﻿87 
  

  

  form 
  seem 
  to 
  fonstaiitly 
  accompany 
  the 
  expression 
  of 
  all 
  

   the 
  phenomena 
  of 
  active 
  change 
  in 
  living 
  cells, 
  such 
  as 
  

   growth 
  and 
  division. 
  Networks 
  have 
  been 
  described 
  in 
  

   nuclei 
  ; 
  the 
  latter 
  are 
  known 
  to 
  expand 
  and 
  contract 
  ; 
  

   elongate 
  in 
  the 
  direction 
  of 
  certain 
  lines 
  of 
  force 
  ; 
  again 
  

   withdraw 
  into 
  a 
  gl(>l>ular 
  form, 
  so 
  that 
  Flemming 
  has 
  

   proposed 
  the 
  terms 
  diastole 
  and 
  systole 
  for 
  these 
  w(mder- 
  

   ful 
  phenomena, 
  which 
  suggest, 
  if 
  they 
  do 
  not 
  prove, 
  the 
  

   existence 
  of 
  forces 
  of 
  repulsion 
  and 
  attraction 
  in 
  active 
  

   labor 
  in 
  the 
  heart 
  of 
  every 
  living 
  cell. 
  AVe 
  have 
  these 
  

   phenomena 
  presenting 
  themselves 
  to 
  our 
  vision 
  in 
  the 
  

   eggs 
  of 
  the 
  oyster 
  and 
  clam. 
  The 
  protoplasm 
  of 
  the 
  egg 
  

   tremulous 
  with 
  an 
  intense 
  life 
  pent 
  up 
  and 
  energetically 
  

   trying 
  to 
  unfold 
  itself 
  socm 
  causes 
  the 
  vitelline 
  membrane 
  

   to 
  quiver 
  and 
  work 
  in 
  rolling 
  waves 
  and 
  the 
  egg 
  assumes 
  

   very 
  rapidly 
  the 
  form 
  shown 
  in 
  Fig. 
  4 
  as 
  

   seen 
  from 
  below, 
  and 
  Fig. 
  5 
  as 
  seen 
  from 
  the 
  

   side. 
  The 
  two 
  centres 
  of 
  force 
  or 
  nuclei 
  

   are 
  here 
  indicated 
  as 
  two 
  small 
  clear 
  spheres 
  ; 
  

   near 
  the 
  central 
  ])art 
  of 
  the 
  two 
  cells 
  which 
  

   have 
  been 
  defined 
  by 
  a 
  period 
  of 
  activity 
  just 
  

   past. 
  The 
  forces 
  of 
  growth 
  now 
  remain 
  qui- 
  Figure 
  4:. 
  

  

  escent 
  for 
  a 
  space, 
  to 
  be 
  exhibited 
  in 
  one 
  

   MrSr^y^^^y^C^ 
  of 
  their 
  supremest 
  moments 
  of 
  activity 
  

  

  "' 
  'ti(m 
  of 
  the 
  largest 
  

  

  ig 
  separted 
  to 
  form 
  

  

  a 
  smaller 
  cell 
  or 
  micromere. 
  At 
  the 
  same 
  

   Figure 
  T). 
  time 
  what 
  was 
  the 
  small 
  cell 
  or 
  micromere 
  

   in 
  Fig. 
  o 
  is 
  as 
  energetically 
  dividing 
  into 
  ^^0i 
  

   two 
  smaller 
  cells 
  or 
  micromeres. 
  The 
  

   result 
  is 
  three 
  micromeres. 
  Looking 
  more 
  4:V 
  

   closely 
  at 
  the 
  figure 
  we 
  see 
  what 
  ap- 
  

   pear 
  to 
  be 
  lines 
  of 
  force 
  running 
  from 
  

   the 
  faintly 
  marked 
  nuclei 
  of 
  each 
  of 
  two 
  Figure 
  6. 
  

   cells 
  to 
  that 
  of 
  two 
  others. 
  The 
  nucleus 
  of 
  the 
  large 
  

   cell 
  is 
  in 
  vital 
  relation 
  with 
  that 
  Avhich 
  is 
  budding' 
  from 
  

  

  fev'""^-'":'',^^ 
  ^-"^ 
  ^^^^- 
  ^'' 
  ^^^ 
  which 
  a 
  pon 
  

   %r«>'{t\v>X?2^ 
  cell 
  or 
  megamere 
  is 
  bein^ 
  

  

  