﻿98 
  E. 
  J. 
  ALLEN. 
  

  

  methyl-blue-eosin. 
  Cells 
  of 
  each 
  of 
  the 
  three 
  types 
  possess 
  

   long 
  necks 
  opening 
  at 
  the 
  exterior 
  as 
  above 
  described. 
  

  

  Type 
  A. 
  — 
  Fig. 
  26 
  represents 
  a 
  section 
  of 
  a 
  type 
  of 
  gland- 
  

   cell 
  which 
  occurs 
  in 
  cirri 
  from 
  all 
  parts 
  of 
  the 
  body. 
  In 
  

   those 
  on 
  the 
  anterior 
  segments^ 
  from 
  1 
  to 
  13^ 
  it 
  is 
  the 
  only 
  kind 
  

   found. 
  In 
  the 
  cirri 
  of 
  the 
  segments 
  behind 
  the 
  thirteenth 
  cells 
  

   of 
  this 
  character 
  are 
  not 
  numerous 
  and 
  general, 
  but 
  some- 
  

   times 
  occur 
  towards 
  the 
  distal 
  end 
  of 
  the 
  cirrus 
  (cf. 
  fig. 
  24, 
  

   the 
  very 
  dark 
  cells). 
  These 
  cells 
  stain 
  very 
  deeply, 
  the 
  pro- 
  

   toplasm 
  being 
  crowded 
  with 
  granules, 
  which 
  take 
  on 
  an 
  in- 
  

   tense 
  blue 
  colour. 
  There 
  are 
  also 
  present 
  a 
  number 
  of 
  short 
  

   rods 
  and 
  particles 
  of 
  different 
  shapes, 
  which 
  are 
  even 
  more 
  

   deeply 
  stained 
  than 
  the 
  granules. 
  The 
  nucleus 
  stains 
  red 
  

   with 
  the 
  eosin. 
  It 
  contains 
  one 
  large 
  mass 
  of 
  deeply 
  staining 
  

   chromatin 
  (nucleolus) 
  surrounded 
  by 
  a 
  clear 
  space. 
  This 
  

   space 
  is 
  bounded 
  by 
  a 
  membrane, 
  and 
  attached 
  to 
  this 
  mem- 
  

   brane 
  is 
  a 
  hemispherical 
  cap 
  of 
  deeply 
  staining 
  substance 
  

   half 
  enclosing 
  the 
  nucleus. 
  A 
  section 
  through 
  this 
  cap 
  gives 
  

   the 
  crescent-shaped 
  figure 
  shown 
  in 
  fig. 
  26 
  (PI. 
  10). 
  The 
  

   relation 
  of 
  the 
  cap 
  to 
  the 
  nucleolus 
  reminds 
  one 
  of 
  the 
  

   relation 
  of 
  the 
  yolk 
  nucleus 
  of 
  the 
  ovum 
  to 
  the 
  germinal 
  

   vesicle 
  (cf. 
  fig. 
  Gl). 
  The 
  remainder 
  of 
  the 
  nucleus 
  — 
  that 
  is 
  to 
  

   say, 
  the 
  space 
  between 
  the 
  nuclear 
  membrane 
  and 
  the 
  nucleolar 
  

   membrane 
  and 
  cap 
  — 
  is 
  filled 
  with 
  a 
  large 
  number 
  of 
  small 
  

   granules, 
  stained 
  red 
  with 
  the 
  eosin, 
  but 
  not 
  taking 
  on 
  by 
  

   any 
  means 
  such 
  an 
  intense 
  colour 
  as 
  the 
  nucleolus 
  and 
  the 
  

   nucleolar 
  cap. 
  

  

  Type 
  B. 
  — 
  Figs. 
  27 
  and 
  28 
  represent 
  sections 
  through 
  the 
  

   type 
  of 
  gland-cells 
  which 
  occupy 
  the 
  greater 
  part 
  of 
  the 
  

   bodies 
  of 
  the 
  cirri 
  on 
  all 
  the 
  segments 
  from 
  the 
  fourteenth 
  

   backwards. 
  The 
  change 
  from 
  cirri 
  packed 
  with 
  cells 
  of 
  

   Type 
  A 
  in 
  segment 
  13 
  to 
  those 
  containing 
  almost 
  entirely 
  

   cells 
  of 
  Type 
  B 
  in 
  segment 
  14 
  is 
  very 
  marked. 
  

  

  Cells 
  of 
  this 
  type 
  have 
  a 
  ground 
  substance 
  with 
  a 
  homo- 
  

   geneous 
  appearance 
  — 
  or 
  showing 
  in 
  preserved 
  material 
  at 
  

   most 
  a 
  faint 
  indication 
  of 
  a 
  network 
  — 
  which 
  stains 
  pale 
  blue. 
  

   In 
  this 
  ground 
  substance 
  are 
  a 
  number 
  of 
  rods 
  (sections 
  of 
  

  

  