
  to 
  be 
  seen 
  on 
  the 
  sur- 
  

   face, 
  the 
  latter 
  unquestionably 
  forming 
  orifices 
  of 
  entrance 
  into 
  the 
  vast 
  

   s} 
  r 
  stem 
  of 
  canals 
  of 
  which 
  the 
  proper 
  system 
  of 
  the 
  cord 
  is 
  composed. 
  

  

  The 
  epithelium 
  varies 
  somewhat 
  in 
  its 
  arrangements 
  near 
  the 
  placenta 
  

   and 
  near 
  the 
  foetus. 
  

  

  In 
  the 
  former 
  position 
  the 
  cells 
  are 
  smaller, 
  more 
  irregularly 
  jointed, 
  

   and 
  apparently 
  somewhat 
  more 
  elongated 
  in 
  the 
  direction 
  of 
  the 
  long 
  axis 
  

   of 
  the 
  cord 
  than 
  they 
  are 
  near 
  the 
  foetus. 
  

  

  The 
  whole 
  appearance 
  of 
  the 
  cells 
  gives 
  the 
  impression 
  that 
  the 
  cover- 
  

   ing 
  is 
  older 
  here 
  ; 
  and 
  in 
  the 
  canals 
  and 
  in 
  the 
  stomata 
  are 
  to 
  be 
  seen 
  rows 
  

   of 
  minute 
  refracting 
  globules, 
  visible 
  only 
  under 
  very 
  high 
  powers, 
  the 
  

   nature 
  of 
  which 
  I 
  have 
  been 
  unable 
  to 
  make 
  out, 
  as 
  they 
  appear 
  only 
  

   after 
  deep 
  silver-staining. 
  

  

  III. 
  The 
  alveolated 
  canalicular 
  tissue 
  of 
  the 
  cord 
  is 
  divided 
  through- 
  

   out 
  its 
  entire 
  length 
  into 
  three 
  columns, 
  the 
  divisions 
  between 
  which 
  are 
  

   not 
  visible 
  to 
  the 
  naked 
  eye, 
  but 
  become 
  very 
  perceptible 
  when 
  one 
  of 
  the 
  

   columns 
  is 
  injected 
  by 
  Recklinghausen's 
  method. 
  

  

  When 
  the 
  canals 
  are 
  empty 
  they 
  present 
  the 
  appearance 
  of 
  fibrous 
  

   tissue 
  by 
  the 
  collapse 
  of 
  their 
  walls, 
  and 
  when 
  partially 
  distended 
  they 
  

   look 
  like 
  stellate 
  cells. 
  This 
  has 
  led 
  to 
  the 
  erroneous 
  description 
  of 
  a 
  

   fibrous 
  matrix 
  in 
  which 
  occur 
  stellate 
  cells. 
  In 
  the 
  lacunar 
  spaces 
  of 
  the 
  

   canals 
  the 
  oval 
  nuclei 
  are 
  imbedded. 
  

  

  These 
  nuclei 
  do 
  not 
  alter 
  their 
  shapes 
  or 
  positions. 
  

  

  In 
  injecting 
  this 
  system 
  of 
  canals, 
  the 
  fluid 
  passes 
  more 
  readily 
  in 
  the 
  

   direction 
  from 
  the 
  foetus 
  to 
  the 
  placenta 
  than 
  in 
  the 
  reverse 
  way. 
  

  

  During 
  the 
  process 
  minute 
  streams 
  of 
  the 
  injection 
  may 
  be 
  seen 
  flow- 
  

   ing 
  from 
  the 
  surface 
  of 
  the 
  cord 
  ; 
  and 
  these 
  are 
  not 
  due 
  to 
  rents. 
  

  

  Transverse 
  and 
  longitudinal 
  sections 
  of 
  the 
  injected 
  columns 
  show 
  that 
  

   the 
  canals 
  are 
  stellate 
  in 
  every 
  plane. 
  

  

  In 
  the 
  alveoli 
  between 
  the 
  canals 
  the 
  wandering 
  cells 
  are 
  found. 
  Silver- 
  

   staining 
  shows 
  that 
  these 
  canals 
  are 
  walled. 
  The 
  nuclei 
  are 
  not 
  fusiform, 
  

   for 
  when 
  magnified 
  1000 
  diameters 
  they 
  are 
  seen 
  to 
  be 
  oval 
  and 
  provided 
  

   with 
  a 
  very 
  small 
  nucleolus. 
  The 
  statement 
  that 
  they 
  send 
  processes 
  into 
  

   the 
  branches 
  of 
  the 
  canals 
  is 
  due 
  to 
  an 
  optical 
  illusion, 
  dispelled 
  by 
  the 
  

   use 
  of 
  high-power 
  immersion 
  lenses. 
  

  

  The 
  round 
  cells 
  which 
  occur 
  in 
  the 
  alveoli 
  have 
  very 
  large 
  nuclei, 
  quite 
  

   disproportionate 
  to 
  the 
  surrounding 
  protoplasm. 
  

  

  They 
  are 
  not 
  constant. 
  In 
  some 
  cords, 
  especially 
  those 
  removed 
  from 
  

   large 
  children, 
  they 
  are 
  found 
  very 
  scantily, 
  whilst 
  on 
  the 
  cord 
  of 
  a 
  small 
  

   eight-months' 
  child 
  they 
  were 
  found 
  to 
  be 
  extremely 
  abundant. 
  

  

  They 
  are 
  also 
  often 
  more 
  numerous 
  in 
  some 
  parts 
  of 
  the 
  cord 
  than 
  in 
  

   others, 
  and 
  in 
  one 
  district 
  of 
  the 
  cord 
  than 
  in 
  another. 
  

  

  They 
  are 
  most 
  abundant 
  near 
  the 
  umbilicus 
  and 
  near 
  the 
  capillaries. 
  

   They 
  may 
  be 
  seen 
  moving 
  on 
  the 
  warm 
  stage 
  and 
  exhibiting 
  amoeboid 
  

   movements 
  after 
  having 
  taken 
  up 
  litmus 
  colour. 
  

  

  