﻿Studies 
  on 
  Synapsis. 
  

  

  269 
  

  

  demonstration 
  of 
  such 
  an 
  occurrence 
  in 
  the 
  oogenesis 
  of 
  insects 
  might 
  well 
  

   provide 
  a 
  basis 
  of 
  reconciliation 
  for 
  the 
  rival 
  hypotheses 
  of 
  parasyndesis 
  and 
  

   metasyudesis 
  (telosynapsis), 
  the 
  synaptic 
  phase 
  in 
  the 
  oocytes 
  of 
  the 
  

   Hymenoptera 
  was 
  selected 
  for 
  the 
  first 
  of 
  the 
  present 
  series 
  of 
  studies. 
  In 
  

   addition 
  to 
  the 
  two-fold 
  problem 
  already 
  stated, 
  there 
  have 
  arisen 
  several 
  

   subsidiary 
  questions 
  in 
  the 
  course 
  of 
  the 
  investigation, 
  notably 
  the 
  peculiar 
  

   character 
  of 
  the 
  mitotic 
  figure 
  during 
  ookinesis 
  in 
  certain 
  families, 
  and 
  the 
  

   significance 
  of 
  certain 
  bodies 
  characteristic 
  of 
  the 
  Hymenopteran 
  egg, 
  

   namely, 
  the 
  so-called 
  germ 
  cell 
  determinants 
  and 
  the 
  remarkable 
  secondary 
  

   nuclei. 
  

  

  Wherever 
  possible 
  I 
  have 
  avoided 
  the 
  use 
  of 
  sublimate 
  fixatives 
  employed 
  

   by 
  previous 
  workers. 
  Bouin 
  gave 
  excellent 
  results 
  ; 
  but 
  the 
  best 
  prepara- 
  

   tions 
  were 
  obtained 
  by 
  the 
  use 
  of 
  Flemming 
  modified 
  to 
  increase 
  its 
  penetrating 
  

   power 
  by 
  means 
  of 
  a 
  trace 
  of 
  urea. 
  

  

  1. 
  Cynips 
  Kollari. 
  

  

  Gynips 
  kollari 
  is 
  the 
  gall 
  wasp 
  which 
  causes 
  the 
  exceedingly 
  common 
  

   marble 
  gall 
  to 
  develop 
  from 
  leaf 
  buds 
  of 
  the 
  vegetative 
  shoot 
  on 
  the 
  oak. 
  

   Its 
  special 
  interest 
  for 
  present 
  purposes 
  consists 
  in 
  the 
  fact 
  that 
  unlike 
  the 
  

   other 
  gall-makers 
  which 
  infest 
  the 
  oak, 
  Cynips 
  displays 
  no 
  alternation 
  of 
  

   sexual 
  and 
  parthenogenetic 
  generations. 
  A 
  sexual 
  brood 
  is 
  lacking 
  in 
  the 
  

   life 
  cycle 
  ; 
  not 
  only 
  is 
  the 
  species 
  exclusively 
  agamic, 
  but 
  it 
  is 
  composed 
  

   entirely 
  of 
  females. 
  It 
  has 
  been 
  chosen 
  for 
  investigation 
  not 
  with 
  a 
  view 
  to 
  

   elucidating 
  directly 
  the 
  chromosome 
  cycle 
  of 
  a 
  form 
  which 
  produces 
  females 
  

   from 
  unfertilised 
  eggs, 
  since 
  the 
  difficulty 
  of 
  inducing 
  it 
  to 
  breed 
  in 
  captivity 
  

   is 
  too 
  great 
  ; 
  but 
  it 
  was 
  hoped 
  that 
  it 
  would 
  assist 
  in 
  interpreting 
  the 
  

   phenomena 
  which 
  have 
  already 
  been 
  investigated 
  in 
  another 
  agamic 
  Cynipid, 
  

   Bhodites. 
  

  

  The 
  somatic 
  divisions 
  were 
  studied 
  in 
  the 
  young 
  pupae 
  in 
  epithelia, 
  nerve 
  

   cells, 
  developing 
  wings 
  and 
  other 
  centres 
  of 
  cell 
  multiplication. 
  The 
  

   ■chromosomes 
  in 
  Cynips 
  are 
  unbent 
  and 
  filamentous 
  ; 
  their 
  number 
  is 
  20, 
  as 
  

   in 
  Neurotervs. 
  The 
  same 
  number 
  is 
  found 
  in 
  dividing 
  follicle 
  cells, 
  an 
  

   anaphase 
  of 
  which 
  is 
  shown 
  in 
  Plate 
  4, 
  fig. 
  2. 
  I 
  have 
  not 
  observed 
  either 
  

   asters 
  or 
  centrosomes 
  in 
  connection 
  with 
  the 
  spindles 
  of 
  somatic 
  figures, 
  as 
  

   illustrated 
  in 
  fig. 
  1 
  from 
  the 
  larval 
  gut. 
  

  

  Early 
  History 
  of 
  the 
  Oocyte. 
  

  

  In 
  the 
  full 
  grown 
  larva 
  the 
  ovaries 
  are 
  small 
  spherical 
  bodies 
  surrounded 
  

   by 
  a 
  capsule 
  of 
  connective 
  tissue 
  and 
  consisting 
  of 
  undifferentiated 
  cells 
  

   with 
  granular 
  nuclei 
  (fig. 
  3). 
  Mitoses 
  are 
  extremely 
  rare 
  ; 
  it 
  seems 
  that 
  

  

  