﻿36 
  

  

  H. 
  S. 
  Pratt, 
  

  

  granules 
  than 
  the 
  nuclei 
  of 
  the 
  other 
  cells, 
  and 
  a 
  nucleolus, 
  and 
  thus 
  

   deveiops 
  into 
  the 
  ovuui 
  of 
  the 
  future 
  lower 
  follicle 
  of 
  the 
  ovariole 
  

   (PL 
  III, 
  Fig. 
  12 
  ovar. 
  2). 
  Almost 
  simultaneously 
  witli 
  its 
  appearance. 
  

   but 
  yet 
  a 
  little 
  later, 
  the 
  nutritive 
  cells 
  of 
  the 
  same 
  follicle 
  differ- 
  

   entiate 
  (n.ce). 
  They 
  are 
  a 
  trifle 
  smaller 
  than 
  the 
  young 
  ovum 
  but 
  

   have 
  nuclei 
  which 
  contain 
  nunierous 
  chromatine 
  granules 
  and 
  can 
  be 
  

   easily 
  distinguished 
  frorn 
  it. 
  The 
  ovum, 
  nutritive 
  cells, 
  and 
  follicular 
  

   epitheliura, 
  which 
  have 
  thus 
  beconie 
  differentiated 
  in 
  the 
  lower 
  portion 
  

   -of 
  the 
  common 
  follicle. 
  are 
  at 
  first 
  not 
  separated 
  by 
  any 
  constriction 
  

   from 
  the 
  still 
  undifferentiated 
  cells 
  which 
  are 
  destined 
  to 
  form 
  the 
  

   upper 
  or 
  younger 
  follicle 
  of 
  the 
  ovariole. 
  They 
  grow 
  rapidly. 
  how- 
  

   ever, 
  and 
  increase 
  in 
  size, 
  and 
  soon 
  a 
  constriction 
  appears 
  which 
  

   separates 
  them 
  from 
  the 
  upper 
  portion 
  of 
  the 
  common 
  follicle, 
  and 
  

   thus 
  divides 
  this 
  structure 
  into 
  the 
  two 
  follicles, 
  in 
  the 
  lower 
  one 
  of 
  

   which 
  the 
  distinctive 
  cellular 
  elements 
  have 
  all 
  differentiated, 
  while 
  

   in 
  the 
  upper 
  one 
  differentiation 
  has 
  so 
  far 
  lagged 
  behind 
  that 
  the 
  

   cells 
  only 
  show 
  an 
  indistinct 
  Separation 
  into 
  outer, 
  follicular 
  epithelium 
  

   and 
  central 
  cells, 
  as 
  is 
  shown 
  in 
  ovar.l 
  Fig. 
  12 
  and 
  also 
  in 
  both 
  

   ovarioles 
  in 
  the 
  right 
  ovary 
  and 
  ovar. 
  2 
  of 
  the 
  left-hand 
  ovary 
  in 
  

   Fig. 
  11. 
  

  

  Ovar. 
  2 
  in 
  each 
  of 
  the 
  ovaries 
  of 
  Fig. 
  11. 
  being 
  the 
  smaller 
  of 
  

   the 
  two 
  in 
  each, 
  the 
  development 
  of 
  its 
  follicles 
  is 
  almost 
  entirely 
  

   checked 
  after 
  the 
  condition 
  above 
  described 
  has 
  been 
  attained. 
  by 
  

   the 
  enorinous 
  growth 
  of 
  the 
  lower 
  follicle 
  of 
  the 
  other 
  and 
  larger 
  

   ovariole 
  of 
  the 
  ovary. 
  Thus 
  we 
  see, 
  for 
  example, 
  that 
  after 
  the 
  lower 
  

   follicle 
  of 
  the 
  smaller 
  ovariole 
  has 
  reached 
  the 
  condition 
  represented 
  

   by 
  fol.4 
  in 
  Fig. 
  11, 
  it 
  remains 
  stationary 
  during 
  the 
  increase 
  in 
  size 
  

   of 
  its 
  large 
  neighbor, 
  fol.2, 
  and 
  until 
  this 
  follicle 
  has 
  become 
  rnature 
  

   and 
  has 
  discharged 
  its 
  ovum. 
  The 
  same 
  fate 
  also 
  follows 
  fol.3, 
  Fig. 
  11, 
  

   which 
  is 
  no 
  larger 
  than 
  fol.4, 
  although 
  it 
  is 
  older, 
  and 
  also 
  the 
  largest 
  

   follicle 
  in 
  Fig. 
  12, 
  which 
  has 
  just 
  become 
  the 
  chief 
  follicle 
  in 
  the 
  

   ovary 
  by 
  reason 
  of 
  the 
  recent 
  extrusion 
  of 
  the 
  ovum 
  from 
  this 
  ovary, 
  

   is 
  no 
  bigger 
  than 
  fol. 
  3 
  and 
  fol.4, 
  Fig. 
  11. 
  

  

  If 
  we 
  could 
  follow, 
  now, 
  the 
  growth 
  of 
  the 
  larger 
  ovariole 
  

   {ovar.l) 
  in 
  the 
  small 
  ovary 
  represented 
  by 
  Fig. 
  12, 
  we 
  should 
  notice 
  

   that 
  now 
  that 
  its 
  lower 
  follicle 
  has 
  become 
  the 
  largest 
  follicle 
  in 
  the 
  

   ovary 
  and 
  is 
  given 
  a 
  chance 
  to 
  grow 
  (by 
  the 
  disappearance 
  of 
  the 
  

   ripe 
  ovum 
  in 
  the 
  other 
  ovariole), 
  it 
  increases 
  in 
  size 
  very 
  rapidly. 
  

   Its 
  smaller 
  follicle, 
  however, 
  which 
  up 
  to 
  this 
  thne 
  has 
  undergone 
  

   no 
  development 
  except 
  into 
  outer, 
  follicular, 
  and 
  inner 
  cells, 
  would 
  

  

  