﻿NOTES 
  ON 
  SPOKOZOA. 
  157 
  

  

  I 
  thinkj 
  agree 
  with 
  Smith 
  and 
  Johnson 
  that 
  the 
  two 
  are 
  in 
  

   some 
  way 
  related. 
  

  

  The 
  chief 
  difference 
  between 
  them 
  is 
  that 
  in 
  the 
  former 
  

   there 
  is 
  no 
  " 
  budding 
  ^' 
  nor 
  anything 
  analogous 
  to 
  the 
  forma- 
  

   tion 
  of 
  schizontocytes. 
  As 
  the 
  young 
  parasites 
  grow 
  the 
  (at 
  

   first 
  single) 
  nucleus 
  divides 
  successively 
  to 
  form 
  a 
  great 
  many, 
  

   evenly 
  distributed 
  throughout 
  the 
  cytoplasm. 
  The 
  latter 
  

   then 
  segments 
  up 
  around 
  these 
  daughter-nuclei, 
  and 
  there 
  

   result 
  numerous 
  " 
  falciform- 
  bodies," 
  which 
  are, 
  however, 
  not 
  

   nearly 
  so 
  sickle-shaped 
  as 
  the 
  merozoites, 
  but 
  more 
  of 
  an 
  

   elongated 
  lozenge 
  form. 
  Each 
  of 
  them 
  is 
  about 
  7 
  /i 
  by 
  2 
  /u, 
  

   aud 
  possesses 
  a 
  rather 
  small 
  nucleus, 
  centrally 
  situated. 
  The 
  

   further 
  history 
  of 
  these 
  bodies 
  was 
  not 
  followed 
  ; 
  the 
  authors 
  

   suggest 
  that 
  the 
  process 
  may 
  represent 
  either 
  schizogony 
  or 
  

   microgametocyte-formation, 
  saying 
  that 
  the 
  position 
  is 
  a 
  

   favourable 
  one 
  for 
  the 
  development 
  of 
  either 
  phase, 
  but 
  they 
  

   do 
  not 
  decide 
  between 
  the 
  two 
  hypotheses, 
  though 
  perhaps, 
  

   on 
  the 
  whole, 
  rather 
  inclined 
  to 
  support 
  the 
  latter. 
  Nothing 
  

   in 
  the 
  nature 
  of 
  macrogametocyte-formation 
  was 
  noticed. 
  

  

  I 
  propose 
  now 
  to 
  summarise 
  my 
  reasons, 
  most 
  of 
  which 
  will 
  

   be, 
  I 
  think, 
  already 
  evident, 
  for 
  considering 
  that 
  the 
  more 
  

   fully-described 
  part 
  of 
  the 
  life-cycle 
  of 
  Klossiella 
  is, 
  in 
  

   reality, 
  only 
  the 
  schizogonous 
  phase 
  — 
  serving 
  for 
  auto-repro- 
  

   duction, 
  and 
  not 
  the 
  sporogonic 
  phase 
  — 
  producing 
  resistant 
  

   spores 
  capable 
  of 
  transmitting 
  the 
  species 
  to 
  a 
  fresh 
  host. 
  

   The 
  spore-forming 
  cyst, 
  or 
  oocyst, 
  in 
  the 
  Coccidia 
  is 
  the 
  result 
  

   of 
  fertilisation 
  of 
  a 
  macrogamete 
  by 
  a 
  microgamete, 
  aud 
  may 
  

   be 
  looked 
  upon 
  as 
  the 
  final 
  stage 
  of 
  the 
  life-history 
  undergone 
  

   in 
  the 
  host. 
  Representing, 
  as 
  it 
  does, 
  the 
  termination 
  of 
  

   growth, 
  the 
  large 
  niacrogametocyte 
  up 
  to 
  the 
  time 
  of 
  matura- 
  

   tion 
  is 
  contained 
  within 
  an 
  atrophied 
  host-cell, 
  from 
  whose 
  

   shrunken 
  and 
  shrivelled 
  remains 
  it 
  is 
  set 
  free 
  prior 
  to 
  fertili- 
  

   sation. 
  After 
  conjugation 
  (indeed 
  in 
  some 
  cases 
  before, 
  e. 
  g. 
  

   in 
  Coccidium 
  proprium 
  and 
  C. 
  faurei) 
  a 
  cyst-membrane 
  

   is 
  rapidly 
  secreted 
  round 
  the 
  oocyte 
  (now 
  the 
  sporont), 
  which 
  

   becomes 
  thick 
  and 
  tough 
  and 
  affords 
  protection 
  to 
  the 
  

   developing 
  contents. 
  Obviously, 
  no 
  further 
  increase 
  in 
  size 
  

  

  