﻿100 
  

  

  2, 
  3 
  and 
  5, 
  PI. 
  VI. 
  This 
  protuberance 
  is 
  longer 
  in 
  one 
  di- 
  

   rection 
  than 
  in 
  the 
  other, 
  its 
  outline 
  marking 
  an 
  oval 
  upon 
  

   the 
  surface 
  of 
  the 
  vitellus. 
  Soon, 
  at 
  the 
  shorter 
  diameter 
  of 
  

   the 
  " 
  limb," 
  a 
  very 
  slight 
  line 
  of 
  crinkling 
  of 
  the 
  tissue 
  can 
  

   be 
  seen 
  upon 
  the 
  surface, 
  extending 
  from 
  one 
  side 
  to 
  th*? 
  

   other, 
  Fig. 
  4, 
  PL 
  VI. 
  The 
  crinkled 
  appearance 
  very 
  soon 
  

   passes 
  away, 
  and 
  the 
  tissue 
  beneath 
  becomes 
  depressed 
  into 
  

   a 
  sharply 
  defined 
  groove, 
  which 
  extends 
  to 
  near 
  the 
  base 
  of 
  

   the 
  ''limb/' 
  and 
  divides 
  it 
  into 
  Iavo 
  nearly 
  equal 
  hemis- 
  

   pherical 
  lobes, 
  Fig. 
  6, 
  PI. 
  VI. 
  

  

  As 
  soon 
  as 
  the 
  groove, 
  or 
  segmentation 
  furrow, 
  has 
  at- 
  

   tained 
  its 
  greatest 
  depth, 
  it 
  begins 
  to 
  close 
  again, 
  imtil 
  it 
  is 
  

   only 
  about 
  half 
  its 
  former 
  depth, 
  in 
  which 
  condition 
  it 
  

   remains. 
  

  

  A 
  second 
  faint 
  line 
  of 
  crinkling 
  of 
  the 
  tissue 
  can 
  now 
  bo 
  

   seen 
  along 
  the 
  centre 
  of 
  the 
  '' 
  limb 
  " 
  at 
  right 
  angles 
  to 
  the 
  

   first 
  segmentation 
  furrow, 
  Fig, 
  6, 
  PI. 
  VI. 
  

  

  This 
  crinkling 
  appearance 
  soon 
  disappears, 
  as 
  in 
  the 
  first 
  

   case, 
  and 
  a 
  second 
  segmentation 
  furrow 
  is 
  formed, 
  dividing 
  

   the 
  "limb" 
  into 
  four 
  rather 
  obtuse 
  papillas. 
  From 
  this 
  

   time 
  forward 
  there 
  is 
  no 
  regularity 
  in 
  the 
  number 
  of 
  the 
  seg- 
  

   mentation 
  furrows, 
  or 
  in 
  the 
  segmentation 
  of 
  the 
  papillj« 
  

   upon 
  different 
  portions 
  of 
  the 
  " 
  limb." 
  Sometimes, 
  one 
  of 
  

   the 
  four 
  segmental 
  papillcc 
  already 
  formed 
  will 
  divide 
  and 
  

   form 
  two 
  complete 
  papillre, 
  before 
  there 
  are 
  any 
  signs 
  of 
  

   division 
  in 
  the 
  remaining 
  three. 
  We 
  thus 
  have 
  a 
  form 
  with 
  

   an 
  odd 
  number 
  of 
  papilla9. 
  Fig. 
  7, 
  PI. 
  VI. 
  Sometimes 
  

   this 
  segmentation 
  will 
  extend 
  to 
  one 
  pair 
  of 
  papillee, 
  and 
  

   after 
  they 
  arc 
  segmented 
  and 
  nearly 
  ready 
  to 
  segment 
  a 
  

   second 
  time, 
  the 
  other 
  pair 
  or 
  pairs 
  will 
  segment. 
  Although 
  

   the 
  segmentation, 
  as 
  thus 
  seen, 
  is 
  not 
  a 
  regular 
  system 
  of 
  

   bilateral 
  coincident 
  divisions 
  of 
  the 
  four 
  original 
  papillas, 
  

   and 
  of 
  the 
  new 
  divisions 
  in 
  their 
  turn,- 
  since 
  an 
  odd 
  number 
  

   of 
  divisions 
  is 
  perhaps 
  as 
  often 
  seen 
  as 
  an 
  even 
  number, 
  jet 
  

   this 
  segmentation 
  is 
  always 
  accompanied 
  by 
  the 
  faint 
  crink- 
  

   ling 
  lino 
  of 
  depression 
  in 
  tho 
  tissue 
  ; 
  the 
  disappearance 
  of 
  

  

  