﻿SPERMATOGENESIS 
  OP 
  PEREPLANETA 
  AMElilOANA. 
  581 
  

  

  carried 
  out 
  in 
  order 
  to 
  get 
  rid 
  of 
  a 
  portion 
  of 
  the 
  chromatin 
  

   in 
  the 
  spermatid. 
  

  

  The 
  extra-nuclear 
  chromatic 
  body 
  has 
  often 
  been 
  figured, 
  

   but 
  less 
  frequently 
  described. 
  Hermann 
  describes 
  a 
  chro- 
  

   matic 
  strnctui'e 
  in 
  the 
  spermatid, 
  which 
  is 
  probably 
  the 
  

   homologue 
  of 
  the 
  one 
  under 
  consideration 
  (' 
  Arch. 
  f. 
  Micr. 
  

   Anat., 
  Bd. 
  xxxiv). 
  One 
  of 
  us, 
  during 
  investigations 
  on 
  

   mammalian 
  spermatogenesis, 
  have 
  described 
  the 
  nuclear 
  

   origin 
  of 
  the 
  extra-nuclear 
  body 
  in 
  the 
  spermatid 
  of 
  the 
  rat 
  

   ('Internat. 
  Monatschr. 
  f. 
  Anat. 
  u. 
  Physiol,' 
  Bd. 
  xi, 
  1894). 
  

   But 
  until 
  more 
  is 
  known 
  of 
  the 
  behaviour 
  of 
  the 
  nucleolus 
  in 
  

   the 
  late 
  phases 
  of 
  both 
  spermatogenesis 
  and 
  oogenesis, 
  in 
  

   different 
  types, 
  all 
  attempts 
  to 
  draw 
  theoretical 
  conclusions 
  on 
  

   the 
  function 
  of 
  this 
  body, 
  and 
  the 
  part 
  it 
  plays 
  in 
  the 
  

   problems 
  referred 
  to 
  in 
  the 
  introductory 
  portion 
  of 
  this 
  

   communication, 
  must 
  be 
  of 
  little 
  value. 
  

  

  EXPLANATION 
  OF 
  PLATES 
  44 
  & 
  45, 
  

  

  Illustrating 
  Mr. 
  J. 
  E. 
  S. 
  Moore's 
  and 
  Mr. 
  L. 
  E. 
  Robinson's 
  

   paper 
  "On 
  the 
  Behaviour 
  of 
  the 
  Nucleolus 
  in 
  the 
  

   Spermatogenesis 
  of 
  Periplaneta 
  am 
  eric 
  ana." 
  

  

  All 
  the 
  figures 
  were 
  drawn 
  under 
  Zeiss' 
  2 
  mm. 
  Apocliromatic 
  Immersion, 
  

   1"40 
  n. 
  a., 
  with 
  No. 
  18 
  ocular. 
  

  

  «c.' 
  = 
  nucleolus 
  of 
  somatic 
  division. 
  «c." 
  = 
  nucleolus 
  of 
  heterotype 
  division. 
  

   a. 
  = 
  archoplasm. 
  /(-. 
  = 
  kary 
  osomes. 
  /. 
  nc.',/. 
  nc." 
  = 
  fragments 
  of 
  the 
  nucleolus 
  

   in 
  the 
  somatic 
  and 
  hetereotype 
  divisions 
  respectively, 
  nc.'" 
  = 
  nucleolus 
  of 
  

   spermatid, 
  in. 
  nc!" 
  = 
  intra-nuclear 
  portion 
  of 
  spermatid 
  nucleolus, 
  ex. 
  nc.'" 
  

   = 
  extra-nuclear 
  portion 
  of 
  spermatid 
  nucleolus. 
  B. 
  m. 
  = 
  intermediate 
  body 
  

   of 
  Flemming. 
  N. 
  = 
  Nebenkern. 
  

  

  PLATE 
  44. 
  

   Fig. 
  1. 
  — 
  Somatic 
  cell 
  in 
  resting 
  condition, 
  showing 
  nucleolus 
  in 
  early 
  state. 
  

   Figs. 
  2 
  — 
  4. 
  — 
  Somatic 
  cells 
  showing 
  differentiation 
  of 
  chromosomes, 
  with 
  

   condition 
  of 
  the 
  nucleolus 
  during 
  the 
  somatic 
  prophase. 
  

  

  Fig. 
  5. 
  — 
  Somatic 
  cell 
  showing 
  development 
  of 
  the 
  spindle 
  and 
  extrusion 
  of 
  

   the 
  fragments 
  of 
  the 
  nucleolus. 
  

  

  